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RotoGoat's blog
Posted by RotoGoat | May 13, 2012 @ 02:09 AM | 2,923 Views
Just finished a new depron foamie.

110g loaded , 335mm Wingspan
SkyAngel 35mm EDF (F-86 donor)
2 x HK 4.3g Servos
Rhino 3S 360mAh
Turnigy Plush 12A

Wing is 2 layers 2mm Depron with fibreglass spar 3mmx1mm
The rest is a mixture of 2 and 3mm depron. Vectoring vanes are 1mm ply.
Canopy is carved balsa with magnets to secure it.

Maiden taken in high wind bit it looks to be a nice flier. Slows down very nicely and will cruise on 1/3 throttle.
I must say it flies much better than the F-86 that donated the powerplant.
I cant wait for this wind to die down!!
Posted by RotoGoat | Jan 07, 2012 @ 11:08 PM | 2,752 Views
Modified the control arms on the vanes to give a bit more throw. Its pretty much maxed out now with minimal movement of the elevons. I flew a few packs out this morning and I finally have victory. I can slow it down and fly at perhaps 40-45deg AOA at a nice slow pace. It does rock back and forth in the roll axis a bit, but is now contollable at low airspeed. It is reluctant to get back on step if I have increased AOA and throttle to max. I have to drop the nose to get it going again, and I need a little height to do that. There is just no more oomph to punch out effectively.
I am pretty happy with it and will continue to try a few more things to give a bit more performance. There is a little slop in the TV system linkages that will improve control marginally, and I can bring the control rods for elevons back on thier servo horns to the closest hole to the servo in the search for some more resolution instead of dialing the rates back on the transmitter.
I will try to convince someone to come and film it next time I go out. It can be dificult as I am a lone wolf with no-one else around even remotely interested in this stuff.
Posted by RotoGoat | Jan 07, 2012 @ 09:08 AM | 2,633 Views
Reworked the TV vanes and gave it a go. Works much better but still not quite enough for the roll situation. I had the thing hovering stationary against a stiff breeze but it just did not seem to respond well enough to aileron input. I have setup the dual rates so I can switch over for high alpha to give a bit more throw on the aileron with the same elevator throws I am currently running as they seem to be sufficient. Problem is that it is quite squirrely as it is in normal flight. I may have to mess with the rear linkages to get more throw on the TV vanes without affecting the control surfaces on my wings
Heres a shot of the modified assy.

I am working on an idea to instal this setup onto a standard F-86 with the standard servo setup as we speak.
Posted by RotoGoat | Jan 06, 2012 @ 05:13 AM | 2,949 Views
Maidened the Modded F-86 with thrust vectoring this arvo. First flight there was little if any difference to handling. I made two other flights moving the TV control rods out to max. A bit better handling. I think I need a little more area on the vanes. The final flight I made I put fibre tape extensions on the vanes, but they were a little flexy so not much different. I also cut away some of the rearward extension of the fuselage that runs out from the root of the tail. Tonight I will replace the vanes with larger area ones and see how it goes tomorrow.
It has helped to enable me to bleed off speed by cutting power, nose up then reapply power to bring on high alpha flight. I do not however have enough roll authority to make it a comfortable proposition.
Posted by RotoGoat | Jan 06, 2012 @ 02:08 AM | 3,028 Views
Heres the Thrust Vectoring setup installed. TV system weighs 1.4g.
Posted by RotoGoat | Jan 05, 2012 @ 08:50 PM | 3,166 Views
Got bored with my SkyAngel 35mm EDF F-86 so I did this to it.
The wing is full airfoil and is bigger which helps it glide a bit better power off than the F86 wing did. I might move the wing rearward about 25mm as I am flying with ballast on the nose which I would like to eliminate.
Maiden was an interesting if not frightening experience as it was way tail heavy, so it pitched up and down violently with even the slighteset control inputs. Luck alone got it down safely, but it lived to see another day.
Flys really well now and goes like a bat out of hell!!

