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Old Sep 02, 2011, 10:06 PM
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SNice-mitar -Scimitar Wing Clone...just couldn't help myself...sorry!- video & PLANS!

Always wanted to get into wing-type models, but never liked the looks of the stryker... Built a few funjet clones (Prime-Jet 8)- great flyers! Once I saw the Scimitar, I knew I had to have one, but it is well out of my budget...so... here goes!!! May add the thrust vectoring at a later point depending on how she flies...

Got the model done... prototype-done...maiden video -done (posted below)

She flies!!! So, as promised, plans are below. I have also scaled them up to a 34" version for those that would like to use a traditional parkjet power system with a 6" prop. Plans are pretty freeform so you can put stuff wherever you like. I suggest building the airframe first and then cut areas for servos, motors, cooling vents, hatches, etc... be sure to post pics! Enjoy!

Stats for the 28" prototype:
WS: 28"
KFm4 airfoil
AUW: 11.4oz - 1000mah 3S lipo; 12.7oz - 1300mah 3S lipo
Airframe minus batt: 8.4oz
Bare airframe (unpainted, no electronics): 3.1oz
Lipo: 1000 - 1300 3S lipo (25-30C) -- (I prefer the 1000mah 3S 30C)
ESC: 30A (all I had available - min 20A; 25A to be safe)
Servos: 2x9g (elevons); 2x5g (rudders)
motor:2800KV outrunner
Prop: 5043; will also try 5x5 speed
Prop UPDATE: 6x4 - it's close, but it will fit between the rudders - this is my favorite prop - the acceleration is quick - she will shoot wherever the nose is pointed - much easier to get out of "sticky" situations...

CONTROL THROWS (28" Version):
These are my settings -- adjust to your liking!!! Note - I do not use dual rates on this model - only expo. Elevator throws are very aggressive at endpoints. Too much elevator sits her on her tail and reduces airspeed to near zero (see video). Be sure you have the thrust (or altitude) to get out of this! If not, I would strongly suggest reducing elevator throws.

ELEVATOR: 3/4" up; 3/4" down -- 50% expo
AILERON: 7/8" up; 1" down -- 35% expo
RUDDER: 1-1/4" left/right -- 25% expo


Explanation of 3-Stage wing profile:Below you will find a diagram detailing how I sanded the leading edge. The wing has a 3-stage leading edge profile. Not sure how much of a difference this makes - but it works for me! The theory behind the 3-stage sanding was to create reflex and improve stall characteristics for maneuverability. It seems to work wonderfully, but is untested b/c I never flew it without the 3-stage leading edge...


Compilation Video w/ 6x4 prop!:
SNice-Mitar Fun: R/C Mini Scimitar Wing Clone (6 min 51 sec)


Maiden video - 1000 & 1300 lipos:
SNice-Mitar: Mini Eflite Scimitar Clone - The Maiden (9 min 31 sec)


Since the maiden video, I have greatly reduced the elevator throws, and added additional support to the wing. I also now mount my batteries flat. In the maiden, I had the battery mounted sideways which was making the roll very sloppy. Roll is much more axial with the battery in the flat position. With the above adjustments, I can now knife-edge with rudder and a little bit of aileron input. Once I get some more stick time, I will post a short highlights video.
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Last edited by SNice; Nov 03, 2011 at 10:32 AM. Reason: updates
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Old Sep 03, 2011, 02:32 AM
ROFLCOPTER
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This is relevant to my interests!
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Old Sep 03, 2011, 02:41 AM
Slopeosapien
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Mine too!!
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Old Sep 03, 2011, 03:36 AM
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iam in on this one too.
RCT
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Old Sep 03, 2011, 08:35 AM
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Can't wait to see how she flies!
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Old Sep 03, 2011, 03:32 PM
rcflyer
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Looks awesome!!
Are you doing TV?
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Old Sep 04, 2011, 01:49 PM
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Thanks guys!

For the initial prototype, it will not have TV. I just want to see how the airframe does. However, I have thought about the TV... It could be accomplished by movin the motor mount forward and getting the rudders in the propwash OR with a mechanical system. If I go the mechanical route, I would definitely want 360deg TV instead if just yaw.

The build is going great. The prototype has a ws of 28in. I was worried about the size - after I cut everything out, I was thinking I should have gone smaller for the intended power system (emax2805 2800kv, 5x4.3 prop, 1000mah 3s lipo). But after I weighed everything - I was under 10oz! The power system will be fine - right now I have it on a heavier, smaller plane.

...maiden should not be too far off!
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Old Sep 06, 2011, 07:55 AM
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Yup, found it, watching this one too! w.
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Old Sep 07, 2011, 02:56 PM
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Build progress....

WS: 28"
Airframe wt. (so far): 2.8oz

So far so good... all the parts have fit together really well. I even figured out a way to preserve the rudder for belly landing (+1 Snice-mitar; 0 Eflite Scimitar).

I planned on installing a 9g rudder servo in the fuse and linking it with flexi-rods. However, to get the desired cg, the batt, ESC, RX will be pretty far back in the fuse (where I intended on putting the rudder servo) I now think that I will just install 1 5g servo for each rudder. That may give me a cool airbrake mixing option!

Still pondering the TV. I've looked at a bunch of homemade setups using heli swashplates, etc. I've looked at videos of funjets and the real scimitar spinning and flipping in the air. I really have no interest in spinning or flipping in the air at lightning speed. However, a stationary hover would be cool (to me) - but I think it would be very tough given the position of the CG. I think she will knife edge and high alpha great on her own w/o TV. ...so the TV will be on the backburner for now... maybe a V2 upgrade...
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Old Sep 07, 2011, 05:22 PM
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looking awesome! keep up the good work! It will fly SUPER NICE!


ALBRT
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Old Sep 07, 2011, 06:32 PM
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oooo that is f-ing pretty.
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Old Sep 08, 2011, 01:28 PM
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Thanks guys! Hopefully I will be able to install some of the electronics tonight. This build is going much slower than I expected -- work has been pretty hectic lately!
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Old Sep 08, 2011, 11:31 PM
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I like how you did the landing skids: simple and adds very little drag. Will have to steal it for my next build.
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Old Sep 09, 2011, 05:17 AM
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Nice one....You beat me to it...Well done, its looking good..

I saw the videos of the actual model for the first time the other day and had to add a KFm4 build to my list..

Now I will wait for your plans..

