RC8 Brushless Discussion

[Cain]

With the variety of guys out there with RC8s, I thought it may be useful to have all the info in one place on what they are finding works, what doesn't, etc.

Right now I am looking to move to an RC8 from an MBX5.

My ESC and motor setup will be a modded mamba max and a 1512 2.5D motor.

I am deciding between an RC Product Designs motor mount, or the RC Monster motor mount. As I have been told, the RC Product Designs motor mount can take more pinion options in the lower range (down to 12T), but with the 1512 2.5D motor, I don't think its a concern I believe.

What gearing ranges do you guys recommend to have for this motor? I was thinking 16T to 18T.

Also, if I went with the 44T spur gear, how would this affect your recommendation on pinion sizes versus the 46T one?

Also, anyone got example information they put into this calculator for an RC8?

http://www.scriptasylum.com/rc_speed/index.html

Thoughts on this anyone?

[Cain]

I decided to go with the RC Product Designs full conversion. I like how the RC Monster mount is anodized, but I like the gearing ranges of the RCPD mount better.

My setup should be along the following lines:

RC8 Factory Team
RC Product Designs RC8 Conversion
PolyRC PQ6000XP 4S 25C Lipo Battery
Neu 1512 2.5D Motor
Modified Mamba Max ESC w/ RC Monster BEC

For pinion ranges using the supplied modified 46T spur gear, I am looking to go with a range of 16, 17, and 18T pinions for now based on how well 16T with the 44T spur has worked for pipeous. difference on my calculations should only be a 1tooth increase when using the 46T spur.

As for leakage from the diff, from my reading there could be some slight gear flex, or, over filling of the diff.

[pipeous]

I think you'll find the rcpd motor mount sits the motor higher off the chassis which is why it gives more gearing options. I am running 16/44 and a 2.5D and if anything I would want to gear up on the pinion for a little more tops speed, but so far I haven't needed to change anything for the 2 tracks I have run on.

[Cain]

Thanks for the info!

[lutach]

Originally Posted by Bomb-Proof

Just wanted to chime in, I have one in the works also. I am machining a motor mount, motor support, battery tray, etc for it now. Tryin the 7XL with good bearings and 4s, I will upgrade motors as I feel the need. As little as we have offroad races here, it will be fine.

Sorry to hijack the thread. I was wondering if you still have center drive shaft for the Bomb-Proof truggy? Also, is there a way you can make a 2 center motor mounts for the truggy? One for Lehner 22 series and the other for normal 25mm spacing, but for M4 screws? Please shoot me a PM.

Regards.

yea man, I can help ya out.


Just about have the battery tray finished for the RC8 now, so far so good. My main issue I think is the lipo doesnt look like it will clear the body. It looks like the 4s 8K pack sits too high sitting the highest way, but balances the 7XL much better like that.

[pipeous]

That's a pretty big pack.. most are running 5k or 6k packs.

[Cain]

The 8000mah 4S pack does add a lot of heft. But, if done in two split packs balanced, may work well enough.

I am wondering if with heaver motor setups, you need to go with a more powerful motor by default to get a better power to weight feel.

So who has the best quality pinions to get for the best price?

Yep, the 8K is a lil bigger than most I see on here, but I am giving the truerc lipos a try. Since they are not 20c packs, I kinda had to go to 8K IMO. Plus, I typically run multiple vehicles at the races, and having extra runtime is kind of a buffer for me having to charge all 3. So, the downside is the pack wants to sit higher than the body. But, its nothing I can solve..so we will see.

[RC-Monster Mike]

" am deciding between an RC Product Designs motor mount, or the RC Monster motor mount. As I have been told, the RC Product Designs motor mount can take more pinion options in the lower range (down to 12T), but with the 1512 2.5D motor, I don't think its a concern I believe."

All our Motor mounts accept 12-25t pinions on the stock spur in theory - FYI. Any "more options" that may be available will likely be useless, as I can't see running a pinion(or finding one) outside this range. The limiting factor on the RC8 will be the rear chassis brace and not the motor mount itself (RC-Monster or RCPD most likely), particularly with a finned Neu. The RC8 uses truggy ratio front/rear diffs anyways, so actually using anything near a 12t would be uncommon in most cases(with 1512/2.5d especially), but the adjustment is there onall of our mounts. :)

[Cain]

thanks for the info. I had to order another RC8, this time a NIB one so I am waiting on that.

Right now I am debating still 4S versus 3S, and going with a higher kv motor like a 1.5D with the 3S setup. The batteries are rated to handle this, so no worries there,and in theory, performance should be what I am looking for and save some weight too.

Battery I am looking at right now is the 25C PQ6000XP packs, either in a 3S or 4S Configuration.

I really like higher voltage, but the 3s should be an excellent set up. I debated it also, but when in doubt, add voltage. I had heard alot of success stories about 3s, and a couple guys saying 4s was too much. I personally like excess power, even if I dont use it 95% of the time. I like the idea of lighter weight, so its really a toss up.

[Arct1k]

4S with ubec is not issue on a MM - start there...

[Cain]

had had the 4S setup and my mamba max has the UBEC. I know someone who is testing the 3S setup right now with a 1.5D motor. Once I get word back from him, I will decide on what to order. May need to sell the 2.5D then and get a 1.5D.

What gearing are you RC8 guys having luck with, and what kv?