Modified Tiny trainer not so tiny lol.

[scoooter]

Ok so long story short. I built my tiny trainer and on the way to the field to do maiden flight I tripped .... Needless to say it wasn't good broke fuselage at tail. Go back to house had a stiff drink and started over. Now the brilliance sets in and I remember experimental airlines square tube fuselage. Ok nuff said I am a scratch builder.... Don't forget this is first plane lol. Anyway I got it all together back to the field we go.... First flight is all of 2 seconds out of hand straight into the ground. Broken prop. Popped wing rubber bands. Basically just a scuff up . Change the prop reattach the wings. ... Back to re launch... Bam another 2 second flight this time another broken prop and wing attachment point is really sloppy. Back to the house to reinforce wing attachment points and order some more props.
A few days have passed and it has been windy and rainy. But I took the time to weigh my not so tiny trainer wow 17 ounces . Now I'm questioning is the 1806 2400kv motor going to be big enough to tote this monster off the ground? Should I order some bigger props oh what a mess. Questioning everything.
Any help would be much appreciated.

 

[scoooter]

Here are some pictures of the franken trainer

 

[GliderFlyer]

Ok so long story short. I built my tiny trainer and on the way to the field to do maiden flight I tripped .... Needless to say it wasn't good broke fuselage at tail. Go back to house had a stiff drink and started over. Now the brilliance sets in and I remember experimental airlines square tube fuselage. Ok nuff said I am a scratch builder.... Don't forget this is first plane lol. Anyway I got it all together back to the field we go.... First flight is all of 2 seconds out of hand straight into the ground. Broken prop. Popped wing rubber bands. Basically just a scuff up . Change the prop reattach the wings. ... Back to re launch... Bam another 2 second flight this time another broken prop and wing attachment point is really sloppy. Back to the house to reinforce wing attachment points and order some more props.
A few days have passed and it has been windy and rainy. But I took the time to weigh my not so tiny trainer wow 17 ounces . Now I'm questioning is the 1806 2400kv motor going to be big enough to tote this monster off the ground? Should I order some bigger props oh what a mess. Questioning everything.
Any help would be much appreciated.

When you say modified, does that mean scaled up size too? 17 ounces is a lot for a mini. There are some calculations you can do to find how many watts you need to power your airplane. Let me see if I can find them...

 

[Corsair714]

Wow that's a heavy plane. Just wondering what do you think the cause of the crashes were? Was the elevator reversed or something? Not sure if you would e up for it, but you could always build a second tiny trainer? A lighter one.

 

[Corsair714]

When you say modified, does that mean scaled up size too? 17 ounces is a lot for a mini. There are some calculations you can do to find how many watts you need to power your airplane. Let me see if I can find them...

I think it's like 100 watts per pound or something like that.

 

[GliderFlyer]

https://www.horizonhobby.com/on/dem...lt/Manuals/EFLDeterminingPowerRequirement.pdf
Here it is. What battery and esc do you have?

 

[mastermalpass]

17 Ounces shouldn't be too much for a 25" wing, what's the wingspan? I've lifted 30-32 ounces off the ground with a 30" BiPlane spinning an 9" prop... It wasn't easy. lol But you get the point.

Is it nose-diving when launched? Check that the Center of gravity is at the first fold in the wing. Then maybe add a bit of up trim as an extra measure.

 

[Corsair714]

17 Ounces shouldn't be too much for a 25" wing, what's the wingspan? I've lifted 30-32 ounces off the ground with a 30" BiPlane spinning an 9" prop... It wasn't easy. lol But you get the point.

Is it nose-diving when launched? Check that the Center of gravity is at the first fold in the wing. Then maybe add a bit of up trim as an extra measure.

Just remeber that's a really small motor. That's what you use on a mini scout and those things way like 250g or less. You can only put on so big a prop.

 

[Corsair714]

I usaully fly with a bit more power than needed. I would rather have more than needed than not enough. My simple scout put's out 500 wats and It ways about 600 grams. Of course that's a bit overkill, but it's fun.

 

[GliderFlyer]

So I was calculating, if you have a 3-cell lipo and the flite test 20a esc, that gives 198 watts.
Your tiny trainer weighs 1.0625 lbs (I'll just round that to 1), and a trainer airplane needs 70-90 watts/lb.
If my calculations are correct, then that setup has enough power for your tiny trainer to have unlimited 3D performance.
I better check my calculations again.

 

[scoooter]

Thank you guys for all the help. So I used the wings that are for the glider for tiny trainer no aleron. they measure 37.5 inch from tip to tip. Fuselage comes in at the same as the original at 27.5 in as my original plans. tail measure 12 in and horizontal stabilizer (rudder) is 5.75.
Power is an inexpensive 1806 2400kv motor with 30 amp esc. Flying a tattu 2s 650 may battery cg comes right in the high point of the wings which is about 1in back of leading edge. Prop is a 6030. I also re weighed the plane 368g or 13oz sorry for the mistake.

