Drive shafts direction question

[oldnick]

I'm trying to pin down some specs for a project, which will aim to improve upon my gmade gs02f's weaknesses.

Plan is to ditch the 2-speed transmission and mount the motor LCG stylee.

Most of the compact LCG style transmissions run the shafts in the same direction, whereas the Buffalo runs in opposite directions to reduce torque twist - how much of a difference does this make for crawling?

I like to run with fairly stiff damping, and don't want to lose what little side hilling stability I currently have.

Ps I'm doing this on a tight budget, so AliExpress options rather than lovely rc crawler porn solutions please!

 

[HumboldtEF]

Counter rotating driveshafts in theory reduce torque twist, in practice it may reduce it a little but nothing will entirely eliminate it. I think this kind of setup has become much less common as its not super effective. Almost all modern comp rigs dont use counter rotating shafts. Even an MOA with no shafts can still end up with gobs of torque twist (due to super soft suspension).

Since your diffs are made for counter rotating shafts thats a bit of an issue if you end up switching to a non counter rotating transmission. One diff would be running its gears backwards and the gears wont be as strong going this direction. There are a few options out there, although I can only think of one at the moment: Dlux Fab's CheezBerger

Sorry I know thats not a budget option. I dont think making a GS02F a LCG rig will be easy or cheap but hopefully I'm wrong!

 

[89Industries]

My first question is what happens to the direction of your wheel rotation at each axle if you switch the direction of one driveshaft? Is there a way to reverse the wheel rotation through the differential at the axle (flip over the ring gear to the other side of the pinion)?

On the Axial axles I have most experience with there is not space to flip the ring gear in the differential housing.

Also, none of my trucks have driveshafts rotating in opposite directions so I do get some torque twist. You learn to drive with it and how it reacts. Portal axles reduce it as well but you can certainly drive just fine with it.

I'm curious what weakness you are dealing with by removing the 2 speed transmission as well? I have no first hand experience with the GMade trucks but have considered trying one out in the future.

 

[oldnick]

There will be a plastic portal axle going in the back to solve that, my existing axle doesn't look to be flip-able.

This will have the bonus side effect of getting away from the weak sintered bevel gears that gmade are infamous for!

I don't use the higher speed at all, and the transmission puts the motor high over the front axle so fancied a tinker with it on the cheap.

 

[89Industries]

cool, got it. wondered why not just lock the transmission in one gear but sounds like that's asking for a ticking time bomb. Having a set of sintered gears grenade in my VS4-10 phoenix transmission I understand the issue fully.

I'd say go for it. I doubt you will regret it from the extra torque twist stand point.

 

[ferp420]

they sell cheap 3 gear with counter rotating shafts
also you can use them as a transfer case with a forward mounted motor for some extreme low gearing ive layed them down to save space to if your planing a interior or to keep the weight lower in the chassis

 

[oldnick]

I'm under no illusion that I can turn the Buffalo into an LCG - there is a saying about silk purses and sow's ears - but I'm hoping to improve on what I've got.

I'm planning on building a cheap lightweight lcg chassis in the future, but at the moment I have a Buffalo that keeps falling over

There are some Currie/F9/Capra axles on "no money for RC" on AliExpress that look to have flip-able diffs, also means I'll have options to underdrive the back end regardless of the trans ratios.

I should be able to fit a smaller LiPo (currently running 3s 2200 mAh) on its side in front of the front axle, lay the servo flat and move the esc and Rx to behind that, which will hopefully retain the 60/40 weight balance but with the weight lower down.

My boy will be gutted though, he likes to do doughnuts in the sand in high gear with it lifting a wheel, I am a killjoy!

 

[ferp420]

alliX 3 gear
Just found this amazing item on AliExpress. Check it out! $40.99 45%OFF | AXSPEED Metal Transmission Case Reverse Rotation Gearbox with Gear for 1/10 RC Crawler Car Axial SCX10 Upgrade Parts

https://a.aliexpress.com/_mKzYf4U

 

[ferp420]

sherbert ebay is cheaper

1PC Metal Reverse Transmission Box Gearbox For 1/10 Axial SCX10 RC Crawler Car | eBay

For AXIAL SCX10. Fits for Axial SCX10. Belt Drive Transmission Gear for 1:10 RC Axial SCX10 & SCX10 II 90046 Gearbox. 2.2" Beadlock Wheel Rim for RC Crawler Car TRX4 Axial SCX10 RR10 Wraith. Foam Sponge For 2.2" Wheel Tires RC Crawler Car Axial SCX10 90046 TRX4 TRX6.

www.ebay.com

 

[ferp420]

the ebay 1 has the reversable top shaft also