Please dont forget to add your build link in the KF builds thread here http://www.rcgroups.com/forums/showt...122108&page=13

thanks dave
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Old Sep 12, 2011, 09:35 AM
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...Almost there.... got her painted -- look familiar? All servos are installed, and control surfaces linked up. Did a glide test of the bare airframe to determine cg. Got a great glide.

Left to do:
- Cut hatch, install ESC, RX, Batt.
- Touch up any rough spots on paint job
- Add clear packing tape to wing leading edges and bottom of fuse
- Maiden!!!
- Plans!!!

other notes:

I tried something new with the leading edge of the wings on this model. The inner part (strakes) - I sanded the leading edge closer to the top of the wing. From the break to the fence, I sanded the leading edge to the center of the wing; and from the fence to the tip, I sanded the leading edge towards the bottom of the wing. I am hoping this will improve slow speed handling and ward off stalls.

I think my aileron servo placement for this prototype will be fine, but for larger, faster versions, I think I would install the aileron servos further out on the wing and perpendicular to the hinge line.

davereap - I will definitely post link and video to your KF thread!
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Old Sep 12, 2011, 02:36 PM
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Quote:
Originally Posted by SNice View Post
- Plans!!!
Looks great. it is on my winter build list.

ciao
M.
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Old Sep 12, 2011, 02:52 PM
skumgummi dave
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SNice:

Beauty Job!
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Old Sep 12, 2011, 05:16 PM
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That is so pretty I want to have its children.
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Old Sep 12, 2011, 08:00 PM
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Watching this......
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Old Sep 12, 2011, 11:27 PM
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Surfs up. I bet she'll wind surf with the best of them. I like, I like.

Ksqm
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Old Sep 14, 2011, 02:26 PM
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Any updates? I am really looking forward to hearing how she flies!
If I have to wait too long I may end up winging it and throw something together myself.
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Old Sep 14, 2011, 09:14 PM
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Maiden!!!

Finally got her up in the air for a very successful maiden! She performed beautifully - no bad tendencies at all. Super stable and tracks like an arrow. Carves up the sky like none of my other planes - truly a "bank and yank" experience! But you have to be careful, because too much "yank" and it's like putting the brakes on - she will "skid" in the air and slow to a crawl in no time. The controls get real mushy at slow speeds - you either need to be quick on the sticks or have enough altitude to recover (it happens a few times in the video). I will definitely dial down the elevator throws a bit.

I usually like to slow planes down and get them in high alpha, but this one is just too much fun at speed! Zipping around the field was a blast - she does not care if she is upright or inverted - flies the same all around.

The roll was a bit sloppy - need to research on how to fix this - perhaps aileron differential? Definitely need to practice knife edge a bit more - I still get very nervous at high speed knife edge attempts. A more experienced pilot could definitely pull it off!

Another thing I noticed was that the wings were flexing a bit - I'm gonna try and beef up the carbon in the wing a bit which should solve that - it might also help with the roll and the knife edge.

...and now onto the plans! I hope to have them completed over the next few days. I will create plans for the 28" version as well as a scaled up one that will fit a 6" prop.

Stats for the 28" version are as follows:
WS: 28"
AUW: 11.4oz - 1000mah 3S lipo; 12.7oz - 1300mah 3S lipo
Airframe minus batt: 8.4oz
Bare airframe (unpainted, no electronics): 3.1oz
Lipo: 1000 - 1300 3S lipo (25-30C)
ESC: 30A
Servos: 2x9g (elevons); 2x5g (rudders)
motor:2800KV outrunner
Prop: 5043; will also try 5x5 speed

Maiden video:
SNice-Mitar: Mini Eflite Scimitar Clone - The Maiden (9 min 31 sec)
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Old Sep 14, 2011, 10:20 PM
Chad
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WOW I hate how you guys keep building all these planes I cant live without. I will never finish any of my projects at this rate. I was flying my um stryker today and was having a blast with the inverted flatspin. and this one you built here looks like it will fit in perfect with my elevon crew.
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Old Sep 14, 2011, 10:30 PM
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lol! I know what you mean! I need to work on the flat spin! What are the control inputs to enter and maintain the spin. I was just trying things and ended up with more of a "whirly-bird" type spin!
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Old Sep 15, 2011, 01:23 AM
skumgummi dave
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SNice:

Beautiful job. Nice flier! Looking forward to building one for myself...

Thanks, Dave-
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Old Sep 15, 2011, 01:33 AM
Chad
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on my um stryker I do no throttle and full left rudder and full right aileron and full up elevator and it throws it in to an inverted flat spin then i mess with the elvator some but that seems to do a nice flat spin.(just throw the sticks to oppisite corners). it wil not do it regular only inverted. if i give it full left or right rudder and down elevator and left or right aileron it will do the whirly bird thing. odd because on my flying kfm david wing it is just the opposite it wont do it inverted but it will do it normal.
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Old Sep 15, 2011, 03:34 AM
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Snice would you share the sketchup model?
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Old Sep 15, 2011, 07:49 AM
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Thats a great build and some great flying Snice!!!
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Old Sep 16, 2011, 01:34 AM
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PLANS ADDED TO FIRST POST!!!

Original 28" version for 5" props

AND

34" version - better sized for 6" props and larger batteries!

ENJOY! Can't wait to see what y'all do with it! Plans are pretty freeform so you can put stuff wherever you like. I suggest building the airframe first and then cut areas for servos, motors, cooling vents, hatches, etc... be sure to post pics!
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Old Sep 16, 2011, 10:40 AM
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SNice,

Surfs Up!!! I'm in on this one. To simple to build and VERY SLICK. I've yet to build anything more than 18" WS, so I'm gonna scale her down a bit. In calm winds, acrobatics will be fun. But it's when the winds are kicking, that this will be a blast.. More to come!

Ksqm
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Old Sep 16, 2011, 02:52 PM
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Thanks, Guys!

ksqm -- looking forward to that mini mini version too! Let me know if you need me to rescale -- just tell me what size prop you will be using, and I'll see what would fit safely between those rudders.

Got in several more flights. I have resolved the sloppy roll issue -- it seems it was mostly due to the way I had the battery mounted -- in the maiden, I had the battery on it's side. Now I mount it laying flat and the rolls are 95% cleaner - they are still a bit off which I may be able to fix with aileron differential.

I also added an additional carbon spar to the wing between the two rudders -- that is where all the flexing was happening. Now the wings stay flat and there is very little correction required for knife-edge flight (but I still need to practice).

