My first official FT build: the tiny trainer

[messyhead]

Last year I built a modified Tiny Trainer from @Hai-Lee called the MUTTS. It flew OK a few times, and I learned with it, and it's currently being rebuilt for this season.

But I wanted to try the FT Tiny Trainer, mainly for my son to fly, so this just arrived....

First impressions are that it's quite a bit smaller than the MUTTS that I built. Not sure if that's because that plan is scaled up, or I printed it slightly larger. The foam board is also so much lighter than the stuff we can get in the UK. Now I see why there's so many doubts about FT plans using UK foam board, though I know that they still fly well with only slight modifications.

I know this has been built loads, and posted on here already, but I might just add yet another build and flight log, if only for my own records to look back on.

Edit: I'll just correct myself. I measured it side by side with the MUTTS fuselage, and it's the same size. It just looked smaller to me.

 

[TooJung2Die]

The Tiny Trainer is a great airplane! I learned to fly RC with the 3 channel glider wing version. I still build the 4 channel sport wing version occasionally because they are so much fun. Good luck with your TT!

 

[messyhead]

I built the nose last night, and coated it with tape. It's looking quite tidy by my standards, I usually leave ragged edges. At least when my son crashes it, he'll do it in style 😂

I started on the power pack, and had my first problem. The motor mount I have is too big for the firewall...

So I got creative, and countersunk the holes on the firewall and attached it directly to the motor. The other holes need made, I've just used two for now.

Why is this a bad idea? I'm not going to proceed with it until I have a viable alternative, either buying a motor with a smaller plate, or hearing from all you experienced builders that this approach would be ok.

 

[messyhead]

I don't know if the person that 3D printed this tool is on this forum, but if they are, thank you so much. It makes cutting the 45deg edges so much easier.

You can find it on ebay...

https://www.ebay.co.uk/itm/273686575733

 

[TooJung2Die]

Why is this a bad idea? I'm not going to proceed with it until I have a viable alternative

That's not a bad way to mount the motor as long as the screws are not too long and contact the motor windings. Use all four screws and blue Loctite on the threads if you have some. Good start for your TT.

 

[messyhead]

That's not a bad way to mount the motor as long as the screws are not too long and contact the motor windings. Use all four screws and blue Loctite on the threads if you have some. Good start for your TT.

Thanks for the tip about the glue, never thought of that. I'll drill the other holes tomorrow, they're slightly offset from the pre-drilled ones. The firewall is the same thickness as the mount, so the screws are just the right length once I've made a countersink.

 

[The Hangar]

Your build is coming along nicely! I haven't built a tiny trainer yet, but I want to. Maybe if my LHS has the kit it in stock I'll pick it up next time I go...

 

[TooJung2Die]

Thanks for the tip about the glue, never thought of that.

Loctite blue is a thread locker. It's kind of like glue for screw threads but you can remove the screws again in the future (with some difficulty) when you need to. You can use thin CA on screw threads but only when you never intend to take it apart. Ever. Very risky to use CA on motor screws. It is likely to get into the motor bearings.

 

[Hai-Lee]

Loctite blue is a thread locker. It's kind of like glue for screw threads but you can remove the screws again in the future (with some difficulty) when you need to. You can use thin CA on screw threads but only when you never intend to take it apart. Ever. Very risky to use CA on motor screws. It is likely to get into the motor bearings.

I use CA to lock the screw heads to the firewall wood after the screws are fitted and tightened. It locks the screw heads from turning and the wood will break away when I apply force with the screw driver in undoing them. The screws are easy to clean and I then refit to the new firewall.

What works for me!

Have fun!

 

[TooJung2Die]

I use CA to lock the screw heads to the firewall wood after the screws are fitted and tightened.

Yes. Me too when fastening a motor to a plywood firewall. I was cautioning about using CA like you would use Loctite. But I've done it.

