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Sep 18, 2007, 01:11 AM
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Build Log

Funjet / Ultra on Steroids (Current top speed : 182 mph)


This thread started as a build log but now evidently morphed into a hang out place for super fast Funjet and Funjet Ultra setups...So I've started to index all fast setups or useful build pictures as links here...Happy flying !!!

Confirmed Super Fast Records

Psionic001: Fastest yet: 182 mph

Details here

https://www.rcgroups.com/forums/show...&post#16755269

https://www.rcgroups.com/forums/show...&post#16760944

https://www.rcgroups.com/forums/show...&post#16736946

https://www.rcgroups.com/forums/show...&post#16736573

https://www.rcgroups.com/forums/show...&post#16769939

https://www.rcgroups.com/forums/show...&post#16799334

################################################## ################################################## ##

Numb_Thumb: Fastest yet: 154 mph

Details here

Funjet I

May 6th, Blistering fast Funjet on Arc 2T and 6S setup
Feb 19th, EagleTree graphs for a 154 MPH flight

Funjet II

Glassing and Reinforcement
Custom canopy hatch
Custom motor mount 1
Custom Motor Mount 2
Final Assembly

9th Maiden

Funjet III

Airframe Assembly
Motor Mount
Two part Custom Canopy
Cat walk
Maiden

Funjet powered skateboard (Pls do not attempt)

################################################## ################################################## ##

Happy Flying !!!

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Last edited by numb_thumb; Jan 17, 2011 at 11:25 PM.
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Sep 18, 2007, 01:12 AM
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Already thinking about reinforcements


This is my first funjet. Just by looking at the parts and the design, I can say this plane is an easy build. However I think this plane requires minor reinforcements to handle high speeds.
Sep 18, 2007, 01:15 AM
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Twin Carbon tubes


The stock fiberglass tube does not extend all the way to the wing tips and also it flexes more that I wanted to flex. A custom cut carbon tube that extends all the way into fake fuel tanks at the wingtips will help spread the stress to a certain extent.

A front to back carbon tube is a must for my setup. My plan is to go from 3 cell 4 cell and then 6 cell setup, with a long can heavy motor on the back. This carbon tube will distribute the stress of the batterries and the motor evenly throughout the fuselage.
Sep 18, 2007, 01:17 AM
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In case you hadn't noticed


The reason I did not extend the for-aft carbon tube all the way to the front was because

1. I don't want the carbon tube to disform/snap during a unfortunate nose down.

2. The current setup will snap off the foam in the event of a nose down crash just before the battery compart begins (and the carbon tube begins at the front). This will take away much of the impact stress or else it will be distributed throughout the plane (Guess why servo gears rip off in certain type of nose down crashes).

On a worst case scenario I'll end up with a broken nose which most probably can be fixed.
Sep 18, 2007, 01:18 AM
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A little spackle goes a long way


Carbon tubes are covered and the area is re-sanded to restore the contour.
Sep 18, 2007, 01:15 PM
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Getting ready for glassing


Preparation for glassing is underway. I'm using 1/2 ounce, 3/4 ounce and 2 ounce depending on the stress area and also plan to use WBPU and epoxy based resin and hardner for the fuselage.
Sep 18, 2007, 01:16 PM
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Glassing going on


Top right elevon is now glassed. Left side is getting ready. Used WBPU.
Sep 18, 2007, 05:18 PM
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I hate when glassing but I love it when flying a glassed plane


The pic shows glass is drying. Its a overkill to glass the entire fujet (top, bottm, sides, canopy, turtle back) because the EPP foam is better in handling everyday abuses and also I have two carbon tubes extending full length and breadth of the airframe.

May be I will use less glass on my second Funjet. Oh yes, this is my first funjet (aka experimental).

Glassing is a love hate relationship. I hate it when working with messy glassing process but I love it when flying it and showing off to other flyers
Sep 19, 2007, 02:22 PM
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Bottoms done :)


Underside glassing is now complete and dry...
Sep 20, 2007, 12:13 PM
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Top Glassing done


Top glassing complete and dry.

Second round of reinforcement with epoxy based resin in and around the nose and elevons are due next.
Sep 20, 2007, 12:14 PM
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Oops !!!


Almost forgot to glass the stabs.....
Sep 21, 2007, 11:30 AM
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Painting Prep


Next step is to start masking for painting.

The painting scheme I'm thinking of is in line with my stryker's paint scheme, not only because I like it, its different, the visibilty is awesome and I bought two big cans for stryker and and I wanted to use if off before the paint starts drying in the can
Sep 24, 2007, 03:10 PM
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Masking continues....


A black color for elevons and fuel pods would go nicely against any fluroscent color on the wings and fusealge.

So I decided to mask those areas as well. I know few folks out there wondering "I put together a fun jet in 4 hours, why is this guy taking such a loooong time and overkilling it". Well, I have a reason and would like to keep it until a little after maiden.

For now, pls bear with the boring pic of naked funjet with a bit a masking tape for cover
Sep 24, 2007, 03:12 PM
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Color evolving...


This is the first shot of the painted Funjet. The signature of this plane is slowly taking shape.

The masks are still on. I will draw fire scheme on the wing area just like I did for my stryker. It should look really good when completed.
Sep 25, 2007, 02:26 PM
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Another shot from a different angle. The masks are still on.


Another shot from a different angle. The masks are still on.
Sep 25, 2007, 02:29 PM
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Masks off


Masks are removed in the pic. The contours are slowly getting in shape. I plan to use black color to contrast with the orange/yellow combo. That combined with a fire breathing scheme will make it look awesome.