I greatly reduced the throws on the elevator channel -- this made a BIG difference! I'm now more comfortable doing high speed low passes and slow aileron rolls. Still have to fly her smooth and not yank the elevator too hard because she will put on the brakes and start flipping and spinning in the air. I got into a bit of trouble with not enough altitude to recover -- adding throttle worsened the spin, so I cut the throttle and put the sticks in the opposite bottom corners. She went into a whirly bird just in time and plopped down flat -- the canopy popped off, but no damage! whew! (Thanks - TheOne420!!!)

Having a blast with this thing so far -- looking forward to seeing others' builds! (hint...hint...)
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Old Sep 16, 2011, 07:44 PM
Chad
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well I may try it in fanfold foam. I had a job out of town today and stopped in to the Lowes just to check and they had 2 full pallets so I bought one package to see what the fuss is about on all these other threads. I can tell already it is stiffer than the $tree stuff more like depron and cheaper so I may be converting from $tree board to FFF if its as easy to work with.
So my next day off I will be starting this build

oh yeah glad to hear the controls worked for you always feels good to save a plane.
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Old Sep 17, 2011, 05:31 AM
Reap the wild wind
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Joined Feb 2007
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Snice
like you I've been eyeing up the Scimitar and I've also been considering buying the F27Q but they want a fortune for the airframe only kit and I object to buying servos, esc's etc that I already have and which most are upgrading anyway. Thank you for posting on the KF designs thread as this will be on my build list once I've finished Gene's 48" cub. Any chance of scaling up to 38" size?
Head
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Old Sep 17, 2011, 12:27 PM
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AWESOME


plans downloaded

thanks a million

I'm also working on a thrust vectoring system using a heli swash

here is a proto I have been working on

http://www.rcgroups.com/forums/showthread.php?t=1480486
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Old Sep 17, 2011, 12:56 PM
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Quote:
Originally Posted by Razors edge 29 View Post
AWESOME


plans downloaded

thanks a million

I'm also working on a thrust vectoring system using a heli swash

here is a proto I have been working on

http://www.rcgroups.com/forums/showthread.php?t=1480486
DOUBLE AWESOME!!! It's great that we're using the same motor!!! There's more than enough room for the motor to rotate and for the additional servos. The additional weight would not be a problem at all. Balancing would not be an issue as the batteries already sit pretty far back in the fuse...

I could not understand for the life of me why eflite did only did yaw vectoring... I think the 360deg vectoring is the only way to go on this airframe - if you are going to do VT.

I'll definitely be watching your progress on that one!

Headlessagain - I'll scale the plans up when I get a chance (hopefully this weekend). You'll just have to make a few minor adjustments to some of the tabs - nothing big...
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Old Sep 17, 2011, 02:50 PM
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LOL

I thought it looked like you had an Emaxx motor

very cool.

I guess I should out some effort into making my project work before the snow flies

BUT


I've got soo many projects on the go lol

BUT

this one is higher on priority than others


Quote:
Originally Posted by SNice View Post
DOUBLE AWESOME!!! It's great that we're using the same motor!!! There's more than enough room for the motor to rotate and for the additional servos. The additional weight would not be a problem at all. Balancing would not be an issue as the batteries already sit pretty far back in the fuse...

I could not understand for the life of me why eflite did only did yaw vectoring... I think the 360deg vectoring is the only way to go on this airframe - if you are going to do VT.

I'll definitely be watching your progress on that one!

Headlessagain - I'll scale the plans up when I get a chance (hopefully this weekend). You'll just have to make a few minor adjustments to some of the tabs - nothing big...
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Old Sep 19, 2011, 01:04 PM
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Well I downloaded the plans and have started the build.
I have taken the liberty to change a couple of things, namely the lower fuse and the motor mount area. Here are a few pics. I have not notched the wing where the LE meets the fuse and am not sure if I will (seems like something that could easily get damaged). They do kind of define the look of the original CZ Scimitar tho so I may do that prior to painting. Again great build SNice. I hope mine turns out as nice as yours. Hopefully tonight I can tackle the upper fuse & control surfaces.
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Old Sep 19, 2011, 06:30 PM
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United States, AZ, Phoenix
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Quote:
Originally Posted by SNice View Post
Stats for the 28" prototype:
WS: 28"
KFm4 airfoil
AUW: 11.4oz - 1000mah 3S lipo; 12.7oz - 1300mah 3S lipo
Airframe minus batt: 8.4oz
Bare airframe (unpainted, no electronics): 3.1oz
Lipo: 1000 - 1300 3S lipo (25-30C)
ESC: 30A
Servos: 2x9g (elevons); 2x5g (rudders)
motor:2800KV outrunner
Prop: 5043; will also try 5x5 speed
Does the emax CF2805 motor you are using need that 30A ESC? Just curious as I have the same motor but have never used it on 3s, only 2s.
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Old Sep 19, 2011, 09:17 PM
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Hey JBinAZ!

Great progress so far -- lookin good! Can't wait to see what you do with the fuse!

The 2805 probably only needs a 20A ESC -- but I only have one and it's in another plane. I have a bunch of 30A ESC's so that is what I used. I was also thinking of putting a 2212/06 on but there is no need b/c the 2805 has more than enough power for me!

I've heard mixed things about the 2805 on 3s -- but I have never had any problems with mine (I have 2) and I've been running them for a few years now. Just be sure that you check the amp draw on the prop you use. I prop it so that it does not pull over 17A at WOT (the motor is rated for 18A for 30sec. max).

Best of luck with your build! Keep us posted!
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Old Sep 20, 2011, 02:45 PM
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Thanks for the info SNice. I was hoping that I could get away with a 20amp. I do have a 30amp esc, but like you, I would have to rob it from another plane.
I was only able to get a couple of hours in on the build last night. I decided to laminate some thin styrene (.030 I think, maybe thinner) to the control surfaces and vstabs/skids to add rigidity. It worked awesome! For the skid portion I laminated both sides and for all other areas (elevons, verts & rudders) only the styrene on one side. I forgot to weigh the VS prior to laminating, but each came out to roughly 18 grams. BTW, I left the skid portion at one layer instead of doubling them up with foam. I only have a pic prior to trimming the styrene, but will take a more detailed pic later tonight to show the finished VS that has been somewhat airfoiled.
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Old Sep 20, 2011, 02:50 PM
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Styrene lamination!....cool! Never thought of that -- I'm always battling with clear packing tape!