Standard Skyangel EDF
360mAh Rhino 3S
2 x 4.2g HK servos
Orange DSM Reciever
10A Turnigy Plush ESC
Posted by RotoGoat | Jun 13, 2011 @ 07:44 AM | 3,302 Views
I have taken a rest on the Mig-3 to let a few ideas ferment, so I needed a quick build to relax. My Toon Fw190 was born.

It is only at the bare airframe stage so far, but I will recycle the Spektrum AR6400 from my Micro Storch (none of my planes last that long as they are quickly recycled if they sit idle for any length of time.).

Bare airframe at this stage is 7.1g which will be considered heavy to some, but it is my first skeleton model and is covered in plastic shopping bag. If I have any luck with this type of construction, I will get some decent mylar and fit plantraco gear for a much lighter setup.

The final model should weigh in the region on 27g which gives about 2.4oz/sqft. Should float along OK.
Posted by RotoGoat | Jun 09, 2011 @ 04:54 AM | 3,835 Views
Finally got the chance to maiden Mig-3 and am happy to report that it flies!
I am not happy with its performance though.

The finished plane is a bit fatter than the MK1 version at 105g (3.7oz).

On handlaunch it was trying to roll over to the right, and when it finally got going I needed significant left trim to keep it from rolling over. The model was retrimmed for unpowered glide before the next flight but the problem persists.

The amount of aileron trim required for level flight varies strongly with airspeed. The wings look to be straight, but perhaps a slight difference in each side of the wing is causing a problem. The wing construction relied on hand carving so this is a possibility I think. I will build up a stronger version of the original MK1 single layer 6mm depron wing to see if I can get it sorted. Its a real pain in the butt to power back for landing and having the plane roll off to the right, and handlaunches are a bit hit and miss.

The airframe is already quite punished, but is still flyable. I will test a few fixes on this airframe then it will be retired to make way for MK3. I will move CG forward a touch to see if it tames her down a bit as its pretty touchy on pitch. I also have to look at reinforcing the fuselage at the front corners of the battery compartment.
Posted by RotoGoat | Jun 02, 2011 @ 03:37 AM | 3,275 Views
Finally got a shot of the "Canopy Gun" in action. Unfortunately I cannot claim the idea as my own, but I have made my own changes to the design to get what I have.

The pictures really speak for themselves. You insert a hoop of soda bottle, screw on the plug and crank the plug out! Add a heat gun, then crank a little more and hey presto! Almost instant canopy without all the hassle or bulky equipment.
This weekend I will add some canopy framing to the plug using strips of posterboard and see if they will be transfered to the plastic canopy while moulding.
Posted by RotoGoat | Jun 01, 2011 @ 06:21 AM | 3,856 Views
Had a try of my new canopy forming fixture and it seems to work very well indeed. I was too excited and forgot to take a photo while I was doing it, and dont have any more plastic bottles to illustrate the concept tonight but I will post up a few photos of the process tomorrow.

Heres some shots of the results.

Does anybody know what I can use to stick PET plastic to foam?

Next up I'll have to make up a spinner.
Posted by RotoGoat | May 30, 2011 @ 03:42 AM | 3,793 Views
Got all of the electrics installed into the fuselage and am ready to stick everything else together tonight. The decals are just laser printed outlines with sharpie to color it. They are then cut out and glued in place with a UHU Stic.
I will be making up a caulking-gun canopy making thingy to mould a canopy from soda bottle plastic. I forget where I saw that done but wow, what a cool thingy.
Heres a photo of the dry fit of the main components
Posted by RotoGoat | May 28, 2011 @ 08:31 PM | 3,293 Views
Heres a couple of shots of what I got done last night.
The four layers of 6mm depron that make up the fuselage were carved to shape, then 2mm skins were prepared by hand rolling over a table edge. Access hatches were cut before skinning.
I just crashed the Mig-3 MK1 into the deck at full throttle while inverted and its time to strip it out now to populate the new airframe. Should have more to show by tomorrow.
Posted by RotoGoat | May 27, 2011 @ 10:54 PM | 3,521 Views
I have been flying the little wings off this Mig-3 over the last week and I am having a blast. There has been quite a bit of wind here of late and it has been regularly flying 15-20mph winds without a problem. At full throttle the down wind dives have been rather speedy.

