gearing a Stampede for a MM 5700 on 3S Lipo

[fastbaja5b]

Hey guys any ideas on what gearing to use for this?

Have 13/86 at the moment and while that is fine on 2s, on 3s the motor gets a bit warm, I know the Mamba has less torque and more rpm than the VXL so gears completely different, the VXL they recommend 16/86 to 23/86

Any thoughts?

[strada916]

if that is the range you are given I would start at about 19 and then work either side of that. IMO I wouold start at 19 then then work up. If you have some way of checking the motor RPM I would gear the car so that the motor does not exceed about 85% of its max RPM. From that you will get a pinion that will give you a motor safe max speed and if you want more power I would go down a thooth or two, but make sure that WOT is limited.

Just my 2c

[fastbaja5b]

True but the Velineon is a 3500 kv motor which has a lot more torque than the MM motor so naturally I'd need to gear lower.

Just wondering how much lower.

I can't really gear my MM anywhere near what a Velineon would go at as it's a completely different motor! (Feigao based I think)

[don74]

Hey guys any ideas on what gearing to use for this?

Have 13/86 at the moment and while that is fine on 2s, on 3s the motor gets a bit warm, I know the Mamba has less torque and more rpm than the VXL so gears completely different, the VXL they recommend 16/86 to 23/86

Any thoughts?

On a 3S I would suggest going down to an 11T pinion assuming of course the pinion contacts the spur properly. This should lower the motor temps down to that of the 2S level. Kindly note that the 11T pinion would be way under geared for a 5700 on 2S.

My Pede runs a CM36-6900 on 7.2v Nimh 14/86 and the motor is hotter than warm but I've run much hotter on my 2 other MMax/CM36-6900 installations with no problems. In my experience with the CM36 motors hot is acceptable, so a "bit warm" is of little or no concern.

I hope though you have steel internal transmission gears like in the VXL model as plastic will get chewed up with BL power on high traction conditions. A wheelie bar would be a must too. Enjoy.

[fastbaja5b]

Yeah I was going to put a VXL spec transmission in, at present the slipper is set loose to protect the plastic, so she don't wheelie at all (being a revo spec slipper I understand I won't suffer the melted spur syndrome so I can do this for now)

Will probably try a 12/90 ratio for now.

[don74]

Yeah I was going to put a VXL spec transmission in, at present the slipper is set loose to protect the plastic, so she don't wheelie at all (being a revo spec slipper I understand I won't suffer the melted spur syndrome so I can do this for now)

Will probably try a 12/90 ratio for now.

Actually 12/90 will likely perform better overall for the Pede on the 5700 with 3S even as it will run noticeably warmer than the 11/86. It would be wicked fast for as long as it can be kept on a straight line.

[strada916]

just watch the rpm. As most motors do not really like doing near max rpm. they kinda get a little too warm for my liking.

[fastbaja5b]

Yeah 12/90 may be the go, am going to trim the tranny case a bit so I can put a heatsink on the motor and I might chuck a fan on the speedy, that combo has worked well on the E-Savage.