Gotten several more flights in and getting much more comfortable. This bird is most fun carving up the sky at high throttle levels.

I found that by adding a touch of up elevator while rolling makes her roll clean like a drill.

Knife edge is a breeze now -- it turns out that I was putting WAY too much rudder input. All you have to do is roll her on the side, and apply just a touch of pressure to the rudder and she will hold it. Just need to do it 3ft off the deck now!

I finally got a computer radio so I can now experiment with mixes and expo -- both of which I have never used.

I also got a few 1000mah 3s 30C batteries - this is now my favorite battery for this plane. The 1300 25C's are great for wind and longer flights, but the 1000's supply more than enough power and are much lighter.

I'm having so much fun with the 5043 props that I have not had a chance to switch to a 5x5. I even have a 4.75x5.5 that I would like to try - I'm sure the acceleration would be terrible, but I'd like to see if there is any speed increase...
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Old Sep 20, 2011, 03:18 PM
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I tend to use some unconventional materials when building just because it is readily available to me. Running a sign shop has a ton of benefits when it comes to scratch building. It is also nice being able to print full size plans. I have probably thrown away enough fomecor to make you guys cringe. The black lower fuse & motor mount are made from one piece of 1/2" gatorboard which is basically polystyrene foam laminated with a very thin wood veneer. Very rigid and light. It is fun trying new things with the stuff I have laying around or discard on a regular basis.
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Old Sep 21, 2011, 06:50 AM
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If you record some high speed passes close overhead I can try out the rcspeedo doppler app on my android phone and give you some numbers..
The app seems quite accurate enough, and a lot cheaper than a radar gun..
Excellent job done on your new model... dave
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Old Sep 22, 2011, 04:57 PM
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Thanks Dave, on my next video, I will bring her in close for a few passes!

I tried a 6x4 prop today and it is definitely my favorite so far. I didn't think that a 6in prop would clear the rudders but it did. I was also worried about it being too much on the motor but I checked with my watt meter and it pulled 17A at WOT. The motor's max is 18A for 30s. I figured I'd give it a go - and I'm sure glad I did!

She's still fast (fast enough for me in a small field). The main difference is in thrust and acceleration. With the 6x4, the acceleration is so great that I can accelerate out of anything pretty quickly. With the smaller props, the nose would sort of drift until she got enough speed to "fly" again. Now, she'll just go where you point her!
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Old Sep 23, 2011, 09:52 AM
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Hey SNice
I love the way this plane flies, yet another great build.
Andy
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Old Sep 23, 2011, 08:04 PM
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I tried a 6x4 prop today and it is definitely my favorite so far. I didn't think that a 6in prop would clear the rudders but it did. I was also worried about it being too much on the motor but I checked with my watt meter and it pulled 17A at WOT. The motor's max is 18A for 30s. I figured I'd give it a go - and I'm sure glad I did!
That is good to hear. I was planning to modify mine to fit a 6inch prop, but I guess that will not be needed. Any chance you know how much thrust you are pulling with the 6x4 on 3s? I weighed mine the other night and with my mods I was coming in significantly heavier than your raw airframe (150ish grams). I was thinking I may have to get a bigger motor. I ended up ordering a Keda 2730 3000 kv from Strong Rc Motors to try anyways. Should be here on Monday and I hope to have the plane finished by them.
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Old Sep 23, 2011, 10:06 PM
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I just found this thread - looks really nice and thanks for sharing your plans.
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Old Sep 23, 2011, 10:19 PM
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Nice SNice
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Old Sep 24, 2011, 02:36 AM
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Very clean build. What foam glue did you use for the nose laminations? I use UHU Por but it tends to bobble up when sanding and can pull out chunks of foam.How thick is the Plasticard / Styrene sheet you are using and what glue did you use?
Head
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Old Sep 24, 2011, 02:44 AM
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So far I have used 3m Super 77 for all laminations. I used a bit of hot glue boxing out the canopy, and some 6minute epoxy for the magnets that hold the canopy on. Next I will hot glue all or the pieces together (VS, lower fuse) and hold the servos in place. Blenderm tape for the hinges. The styrene that I am using is .030 I believe, but am not sure exactly.
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Old Sep 24, 2011, 05:26 AM
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Very nice JB, looking forward to your paint scheme.
Andy

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Old Oct 08, 2011, 12:37 AM
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Well I have finally been able to get her finished and a new motor mounted. I wonder if Snice has had many more flights with his. Mine turned out a bit different than his and my paint doesnt look anywhere as nice or Snice as his. at any rate, stay tuned for a maiden report!
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Old Oct 08, 2011, 01:17 AM
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Well I have finally been able to get her finished and a new motor mounted. I wonder if Snice has had many more flights with his. Mine turned out a bit different than his and my paint doesnt look anywhere as nice or Snice as his. at any rate, stay tuned for a maiden report!
In a different thread (having to do with foamie addiction, iirc) SNice showed us around his pad. What stood out for me was that every single one of his planes sported an outstanding paint scheme. In contrast, mine are blue...with black writing.

Anyway, nice job! Will await the flight report.
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Old Oct 08, 2011, 08:19 AM
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Thanks for the compliments, guys! I owe everything to these threads! My paint jobs don't compare to some of the works of art that others have done! I only use acrylic craft paint and some brushes. I've tried spray paints, but I am terrible at masking. One day i hope to get into airbrushing!

Best of luck on the maiden, JBinAZ --She's looking great! ...looking forward to that report!.... I've been flying mine a whole bunch --fot her properly trimmed out so she carves up the sky proper. Knife edge is still my weak point but I'll get it down soon.

Got some more video, and also had a few cg related close calls! THIS MODEL DOES NOT FLY WELL WITH A REARWARD CG!!!!! I had to parachute down b/c it was uncontrollable. I got it on video for all to enjoy. Once I get a chance, I will post!
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Old Oct 10, 2011, 12:57 PM
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SNice

Looking forward to seeing the new vids. And BTW, I've followed your builds in the past, and you do build some wonderful planes, and this one is no different.
happy days
Andy
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Old Oct 10, 2011, 07:34 PM
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sweeeeet, bird . gonna start on one tommorow. but im going to go a little extreme with the motor set up , i got a grayson hobby super mega jet motor, ima put into it,
thanks for the plans ,videos,
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Old Oct 10, 2011, 07:46 PM
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Thanks! Awesome -- can't wait to see it with that big motor!!!! Should be SUPER MEGA FUN!What size are you doin'? If you are doing the 28" - just make sure your battery fits! -- you might need to widen the fuse a bit!