I planned to maiden this babe tomorrow but it looks like I have to postpone till next weekend because so far I have only test fitted the hardware for CG estimation. This is one of the things I never hurry up.

Its time to pay some attention to the Projeti. The trim process and maiden is not over yet.
Sep 25, 2007, 02:32 PM
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painting in progress


Elevons, fuel pods and nose are now painted in black
Sep 26, 2007, 02:20 PM
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Fuselage painted black


Fore fuselage is painted in black. I may use tape for rest the area. With this the bulk of the painting work is over.
Sep 26, 2007, 02:21 PM
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While the paint was drying


While the paint was drying, I had put a new elevator control horn for the Su-27. the old horn was getting bent due to stress from high alpha recovery.
Sep 26, 2007, 02:22 PM
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Flame stencil


I saw this scheme somewhere on the web. Tried to do something similar.

This is the hard part. To create and outline the stencil for the flame. I had to reverse it for the left and right side.
Sep 27, 2007, 03:40 PM
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Another angle of flames


Another angle of flames
Sep 27, 2007, 03:41 PM
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Flames - Half Way done.


Flames - Half Way done.
Sep 28, 2007, 06:12 PM
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flyin C's Avatar
Very COOL! Great job!
Very excited to here how it flyes, keep us posted on the build log
Oct 01, 2007, 03:24 PM
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Thanks flyin C. I'm sure will post the details.
Oct 01, 2007, 03:29 PM
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Does look beautiful and lethal at the same time


Does look beautiful and lethal at the same time. A pirate skull in the vertical stabs will make a good fit.
Oct 02, 2007, 07:14 PM
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Show time.....


Its time to forget maiden blues and enjoy the momemt
Oct 04, 2007, 10:55 AM
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Maiden Video


Ok. Here is the maiden video. Nothing crazy though, just some regular maiden trims and manuvers.

Config:

Mega 16/25/3, 6 X 6 graupner, 4S 2200.

I was flying half throttle for most the time.


funjet on Steroids : Part 1 (3 min 52 sec)
Oct 05, 2007, 11:57 AM
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Here we go


I did not build this Funjet for 4S. If I do so it will be a waste of time on all the reinforcements and glassing I did.

More research needed before I give a green light...
Oct 05, 2007, 05:40 PM
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great video. It looked like it was going pretty fast for half throttle...

No, I think you should step it up to 10s!

haha, I think you would be the first to do that if you really were to do it.

How would you compare the handling of this wing to others, such as the stryker, wing warriors?
Oct 05, 2007, 06:45 PM
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Thanks....I wouldn't dare to go 10S, not because the funjet couldn't handle it but for the cost of the equipment involved

I think 6S would be the max for this plane.

I haven't built a wing warrior but built and flown few strykers.

Although stryker is a joy plane to fly, I feel Funjet has bit more handling characteristics and drag is less than stryker.

Also stryker has smaller battery comparment than funjet. However in funjet, there is no easy way to access your ESC, BEC or motor wires once the turtle top is glued in, or at least it is not as east as in stryker.

For speed, stryker would never get close to Funjet's speed with the same setup.

I'm aiming for 150 mph range with 6S in Funjet. Will know for sure in couple of weeks.
Oct 07, 2007, 09:07 AM
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Very nice FJ you have there Numb. I too have an FJ with an ok custom paint job nothing compared to yours of course. I have not flown any of the strykers or wing warriors but this is by far the nicest most care free flying plane I have or have had. Very responsive, quick, and sleek. This is the only plane I have I feel comfortable throwing by myself. Although not looking for the 150 mph area I do like speed and mine is setup to swap from 3s to 4s depending on my mood. My 3s speeds are probably right now in the 65-75 mph range on 3s. Have not taken it to 4s yet as I do not own a 4s pack yet.

Jason
Last edited by FresnoJay; Oct 08, 2007 at 12:19 PM.
Oct 08, 2007, 10:47 AM
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4S will make a real difference. You should go for it. After that, for each cell increase the speed does not increase proportionally.

Post a pic of your Funjet. My paint scheme was based on some other airplane I saw somewhere in the net. Couldn't remember though as it was some time ago. I wish I can buy a air brush to improve my painting skills.
Oct 08, 2007, 12:39 PM
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I added the pics to my original post. The plane also as 3 white stripes on a all black wing for orientation on the bottom. I should be able to start getting 4s packs this week. Looking forward to the performance boost already.

Jason
Oct 08, 2007, 02:57 PM
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The paint job looks nice. I guess the visibility will be good even on a bright sunny day whereas I have tough time with my bright fluroscent colors especially when the plane gets between my eyes and sun.
Oct 08, 2007, 03:48 PM
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Yeah thats one of the things I like about this paint job. Can see it pretty much all the time.
Oct 09, 2007, 05:15 PM
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6S 3800 may not be a good choice


Its going to be a tight fit for the 6S. What I'm more concerned is the air flow to the rear of the plane (to BEC, ESC and motor). It is certainly going to block a good amount of airflow which is not acceptable to me.

Also the wing loading versus weight of the plane doesn't look comfortable for me. I need to do some more math to come to a conclusion.

6S 3800s may be a bit too much for this plane....but I will confirm it either way before actually flying it.