 

[scoooter]

Wow that's a heavy plane. Just wondering what do you think the cause of the crashes were? Was the elevator reversed or something? Not sure if you would e up for it, but you could always build a second tiny trainer? A lighter one.

Cause of crash =noob trying to learn how to fly launch left handed get on control to avoid ground. As flight path is similar to a rock. That would be my guess too much up to avoid ground.

 

[GliderFlyer]

Thank you guys for all the help. So I used the wings that are for the glider for tiny trainer no aleron. they measure 37.5 inch from tip to tip. Fuselage comes in at the same as the original at 27.5 in as my original plans. tail measure 12 in and horizontal stabilizer (rudder) is 5.75.
Power is an inexpensive 1806 2400kv motor with 30 amp esc. Flying a tattu 2s 650 may battery cg comes right in the high point of the wings which is about 1in back of leading edge. Prop is a 6030. I also re weighed the plane 368g or 13oz sorry for the mistake.

Ah that's a better weight.

Cause of crash =noob trying to learn how to fly launch left handed get on control to avoid ground. As flight path is similar to a rock. That would be my guess too much up to avoid ground.

Ha the same thing happened to me with the mini mustang. I never did get it to fly...
Good luck on your next launch

 

[scoooter]

So according to the calculation of 100w per pound I'm great if I'm doing it right 7.4v x 30amp (esc) that equals 220 W so I'm 2x over the rules.

 

[TheFlyingBrit]

Cause of crash =noob trying to learn how to fly launch left handed get on control to avoid ground. As flight path is similar to a rock. That would be my guess too much up to avoid ground.

I have had 5 of these planes and love flying them. Here is my tip remove the prop, fit your battery and balance the plane with the CG slightly nose heavy (nose dips 10 degrees down). Have your transmitter ready, find some long grass and launch it into the wind at a slight downward angle, in theory it should glide nice and gentle although it may wander to either side as its not trimmed yet.
Be prepared to give it a little (and I mean little ) up elevator as its nose heavy. It should give you a smooth glide, if it doesn't then there is something wrong.
If it does glide smoothly use the trims to get it to glide straight, this gives you a slight head start before doing a powered flight.
Now re-fit your prop, this time launch again into the wind but with a slight upward incline and use 3/4 throttle. It should climb gently if not, add a little elevator to help it climb or more throttle (not both, use either or).
Try this and let me know how you get on, good luck

 

[scoooter]

I have had 5 of these planes and love flying them. Here is my tip remove the prop, fit your battery and balance the plane with the CG slightly nose heavy (nose dips 10 degrees down). Have your transmitter ready, find some long grass and launch it into the wind at a slight downward angle, in theory it should glide nice and gentle although it may wander to either side as its not trimmed yet.
Be prepared to give it a little (and I mean little ) up elevator as its nose heavy. It should give you a smooth glide, if it doesn't then there is something wrong.
If it does glide smoothly use the trims to get it to glide straight, this gives you a slight head start before doing a powered flight.
Now re-fit your prop, this time launch again into the wind but with a slight upward incline and use 3/4 throttle. It should climb gently if not, add a little elevator to help it climb or more throttle (not both, use either or).
Try this and let me know how you get on, good luck

Thank you will definitely give it a go.

 

[TheFlyingBrit]

Thank you will definitely give it a go.

Simple rule is, if it will glide then your half way there. If it wont glide then you need to check your: cg, symmetry of your build or control surfaces then start again.

 

[TheFlyingBrit]

Apologies for this and please dont take offence if you have already checked this out and its correct ! Is your elevator operating in the correct direction ? (ie stick down elevator goes up - plane climbs, stick up elevator goes down - plane dives.)
It wouldn't be the first plane to have the elevator (or other control surfaces for that matter) reversed ?
With you saying it heads to ground on launch as opposed to the sky it made me just ponder over that possibility ?

 

[Corsair714]

Ya, you sound good to go there. 368g is alot better than what you said originally. I think you're all set.

 

[Corsair714]

Apologies for this and please dont take offence if you have already checked this out and its correct ! Is your elevator operating in the correct direction ? (ie stick down elevator goes up - plane climbs, stick up elevator goes down - plane dives.)
It wouldn't be the first plane to have the elevator (or other control surfaces for that matter) reversed ?
With you saying it heads to ground on launch as opposed to the sky it made me just ponder over that possibility ?

Ya I broke my first tiny trainer due to a reversed elevator.