Lookin forward to it -- keep us posted!

Thanks for the kind words as well, Aero Andy!
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Old Oct 10, 2011, 10:42 PM
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im going with the larger version . i usually run the smj motor with a 2600mah battery ,on my stryker.which gives me around 85mph ,but ima try and make your model a little lighter so , im looking to go around 100mph , if not id be more than happy with 85mph. i just printed out the plans so God willing i should be up and flying this weekend .
thanks again

cheers
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Old Oct 12, 2011, 03:59 PM
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No luck with the maiden. I seem to be having bad luck when it comes to getting components for this bird. The keda 2730 3000kv motor supposedly puts out 450 grams of thrust with a 4.5x4.5 prop and pulls 19a on 3 cell according to their website. I put my watt meter on it and was showing 27a at not even half throttle and my 20a esc kept shutting off.
I have not given up though, I will get it to fly!
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Old Oct 12, 2011, 09:24 PM
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...sorry to hear that, JBinAZ - sure glad you did a watt meter test! I know mine has saved me several times! Hopefully you get her in the air soon!

Finally got the new footage up! The video below is with a 6x4prop on the 28"ws version. Enjoy - I sure did .
SNice-Mitar Fun: R/C Mini Scimitar Wing Clone (6 min 51 sec)
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Old Oct 13, 2011, 01:05 PM
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The vid was great! I think that your plane has the perfect speed that I desire. Unfortunately mine weighs a few more ounces and I don't think that my Emax would like that. Instead of getting a bigger esc, I went with a different motor. Grayson Micro Jet V3 should be here today. It is probably going to be a little faster than I would like, but I guess I do not have to fly it WOT.
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Old Oct 13, 2011, 01:58 PM
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Great video. She sure has some vertical punch. What make/model of motor are you running?
Andy
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Old Oct 13, 2011, 02:51 PM
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Thanks guys!!

I think the v3 microjet would be a great motor. I have a Grayson v2 parkjet motor that I want to try but it needs a new magnet so it is currently out of commission.

Headless,
It's an emax 2805 2800kv motor. They don't recommend it for 3s but I have been running it on 3s for a while. This is the third airframe it has been on and it has never given me issues other than when combined with bad esc's or batteries.

It's rated for about 17a max so whatever prop I put on it - I make sure it is below that at wot. I usually ran it on 5in props, but I tried the 6x4 and it's very close to the 17a so I'm a little more conservative with the throttle. Motor comes down a little warmer but never hot.
The 6x4 has improved the thrust and acceleration tremendously!
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Old Oct 15, 2011, 12:52 PM
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well i should have mine all done today then i will be able to paint and install all the electronics. i decided to fully assemble and paint it then install the motor servos and all other electrionics.
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Old Oct 16, 2011, 01:12 AM
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well i should have mine all done today then i will be able to paint and install all the electronics. i decided to fully assemble and paint it then install the motor servos and all other electrionics.
Looking forward to seeing it all finished.
Andy
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Old Oct 17, 2011, 06:50 AM
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Hi Snice,
Thanks for providing the plans, looks awesome.

I have printed off the 34" version and will be installing:
6x4 prop
30amp esc
2830 2200kv motor
I have 1800mah lipos so i'll use them.
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Old Oct 17, 2011, 08:55 PM
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well here are a couple pics pre paint. I hope i can get it done this week but I dont know i got a lot a stuff to do this week. but i will be trying.
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Old Oct 18, 2011, 02:09 PM
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Sleek lines, looking good.....

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Old Oct 18, 2011, 03:03 PM
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Looking good TheOne! I still have yet to maiden mine. I was going to maiden it on Saturday, but the place we flew was a bit on the smaller side and I have a feeling that this one could get away from me in a hurry. In the meantime while waiting for the perfect opportunity, I decided to make a smaller pusher to utilize the keda 2730 3000kv motor that I got from StrongRcMotors and run it on 2 cell. I may have two planes to maiden at once!
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Old Oct 18, 2011, 11:55 PM
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2730 3000kv motor that I got from StrongRcMotors and run it on 2 cell. I may have two planes to maiden at once!
Hi JB, is that motor the same as the Blue Wonder 3000kv?
Andy
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Old Oct 19, 2011, 01:28 AM
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I believe so. It is blue. Strongrcmotors.com
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Old Oct 21, 2011, 02:13 PM
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Can i ask.....

Does this fly as stable & quick as a PrimeJet ?

I built a 32" PJ & love it, just starting my 38" PJ & quite fancy one of these too :-)

thanks
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Old Oct 21, 2011, 02:43 PM
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Can i ask.....

Does this fly as stable & quick as a PrimeJet ?

I built a 32" PJ & love it, just starting my 38" PJ & quite fancy one of these too :-)

thanks
Hello jdgto!

I've seen you over on the primejet 8 thread! You have one great looking primejet!!! I've built a few PJ-8's but none were stock -- one was f-18 style with strakes and a v-tail -- the other was a 32" 70mm edf conversion with movable canards, rudders, and thrust vectoring! ...both were great flyers and I had a blast flying them.

IMHO -- This model does better with rudder control, and is more stable at slow speeds. For similar sizes, I believe this one also has a larger wing area. This one might be a little slower due to more drag, but I really couldn't say... I think to have BOTH is the best option, as they are both a blast to fly!!!! Very similar construction as well... Check out the videos in the first posting and you will see how she handles!
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Old Oct 21, 2011, 03:08 PM
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Ni SNice,

I love my little PJet, i know i went a bit lairy with the pea green colour, but she's easy to see & i can fly it nearly as far away as i do my lander hunter.

really must make a start on the bigger version, just have to decide what power plant to go for, & in the meantime do your plans too ;-)

I must say, your plans are fantastic, I have had a look at the 28 and 34 versions & everything looks so clear (and it looks as quick to build as the PJet)

Will post some more pix when i get it built & "decorated", best put your darkest shades on now

Having them all will be a blast - 3 x pjets and a Snice-mitar ;-)
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Old Oct 23, 2011, 02:47 PM
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Well, after a very busy weekend, i have found time to (almost) complete my 39" primeJet, so tomorrow it's time to start my SNice-mitar

Hoping to have it ready to fly by mid-week.

