RC Truck and Construction

RC Truck and Construction (https://www.rctruckandconstruction.com/index.php)
-   Construction Equipment Tech (https://www.rctruckandconstruction.com/forumdisplay.php?f=7)
-   -   gear motor vs differential for larger models? (https://www.rctruckandconstruction.com/showthread.php?t=11299)

carp 02-28-2016 09:57 AM

gear motor vs differential for larger models?
 
Been thinking of building a loading shovel in 1/8 but not sure whether to go with gear motors or build an axle/diff/gearbox setup does either method have advantages or disadvantages? beside the obvious 2speed gearbox?

Rimrock 02-29-2016 11:21 AM

Re: gear motor vs differential for larger models?
 
Generally I would say that planetary gear motors in each wheel hub is the most stable and less complicated solution in a wheeled RC construction vehicle. Fumotec useds that solution for scale 1/14, with MFA gearmotors diameter 32mm. When it comes to scale 1/8 I don't know about similar gear motors that are strong enough to put directly on the wheels, (10-12 inch diameter?) So a better solution is the diff. option I would guess. But if thinking of diffs from like 1/10 - 1/5 RC cars, they would need being connected to a planetary gearbox in the wheel hubs, to be able to transfer the torque needed on those large wheels. Possible the easiest solution is building the whole gearbox/diff/axle set-up from scratch, using more heavy duty gears than comes with any RC car. Then one can possible just forget about planetary gears in wheel hubs, using a solid shaft and large tooted gears in the diff/gearbox. Would possible consider a large brushless motor, of like 500W ++. Another option is using 4 separate gear motors (MFA 32mm planetary gearbox with retrofitted brushless motors for more power, not in each hubs, but 'on-board' the body of the shovel, each connected via shafts/universial joints to a pair of separate bevel gears (like for angle grinders, about 1:3, cheap on ebay) where the diffs. normally are located, leading on to one wheel each...If you can imagine what I mean:) Then one don't need thinking about making diffs..

thetractorfan 03-16-2016 11:23 AM

Re: gear motor vs differential for larger models?
 
Quote:

Originally Posted by carp (Post 140261)
Been thinking of building a loading shovel in 1/8 but not sure whether to go with gear motors or build an axle/diff/gearbox setup does either method have advantages or disadvantages? beside the obvious 2speed gearbox?

It depends on the machine. A gear motor would work better because of the better mounting capabilities. Besides, using gears and differentials will require some lubrication and a few grits of sand can cause serious damage if they get inside. I would go with either clutches or motors. With gears, you will need more bearings and other components to keep it from failing. It only takes a tiny bit or sand or dirt to eat up your bearings or gears.


All times are GMT -4. The time now is 05:29 AM.

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.