Brushless Rock Crawler

[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.