Topic: Copycat tiny trainer (Read 2566 times)

Andy M · « **on:** July 03, 2020, 09:11:35 pm »

This little plane is another one of my friend's designs, his flew so well that I decided to copy it. His is the white one on top of my drawing/tracing of it. Painting mine added 2g, which required a bigger battery to balance the weight of paint on the tail end. Still flies nice, not much different to his one, even though mine is good bit heavier, I was even leaving my sticks alone and just watching it go round in big slow circles, or it can be speeded up a bit with more throttle and a touch of down elevator held in. Responsive if you want it to be, good for tree avoidance, or gentle on the sticks for nice smooth flying. Another nice flying, minimalist design from my friend James. The tailplane slides out and unhooks from the control rod, and the wing folds in half, allowing the whole plane to fit in the box with my tiny delta. 2 planes in such a small box is pretty good going.

Andy M · « **Reply #1 on:** July 03, 2020, 09:15:30 pm »

Tried posting a few more pics but never worked

Andy M · « **Reply #2 on:** July 03, 2020, 09:19:23 pm »

Transport box and 2 planes

Andy M · « **Reply #3 on:** July 03, 2020, 09:22:55 pm »

My version

Andy M · « **Reply #4 on:** July 03, 2020, 09:28:37 pm »

Simple tail end

Andy M · « **Reply #5 on:** July 03, 2020, 09:30:39 pm »

Control rods missing in above pics. These are 1mm carbon rods with paperclip z bends bound with thread and superglued.

Andy M · « **Reply #6 on:** July 03, 2020, 09:53:30 pm »

Other side before battery fitting

Tug Fanatic · « **Reply #7 on:** July 04, 2020, 08:55:34 am »

I enjoy flying these small foam models in places where larger models couldn't go such as our garden. They are great fun but any slight breeze is, as I am sure you know, a problem. Generally Deltas cope better. Is that true of yours?

Andy M · « **Reply #8 on:** July 04, 2020, 11:38:08 am »

Hi, you are right, the tiny delta copes with wind much better, it still gets chucked about but you can level it out easier than the tiny trainer. These little F949 servo/esc/receiver boards are amazing, under 6g, add a motor and a tiny battery and its a complete rc system weighing about 15g. For £13. I paid twice that for a single hitec hs 80 servo back in the day, it looks huge compared to the F949 board.

Andy M · « **Reply #9 on:** July 08, 2020, 06:46:39 pm »

Flying video here
https://youtu.be/TeRVvaz-x5I

Andy M · « **Reply #10 on:** July 13, 2020, 01:09:01 pm »

I have been flying this little plane for a while now, since I lost the delta. One problem I noticed was that the elevator control rod flopped about getting the plane out of its box, this tweaked the servo round a bit, no damage but I have added a small thread loop to prevent this. Also, after a few donks on its nose after hitting stalks of ever higher grass where I fly, the motor stopped running, it had popped the back off, same as ridge runt, a strip of fibreglass packing tape on new motor should help to keep it on, I hope, lol. The motor fit in the nose is perfect, I dont think it actually needs tape. Not as much as I had on it originally, anyway. Great little plane tho. My friend's one is capable of really slow flight, mine has a slightly higher stall speed. It is actually very maneuverable, or can fly big circles with no input on the sticks. Bit like a free flight model, but you can save it if required.

Tug Fanatic · « **Reply #11 on:** July 13, 2020, 02:53:10 pm »

Flies nicely.

One answer to motor damage is a pusher where the nose of the motor isn't the first thing to arrive at the scene of the accident (landing).

Andy M · « **Reply #12 on:** July 13, 2020, 07:36:43 pm »

You are right, the delta's motor never suffered any damage, wherever it is. Lol. It is the downside of having a motor up front. I have wrecked 2 in a week.

Andy M · « **Reply #13 on:** July 14, 2020, 11:27:18 am »

I tried a loop last night, wing folded, plane flopped into barley, opened wing out again, bands hadnt even popped off, and it was ready to fly again. I never managed a loop. It wasnt made for aerobatics, it has automatic wing fold when it gets too many G. Lol.
It was coping with the wind ok last night, then trundling round a small sheltered area I fly from. It has a good speed range and a gentle stall. Its new motor provides plenty power, its not a whizzy one, my last one of them is only getting used in pusher configuration to try and stop it getting wrecked.

Andy M · « **Reply #14 on:** July 21, 2020, 12:26:26 pm »

It turns out that the midknight wing and tailplane look pretty good on the tiny trainer. It flies much the same but with a bit more lift. I want to make up some undercarriage but getting a firm enough fixing might be a problem

Tug Fanatic · « **Reply #15 on:** July 21, 2020, 12:35:41 pm »

Add lightness. Unless you need the undercarriage don't add it.