The boilerplate airframe itself has copped quite a beating but is still flying well. Too low too fast too many times for my skill level. Mk2 is half built with a number of improvements to address a couple of small issues.

First of all, I pulled the wing and gave it a packing tape skin in an effort to reduce the flex when pulling higher G moves. It worked OK but one wing is still flexing a tiny bit more than the other when I really push it so Mk2 has a different wing. The new wing is hand shaped 6mm depron with a 2mm CF spar inset into the top, then a 2mm depron skin over the upper surface. Wing is then skinned in clear packing tape. It is now very strong with little flex.

I needed to replace the nose section, so I also planked the front half with 2mm depron to stiffen it up a bit. The weak spots in the structure are showing themselves and the Mk2 airframe is on its way with revised ESC placement to try to toughen the nose a bit more for crash resistance. I have already inreased downthrust another degree and this has solved the nose up pitch on inreasing throttle setting.

Mk2 fuselage has moved to full fuse design by adding another 6mm layer to bring the battery and ESC within the fuselage. It will also recieve a clear canopy this time round. I will leave the pushrods exposed for this version.

First photo is of the war weary MK1 version with the 2mm planking on forward fuselage. You can see a problem spot just above the rear end of the ESC. It keeps breaking through there and down to the battery..

Second shot is MK2 at this early stage.
Posted by RotoGoat | May 22, 2011 @ 03:57 AM | 3,778 Views
Heres a shot of the latest edition to my flight line. Its a bit ugly at the nose end as I ploughed it in during its maiden. The pilot was able to bail out and was ready for a second flight in no time at all. Tape and glue cures all!
It is based losely around the plans by dz1sfb post number 268 here;

http://www.rcgroups.com/forums/showt...012551&page=18

I just used the outlines and resized it to suit. All electronics positions were revised to suit my needs. Fuselage is 3 x 6mm depron laminated with cutouts for all the bits. I used shaped 6mm depron for the wing with one 2mm CF spar. I rolled a little undercamber into the wing and gave it 10mm dihedral at the wingtips. Also twisted a little washout into the wing after it was finished to help out a bit at low airspeeds. No ballast was required and it dives nice and straight with no tendancy to pull out.

Flys very very nicely indeed! Will buzz around at 1/3 throttle happily. No real vices. It glides very well and will do unpowered landings without drama. One minus point however is that it torques a bit if you bang on the throttle too harshly but I guess that is to be expected at this size. Seems to want to pull up with increased speed, and I am not sure whether it a thrust line issue at this early stage. I will give it a little more downthrust to see if that helps.

455mm WS (18")
89gram loaded (3.1oz)
Futaba R6106HFC 2.4gHz Reciever
2 x 2.5g servos
10A Turnigy Plush ESC
5g HXT Outrunner
360mAh 3S Rhino Lipo
GWS 4040 prop
Posted by RotoGoat | May 12, 2011 @ 09:45 AM | 3,489 Views
Heres a wing that I recently cobbled together using the wing from my wrecked PZ Spitfire.
There is enough thickness in the wing to hide everything away.

Wingspan 870mm
AUW 230g
2 x 9g Corona CS-929MG Servos
10A Turnigy Plush ESC
10g Hextronic Brushless

GWS 4040 prop

The low power setup is due to the fact I wanted long duration at low throttle settings which it delivers. I forget exactly the battery specs, but its a 3s rhino of around 1000mAh capacity. Gives around 20 mins the way I am flying it.
Flys nicely in strong wind with 50-60g balast added to the CG