I have a spare 2200kv 28A outrunner which i am sure will power it ok - probably 250-300 watts on the 34" SM

more soon ............
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Old Oct 24, 2011, 10:12 AM
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Hello all,
I just found this thread and am very interested in giving this a try. I fell in love with the Scimatar when I first saw it and this may be the answer to my limited RC budget. I have a fondness for fast pushers, having owned 2 built from parts Strykers and an original FunJet. I am interested in building the 34" version but have a question or 3. You are using foam board from $tree or BlueCore fan fold foam for the basic material for the air frame? What thickness are you using and what types of glue to use? This will be my first scratch build, but both Strykers I built were heavily modified using only the bare body and hatch, I fabricated everything else from balsa and scrap foam and components salvaged from other planes. One was a conventional pusher (still flying) the second used a 64 mm EDF (RIP). I have many servos, recievers and ESC's laying around to use but only 3s 2200 30c batteries I use in my Stryker and PZ Extra 300 can get smaller ones if need be. I have Grayson Super Mega Jet V3 in Stryker would that be too much for this plane or just right if I use the 2200 mAh battery?
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Old Oct 24, 2011, 11:04 AM
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Hey SNice

I've also got a question for you, I have one of these motors available for the 28" version. Is this motor similar to the 2800kv motor you have, and I'm hoping it will be ok to run on 3s as it states 7.4v in the specs?
Thanks in advance, looking forward to adding a SNice-mitar to my hanger. BTW mine will be made out of 6mm epp #1.7 (30g/l), with carbon tube to stiffen.
Andy

FC 28-05 Brushless Outrunner 2840Kv

Hobby King Spec ;
Weight: 26g (with wire & sticker etc)
Shaft: 3mm
Motor Length: 37mm
Diameter: 28mm
Stator Size: 22x5mm
Suggested prop: 5~6inch
Voltage: 7.4v (2S)
Kv: 2840RPM/V
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Old Oct 24, 2011, 11:09 AM
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Quote:
Originally Posted by MARCOELDRAGON View Post
Hello all,

I just found this thread and am very interested in giving this a try. I fell in love with the Scimatar when I first saw it and this may be the answer to my limited RC budget. I have a fondness for fast pushers, having owned 2 built from parts Strykers and an original FunJet. I am interested in building the 34" version but have a question or 3. You are using foam board from $tree or BlueCore fan fold foam for the basic material for the air frame? What thickness are you using and what types of glue to use? This will be my first scratch build, but both Strykers I built were heavily modified using only the bare body and hatch, I fabricated everything else from balsa and scrap foam and components salvaged from other planes. One was a conventional pusher (still flying) the second used a 64 mm EDF (RIP). I have many servos, recievers and ESC's laying around to use but only 3s 2200 30c batteries I use in my Stryker and PZ Extra 300 can get smaller ones if need be. I have Grayson Super Mega Jet V3 in Stryker would that be too much for this plane or just right if I use the 2200 mAh battery?

well $tree foam is what snice did his original with. you could use that or 6mm depron or fanfold foam like i used. i only used the fanfold because i just got my first bundle and wanted to try it. as far as glue i use gorilla glue to laminate 2 pieces together(clamp between 2 pieces of wood or it will over expand) and Foam Safe CA to glue the airframe. many diffrent glues will work, i have just found these to work best for me. there are a lot of glues that will melt foam as well so just be carefull if it smells strong it will most likely melt the foam.
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Old Oct 24, 2011, 11:29 AM
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I built the 28" version and i have a question. I have the 2730 3000 kv motor and I am curious if it will push this model. if not i will buy the grayson v3 as well but it would be nice if it would work with the one i have. I am willing to try it on 3s as well i also have the 1700kv version but it prob wont cut it right
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Old Oct 24, 2011, 11:54 AM
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For mine, I used 3M Super-77 spray glue for all laminations, and Fabric-Tac for general construction (both available at Walmart). Motor mount is held on with hot glue. I also used a small bead of hot glue to reinforce some seams. The above are all "quick" glues and they allow you to put together an airframe with minimal set time.

The fabric-Tac and the Spray glue both will eat foam if applied too heavily so you have to "learn" how to use it.

I just started using Gorilla Glue and so far, it has been great for me -- I now understand why it is so popular! I'm using it on a large 48" Sbach -- AKA "Snice-bach" (Thanks for the name, TheOne420). The bond is amazing, and it fills gaps nicely. As mentioned above, it needs clamping due to expansion. The only drawback is it takes a bit of time to set.

I think the Mega Jet motor with a 2200 will be fine... I've built several parkjets before with smaller wingspans and less wing area and they have still done well.
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Old Oct 24, 2011, 12:10 PM
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Originally Posted by Aero Andy View Post
Hey SNice

I've also got a question for you, I have one of these motors available for the 28" version. Is this motor similar to the 2800kv motor you have, and I'm hoping it will be ok to run on 3s as it states 7.4v in the specs?
Thanks in advance, looking forward to adding a SNice-mitar to my hanger. BTW mine will be made out of 6mm epp #1.7 (30g/l), with carbon tube to stiffen.
Andy

FC 28-05 Brushless Outrunner 2840Kv

Hobby King Spec ;
Weight: 26g (with wire & sticker etc)
Shaft: 3mm
Motor Length: 37mm
Diameter: 28mm
Stator Size: 22x5mm
Suggested prop: 5~6inch
Voltage: 7.4v (2S)
Kv: 2840RPM/V
Hey Aero --

Yes, that looks like the exact same motor that I have -- specs included -- the only difference is that it does not have an "EMAX" label. I bought mine a few years ago from www.headsuprc.com. I realize you are overseas but you can see the specs here:http://www.headsuprc.com/servlet/the...ushless/Detail

The motor is only rated for 2S -- so use 3S with caution! I used my watt meter and tested several different props on 3S. I "tossed" any prop that put me above 17A at WOT. 5x5, 5x4.3, 4.75x4.75 props all worked well but lacked acceleration. IMHO, the 6x4 APC is the best combo of thrust and speed. It's the one used in the latest video. You can definitely see the difference in punch over the prop I used in the maiden video which was a GWS 5x4.3.
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Old Oct 24, 2011, 05:55 PM
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Here's some pics of my 34" build so far. This is my first pusher-jet, I normally fly my IC trainer, Pilatus PC-9 but have a depron 'cargo twin' also.