Andy M · « **Reply #16 on:** July 21, 2020, 01:46:27 pm »

Dont need it where we fly, to be honest. It would sit on the shelf nice tho. Lol.

Andy M · « **Reply #17 on:** July 23, 2020, 12:43:39 am »

I decided to make up some wheels anyway, thinking that the extra drag might slow the plane even more, and might also stop it from pitching up when throttle is applied. It flies well right down to minimum throttle, losing height isnt easy unless the motor is off, usually turns are used to lose height. so slowing it down with wheels should work. If not, they can be for display purposes. I used the sharp edge of the sour apple drink lid, taped to its 'bottle?' (possible future torpedo?) to cut out wheels and tyres from 6mm depron, 2 layers for tyres, the outer of the tyre was cut out roughly with scalpel then turned gently against my home made sander. A quick hand sand and I am happy with them. The centres have ice cream tub plastic washers (made with a paper punch) glued each side, holes made with pin from both sides before glueing. Bit of paint and they look passable. I will glue the wheels into the tyres with uhu. Undercarriage legs are made from a large size paper clip. I have painted the tyres with pva for a bit of durability.
Wow, first test flight proves it has turned out perfect, doesnt nose over on landings, just sinks down onto tailwheel. Was just flying off road there. Rudder doesnt work well until the speed builds up a bit, it goes right slightly then straightens up, need to check wheel alignment again, could be just prop torque. Well glad I fitted them, looks much better, opens up flying possibilities a good bit, proper take offs and landings, touch and goes and it doesnt seem to notice the extra 4g at all. The drag of the wheels stops it pitching up so much when you give it throttle. Glides in nice for landing. I was a bit disappointed the rudder doesnt work well at low speeds on the ground, I was wanting to try taxi-ing round the living room. Lol. Sure that would go down well. I could get it airborne in the length of the living room. Definately a possibility, it can lift off quick. Bit tight for flying after that. Lol. Had to open the holes on my ice cream tub wheel washers until they rolled freely. 0.61 and 0.58 for big wheels and 0.1g for tailwheel. Tyres are 2 layers of black 6mm, wheels are 1 layer 6mm white. Washers uhu'd on. Will need to find more big paperclips the same, plenty strong for landing.

Tug Fanatic · « **Reply #18 on:** July 23, 2020, 09:44:09 am »

Looks like a Tungra Cub!
Well done.

Andy M · « **Reply #19 on:** July 23, 2020, 11:06:45 am »

A tiny cub is born.
Couple of changes, wing and tailplane painted yellow, added one gram in total. Not bad, I prefer it painted rather than plain white. I also added a more 'piper cub' looking rudder, the original had most of its area up at the top, the new one has most of its area down at the bottom, more in the propwash. Might help ground steering?
Weight is 37.77g now, dont see it being bothered by an extra gram of paint. The ridge runt is nearly twice that and it flew ok apart from me having the control movements set too high. Elmira is 45g, so the tiny cub is still pretty light. A radio controlled plane under 2 ounces is amazing, a whole plane that weighs less than a standard servo!

JimG · « **Reply #20 on:** July 23, 2020, 12:10:32 pm »

Pitching up when throttle is applied generally means that more downthrust is needed on the motor.
Jim

Andy M · « **Reply #21 on:** July 23, 2020, 01:43:31 pm »

The wheels dangling out the bottom seems to have done the same as adding downthrust. I flew it today, no noticeable difference with the extra weight of paint. Great little flier. I am enjoying proper take offs and landings. Still not the best ground steering, I could increase the rudder movement but it would be a bit too responsive in the air. It flies nice as it is, so I dont want to mess about with it too much. I am flying from a narrow road, with kerbs, so it is pretty restricted. It tracks quite straight just as it reaches take off speed. Open area take offs will be easier, with less obstructions. I may experiment with a bit more rudder control, easy to change if its too much.

Andy M · « **Reply #22 on:** July 23, 2020, 04:44:02 pm »

I decided to get more F949 boards, so I had a look on ebay, there were about 20 different sellers had them in stock a couple of weeks ago..... Now they are hard to find, I found one at nearly 3 times what they were selling for originally. I wonder if they have all sold out, or are just waiting to put them on at higher prices.
I looked on amazon, same thing. Then, by typing in different combinations of search words, I found an ad for them at £12.15 each. This is the lowest I can find at the moment, so I have some on their way, 2 months delivery time, slow boat from china. Lol. Just hope they get here ok.

Andy M · « **Reply #23 on:** July 24, 2020, 11:01:29 am »

I landed here, no chance of taking off from it again though. 😁

Andy M · « **Reply #24 on:** July 24, 2020, 03:39:13 pm »

Another video, this time with wheels fitted.
https://youtu.be/ASoP33fpNc8
I videoed this while flying with my other hand.

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Author Topic: Copycat tiny trainer (Read 2566 times)