I've had my brushless Kyosho buggy for almost a year now and I have been very pleased with it. It handles well, is blazing fast, pretty reliable and just plain fun. It is surprisingly competitive with nitro buggies with one exception, the braking. Don't get me wrong the motor brake is strong and can be finetuned via the MM ESC, but it still lacks the same feeling you get from a good mechanical brake setup. My biggest issue is that you cannot adjust brake bias using a motor only brake. So, I decided to mod my exisiting motor brake only buggy and add mechanical brakes. I search this forum (and others) for info and came up with design below. The issue is when using a standard brushless motor (or brushed) mount to power a nitro center diff equipped buggy the motor will not clear the rear disc brake or will not allow a small enough pinion to be used. Nitro cars have a long crank and a clutch bell that allows the engine to clear the brake. To get around this with a brushless setup I decided I needed to move the motor back about 6mm to get the necessary clearence. I made a new motor mount from scratch that attached to the chassis and placed the motor back enough to clear the brakes. The mount was made in such a way to fit very close to the center diff mount which allowed the use of smaller pinions. Since the motor mount was now no longer part of the center diff mount I was concerned with chassis flex causing gear mesh issues. But after looking at my overall design, the aluminum battery tray and special motor bracket (used to hold the Feigao endbells on) seemed to really keep the flexing under control. This buggy is still a work in progress, I still need to mount everything, construct a bracket for the brake servo, hook-up the linkage, setup my ESC and radio mixing, etc. But I wanted to share my project with all of you and perhaps get some constructive feedback. Sorry for the long post.
The problem, motor can won't clear the brakes. Pinion does not reach the spur.
Here is the rough motor mount taking shape.
The solution is to move the motor back.
Mount needs to fit close to the center diff.
With the motor moved back now the pinion reaches the spur.
Bracket to hold Feigao motor together also strengthens the mount/chassis.