If you have a trashed PZ Spit, I would recommend doing this with it.
Posted by RotoGoat | May 12, 2011 @ 09:32 AM | 3,787 Views
Heres a coulpe more shots of the Storch. The brick is easily accessed via a removable hatch that just presses into place. The pushrods are .5mm CF rod running through CF tube where they go through depron.
Posted by RotoGoat | May 12, 2011 @ 07:48 AM | 3,545 Views
Heres a shot of my 1/32 Storch.
All depron construction with a carved 6mm depron wing. All struts ect are CF.
Electrics are all standard Parkzone UM Mustang/AR6400 except that I added a prop saver and a GWS 4040 prop. Wheels are from the Mustang too.
AUW 31g with wingspan of 390mm. Flies nicely enough with scale control surfaces. Paint job is nothing fancy, I usually use Citadel Paints (used to paint Wargaming Minatures). These paints are good in that they are meant to be used diluted and give good coverage with plenty of water. Glazing is just done with black sharpie, but would like to make up a plug to vac-form a decent one with integral wing cradle.
I'll try to get some shots of her in action over the weekend.
The next shot is of a Micro Blu-baby (300mm WS) with EPP fuse. This is what convinced me to build the Storch. Flew beautifully even in wind.
Posted by RotoGoat | Feb 13, 2011 @ 01:02 AM | 3,886 Views
Heres a shot of my scratchie foam 6.5" Micro Racer for Plantraco Micro9 3ch.
Uses miniacts, 90mAh lipo and a 1.6ohm 7mm motor from a cheap micro heli.
Goes pretty good now that it is trimmed. I had to move the battery from beneath the nose to under the wing to achieve good CG. Weighs in at a fat 13g. My first try at putting the miniacts inside a fuselage. I had to de-solder the bahoma connector from the lipo cell and add a wire extension. All 1.5mm depron construction from my own plans. Just need to do up a canopy.
Posted by RotoGoat | Nov 14, 2010 @ 05:49 AM | 4,074 Views
Recently I built a 7" F22 using the kit from a Plantraco Deluxe Starter Set 3. This is the kit for their Komet with the 3 channel Micro9 Rx, 1.7ohm motor and 2 mini-acts. This was my first scratchbuilt micro. I had cut my teeth on a Plantraco Carbon Butterfly and was truly hooked. The F22 weighed in at 15g and flew nicely enough with awesome high alpha but finally wore out after dozens and dozens of flights. I thought I would try something different next. Here is the result.

I started with a 3 view of the Kyushu J7W1 Shinden from a 1:48 Hasegawa model kit. After scanning and scaling I ended up with patterns for a semi-profile with 10.5 inch wingspan. Fuselage was 1.5mm depron skins on a 6mm core with most of the centre removed. Wing leading edge has .5mm carbon CAed in place. There is also a length of carbon running down the spine of the fuselage top and bottom.

This prototype was given slightly enlarged wing surfaces and canard. The canard is a friction fit in a slot in the fuselage so oopsies will dislodge it rather than break it. The canard is also covered in thin packing tape to help its chances of surviving. With the 3.7v 90Ah battery it wieghs in at 14.2g.

I had a bit of trouble trimming the model which I expected, but finally I got it to fly around OK. It may need a little more elevon area and need to shift the CG back a bit. Although I have found bahoma connectors for the battery to be a pain in the ass, it seems to help in crashes by letting the battery go on its own merry way. I have unfortunately lost a battery and one of the antenna wires have broken off the RX board. I will solder up and give it all a go again tomorrow.
Posted by RotoGoat | Oct 02, 2010 @ 07:48 PM | 3,836 Views
I have flown out 20 or so packs on this airframe now and it seems to be vice free. The wing seems to be doing nicely with a soft stall and no tendancy to drop a wing whatsoever. It even glides quite well with power off which was a bit of a surprise.

Heres some footage. Unfortunately it is done on a cellphone camera by an inexperienced person so there isnt a whole lot to see. I am trying to organise some better footage this week.
http://img716.imageshack.us/img716/7805/testflight1.mp4

I seem to be averaging around 6-7mins flight on the 1650mAh 3S. I did a bit more programming on the transmitter and the rolls are looking more axial now. The plane doesn't seem to mind flying inverted as I am able to pull outside loops from level inverted flight. I am surprised at how well the wing is holding up as it only has depron spars and very minimal tape on the underside.

Yesterday morning I had a servo fail during climb out which shut down the reciever. The plane yawed left and crashed into the ground at speed. Only the nose was destroyed luckily so I was able to re-build in a few hours. I had left the pushrods too long and they were fouling the elevon on large throws which I believe led to buring out the servo. I very slightly tweeked the nose upward this time round though as I found it was catching in the grass on landing.