I have used 6mm Depron and have some Tamiya acrylic paints to use but I am undecided on what sort of paint scheme to use!!.
Motor mount - Should I offset the motor mount to counter-act torque roll?
I've also included a pilot figure (4 grams) so should n't be too much extra weight. I have only dry-fitted the tail and fuse so far.

I am using evo-stick 'serious glue' which gives a more solid bond than uhu Por, it is usable for about 3 mins, and is set after about
2 hours (fully set after 24 hours) (UK buyers - you can get at Tesco) you can also use it to fill gaps or joints.
I also have a hot glue gun, but have n't used it yet.
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Old Oct 24, 2011, 07:16 PM
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WoW! Lookin Great, derek35!!! I really like the canopy -- please share details on how you will be doing it -- clear canopies are something I definitely would like to get into!

As for motor offset - I would not add any - I think it may affect the flight characteristics. My motor has no offset and she will hold whatever line you put her in.

The wingspan is pretty large compared to the prop size so I do not think you will need to worry about torque roll -- I would avoid full throttle launches though.

I don't notice any torque roll effects -- even going from slow speed to full throttle - and I have a 6in prop on the 28" airframe.

Once again, great lookin' build!
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Old Oct 24, 2011, 09:47 PM
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Love the cockpit Derek. Can't wait to see it finished.
Well I finally was able to attempt to maiden yesterday. Lets just say it was not a great day of flying in any way. I busted out my go-to puller delta to get my thumbs warmed up. Everything was going just fine, the plane was trimmed out perfectly and responding just as intended. About 4 minutes into flight coming out of a dive she got really squirelly. I tried to limp it back to a closer proximity but she wasn't having it so I cut throttle and plopped her down. Motor mount had loosened from a previous repair explains it all. No biggie, time to maiden a plane! Well as I had mentioned earlier in this thread, I had purchased a keda motor for this plane, but my build came out heavier than anticipated. So I had the keda laying around doing nothing and I decided to build a quick smaller pusher as I have never flown a pusher and kinda wanted to get my feet wet before jumping into the speed demon. Two planes to maiden this day! Battery in and pre-flight check to make sure everything was working as it should. Spool up the motor and it cuts off at half throttle just as it did on 3 cell. Bummer! Oh well I guess it is fly or die on the bad boy, so I pulled out the SNice-mitar variant. (I call it a variant as I changed a few things from his plans.) My buddy launches and when it is safely from his hands I give it some juice and immediately she rolls left and the canopy pops and gets shredded by the prop. It happened so fast and I wasn't exactly sure what was getting shredded so I cut throttle and let her crash. It looked very violent, but upon inspection the only damage was to the last quarter of the hatch and one of the verticals popped loose from the 6 ft drop. No big deal. All is fixable, but after all of that I wasn't quite in the mood to continue for the day. Sorry for the novel, I hope it wasn't too boring.
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Old Oct 24, 2011, 09:54 PM
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Thanks to all for the quick replies. I too use and love the Gorilla glue original formula. I also love my low temp hotglue gun. I have a selection of CA's and even Elmers sitting on my bench. I will get to Lowes and $tree tomorrow or Thursday to see what I can find for foam. Looking forward to giving this build a try. Thanks again.
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Old Oct 25, 2011, 01:13 AM
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"I am using evo-stick 'serious glue' which gives a more solid bond than uhu Por, it is usable for about 3 mins, and is set after about
2 hours (fully set after 24 hours) (UK buyers - you can get at Tesco) you can also use it to fill gaps or joints.
I also have a hot glue gun, but have n't used it yet"
Nice looking build Derek. Thanks for the heads up about the evo-stick 'serious glue' Looks like I'll be making a detour via Tesco's. Be careful with hot glue as the heat of the glue will melt the foam. You really need one that takes the smaller stick and a low temp craft version or this battery one from Maplins http://www.maplin.co.uk/cordless-glue-gun-394165 which is also ideal for field repairs
Andy
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Old Oct 25, 2011, 09:58 AM
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Quote:
Originally Posted by SNice View Post
The motor is only rated for 2S -- so use 3S with caution! I used my watt meter and tested several different props on 3S. I "tossed" any prop that put me above 17A at WOT. 5x5, 5x4.3, 4.75x4.75 props all worked well but lacked acceleration. IMHO, the 6x4 APC is the best combo of thrust and speed. It's the one used in the latest video. You can definitely see the difference in punch over the prop I used in the maiden video which was a GWS 5x4.3.
Hey SNice
Thanks for the confirmation and advice, I think I'll do as you did and put an amp meter on my prop choices before I maiden, just to be sure.
Well, the plans are cut, should get around to some building later in the week.
Catch you later
Andy
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Old Oct 25, 2011, 12:27 PM
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Just got back from Lowes, Home Depot and $tree. Lowes had the blue foam, HD had the pink stuff and I ended up bringing home the best 6 pieces of foam board that $tree had. I liked the price and at least with the paper on it was stiffer than the other two. Much easier to transport in my Cobalt too. I have some CF tube I used on my current Stryker but it is on the thick side so I may get a thinner piece, need some foam safe CA too. I had been considering the Grayson Hobby Micro Jet V3 and building the 28" but just checked and it is out of stock (of course). Going to keep the motor in my Stryker and probably order the Parkjet V2 and just build the 34" as I originally planned. Another option is I have an unused 64 mm EDF, hum I wonder.
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Old Oct 25, 2011, 03:29 PM
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Originally Posted by MARCOELDRAGON View Post
I had been considering the Grayson Hobby Micro Jet V3 and building the 28" but just checked and it is out of stock (of course).
I got mine here: http://www.nanoplanes.net/motors.html
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Old Oct 25, 2011, 05:30 PM
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Thanks for the tip Andy, Think I'll just stick with the evo-stick for the time being BTW don't buy the 5ml tube (3.50) they also have a 33ml tube for 5.00.
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Old Oct 25, 2011, 05:34 PM
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Quote:
Originally Posted by SNice View Post

As for motor offset - I would not add any - I think it may affect the flight characteristics. My motor has no offset and she will hold whatever line you put her in.

The wingspan is pretty large compared to the prop size so I do not think you will need to worry about torque roll -- I would avoid full throttle launches though.

I don't notice any torque roll effects -- even going from slow speed to full throttle - and I have a 6in prop on the 28" airframe.

Once again, great lookin' build!
Thanks for the feedback SNice I'll just square-up the motor mount, will post pics once I have the canopy done.
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Old Oct 26, 2011, 01:21 PM
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SNice (& others with more understanding of airflow than I have)

what is the advantage of the KFm4 airfoil ??