Also I'm not looking for flight time more than 6-7 minutes mixed throttle. At speeds close to 150 mph its no fun flying more than 6 or 7 minutes. So may be a 6S 3300 would be a good choice.
Oct 10, 2007, 12:26 AM
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3300's would be a bit smaller and allow more air around them. But don't forget that the aft section of the plane gets most of its air from the intake molded into the turtle deck just past the FG spar area.

Jason
Oct 10, 2007, 11:44 AM
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That's right, but unfortunately my esc and BEC currently sits well ahead of the rear air intake.

I think I might cut the wires from the motor to esc to move the esc and bec all the way to the back. Then I might have to extend the wire from esc to the battery because it might fall short...
Oct 11, 2007, 11:27 AM
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Actually you might just want to go with smaller packs. Reason being is you would rather have your ESC to motor wires longer than your ESC to Batt wires. I cant site the exact reason as I am not quiet that electronics versed but something to do with interferance. Esc manufacturers typically stae if you have to lengthen one of the 2 to lengthen the ESC to motor wires for this reason.

Jason
Oct 15, 2007, 04:50 PM
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Ordered 6S 3300 mah....
Oct 30, 2007, 06:41 PM
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Great Work


Hi Numb Thumbs:

Excellent work. I saw your 165mph Projeti and was blown away.

I don't have the Projeti but I have recently pushed the Funjet pretty hard.

I have done lots of testing on Mega 25/3 on 4S and 5S but my fastest set-up so far is on the hotter Mega 25/2 with a 2200 mah 4S Li-Power EXTREME 25c-30c. Here are a few Eagletree graphs on that motor and batt with a Graupner 5.5x5.5 CAM SPEED - in flight. Pulled 800 watts in my house and 921 watts peak in sub-zero flight conditions (I live in Canada and fly in the mornings). Temp was -3 Celsius. Max speed 135mph.

First Graph entire flight
Second Graph Snapshot
Third Graph Closer Snapshot

I hope to see your Graphs and Video of your 6S monster. You should hit 150 mph with this airframe on 1200 watts.
Oct 31, 2007, 11:20 AM
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Mach61, Glad to see you have a top dog funjet.

I think if you put a higher capacity battery and put a 6 X 4 or equivalent prop, you can get close to 150 mph.

I just got my brand new TP 6S 3300 extremes and already test flew it once. There is no problem in launching.

I visited Ottawa in winter few years back and saw the frozen river / channel (forgot the name) in downtown Ottawa where people were skating on it. That's terribly cold.
Nov 06, 2007, 04:34 PM
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I did two more flights last weekend with 6S configuration.

I noticed the motor got a bit hot. One reason is that it is not fully exposed as the Projeti and I'm using a 6 X 5.5 graupner speed prop. I bought a 6 X 4 sport prop and also will see if can scoop in a bit more air into the motor area.

Also my canopy got ejected two times (landed safely both times) so I need a fool proof and easy way to fit the canopy. I tried rubber bands and it is kinda inconvenient. I saw an ingenious canopy screw on a Stryker at baylands. I forgot the flyer's name but I think I'm going to copy or improve on his idea. Will post pictures as soon as I find the right components.
Nov 07, 2007, 03:30 PM
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Interesting. Are you running a heatsink on the motor? (I always run one to keep it as cool as possible)

If you want to ram air into the motor, you might try glueing a cut Wendy's plastic spoon just behind the air intake for the motor to act as a ram air scoop - but it will increase your drag co-efficient.

Did you have Eagletree hooked up? I look forward to seeing your Eagletree graphs with the airspeed sensor on this bird.
Nov 07, 2007, 04:20 PM
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I have two heat sinks on the motor. Pictures are available in the build part of this thread.

Plastic spoon is the only handy option I have at this time. I'm more worried about the canopy. I need to find the proper screwing mechanism at osh today or tomorrow.

I'm still fine tuning the Funjet and Tx to fly stable at high speeds. once it is done then it time for some interesting experiments using elogger. That little device is just amazing. Its like having a cake and eating it too
Nov 08, 2007, 01:40 AM
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At these superfast speeds, it is certainly hard to keep the plane perfectly straight and level when tiny input can send it off course. I am adding this unit to the plane to get better data - even though it will add a little weight and cause some drag - http://www.fmadirect.com/detail.htm?...489&section=20
Nov 08, 2007, 11:56 AM
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Interesting.....Let us know how it flies with this gadget.

I have programmed my Tx with 30% throw and 90% expo.This in part helps fly very stable.
Nov 09, 2007, 12:41 PM
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Few more mods to the Funjet


Canopy ejects in mid air :

I saw this genious yet simple setup from a fellow rc flyer at my flying site. It uses a screw that I don't know what it is called availabe at OSH. I glued the bases with CA and then some hotglue on top of it and then reinforced it with popsicle sticks. Looks great and neat. I can now take out the fear of ejecting the canopy at high speeds.

Motor gets uncomfortably warm :

Since the motor is fully enclosed within the fuselage, its gets warmer than I expected. So I used the classic spoon scoop to force a bit more into the rear of the plane.
Nov 12, 2007, 01:07 AM
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I managed 149MPH straight and level today with my FunJet! There was no wind so it was a great day for the speed run. Here some more info...
https://www.rcgroups.com/forums/showthread.php?t=769438
Nov 12, 2007, 12:23 PM
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I test flew the funjet last weekend at wot for few seconds and all I can say is wow. I will leave the rest to speculation till I post the eagle tree graphs.

I think I have tuned the jet good enough to put the eagle tree system on it.

