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Spitfire maiden problems

#1
Here's my FT Spitfire I've been working on:
IMG_20141003_231259.jpg

I finally got everything ready to fly after waiting on components from hobby king (we've all been there) and went out to maiden it. Maybe i should have filmed it for comic relief as it flew, but only to the left and down despite several attempts. Luckily the only damage was a broken prop, of which i had spare. I noticed the rear elevator had come loose somehow (independently of crashing) so i took it back and re-glued it. I checked the balance and noticed it was tail heavy, could this be the issue? This is my first swappable I've gotten fully rigged, i have a baby blender and a mustang that i need to add electronics to still.

I will try and add weight to balance it tonight and try hand launching again, but does anyone have any thoughts on what could be wrong?

I have the 1200kv motor as recommended with a 9*6 slow fly prop
 
#3
Thanks BridgeInspector, I'm hoping I can admire it in the air for longer than 5 seconds. If i can get it off the ground i'll get a couple action shots.
 
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TEAJR66

Flite is good
Mentor
#4
What size battery are you using? Can you achieve balance by moving the battery without adding additional weight? Your prop may be a little big for that motor. On 3S, my son and I have had our best performance on 8X4 and 8X6 props (with that motor).
 
#5
I'm using an 1800mah 3s, I do have some 8x4 props at home so i could try switching those out. If i move the battery all the way to the front of the power pod it is almost balanced but still tail heavy, the foam board im using is a little heavier than DTFB so that may also be part of it. It tries to leap out of my hand when i run the throttle up but im open to any suggestions to get this thing flying.
 

Kenbow

Senior Member
#8
I hate to be the bearer of bad news but I think you will have to rebuild/replace your wing, make sure all your angles are correct first! Contrary to the build video where Josh says it will fly great with a sloppy wing, my experience has proved otherwise. I had the exact same issue and realized that getting the spars in the wing cut as precise as possible is very important. If you look very closely you may find your left wing a little different than your right, probably thicker? I also always maiden a plane before paint.
 
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#9
Thanks Kenbow, as much as the answer sucks im glad someone else had this problem and figured it out. Guess i will be doing the removable wing mod after all. The spars are okay but i think one of the wings wasnt aligned correctly (ie the top and bottom surface arent quite parallel). Yesterday was really windy so didnt get a chance to test anything out. The paint job is basically a custom decal i printed, so its more like a wrap and just needs to be re-output. I guess this is a build thread now...
 
#10
I've smashed, glued, taped and still flown mine. I would check 2 things, your CG, since you said it was tail heavy and what size motor are you using? A park 370 size would be a little under powered. I would use a park 400 minimum. I'm betting its your CG that is making it hard to fly. Let us know how it goes.

Btw, amazing work! Is that paint?
 
#11
I had a similar problem with my FT Cruiser. It always wanted to turn right. I could trim it out but then it flew crooked. My problem was a warped elevator. It acted like an extra set of ailerons. CG is also crucial. I have to agree with Flynn though, that paint job is fantastic.
 
#12
Thanks guys! I'm using the NTM Prop Drive Series 28-26A 1200kv with a 9x6 slow fly prop, I have some APC 8x4-e props that i might try this time to see if it works any better. I am still gonna see if fixing the CG helps at all before totally replacing the wing.

Thanks for the compliments, the paint job is a printed 'skin'. I imported the FT file into Illustrator and convert it to a vector file (some of the planes are available as vectors in the Flite Test repository already) and then created the paint scheme from blueprints and reference images electronically. I then output it on adhesive paper (I work in a graphic design shop) and apply it to the foam. Theres a little bit of guess and check to get everything to line up 3 dimensionally. If I can get it flying I want to build out the engine exhaust and add a few more details, but need to get it in the air first otherwise I'm wasting my time. This scheme is based off of the Tamiya 1/32 Supermarine Spitfire Mk.VIII.
 
#13
re: elevator

I had a similar problem with my FT Cruiser. It always wanted to turn right. I could trim it out but then it flew crooked. My problem was a warped elevator. It acted like an extra set of ailerons. CG is also crucial. I have to agree with Flynn though, that paint job is fantastic.
The elevator had gotten hit by a box blown by a strong wind and knocked loose initially so that may be part of it too. I glued it up when i got back from 'Crash Fest '14' and hand launched it in the back yard but couldnt tell if it was better or not, I was a little hesitant to launch it too high and tree it so i was just trying to glide test it.
 

jayz 84

Posted a thousand or more times
#14
the best thing you can try that has worked for a lot of people ive told is take your pod out and try to move as much of the electronics fwd as possible to help with noise weight. so then youll have battery play to find your cg
 
#15
I started with an 8x4 on mine, with that motor it will probably need 3/4 throttle to fly comfortably. Most of the FT hand launch planes, Spitfire and Racer, will turn to the left upon launch I find. I usually launch with the left hand and be ready with the right hand on the controls.

I can't tell from the picture, but also make sure your prop is on facing the right way.

Also, I know that everyone also has stated that it needs a lot of down trim once you get it in the air.

Good luck!
 
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capeair

Junior Member
#16
Amazing decals

The decals look so wonderful, who cares if it won't fly? I just want it hanging from my ceiling to give my basement a little class.

What product are you using in your printer to make the decals?
 

Kenbow

Senior Member
#17
Thanks Kenbow, as much as the answer sucks im glad someone else had this problem and figured it out. Guess i will be doing the removable wing mod after all. The spars are okay but i think one of the wings wasnt aligned correctly (ie the top and bottom surface arent quite parallel). Yesterday was really windy so didnt get a chance to test anything out. The paint job is basically a custom decal i printed, so its more like a wrap and just needs to be re-output. I guess this is a build thread now...
Took me Three tries, two props, fuse repair and a wing rebuild, but it flies great now! Really scrutinize that wing, mine would not allow me to turn right hardly at all even with full Aileron and rudder. The second attempt ended in a slow left turn death spiral that almost ruined the whole plane!
 

SnowRocker88

Amateur pilot and builder
#18
I will be the echo in the thread by repeating to check that CG. I will quote what has been said and what had to be reiterated to me even..."A nose-heavy plane flies poorly, a tail-heavy plane flies once".
 
#19
Thanks guys...

Thanks for the compliments, the paint job is a printed 'skin'. I imported the FT file into Illustrator and convert it to a vector file (some of the planes are available as vectors in the Flite Test repository already) and then created the paint scheme from blueprints and reference images electronically. I then output it on adhesive paper (I work in a graphic design shop) and apply it to the foam. Theres a little bit of guess and check to get everything to line up 3 dimensionally. If I can get it flying I want to build out the engine exhaust and add a few more details, but need to get it in the air first otherwise I'm wasting my time. This scheme is based off of the Tamiya 1/32 Supermarine Spitfire Mk.VIII.
Do you remove the existing paper first or just go right over it? I have access to large format printers, but not adhesive paper. I've contemplated printing designs, remove the DTFB paper and glue the printed plans with 3 super 77.
 
#20
I will be the echo in the thread by repeating to check that CG. I will quote what has been said and what had to be reiterated to me even..."A nose-heavy plane flies poorly, a tail-heavy plane flies once".
Ive heard that about balancing before, but not put so eloquently :D We had thunderstorms roll through last night so no flying, but I cut my servo leads tighter, i probably had 7 or 8 inches of excess so i clipped them all to the correct length and soldered them to shorter leads into the rx. I also moved all the electronics as far forward as possible. My CG is about a half inch to an inch behind the spar now with the battery as far forward as possible, which is miles better than before. I have a couple fishing sinkers lying around so i was thinking i would try to even the balance out by loading them into the front of the power pod.