danielcaceres91

Thanks Dave and Brenner!

danielcaceres91

Hi Brenner, I managed to take out the collet and remove the contra, now I'm having trouble reinserting the collet. It only goes in a few mm into the motor shaft and I can't put it in all the way, how do I do it?

Brenner

Hey Daniel,

You will need to press it back on using a small press. When you do this the bottom of the motor must be supported by the press. When you press it back on make sure that you press it all the way down so there is no axial play in the motor bearings. If you don't have a press then I suppose you could maybe use a C-Clamp, but I have never done it this way so I can't recommend it from direct experience.

Brenner ...

Joseph Frost

Hi CR Guys, what happened ? 8 month no post? I would like to get CR power unit for one of my giant Bipe foamy currently running "Eflite160 spinning 22x10 on 8S".After looking at it, there's very little avail in this large CR dept. also pretty reach $$$-wise.
I'm not after the speed like F3A pilots, but opposite, for very slow flying 3/D model I preffer larger props (23-26") at very low pitch (5-6) as the torque is my priority.
Am I wasting my time with what's avail or should I pursue it further? TX, for any hints, Joe.

This is the giant model at ~13lb on 8S, 4,5Ah.

Brenner

You're not wasting your time. I think you would like the performance that a modern f3a Contra Drive gives your plane.

With a Contra Drive you are going to want a much higher pitch than you would use with a single prop Drive. This is because each prop on a Contra Drive absorbs half the power absorbed by the single prop on a single prop Drive. Your 5" - 6" pitch would be equal to 10" - 11" pitch on an equivalent Contra Drive system. The lowest pitch that you can find for an f3a Contra Drive system is 18" of pitch. However, I think that this would actually work well for your plane. Anything smaller won't fly your plane fast enough to stay in the air.

Brenner ...

Joseph Frost

Hi Body, TX for getting back, this model is something totally different to regular Patternship, it has 3X lighter wing load, flying like a snails speed so my last concern is staying in the air. As I mentioned I'm not after speed but "Torque", with larger prop diam. and minimal pitch. I'm more after wider wash over the tab controls at slow speed for slow 3/D manuevers, and quick control response.
I can see the problem with the available props with only high pitch for F3A, (the last thing I'm after!) but I do believe I might get variety I'm after if I look into drone ones.
Look, I'm currently flying 3 CR models (micro lights) and I find the lowest pitch works best for my requirements. Going as low as 2.5-2.8 at 10" Carbon ones from PT in CZ.
But first I have to look what kv motor might be the best for my application, so I'll do more fishing around. Regards, J.

I'm reducing pitch to minimum by prop mods to get the best out of it.

Lowest pitch works the best in this application, "slow-low&close"