This weekend, weather permitting, should be the start of very interesting series of tests.

Happy flying !!!
Nov 12, 2007, 05:48 PM
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Quote:
Originally Posted by numb_thumb
This weekend, weather permitting, should be the start of very interesting series of tests.

Happy flying !!!
Sweet
Nov 20, 2007, 07:49 PM
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Hey Numb Thumbs,

Any Funjet flying recently? Are you finding it harder to hit high speeds on the Funjet compared with the Projeti? The Projeti does seem more aerodynamic.

I have been working on the Lynx and my Funjet is sitting in the corner waiting of the FMA Co-Pilot, which just came in tonight.

You should get a Lynx and see how fast you can push it. Seems even more aerodynamic than the Projeti.
Nov 20, 2007, 08:05 PM
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Flew last weekend and the speed was pretty scary

it is more stable than the Projeti but it has tons on inertia. Even if I throttle down after few seconds of WOT it keeps going and going. I guess the weight factor of 6S 3300 extremes are in part to blame .

May be couple more trims and then I will be all set to put the logger. When I put the eagletree on the funjet I want to focus on flying the plane, not struggling to control it. You know what this means at 160 + mph speeds

I have Thursday, Friday, Sat and Sunday off so definitely I will put the logger before Monday.

Also Arc 1.5 turn motor is sitting at my desk and so is a ritewing demon. So many things to do and too little time

I can't think of another plane (lynx) at this time. But I'm sure I can get it close to 150 using the same setup on the projeti and esc timing set to advanced.
Nov 26, 2007, 12:42 PM
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I thought I finally tuned my funjet to my satisfaction.

I test flew the funjet last week and realized it was not fully tamed. I can do nascar style merry-go-round up in the air at 150+ mph (that's my guess right now) but trying to do level flight close to ground is simply not possible yet.

The reason I guess is, before the funjet can reach its terminal velocity it goes past me and becomes a dot and if I wait till that point of time I will surely lose the plane. So its a constant control game where you have to control the plane all the time instead of just flying it.

Also I tried to climb and then desend (avoiding the word 'dive' ) at the turns and realized the plane just keeps on going when climbing instead of reducing speed. The biig reason for this behavior (unlike the projeti) is that funjet is hauling a 6S 3300 mah battery and the plane is glassed with 2 oz cloth and commerical epoxy based resin (or else it will shred into pieces at this speed). All this results in huge inertia that keeps the plane going and going even after I reduce the throttle.

I may have to play with the expos and the throws to find a sweet spot where I can handle the turns comfortably and also make sure I'm not putting excessive G's in the jet when turning.

It might take another week or so before I can put the eagletree in the funjet and get a hang of it.
Dec 01, 2007, 03:43 PM
Annoying people since 1970 :)
It makes me wonder how some guy's are able to run pylon racers at close to 200mph! How are they able to see the plane for long enough to get to those speeds?
Dec 03, 2007, 03:19 PM
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-------------------------------------------------------------------------
200 miles per hour = 89.4 meters per second = 293.2 feet per second
-------------------------------------------------------------------------

293.2 feet per second.

Do I have to say more?
Dec 17, 2007, 12:23 PM
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Propped Up


After getting a hang of it using a 6 X 4 sport prop, I upgraded to a cam 6 X 6 prop. Static amps was around 58 and close to 1150 Watts. My 6S 3300 extremes are capable of 83 Amps continuous. Sweet. I can forget the batteries for the moment and focus on the motor. Time to buy a IR temp gauge.

It is scary fast and Tom said to me it made it look a 102 mph twister standing still when the Funjet zipped past it.

Couple more flights and I'm ready to put the eagletree on it to measure the parameters. Dave @ lightflightrc.com let me borrow his howfast gadget. I will run that in parallel to the eagletree airspeed expander just to make sure the air speed is consistent between two different gadgets.

Big Rick suggested a nice mod to reverse the airscoop at the rear end of the canopy to create a vaccuum effect inside the funjet, thus reducing the air pressure inside the fuselage. I plan to measure the speed and rpm before and after reversing the airscoop to understand the impact of this change.
Dec 30, 2007, 08:53 AM
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Wingtip stab's


This is what i've done to my funjet. I have cut to fit the vertical stabs on the wing tanks to enhanced the look and found out that it looks way better than stock . But by doing this it changed the stability of flight- it will be unstable due to the stabs moving forward. So what i have done is added an extra vertical stab in the middle turtle deck right behind the air vent to compensate for the instability issue. I had not glued them on yet but, taped them on for flight testing. It flies more scale than anything (at least with my set up tp2409-12 ,apc 7x5 prop). Will be doing more flight testing when the weather clears.
Dec 31, 2007, 02:28 PM
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Very interesting...It looks great and different from the stock setup.

Any idea how 3 vertical stabs instead of 2 will add to the already draggy airframe.

I wish you tested only with the center stab first before putting them on wing stabs. May be it would had flown very stable. May be not. I tend to think the closer the vertical stab is to the thrust line / center of the plane, the more stable it will be.
Dec 31, 2007, 05:34 PM
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Quote:
Originally Posted by numb_thumb
Very interesting...It looks great and different from the stock setup.

Any idea how 3 vertical stabs instead of 2 will add to the already draggy airframe.

I wish you tested only with the center stab first before putting them on wing stabs. May be it would had flown very stable. May be not. I tend to think the closer the vertical stab is to the thrust line / center of the plane, the more stable it will be.

