whats the best gear ratios

[losikid]

I'm doing a little r&d work for a crawler idea i'd like to get out of my brain and into an actual crawler. Right now i'm trying to work out a few kinks concerning how to get the right gear reduction/gear ratio. In genral for a super class crawler what would be a good ratio to start with using 540 brushed motors, possibly brushless.

I have a general image/design of a motor in wheel crawler. I figured someone made a small bolt on gear box but most i could find was a 16:1 from rc4wd. so i'm considering making my own gear box/tranny that will keep a motor and tranny mostly concealed in a wheel.

I'm not super familier with a super class crawler, or many other crawlers than my losi which right now i'm at like a 50:1 which i like quite abit. Any help on gearing ratio it sure help me out. For now i'm just trying to get it on paper and i'm gonna try to start building it towards the end of the year at least hopefully have it built before next comp season. Then if it works well get a 2.2 built using the same concept. Thanks

[JeremyH]

Well, I have run both the low and high ratio on my super bullies and I can tell you that the 65:1 ratio is MUCH better suited for crawlers with large tires. With this ratio, you have more gearing options (lower turn motors, different pinions). With the 38:1 I was pretty much stuck with 55T motors and 10T pinions...

[losikid]

Well for now i'm gonna need to stick with one setup without pinion adjustability. And i'm thinking only way to get the low ratio in such a small are is to use some sort of worm gear, either out of the micro or 2.2 losi becasue then i'l have the ability to have a 12:1 21:1 and a 25:1 then like a 2:1 or 4:1 bolt on gear box from rc4wd. I may also do a pinion spur setup with the worm

[JeremyH]

The micro?!?! I would stay AWAY from anything on that truck when building a super. You really need to remember that supers run much larger tires which will exert a very different force on the internals of the axle than your other crawlers. At first attempt on my super, I was running the same gearboxes as I was on my 2.2....and I broke parts at nearly every outing. I have never broken any of those parts on my 2.2.

[losikid]

what do you think how to get a low 50:1 gear ratio in lets say 5 cubic inches including the motor which takes up about two. Also remeber this is per wheel, so i'll have this just using the toque that is applied to a single wheel, not a whole a axle or a whole crawler.


Whats the gear ratio's you get out of the gear boxs on a super?

[JeremyH]

Well, I've never seen a truck that has one motor per wheel....but it's doable. I believe there was a french guy who started a project like this, but I dont recall the outcome.

On my super, I run the RC4WD Super Bullys 65:1 gearboxes...

[losikid]

Yea, well i had an idea year or so ago about this and i posted a thread to see if anyone else has done this and got flamed quite abit, so its been bugging me eversince. I'm taking a machining class throught next school year, and i talked to my instructer and he said i would be able to work on my own project so this is it. More and more i get in depth everything is going have to be custom, except motors and and esc's. I'll probably have to make a custom radio too.

Anyways are the super bully gear boxs the same size as the 2.2's how much bigger are they? I'm looking at 2.2 bullys right now and i may be able to get them into a super wheel. does 65:1 seem to give plenty of wheelspeed and and torque, what motors are you running?

[JeremyH]

The 65:1 gears have an extra gear inside them....they are a bit larger than the 38:1.

I am currently running 55T motors, but only because I just switched from the 38:1 gearboxes. They would probably work best with 45T motors....

[losikid]

How do you think the new heavy duty worms hold up, i'm thinking about using those and a blc regear and make custom sealed gear boxs to bath the worms in oil, and new axles too.