Brushless Rock Crawler

[MetalMan]

The unloaded kv is 4400, but loaded is closer to 3000. It is 2.84" long x 1.41" diameter. Feigao S series are 1.97" long x 1.41" diameter.

[Xtreme R/C]

How bout a novak 5800 or a LRP Sphere and Neo?

Both are rated for 7 cells (8.4V) so I could use a 2 cell lipo (7.4V). If geared for a crawl, either one should give me lots of torque, smooth throttle responce, and good run times.

Any other sugestions?

[Rtsbasic]

I'd recommend sensored over sensorless for this. Any of the Novak or LRP systems would work, but bear in mind they have a pretty high kv so would need to be geared accordingly. The GTB can safely be ran on 2s lipo as well I've read. The GTB with the 8.5 motor would be a good combo for your project in my opinion.

[squeeforever]

i would personally go with the hv-maxx as it will provide more torque than the gtbs.

[coolhandcountry]

From my experences. you can run a brushless motor under geared if you run a low cell count and a high turn motor. This in turn keeps the rpm down and the heat factor. The sensored is a good option. May look at the aevox motors for that or novak. Keep in mind of what shaft you will need as well for pinion selection. good luck on project.

I don't know that you could get it geared down enough without going to a airplane reduction like a GD600 or something, it might have a lot of torque, but you just don't need the rpm. For right now, brushed is FINE for crawling, in fact, I'd say it's even better. The main motor that most guys run is the Integy 55x1 comm lathe motor (slow, but tons of torque), and for $20 a motor, why wouldn't you go with it. The brush wear is non existant, and they take beating after beating on Clod gearboxes that slam against the rocks.

Oh yeah, one other thing. Anyone ever see the vids from the ORCRC (Oregon Radio Controlled Rock Crawlers) gang? One thing they're always doing is playing in or around water on darn near every course. The trucks are repeatedly rolled into puddles, driven through mini ponds to get to the next obstacle, and generally beaten senseless. I would keep my $200+ bl systems as far away from a crawler as possible, and I'm just fine with running a Super Rooster and dual 55t lathe motors.

If you haven't already, check out www.rccrawler.com for any other info on both this topic (johnrobholmes had a bl crawler) or any other random crawler question.

[Xtreme R/C]

I know the integy 55 turn lathe motor is a commonly used crawler motor. I was just wanting to do something different. I like brushless for the low maintinance. I have a SS5800 I could steal out of my XXX-4 G+, won't be racing that till spring. And It's kinda been shelved since I got my X-5.

I've been to rccrawler, I like the vids people post in the forums. As far as running in water, my truck will never see that. I can't abuse my stuff like that. Some of those video's on there they drive completly uderwater for a short time. Looks cool util you have to replace all your electronics cuz your waterproofing job wasn't as good as you thought it was, LOL.

Most of the crawler out there are clodbuster axle based. I want to build a shafty. One motor with at gearbox and front and rear drivshafts to a solid axle setup.

I'm gonna need a 1/8" shaft for the pinion I'll have to use. So it looks like I'll be going with the novak setup, the 5800 or maybe the 4300. It would require less gear reduction in the trasmission to get the crawl speeds I'm looking for.

Thanks for all the help, I'm a long way from where I started, wanting to use a 40t bl thinking it would be comparable in torque and rpm to a 55t integy lathe motor.

I never really followed what he did, but check out johnrobholmes bl crawler project that he did, I think he used a airplane motor.

I had a SS5800 in my Pede for a while, then bumped it to my RS4MT, it was pretty "meh" once I got my Lehner 5300. :D

[MetalMan]

Originally posted by dabid
I think he used a airplane motor.

We all use airplane motors :L:. Some are just more car-suited than others :p.

[Serum]

or are it all boat motors, more car-suited...? :p

[nbcaznmaster]

or...we could stop using "OR"s to begin the statements! lol

what I mean is that he used a smaller 380 or something close to it, maybe an outrunner.......but I got no idea.

[Xtreme R/C]

Well, I got my planetaries yesterday.

They are a little lower than I thought and have a good sized jump when going from 2 stage to 3 stage. They have a reduction of 4.5 each.

2 stage would give me a tranny ratio of 20.25:1
3 stage would give me a tranny ratio of 91.125:1

So 3 stage planetary with a diff ratio of 3.3:1 would equal a crawl ratio of 300.71:1 :eek:

But with a hight Kv motor like the NEO at 6500 rpm/V on a 2cell LiPo with LST tires would give me a top speed of 3.30 MPH. Thats about what I'm shooting for 3-5 MPH. I might have to put a 1:2 gearset in the tranny to have a HI/LO setup so I can move around and positon a little faster and shift into LO to crawl. High gear would be 6.6mph and low would be 3.3mph.

[crazyjr]

Thats a cool idea. where did you get the planetaries

[coolhandcountry]

Could you take a pic of this planteries.