Thanks numbthumb. Yes it does look great. I often wondered how it would look with the stabs on the wing tanks .
Well, about the 3 stabs instead of 2 well, the 3rd stab (in the middle) was out of necessity to get the airframe stable even though it would sacrifice speed by being draggy. But I know, I know this is a thred about the Funjet being on steroids. But for some reason I kept thinking this thred was on mods some how. Oh,well. Maybe I'll put a large motor on it after every-thing said and done.

Anyway, about testing with only one stab,well, don't think it didn't cross my mind. In fact the Tornato fighter jet with the one Large stab came to mind in comparison to the F-14 Tomcat with two( like our funjet). Actually Numb, It looked soooo nice with the two stabs at the wing tanks that I WAS HOOKED! About the center stab being in the center of the thrust line, I don't know, although that's an interesting analogy. But I do know that if it was not for the center stab with the other two it would not have flown stable.

To tell you the truth I'm not looking for a real speed demon right now. I want to at least make sure the airframe is stable first then...who knows Whooosh!!!
Last edited by anthodenn; Dec 31, 2007 at 05:40 PM.
Jan 01, 2008, 08:17 AM
Annoying people since 1970 :)
For your info, the TT Velocity becomes much more stable when the wing tip fins are moved inboard.
Jan 02, 2008, 04:06 PM
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Funjet experiment with 6S and 6.5 X 6.5 prop


Finally I was able to fry my mega 16/25/3 motor. Everything else worked fine and hence I was able to land safely.

It took 3 minutes of continuous WOT, 6.5 X 6.5 speed prop, 6S 3300 mah extremes, > 1600 watts to fry it.

Next step is to cut the 6.5 X 6.5 prop to 5.5 X 6.5 and put another mega 16/25/3 or an Arc 28-47-1.5 motor with a 4.7 X 4.7 cam prop.

So far my fastest speed was 144 mph level and 159 mph in a shallow dive.

To be continued.....
Jan 30, 2008, 01:54 AM
RC pilot by soul
interesting thread - thanks !
Jan 30, 2008, 12:44 PM
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I have installed Arc 28-47-1.5 in my funjet and currently doing some experiments with caution.

5s 2500 mah lipo and a graupner 4.7 X 4.7 pulls 64 amps.

6S 3300 mah lipo and a graupner 4.7 X 4.7 pulls 85 amps.

I cut a graupner 5.2 X5.2 prop to somewhere around 4.3 X 5.2 and it gulps around 80 amps with a 6S but the results are very promising.

The lvc kicks in after 10 seconds of full throttle so last week I took the esc to my local hobby shop and had lvc programmed to 16 volts and the esc time set to high advanced

Weather is not cooperating very much on weekends but I hope to put a eagletree soon to get all the parameters.

Soon, I might very well officially say I have the fastest funjet flying around. Looks very promising as of now.

I need more patience and money

Happy flying !!!
Last edited by numb_thumb; Feb 14, 2008 at 06:02 PM.
Feb 14, 2008, 05:57 PM
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Arc installation


Few pictures of the motor installation...I have very good chance to make history....will know in few days

Happy flying !!!
Feb 14, 2008, 06:25 PM
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Quote:
Originally Posted by wastegate
It makes me wonder how some guy's are able to run pylon racers at close to 200mph! How are they able to see the plane for long enough to get to those speeds?
Forget the ability to see the plane for a moment.

Assuming a 4.1 pitch speed prop, a motor has to spin 52000 RPMs to get to theoritical 200 mph.

Take into account motor efficieny loss, drag, resistance et al, we need close to 60,000 rpm on a 4.1 pitch prop to get over 200 mph.

Does anyone know any motor (with proof like eagle tree please) to show their motor can turn a 4.1 prop to 60000 RPM.

I know some of them will say Neu. But please I would love to get some realiable proof (like eagle tree or an industrial RPM sensor etc) and the proof your motor and plane survived after hitting that sort speed/rpm.

------------------------------------------------------------------------

What frustates me is that some stupid people claim incorrect speeds without any proof or by showing incorrect doppler graphs. Doppler graphs are good for a honest, disciplined flyer who read the manual and understand completely and follows it correctly.

Doppler can be easily skewed just by climbing slighty after going past the recording device. The faster you climb the faster the speed it records.

Happy Flying !!!
Last edited by numb_thumb; Feb 14, 2008 at 07:19 PM.
Feb 18, 2008, 12:06 PM
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Funjet test results are now available


As planned I ran the funjet thru series of tests during the weekend. I put the eagletree on two of the flights, one with a controlled throttle and the second one with WOT .

I got some very impressive numbers from the eagle tree and I'm sure very few people may have achieved that kind a numbers and took the plane home in one piece

I will post the graphs and the dashboard data tonight. I must remember to post a warning it is not a recommended setup and is very dangerous.

Happy Flying !!!
Feb 19, 2008, 04:17 PM
Registered User
Thread OP

Its official : 154 mph !!!


Do not attempt this setup. The amps and watts were pushed this high purely for experimental purpose. you have been warned. I damaged my ESC in this flight now it won't recognize 5S/6S. It will only respond if I put a 4S. Funny but I guess the ESC is done for good. Its official now : 154 mph. It took amost 6 months of trial and error and various prop combinations to come upto this point.

This is the only flight I have opened up the throttle and flew based on my instincts.

