General RCH Trainer newbie question

Jörg Schulz

New Member
Hi all !
I would like to build the RCH trainer like others already done.
Tony made a fantastic work with this building videos !!
So I started to printing out the plans and ordered Depron (3 and 6 mm) from Germany (quit expensive here in Sweden).
I have already motors for my tricopters 1000kv 210W and 25 and 30 A turnigy ESC´s and 9g servos laying around but maybe i got som 1400kv and 1800kv motors :)

Now my question !
What i am wondering about are the Control horns .. There i am stuck ( i don´t know which Control Horns i need to order) because these is my first rc plane i build from Scratch .
So i made som investigations on our local hobby shop and on HK
Can i use these Control horns or do i need bigger/smaller ones ?
http://hobbyking.com/hobbyking/store/__36258__Control_Horns_16x20mm_10pcs_EU_warehouse_.html
There are even Control Horns 13.5x16mm and 20 x 27mm ..So big question for me :)
And do i need "celvis clips" or not for the linkage ?

thanks for pointing me in the right direction
/J
 

Derek

Well-Known Member
Yes, those control horns will work just fine. Another option would be to use cut popsicle sticks, about 3/4" long (19mm). Apply some thin CA glue (super glue works too) to both sides of the cut popsicle stick. Drill a hole about 1/8" (3mm) from the tip for the push rod. You can use nylon clevis's for your control surfaces or you can just make a "Z" bend at the tip of your push rod and add that to your control horn or cut popsicle stick. Use hot glue to apply the popsicle stick to your control surface. Both methods work well. It's all up to you. The store bought parts look cleaner and are easy to install. The cut popsicle stick with a "Z" bend pushrod are cheap and also easy but don't quite look as good.

Also...since you are using Depron...if you can, cover your Depron with clear or colored packing tape. The packing tape will not add a lot of weight but it will add a great deal of strength.

Good luck and keep asking questions if you need more help.
 

Jörg Schulz

New Member
Thanks Derek
I sorted out and made my order for the Control horns,
Wondering about the motor i already have at home its a 1000kv (i had one extra)
Rpm/V: 1000kv
Shaft: 3.17mm
Voltage: 2S~4S (7.4v to 14.8v)
Weight: 52g
Watts: 210w
Max Current: 21A
ESC: 30A
Suggested Prop: 8x4 (4S) ~ 10x7 (2S)

i flying my tri with these motor on a 3S and 8x4.5 gws props on 4S i use 9x5 props .
BUT i wondering the thrust on this motor (210W) IMHO should be enough to come up in the air with the RCH trainer , or i am wrong ?
 

Derek

Well-Known Member
As far as the motor choice...I'm not certain. Keep checking back to this thread for a response from Tony. He's much better at motor selection than I am. On my RCH Trainer, I used a Turnigy D2836/8 1100KV motor with a 9x5 prop and was getting a bit over 300 watts with a 3S 2200mAh lipo. I used a 40amp esc and an external bec because I was running 6 servo's (1 for rudder, 1 for elevator, two for ailerons, and two for flaps). This motor with this prop....the plane literally jumps off the ground.

Anyway...Tony will be around to answer your question about the motor.
 

Tony

Staff member
That motor will work, although it is a bit under powered and light. Stick a 10x6 prop on it and you should be just fine. It just will not fly all that fast, but it will be very easy to control.

FYI, the foamboard that I used in the video is 5mm thick (yup, I had to measure it lol). So I would build this out of the 6mm depron. Make sure to put spars in the wing and tail feathers to help from folding them up.

Can't wait to see it.
 

Jörg Schulz

New Member
Thanks Tony, But i think with a 10x6 props this motor get very warm on a 3S (already warm on a 9by5 prop on my tri)
Ok, i did my lesson and read more about Motors,props and thrust on RC planes. Quite diffrent from Tri´s
I have also found one NTM 2826 1000KV 300W . Iwill give it a try and test with diffrent combinations of 210W and 300W when i am ready with the trainer.
If it doesnt work as expected with this motors , no problem i order som "propper" motor for this type of rc plane ....
Will be back with more questions before i got this bird in the Air :)

Cheers
J

- - - Updated - - -

FYI, the foamboard that I used in the video is 5mm thick (yup, I had to measure it lol). So I would build this out of the 6mm depron. Make sure to put spars in the wing and tail feathers to help from folding them up.
Can't wait to see it.

Thanks for that Tony, i get my Depron next week , try to make a logbook about my scratchbuild an post it here !
 

Tony

Staff member
One thing to remember is with a plane, the motor will "unwind". Meaning, there will be less torque on the motor and less power required thus less heat. It's worth a shot. If you have a 9x5 already, then try it with that.
 

Derek

Well-Known Member
Well...that NTM 2826 1000KV should work really well. 300W would do very nicely. With a 10x6 or even a 10x5 prop on that motor, I would think it would work. Go ahead and get the plane built, pop that motor on it with a matching ESC and test fly it for 2-3 minutes. Bring it down and check the temperatures of the motor and ESC..I think you'll be in good shape.
 

Jörg Schulz

New Member
Didn´t get it right today, printed out the v3.1 plan , now my stupid question. Should i cut on the "red lines" to the right/left/up and down of all slides before i tape it together ?... Looking on Tonys videos but the plan there are the older ones, right ? ..
 

EyeStation

Well-Known Member
The red lines are where the overlap does occur, but I have found out they don't always line up like you would expect. Like the way the text seems to be missing in the union of two pages. I have learned to line up the major structure lines when joining the pages. With more than 1 continuing line through the two pages, I would make sure a straight line and an angled line both continue on properly before committing to tape. From there you will see the text is not the best way to align the pages.
Hope this helps and Good Luck with the build!
 

Jörg Schulz

New Member
The red lines are where the overlap does occur, but I have found out they don't always line up like you would expect. Like the way the text seems to be missing in the union of two pages. I have learned to line up the major structure lines when joining the pages. With more than 1 continuing line through the two pages, I would make sure a straight line and an angled line both continue on properly before committing to tape. From there you will see the text is not the best way to align the pages.
Hope this helps and Good Luck with the build!

Thanks EyeStation, helps me !!

/J
 

Tony

Staff member
Yes, you will cut the pages on the solid red lines. This is where the pages will be taped together. In my testing, I have had good luck with the new designs lining up pretty well. Only off by a 32nd" or so.
 

EyeStation

Well-Known Member
I don't know if it helps, but I only trim the one side of the red line. the other page that mates to it I leave the extra paper on to overlap my unions. I will usually spot tape the image side and then flip it over and tape all the seams. Seems to add some structure to the template.
 

Jörg Schulz

New Member
Hi,
Finaly i got my depron today, so now i can start to build the RCH trainer. But i have a question about depron. I ordered 10 x 6 mm and 10 x 3mm depron. Can i just glue together 2x3mm depron and use it for the wings ? or are there considurations about stability ?.
AND, For the last 10 years i build Kites (one , two and 4 liners) and have a lot 3,5,and 6 mm CFK so i wonder if i should take 2 of theses 5 or 6 mm CFK tubes and put it into the wings for stability ..

I will post some pictures to clarify my questions :)

cheers
/J
 

Tony

Staff member
I would build the wing out of the 6mm, nto the 3mm. And yes, you must use some kind of carbon fiber spar in teh wing when you use depron. Can't wait to see the progress.
 

Tony

Staff member
I would put the rod close to 50% chord, but still under the top flap, so about 40%. If you put it in the front like you have illustrated, it will allow the back of the wing to flex. You can also run a second one if you wish, which would be even better.
 
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