Just got my plans sorted for the vinyl cutter & the KFm4 seems to use a lot more material - more weight etc.

Is there any reason why it would not fly without them ?

I have read a bit about it but became confused very quickly - need somebody to translate into idiot terms for me :-)
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Old Oct 26, 2011, 02:47 PM
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Hey jdgto,

In short, the plane will definitely fly without the KF Panels -- but I don't think it would feel as "solid" in the air...

I am a strong supporter of the KFm4 airfoil. Ive used it on most of my foamies (mostly jets/deltas, and one 3D plane). You will hear arguments on both sides as why or why not to use it but in my experiences it:
-provided stability to my airframes in flight
-handles wind VERY well
-creates a symetric wing profile (KFm4)
-improves slow speed flight (reduces wing rock in high alpha - KFm4)

In my experiences, when you can't or don't feel like building a wing with a true airfoil, the KF is the next best option.

Here's an excerpt from another post of mine where someone asked a similar question:

I am by no means an expert on the KF airfoils but I am big fan of them! - I use them whenever I can -- mostly due to ease of build, and it allows me to sandwich my spars in the wings! Also, using the KFm4 allows me to build very symmetrical wings. I was always worried about twists and deformities in built up wings.

I don't have much to compare to as everything I'm flying right now has a KFm4 on it. I'm also a much better pilot and builder now than when I first started to build so it is hard to make a useful comparison with earlier airframes.

I definitely prefer a KF airfoil over a flat plate (unless the build is extremely light). When I built flat plate wings, they always felt "jumpy" in the air, especially in windy conditions. When I moved to KFm2 airfoils, they flew better (to me) but I experienced a lot of wing rock at slower speeds.

Once I added the extra step on the bottom (KFm4), my planes finally felt and behaved as if they were truly flying through the air as opposed to "sliding". They handled the wind better, were extremely stable, and felt a bit faster too. There was also a significant reduction in wing rock at slow speeds and high AOA.

That's my $0.02 on the subject!

Here is a great video by Dave Powers where he tests a few different KF airfoils on the same plane...
KF Airfoil Testing!!! (see sidebar) (9 min 25 sec)
!
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Old Oct 26, 2011, 02:53 PM
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Bristol,UK
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Have at look at this KFm testing video from RC SuperPower's
http://www.youtube.com/user/RCSuperP.../1/6H-s7yuJcwk
He trys KFm 1,2,3 & 4 airfoils by taping each profile to the same plane back to back
Andy
Shuck's, beat me to it
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Old Oct 26, 2011, 09:54 PM
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OK I decided what to do about this build. I'm going to build 2. First one I start tomorrow when I get foam safe CA and smaller diameter CF tube or rod will use the EDF, servos, ESC and Rx I have lying around already. It will be a 34" and elevons only and probably be a bit rough, building it mainly to get used to using the foam. If the first one goes well 2nd one will get the GH Micro Jet V3 and Hitec servos and nice finish and paint.

Update no Foamsafe from any local source. Ordered some Great Planes Med CA from ebay. Experimenting with some of the various glues I have onhand. Beacon 527 and Future Glue both no good. Low temp hot glue and either Gorilla glue original or dries white will work but are messy. May get some Elmers Max to try while I wait for foamsafe to get here.
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Old Oct 28, 2011, 10:15 AM
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Hi SNice

I've started my build, and it's going together well, must be the great plans you provided..
He's a quick question. Aerodynamically, what do the the wing fences add to the design and flight characteristics?

Andy
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Old Oct 28, 2011, 01:01 PM
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Quote:
Originally Posted by Aero Andy View Post
Hi SNice

I've started my build, and it's going together well, must be the great plans you provided..
He's a quick question. Aerodynamically, what do the the wing fences add to the design and flight characteristics?

Andy
Thanks for the compliment on the plans! I am glad it is going together well for you so far!

When I was modelling this model (remember this is a clone of the eflite scimitar - designed by Quique Somenzini), I had the same question!

From Eflite's website:
"The fantasy-scale Carbon-Z Scimitar, designed by world aerobatic champion Quique Somenzini, bursts open the performance envelope with an evolutionary tailless swept wing."

So... this airframe was designed to have a large flight envelope and be extremely maneuverable...

Here's what I learned -- man, I love this stuff!!! Just so you know, I look at the big picture - I'm not too concerned with equations and fomulas -- these are just models and I'd rather be building, designing, or flying!

Anyway, with swept wing aircraft, there is an additional flow of air that travels from the root of the wing towards the tip. This condition is worsened by air also being forced towards the tip of the wing by the sweep of the leading edge.

Why is this bad? Well, the air at the wingtips can get to the point where there is more air moving out than over! This is bad for two reasons - and one is much worse than the other.

First, the ailerons will loose a lot of their effectiveness and you will see a large reduction in roll authority.

Second, is a very bad stall! Essentially, when the plane nears stall speed, the spanwise airflow makes the effective speed of the airflow over the wing WELL below the stall speed of the rest of the wing. In other words, your wingtips are no longer flying.

For swept wing aircraft, the wingtips are generally behind the cg. When the wingtips are "flying" the lift they generate naturally pushes the nose of the plane down. Therefore, without the lift from wingtips, the nose will pitch up (on a normally balanced aircraft).

So essentially what we have is a sharp pitch up when the wingtips stall, then the entire wing stalls due to slow speed and high AOA -- and then the plane will drop out of the sky --- aka - the "Sabre Dance" (F-86's, F-100's stalled in this manner)

The wing fences stop the spanwise flow and redirect it towards the back of the wing. The notch towards the root of the wing also serves the same purpose.

From personal experience - I built a prime-8 min funjet and modified it by adding f-18 style strakes to the wing. The plane behavied exactly as described above until I added wing fences (Prime-8's suggestion).

...so I do think it will fly without them, but the model will not be as rock solid or forgiving in the air!
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Old Oct 28, 2011, 02:25 PM
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Since you mentioned the F-86 take a look at its great rival the MIG 15 and you will see some very prominent wing fences. Winglets can serve the same function.
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Old Oct 28, 2011, 03:03 PM
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Thanks SNice

Wing fences... that was a splendid write up, are you an aircraft designer in disguise?
Stable flight is good for me, so I'll be fitting them as your plan. Many thanks for the info, I guess you can learn something every day.
Andy
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