Following are the issues I noted during the flying

1. At WOT I felt the prop was not biting as I expected. A detailed analysis of the eagletree graphs confirmed that. I had a custom cut 4.1 X 5.2 graupner prop. I guess the thrust was too low for it to byte properly. And the elogger shows that the parameters logged were quite consistent with prop not biting scenarios. It kinda a gave me a feeling the plane was skidding at will over a sky full of ball bearings.

2. Learned a good lesson with what's called terminal velocity. For high RPM motor and high pitch prop combination, its obvious we lose thrust but another issue is its takes loooong time to reach the terminal velocity. In other words, When I flew WOT starting at one end of the field, the plane started acclerating and kept going faster and faster but never reached its max speed because its already now at the other end of the field (and my vision) and I had to slow down and start my turns.

To prove this I took the plane a bit higher and to the right end of my field and before even making the turn I went WOT and turned and decended gently. This helped the plane acclerate quickly and hence the plane had enough time to get to the logged speed (154 mph). I would never do this again because I had to take the plane far away and I felt very uncomfortable trying to turn it because all I saw was a small patch of bright orange red color of the plane. I turned with my instincts and it worked more or less as expected.

Next time, may be I need to field spotters at left and right ends of the field with a radio to communicate but I don't know how practical that would be.

Debrief:

Battery : 63 degree celcius (I bought a new infrared temp sensor but forgot to set the readings to show in fahrenheit.

Motor : A bit difficult to point at the right spot with the temp gun but the best reading I got was 49 degree celcius.

ESC : 65 degree celcius.

My adrenaline : thrice the legal limit

All other parameters are in the graph.

Happy flying !!!
Last edited by numb_thumb; Feb 20, 2008 at 11:53 AM.
Feb 19, 2008, 07:00 PM
Registered User
Thread OP
Before flying the funjet I cross checked the RPM with a optical RPM sensor from fellow flyer at the field.

I plugged the eagletree in live mode and ran up the rpm to 28000 and the optical rpm sensor matched the number exactly.

Based on the RPM and prop pitch , the theorotical pitch speed comes close to 215 mph. so a 60 mph difference between theoritical and practical speed is too much to comprehend (or at least this is the first for me). This again reiterates my guess that the prop was not biting properly or it could also mean the airframe has hit its wall where the drag overcomes the thrust and speed offered by the prop.

I will know more details when I try this motor on my Projeti. It is much more aerodynamically smoother than Funjet.
Last edited by numb_thumb; Feb 19, 2008 at 07:15 PM.
Feb 20, 2008, 01:11 AM
Registered User
Thread OP

Correction


Just noticed the rpm is not 47K. It is actually 44K. When I plug in the eagletree to the plane, it spikes very high but randomnly for a microsecond and hence it was showing 47K.

I have uploaded the correct dashboard.

Happy Flying !!!
Feb 20, 2008, 06:14 PM
No Guts, No Glory
flyin C's Avatar
Very, Very... NICE!

Well done Numb thumb!
Feb 22, 2008, 12:52 PM
Registered User
Thread OP
Thanks flyin...It was a long road though. I had to do one thing at a time, test it, get comfortable flying it and then go to the next step.

I have installed a mega 16/25/3 back on the Funjet. I'm working on a custom graupner speed 5.5 X 6.5 prop. That setup should give almost close to the current speed but will less amps. Later I would like to put a mega 16/25/2 or Arc 20-47-2 turn motor. That will probably the final setup for the funjet. I don't think I can push the setup any further than this.

A couple of other projects are in line. a microjet and a lynx, both on 5S

happy flying !!!
Feb 22, 2008, 03:08 PM
Annoying people since 1970 :)
If you're having trouble seeing the Funjet at distance and speed, I wouldn't bother with the Microjet. It may look only a little smaller on the bench but there's a huge difference in the air! Good work by the way, I guess that makes you the current proven Funjet speed record holder?
Feb 22, 2008, 04:42 PM
Registered User
Thread OP
I guess this is not the end of road for the Funjet yet. I have few more setups to try including different custom prop sizes and mega 16/25/3, 16/25/2 or Arc 28-47-2.

I see few advantages in the Microjet in comparision with the Funjet. The Microjet is less draggy, weighs less than funjet but the power system is almost same as funjet . What this boils down to is

1. I don't have to take the microjet far away from me to make it reach its terminal velocity. In other words, with the same power setup as of the Funjet, microjet will perform at least 50% or more than Funjet, which equates to less time to reach its terminal velocity. Of course this is all my theory and may go wrong in reality.

2. I'm going have a hard time hand launching this thing with a long can motor and 5S 2200 mah battery. This plane will also have triple carbon tube reinforcement and 100% fiber glass covering (Including the canopy and the turtle) with commercial grade thin resin.

Initially I will go with a 4S, get comfortable and then go with a 5S.
Feb 22, 2008, 05:05 PM
Annoying people since 1970 :)
Yes the Microjet is much quicker than the Funjet using the same power system but it flies nothing like the Funjet. It is so twitchy that it scares me and I have -70% expo dialled in! The heavier it got, the worse it got so I went back to a simple 3s outrunner combo. Keep it as light as you can, if you can! BTW, there's a guy with the username Cartman who has/had an MJ radared at over 180mph here
Feb 22, 2008, 06:33 PM
Registered User
Thread OP
I've seen this video before. From the numbers he had posted in the video I can see he pretty much squeezed all he can from his setup.
My gut feeling tells me I might be able to beat his speed. If not at least I will show the eagle tree graphs for all the flight parameters for whatever speed I can get.

