IMAC Scratch build Laser 200

[BalsaDust]

Yes opentx is awesome. I personally always do my initial program in companion but after that unless I feel I need to make a major change I do it from the radio.

 

[-Rick-]

I prefer to work on the radio, when I am close to what I want I turn on the plane and fine tune.

 

[TonyHallo]

Yes opentx is awesome. I personally always do my initial program in companion but after that unless I feel I need to make a major change I do it from the radio.

Companion is a great tool. I do the same, initial program in Companion then set the center, end points and rates on the plane. I used Companion to sequence doors and tail wheel retract using slow and delay functions, no need for one of those fancy control boxes. If you think of what you would like to do, you can make it happen in OpenTX.

 

[Forgues-Research]

got the CG located using full size technology, with weigh scales, and doubled check on the drawings, exactly right, but still need to add weight to the nose as the electric motor weighs much less then a 120cc gas engine, now to add this weight as far forward as possible, so as not to add too much weight . Also the plans calls for 13 kg and mine so far came out to 12.93818 kg, but still need to add the nose weight for proper balance which will bring it over 13 kg a bit, I think had I done the old school and use long push rods for the tail , with the servos in the front, I would have been ok but it is what it is

 

[TonyHallo]

Boy do I love the HP calculator with RPN, can't be beat. That wing looks awful thick, don't think you will need flaps or spoilers!

 

[Snoopy1]

Have to agree that old HP calculator brings back some old memories.

 

[Forgues-Research]

Boy do I love the HP calculator with RPN, can't be beat. That wing looks awful thick, don't think you will need flaps or spoilers!

As for the HP calculator, the one in the picture , I have had it since the mid 80's, I do have another one just incase
Ya the wing is thick, built according to the plans and I believe it was designed for hard core 3D , but I am not a 3D flyer so the good news , it has more drag, meaning I can slow it down I think

 

[TonyHallo]

I'm sure it will.

 

[Forgues-Research]

I need help, on the drawings, in the photo attached, look where it says the CG should be, but I find that too forward, what do you guys think , and in your opinions, where should it be

 

[Snoopy1]

Have to agree with that does not look correct. But it would be a safe place to start at. Just layout the wing on a piece of paper and get the 25% Mac position and start from there.
One thing looking-at the drawing the wing aspect ratio looks high, looking at the drawing it could as high as 15% or more. All I can remember some time ago when wings were at those numbers CG location was anywhere from 20 to 25% Mac. As the wings dropped down to 10% ratios and the weight started to drop did the CG location start to move aft. Like to day I am flying around 30 to 35% CG locations.