 

[messyhead]

Fuselage done. I'm liking these speed build kits, so much easier than making templates and cutting all the parts. Though I like the satisfaction of scratch building.

Now for the wing. As this is going to be for my son to learn with, I'm making the trainer wing.

 

[messyhead]

So everything's built now, but I've got the fun part of trying to squeeze all the wires and stuff inside. I've got a 3s battery, which is a little too big to fit in the nose, unless I put it on it's side. It's like a jigsaw trying to fit everything in.

 

[messyhead]

Well, she's built, apart from the wing covering.

However, with the 3s 1300mah in the nose, it's way too nose heavy. I'm going to have to try and move things around and try and get the battery close to the wing LE for it to balance. Or I might just order some lighter 3s batteries. I need to do a refresher read on batteries and the power draw. 1300mah are probably too big for what I'm flying just now.

It would only balance with the battery this far back.

 

[messyhead]

Oh, and I had to shave some foam off the inside cheeks of the nose to fit that battery in

 

[The Hangar]

Well, she's built, apart from the wing covering.

However, with the 3s 1300mah in the nose, it's way too nose heavy. I'm going to have to try and move things around and try and get the battery close to the wing LE for it to balance. Or I might just order some lighter 3s batteries. I need to do a refresher read on batteries and the power draw. 1300mah are probably too big for what I'm flying just now.

View attachment 161319

View attachment 161320

It would only balance with the battery this far back.

View attachment 161321

I would recommend getting some smaller packs since they are lighter and that will let the plane fly slower, which will make it easier to fly.

 

[messyhead]

Yeah, I think I will. It's purpose to teach my son to fly, so I don't need it to be quick.

I'll look for some 2s to use with it. I might nip to the local model shop tomorrow and see what they've got.

 

[TooJung2Die]

I'll look for some 2s to use with it.

That's what I would suggest for a new pilot. I remember my first TT built as you did balanced perfectly with a 850 mAh 2S up front. A 3S battery was too terrifyingly fast.

 

[messyhead]

My FT family almost ready to fly. Tiny Trainer on the left, MUTTS on the right.

I need to get some 2s batteries for the TT and some props, then get them both balanced.

The TT weighs in at around 290g.

The MUTTS is 550g with a 3s battery. That's mainly due to the heavier foam board, but the bigger wing generates enough lift.

I can't wait to get out. However being in the UK, there's the small matter of getting registered first for me and my son.

 

[messyhead]

The 2s batteries arrived this evening, so I'll get the TT finished tomorrow. Today I finished off the rebuilt MUTTS and it's ready to go too, and I added flaps and some mixes so can't wait to see how it flies.

I also got my operators Id today, and the weather for tomorrow looks perfect, so definitely going to get the maidens done.

I'll try and video it, but I've not got a go pro or anything, so no guarantee.

 

[messyhead]

Well the maiden happened today. The TT flew well, but it was a bit gusty, and it struggled in the wind. So I landed it before I broke it.

The MUTTS flew really well in the wind, and I got 2 decent flights in. But broke the prop on the first landing even though it was soft, and on the second flight, I got mixed up with the controls, rolled left instead of right and hit the dirt. The plane is fine though, but broke the only other prop I had, so that's the end of flying till I get more. I think I'll try and get some folding ones, or cheap APC ones. I had Master screw ones, but they're £8 a pop, so not cheap.

I wasn't able to get any videos.

I'm thinking that maybe joining a club would be the next best move for a couple of reasons. The field I went to today was busy with dirt bike riders and dog walkers, so I had to walk a fair bit to get clear of them.

But secondly, and probably the main reason, is that I didn't feel confident flying. I was mostly in control, and felt ok, but I could feel a nervous twitch in my thumbs on the controls, and didn't like the feeling. I think I'd be better in a club with an instructor buddy boxing, until I've got my confidence, and I suppose they'll also put me through the BMFA certificate. And I'll have access to a dedicated flying field.