Any plane at this speed feels twitchy, Microjet twitches more. I got used to it so I don't worry about it any more. My main concern is in launching the plane. For some reason I can't convince myself to get a bungee either.

Anyways I have couple more months before I can work on this. Probably lynx is next.

happy flying !!!
Feb 23, 2008, 01:11 PM
Annoying people since 1970 :)
My Lynx has been built for 2 months but has not been flown yet as it looks so nice I don't want to spoil it ! I'll be using a 3s with a KA450 (3200Kv) motor and an APC4.75x4.75 but may have to prop down. My biggest concern is enough cooling air to the battery.
Feb 25, 2008, 11:58 AM
Registered User
Thread OP
I'm building a lynx for the friendly competition for the fastest lynx. I will keep the details confidential till I can be sure I can break the current top speed. I will post a a build thread after my maiden.

I built it to fly tough and mean so its more strong than pretty. I will have no trouble it it eats grass during maiden Also the airframe is so cheap, you could stock them up and build as many as you want.
Feb 26, 2008, 11:56 PM
Flying motor mount master
fly_boy99's Avatar
Good job there numbs!!!

I will be out at the field tomorrow with a brand new motor on the Lynx to see how it fares on 4S and then I might try to squeeze 5S!!!
Feb 27, 2008, 12:30 PM
Registered User
Thread OP
Brian,

Bring it on. In couple more weeks we can race . I will bring my lynx to the field this weekend. It might not be fully done by then but you can take a look at my build and see if it has the potential to break the current speed record.

And yes, I carved enough foam to put a 5S 2500 25C battery comfortably (with space on the sides and top for air to pass thru. . A couple of beers when carving foam did wonders !!!.

It has a total of 5 carbon tubes and glassed top to bottom, front to back using commercial grade thin resin. It now looks like (as someone said) "A stiff teen in her prom dress".

Happy flying !!!
Mar 01, 2008, 09:41 PM
Watch for terrorists buying RC
flythetailoff's Avatar
Any of you guys tried the Super Parkjet Little Screemer? It's a 135mph setup that is so light you can do highalpha stuff. The setup is a 4s 1320 Thunder Power pack, and a 6x5.5 apc prop. It will fly so slow that you can just catch it, and has amazing vert. Hobby Lobby has that motor on sale for less than $50.00
Mar 03, 2008, 12:11 PM
Registered User
Thread OP

Super Parkjet Little Screemer


It is not a good choice for me because I'm trying to exceed the 150 mph + range and this motor falls right out of my scope.

Speed costs money. There is no short cut to this theory (yet).

Happy flying !!!
Mar 03, 2008, 03:41 PM
Registered User
Thread OP
135 mph does not look right . And with 4S 1320?????

Could you verify your numbers again?

Happy flying !!!

Quote:
Originally Posted by flythetailoff
Any of you guys tried the Super Parkjet Little Screemer? It's a 135mph setup that is so light you can do highalpha stuff. The setup is a 4s 1320 Thunder Power pack, and a 6x5.5 apc prop. It will fly so slow that you can just catch it, and has amazing vert. Hobby Lobby has that motor on sale for less than $50.00
Mar 05, 2008, 10:50 AM
Registered User
could you run 2 3cell batts instead of a 6s on this fast funjet setup?

what about a 4s + 2s setup?

i don't have 6s or a 6s charger, that is why i'm asking.

are 2200 mah TP exV2 too small for this application? does it have to be 3300 mah or bigger?

where'd you get the heat sinks? what type?

thanks - Bob
Last edited by pairadocs; Mar 05, 2008 at 10:56 AM.
Mar 05, 2008, 12:27 PM
Registered User
Thread OP
Bob,

You can certainly put two 3S 2200 in series to make a 6S and same goes with a 4S + 2S setup. However when supplying high amps, each of the batteries may or may not discharge at the same rate and it becomes mandatory to use a balancer when charging. There are few more subtle differences like the cycles on both the packs (The closer the better) etc.

Also the pros of using a higher capacity battery (3300) is that it can supply more continuous amps to the motor. This is very helpful in going past 150 mph +.

Quote:
Are 2200 mah TP exV2 too small for this application
No but you may not get very high speeds. Speed requires the right combination of motor / prop and battery. If one of them is insuffcient you can still fly it but not at high speeds. There are quite a few parameters that dictate how fast you can go.

My heat sinks are regular 28 mm heat sinks. I cut the fins (otherwise it wouldn't go inside the fuselage) I slid two of them on the long can motor.
Mar 05, 2008, 01:49 PM
Registered User
Quote:
Originally Posted by numb_thumb
Bob,

You can certainly put two 3S 2200 in series to make a 6S and same goes with a 4S + 2S setup. However when supplying high amps, each of the batteries may or may not discharge at the same rate and it becomes mandatory to use a balancer when charging. There are few more subtle differences like the cycles on both the packs (The closer the better) etc.

Also the pros of using a higher capacity battery (3300) is that it can supply more continuous amps to the motor. This is very helpful in going past 150 mph +.



No but you may not get very high speeds. Speed requires the right combination of motor / prop and battery. If one of them is insuffcient you can still fly it but not at high speeds. There are quite a few parameters that dictate how fast you can go.

My heat sinks are regular 28 mm heat sinks. I cut the fins (otherwise it wouldn't go inside the fuselage) I slid two of them on the long can motor.
thanks for the help.

i was going to use 2 new TP 2200 extreme V2 3 cells - what do you think of that? they are of equal cycles, etc.

is the high speed attainable with so much less mAh?

