My Trex 700 nitro to Electric conversion build
Thought I would post some pics of my current project. I am converting a Trex 700 nitro heli to ePower. This is a 90 size heli.
Items being used:
-eConversion kit from Bobby at RRE models
-Scorpion 4035-400kv motor
-20 tooth revco steel pinion (mod .7)
-Castle Creations 85a high voltage ESC
-(2) Turnigy 6s 5000mah packs in series for a 12s configuration.
I wanted a conversion that would use almost all stock parts in the event of crashing and also something that was powerful but with good flight times. There has been a lot of people using higher rated motors but the issue becomes stripping main gears unless you go with a mod 1 gear and pinion. After talking to a lot of people this setup is a good all around conversion and with careful gear meshing the gears survive fine.
The idea here is to go with a lower KV motor and higher tooth count pinion. This setup is actually very efficiant from the tests they have done. For my style of flying I expect around 5 minutes.
I have just started but here are a few pics. I will post more as I progress right to the end.
The rear 6s pack will eventually mount straight up where it is sitting. I need to fab a plate for mounting purposes.
A big 'honkin' pinion :-)
A big 'honkin' motor too :-)
Ha... ya. I need to fabricate a mounting plate.
Mark, I can't wait to see her fly. WoW man, Wow.
Wow That is one fabulous project. Cant wait to see her fly. Have fun, Good luck
Test flight #2
Nice,
Glad it converted so well.
So no mo' nitro for you! Cool strobe effect on those blades and the sound of the engine seemed like it was a turbine screamin' in there. Didn't hear any loading up either, so does that mean you can start doing REALLY extreme stuff? he he he. Waaay low on one of those passes. You da man.
Powerful you have become, the dark side I sense in you.
Wow, intense MOD Mark! Awesome job. Somebody even 'mowed' the field for you...
Assume the blades are spinning slower than with nitro?
Mike
The video was from my iphone so the frame rate messes with the blades. Kinda like a strobe light.
Actually the head speed is just over 2000 rpm 
which is pretty fast for a 90 right? or about average?
Hey Jon! For a NITRO 90 that would be high since most nitro engines the RPM would be out of the power band and be hard on the engine. Typically more like 1850-1960ish depending on style I suppose.
2000+ is downright ballastic on an epowered machine. I have since backed it off and will try 1860ish for some extended flight times. Close to 7-7:30 minutes I would say at that head speed.
I think that rear battery pack tray could probably use a little work