MF01X RWD Setup

[Kowalski86 5262]

I'm doing some cheap upgrades on my MF01X Rally Bug, and I was thinking of making it RWD both for accuracy and to reduce heat on the motor, should I remove the front dogbones and the driveshaft or just the driveshaft? And on a side note, how important is an aluminum motor mount if I stick with the torque tuned motor?

[OoALEJOoO 3830]

I've run my two MF-01X with Torque-Tuned and Silve-Can motors using the stock plastic motor mount without any overheating problems, even in tropical weather. Still, running cooler is always a good idea and recently found a way to better install a regular cooler on my MF-01X Beetle rally car. This will cool much more than the aluminum motor mount. Depending on your cooler width, you might need to trim some of the fins to make it slide a bit deeper into the motor.

For a RWD conversion, there are several options.

1) Remove front-end. I would not recommend only removing the front dog-bones as this will make the gearbox joints fall off. This in turn would offset the front differential and possibly bind with the G3 gear. I would recommend removing dog-bones, gearbox joints, bearings, F7 and differential gear. You could also remove the G1 and G3 gears & bearings to shave some weight. You will need to seal the openings into the gearbox (especially if you keep gears G1 and G3) to avoid trouble because of debris entrance. The benefit of this option is reduced weight and, since you keep the central prop-shaft, you don't have to seal its openings.

2) Remove the central prop-shaft. This is the easiest method and the one I would recommend. Removing the prop-shaft is quite easy, you would need to seal the openings it would leave behind to prevent debris entering the gearboxes. The benefit of this is that you can keep your front differential, which will allow some tuning. You can remove G1 and G3 if you want to save some weight. I've found that converting a 4WD car into RWD often results in severe power oversteer. By locking (or better yet, putty stiffening) the front diff, this issue can be greatly mitigated. This mostly applies to surfaces with moderate-to-high grip. If you run in gravel, a locked front diff might result in off-power understeer. This brings us to the next option:

3) Combine 1) and 2), that is, remove the front-end and also the prop-shaft. You get the most weight reduction and *maybe* the better handling car for very loose surfaces (but not for higher-grip surfaces as mentioned above).

4) Any of the above but add a gyro. A cheap one (~25 bucks) can make a basher a lot more fun. You can plug the gyro's gain control to ch3 of your transmitter and control its gain via EPA. I have a transmitter with ON/OFF Ch3 and have set the ON to 20% EPA, and the OFF to 0% EPA (gyro completely off). Being now RWD, you will only have rear brakes, which can be fun to pull hairpins, but difficult if you want to brake hard in a straight line. The gyro can help with this.

Good luck!

[alvinlwh 8240]

6 hours ago, OoALEJOoO said:

you might need to trim some of the fins to make it slide a bit deeper into the motor

I noticed that the heat on a brushed motor are mainly on the endbell, not the drive end so there maybe no need for shoving it in deep.

However, a suggestion will be thermal tape/paste (tape is less messy) to help the heatsink more. I had tried it and it do work.

[Nikko85 4740]

You could lower the pinion if heating is a real issue, it will go to a 13T pinion. I've never found it gets that hot myself on NiMH.

I agree with @OoALEJOoO on ways to make it 2WD, but I do like the handling as a 4WD vehicle!

 

 

[Kowalski86 5262]

2 hours ago, Nikko85 said:

You could lower the pinion if heating is a real issue, it will go to a 13T pinion. I've never found it gets that hot myself on NiMH.

I agree with @OoALEJOoO on ways to make it 2WD, but I do like the handling as a 4WD vehicle!

 

 

One of the wheel pins had been missing (which I hope didn't damage anything), which might be why it got hot. I didn't have any heat sinks on it at the time.

Either I'll go with option 2 or I'll leave it as it is. I do like how it drives and its my only 4WD RC atm. 

I've been having issues with getting the stock pinions grub screw to grip the motor so I have some steel ones in the way, 16t, 18t (incase if 20ts too much), and 20t. .6 Metric, I made sure to get something to Tamiyas spec.