Is the only sacrifice with my setup flight time would be shorter?
Mar 05, 2008, 02:06 PM
Registered User
Thread OP
Quote:
Originally Posted by pairadocs
thanks for the help.

i was going to use 2 new TP 2200 extreme V2 3 cells - what do you think of that? they are of equal cycles, etc.
Sounds good. Always use a balancer when charging.

Quote:
is the high speed attainable with so much less mAh?
Not likely with Funjet. May be possible with othe small planes with a nice profile (projeti, microjet etc) Continous amps is still around 55 amps. It will go fast but not faster Also it depends on the motor and prop size.

Quote:
Is the only sacrifice with my setup flight time would be shorter?
Shorter flight time and whatever speed you can get out of 55 amps (continuous amps). All my setups (at WOT) mostly never exceed the rated contnous amps of the battery. I don't want to screw up the battery for the sake of going fast.

After getting a feel for 6S setup you can reduce the LVC to 2.5 volts per cell. this will extend your flying time a bit and also increase the performance a bit. Many flyers have their own opinion about this but my experience tells its ok to set the lvc cutoff to 2.5 volts per cell but prepare and land as soon as the lvc kicks in.
Mar 05, 2008, 02:39 PM
Registered User
I always balance - good point.

I am using the same mega 16/25/3 you did, and a graupner cam speed prop - was planning on a gcs 5.9x5.9.

It sounds like i need a 6s batt to get what you did out of the abovementioned setup, right? sorry for my novice battery knowledge, but i don't know why it isn't the same as two 3cell batts of same brand (TPexV2 for example)??

thanks again for all you answers. this is one of my winter build projects.
Mar 05, 2008, 03:21 PM
Registered User
Thread OP
Let me put it this way. To get the same performance I got on my Mega 16/25/3 setup, you need one 6S 3300 mah or two 3S 3300 mah or any other combo that can equate to 6S 3300 mah.

A 3300 TP battery can supply 85 amps continous. A 2200 TP battery can supply only 55 amps continuous. This wll limit how fast you can go. Try a software like motocalc and you can get some ball park numbers on speed for various setups.

Also on 6S and 5.9 X 5.9 you need very good throttle control. I would recommend to start with 3S and then go up after checking the amps, motor, esc, battery temperature etc for each increase in cell count.

happy flying !!!
Mar 06, 2008, 07:09 AM
Registered User
thanks numb,

now i understand fully. off to buy a 6 s battery! and charger! and heat sinks!!!
Mar 07, 2008, 01:44 PM
Registered User
Thread OP
My funjet is temporarily out action until I get back my repaired or replaced ESC from CC.

Its times to focus on the Projeti and get it going while the funjet rests.

Happy Flying !!!
Apr 02, 2008, 01:45 PM
Registered User
Thread OP

Funjet in major service


Funjet is being overhauled completely to check all components.

A new 80 amps CC esc and a park bec is in place. All other components looks ok.

I'm attempting to go past 154 mph this time. Can't decide between Mega 16/25/3, Mega 16/25/2, Arc 28/47/2.
Apr 02, 2008, 05:44 PM
Here comes the rooster...
JesseB's Avatar
'bout time you got back on the FJ.
Apr 02, 2008, 05:46 PM
Here comes the rooster...
JesseB's Avatar
And how'd you get that heat sink in and out of the motor mount? Did you modify it?

I had one on my ARC, but realized that I couldn't get it past the attachment points on the plastic ring. I have to figure out how to use one if I'm going to over power my FJ.

Jesse
Apr 03, 2008, 10:57 AM
Registered User
Thread OP
Getting a ESC repaired takes a very long time nowadays...I didn't want to buy a new one knowing I will get back the reaiped one soon.

I bought GWN heat sinks (two of them) and the cut the fins off using dremel. It slides in and out easily. Heatsink helped extend the life of my motor.
Apr 03, 2008, 02:33 PM
The Kid
Thekid3418's Avatar
I would definately go with that arc 2T (possibly becausue im biased and want to get the same motor and would like to see what it can do...). BUt with that motor and 6s you'll be at 35k+ rpm, 5k more then what the ritewing guys get with their arc 1.5's and those wings are going 150 mph, so i think in a streamlined Funjet with more power then the ritewing, you could smash your old record.
Apr 07, 2008, 11:29 AM
Registered User
Thread OP
Installed a 28-47-2 on the Funjet last weekend and had initial flights go smooth. All trims are complete. I need the tune the amps to around 80 WOT by cutting a 6.5 X 6.5 or higher prop. I may go higher if 80 amps does not break 154 mph.

If all goes well I will shoot for a record this Sunday.

Happy flying !!!
Apr 07, 2008, 09:57 PM
Registered User
bdp3822's Avatar
Anyone ever tested the Funjet as a "puller"? I was just wondering how much the plastic exhaust tube limits the efficiency of the smaller props 4.75X4.75 for example...

Bryon
Apr 11, 2008, 01:04 PM
Registered User
Thread OP
I don't have the time to prove it but based on my experience with Funjet and different props and other settings, I believe smaller prop has an impact on the speed because of the bulky fuselage.
May 02, 2008, 11:04 AM
Registered User
Thread OP
If the whether cooperates then there might be a video and eaglree tree performance graph this Sunday. Power setup is the same except I now have a Arc 2T motor instead of the 1.5

Happy flying !!!


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