direct drive crawler. - RC-Monster Forums

traxxasrevony · **direct drive crawler. -** 08.25.2009, 09:24 PM

well i have a axi 4130 outrunner that has sat idle too long so i came up with the idea to remove the trans and motor from my ax10 and replace it with the 4130 in a direct drive setup. the 4130 is about the size of the trans and motor combined.

just need to come up with a was to connect the drive shafts so if anyone has an idea throw it up. pics to come soon

BL_RV0 · 11:42 PM

You better check your reduction ratios... Odds are the motor will spin WAY too fast. About the driveshafts, slide the motor's shaft back, so it comes out both sides of the can

traxxasrevony · 08.25.2009, 11:46 PM

the motors is only 285 kv. im sticking to nimh packs anyways and 6 cell at the most which is only about 2k rpm. i had a brushed system with a 2k kv motor on 2s lipo and it was a fast walk. i plan on it being a trail tuck somtime in the near future so some speed isnt a bad thing.

BL_RV0 · 08.26.2009, 12:02 AM

You will have very low efficiency at that speed.

traxxasrevony · 08.26.2009, 12:09 AM

is there anyway to figure that out. like a calculator.

MetalMan · 08.26.2009, 03:26 PM

There is a calculator:
http://scriptasylum.com/rc_speed/_solver.html

Ian is right, it will spin too fast. For a typical crawler anything more than about 5mph is useless IMO (your top speed would be about 10mph). And with the 4130 on that low of voltage I think you will have issues with cogging, which is the nemesis of a crawler. Here's the best I have come up with for a crawler:
http://smg.photobucket.com/albums/v1...de/King%204x4/
You can see the evolution of my crawler, but unfortunately I don't have more recent pics up.
Basically, it's got a kv of about 750, on 3s Lipo. Overall gear reduction including diffs is 16.9:1. Cogging is nearly nonexistant with the Sidewinder.

traxxasrevony · 08.26.2009, 10:06 PM

its only a crawler at the moment. im waiting for school to start and my tech class to get rolling so i can use our 3d program and laser engraver to cut out styrene templates for frame rails. that will then be transfered over to aluminum. this is going to be a trail truck with leafs front and rear in the near future. after that i intend on getting something like the rc4wd timberwolf as a comp rig. so some speed isnt a bad thing. i could also step up voltage once the new chassis is produced. (better batt layout) and get a underdriven gear set for the axles