My BL Savage

I think I'm going to first go with a standard slipperential with a revo slipper, this will allow me to put the motor in a good distance above the driveline. It will also allow me to use a somewhat crazy idea to adjust the gear mesh (not having to move the motor to adjust it). I wish I could explain it with words, but I'll have to draw it to explain. On to Solidworks tutorials!

Just doing some gearing calculations, and I was wondering what I should aim for to be the final reduction ratio with my setup?

[lincpimp]

Not sure, what motor, batterys, etc are you planning on using. I usually aim for around 35k rpm motor speed, and 40mph vehicle speed. You are going to use the revo spur gears, correct? So you have 36, 38, 40t spurs and pinions from 25t down to whatever will fit without having part of the gear reduction assembly contacting with the motor.

I'm using an LMT 2240 14t (1057 KV) on either 8s or 10s lipo, 40 series Moabs. Using BrianG's calc I can get anywhere from 10:1 to 20:1 fairly easily, but is there a way to calculate the optimum ratio for my truck?

[lincpimp]

Somewhere between 15:1 and 17:1 looks good. That would be pinion/spur of 18/40 (primary) and secondary of 20/46 for 10s lipo. For 8s lipo you could do 20/40 primary ratio

Alright thanks! I think I have a good pinion selection for the 14:1-17:1 range if I go with a Revo-style slipperential, which is probably going to be my route.

I now have another question (which is somewhat unrelated), but does anyone know if Brushless setups have regenerative braking like Hybrid cars do? Reason I'm wondering is because I'm thinking of using mechanical brakes for the bias (and to have less strain on the motor/esc), but if there would be a noticable decrease in runtime, I'd veto it. I'm assuming that regenerative braking hs something to do with mechnical brkes on a hybrid car, and wouldn't be applied to this scale of a system, but just wondering.

Also, how many amps does a normal radio setup pull? By "normal" I mean dual steering servos and a reciever. And if I use an external BEC, wouldn't it put a bit more strain on the batteries than if I used a seperate reciever pack? (might seem random, I know, but I just want to know if I should get an external BEC or not, rather use a reciever pack if there is a difference).

[lincpimp]

They do have a form of regerative braking. I would say that you may have issues finding a car esc that can handle 10s lipo? Do you have one in mind?

You may have issues fitting the brake disk on the end of the slipperential assemble that the slipper and spur is on. You may have to put that disk on the diff case.

I would suggest a castle creations bec. Very light, and small, and adjustable with the castle link, plus it has plenty of power to run a pair of servos (or 10 if you want). It works alot better than a rx pack, as the voltage is rock solid all of the time. Plus you never need to charge it!