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Pumpkin drop event

Tiny trainer derivative

bracesport

Well-known member
#1
Hi there fellow fliers - Here is my derived version of Josh's tiny trainer.

I am basing the build techniques on my first trainer in this article https://www.flitetest.com/articles/nube but dimensionally it is a tiny trainer. You can download the PDF drawing here if you're interested to give it shot, and I'll post here the build as I do it - mostly its a difference in the fuse build. It's a 1050mm wing with smaller wing tip polyhedral so I can have ailerons and elevator (no rudder) as I am a fan now of bank and yank!

Originally I posted this with a 1200mm wing which was bigger than the original Tiny Trainer, so I have updated the images and the link to the PDF plans.

Let's see how we get on!

Phil

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bracesport

Well-known member
#3
SO I made a start in the weekend on the fuse. In fact, as you can see I'm making two at once - one for the brother in law and one for my son! The plan above is a near copy of the TT with the fuse being folded with a cut and tuck to make the tapers. The idea is that it is fast to make without requiring much in the way of a template. my control surfaces are interwoven taped hinges which require no taper cuts so again it's all rather simple. When glueing parts together I usually remove the card and packing tape for a better bond.

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mayan

Well-known member
#4
@bracesport what? When did this happen? How can I have missed this. Great plan there buddy, looking amazing. I would really like to find out how it flies if it even stabler than the TT oringinal glider wing set. Please do post a video of it's maiden.
 

bracesport

Well-known member
#5
Once the tube is formed I cut wedges out to form the tapers. I would be possible to make some of the tapers with more complex folding of the tube, but the goal was to show how simple and quickly you can make progress! I hot glued the wedges to form the tapers and retaped the joins.

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bracesport

Well-known member
#6
Starting from scratch the sheet size was 60x20cm and I taped one side with the coloured packaging tape.

The fold dimensions for the tube were pretty simple as shown in the images, and with the card removed from the 5mm fold tracks, use a skewer or similar to deform the foam before bending.

Next, I fold the first edge (maybe over fold it a bit) then I run a line of glue into the track and fold, hold, and set it to a square edge (with the help of my son)! Make sure you add a joining strip to the first folded edge to complete the tube with an internal seam. Then I chase the folds around and form the tube. You can actually fold it all up without tools as I show in my pictures, but they do help with keeping things square, flat, and assists in cooling the glue quickly.

Hope this was helpful?

I'll RP a plastic motor mount and post the wing construction next, but it is a more 'FT' style construction.

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bracesport

Well-known member
#8
@mayan - for the bro in law he is a complete nube so I will make it rudder and elevator. My son is 5 and I hope to buddy him with two Tx's but am planning on having ailerons and elevator like my bigger trainer as I am a fan of the bank and yank at the mo!

I may even try a bit of soaring with the TT derivative!

I've had a bit of building on lately (more building, less flying sadly)! The 'Vista' in the middle is nearly there and ready-ish to fly, but I want to thrash the trainer to up the confidence! On the far left is an all-glass hotliner that I'd like to fly one day!

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bracesport

Well-known member
#9
It took me 90mins to make two sets of the wing blanks which was kinda nice as my last wing took weeks adding a fibreglass skin! The wing blanks are 510x240mm and marked up for folding as shown below. I ran a skewer down the bend lines and a blunt dowel down the main fold as it has to bend right over during forming.

After cutting the wing tips I taped the exposed underside surfaces making sure where the glue goes to expose the bare foam! My glueing process is first to add glue to the main fold and wing spar, plus a little into the longitudinal bends for the aerofoil section where the tips are unsupported by the spar and underside, then fold and hold the complete wing in shape. Then add the glue into the trailing edge join to complete each wing section. Each wing is half yellow and blue for helping with turning visibility.

The wing for my brother in law will certainly be polyhedral, but now I'm thinking whether to make the aileron wing version a sports wing? Any ideas on whether that would be more suited to sloping?

Also, there is a picture of the simple RP'd motor mounts.

So far so good!

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bracesport

Well-known member
#12
One down!

This first one is for the brother in law and I decided to keep it more true to the TT with the main wing flat at the centre join.

I glued the wing permanently in position and stripped out the tape and card to ensure great adhesion - I have not had much success with rubberbands!

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bracesport

Well-known member
#13
I have got three motors - two modern 1100Kv rear mounts (which I run folding 11x6 props) and one older inrunner RCer BL4-15-4 1810kv 250w. Given I smashed my trainer in the weekend, I think its time to make an RP motor mount for the RCer BL4 that can fit my trainer (as I am rebuilding the nose) so I can put 1100Kv into one of the TT's and get it in the air!
 
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bracesport

Well-known member
#14
Given the nose damage to my 1.2m trainer in the weekend, I'm thinking that when I make my next fuse I'll attempt to reinforce the folded corners with skewers inserted into the fold with the glue - I think it might be achievable!

Just a note on the permanently glued wing - my 1.2 m trainer cartwheeled at a reasonable speed and broke off the motor mount but there was no damage to the wing joint! I think I will stick with this method for the two TT's.
 
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bracesport

Well-known member
#16
Hopefully, I can get some time tonight to sort the second TT with a speed wing and ailerons!

In the meantime, I've thrown the motor mount for the inrunner RCer BL4 on the RP machine with some holes in the front face for venting - this should fit nicely on the rebuilt nose of my 1.2m trainer!

Gotta love the RP world!
 

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bracesport

Well-known member
#17
As you know I am building two TTs - one with a polyhedral wing/elevator/rudder, and one with a polyhedral wing/ailerons/elevator and given they are for my brother in law and son, I thought I should build a third one for me!

All three have a 1.0m wingspan - this one will have the sports wing/ailerons/elevator and V tail! The fuse is slightly more tapered, the back edge of the wing is curved - otherwise, it's just a TT!
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bracesport

Well-known member
#19
I think the main wing will look better if I angle the leading edges slightly. The CAD is tweaked and I like the look of them at 2 deg per side so I'll lock and load!

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daxian

Well-known member
#20
would be nice to see where you put the electronics/battery and servo's ....be a tight fit for the ailerons ,i would think !!
love the use of the noobtube type fuse ....