Mid motor Bandit project

[PhilV]

So I’ve seen a few versions of the mid motor Rustler and Slash on this forum and the Traxxas forum, and I decided to give it a try myself. Except I want to do a Bandit. I’m starting from nothing and going from there. I did pick up a partial roller of a Rustler which I can get a few pieces from, and everything else I’m going to be buying piece by piece. RC10Nick’s Slash and Rustler are big inspirations, but one photo from one of his threads really stuck in my mind. It was a photo posted by Marshky that really got me thinking. It was a Nitro Hawk trans with an e motor mount attached. That’s the route I decided to go with. I’ll post some photos and let you all see my progress so far. This is going to be a long process, and I just want to document it as I go. Hopefully I will be able to update often, but this is going to be done in my spare time at work and hopefully with as little budget as possible.





Oh, and this is just a mock up chassis. I plan on using some G10 for the final version. I just happen to have this material on hand to make sure my hole placement is correct. It’s actually too short. I only had a 7x12 inch sheet. So the length is only 12” instead of the over 13” a stock chassis is supposed to be. But this material is surprisingly rigid. It’s 1/8” thick, and there are 2 layers of 1/32” aluminum sandwiching a 1/16” piece of high density plastic. I have more of this material in a bigger sheet. I may try And actually use it. Just for fun.

[GoMachV]

Looks good! That material sounds interesting.

The nitro stampede/rustler/slash trans and rear bulkhead are good candidate as well. Really the only drawback to the nitro trannys is that you can’t fit the modern slipper directly.

[Chewbacca]

Looks good! That material sounds interesting.

The nitro stampede/rustler/slash trans and rear bulkhead are good candidate as well. Really the only drawback to the nitro trannys is that you can’t fit the modern slipper directly.

Do the Nitro trannies have different internals than the Rustler / Bandit? More precisely a different top shaft? If so the STRC conversion wouldn't work I guess.

In that case my Franken-Slipper conversion (I know this is the second time I'm suggesting this) would work.

Franken-Slipper

I recommend Serpent spur gears and slipper pads, they fit the friction discs better dimensionally.

I like the idea using the nitro transmission. If you want to stick with the standard Transmission and flip it backwards, the RPM tranny case seems to be a good choice.

[GoMachV]

The internal gears are different- and 32 pitch.

[PhilV]

That chassis looks great!! I hope my final product is half as nice.
I’m going to try the nitro hawk trans and slipper and see how it goes. One thing I’m not liking right now is the 3mm screws into the bottom of the trans case. I feel like these are going to strip easy. I am taking it in an out a lot though. So maybe just a new case when I get this thing going.
I went with the nitro hawk trans for a couple reasons. The main diff is the same as a rustler/bandit/slash. But the other two gears and top shaft are different. Not that big a deal. Also, the rear shock tower is in pretty much the same position as the bandit/rustler/slash. The draw back is the shock tower mount is no longer available, but I think I can fab something.

Looks good! That material sounds interesting.

The nitro stampede/rustler/slash trans and rear bulkhead are good candidate as well. Really the only drawback to the nitro trannys is that you can’t fit the modern slipper directly.

[PhilV]

I’m waiting on my rear shock tower to come in so I can make a mount for it. But in the mean time I made a motor mount. I didn’t want to hang it off the trans case though. So I mounted it to the chassis. It might be to big with too much lateral adjustment for the pinion though.

[matt1ptkn]

Very nice machining work on that motor mount!

[juicedcoupe]

But in the mean time I made a motor mount. I didn’t want to hang it off the trans case though. So I mounted it to the chassis.

I'd probably still have it attached to the transmission. Otherwise, they can flex independently of each other. Chassis flex might open and close the gear mesh, destroying gears (and maybe more).

[PhilV]

But in the mean time I made a motor mount. I didn’t want to hang it off the trans case though. So I mounted it to the chassis.

I'd probably still have it attached to the transmission. Otherwise, they can flex independently of each other. Chassis flex might open and close the gear mesh, destroying gears (and maybe more).

Thanks. I wanted the mount to look good.

I too was thinking that it might flex. I’ll give this a try just to see if it works. I’m actually not even sure if the way I designed it will work. After looking at it I probably have to raise the height of the motor to ensure I can still engage the spur gear as I go up and down in pinion sizes. Am I wrong in thinking that?

[juicedcoupe]

After looking at it I probably have to raise the height of the motor to ensure I can still engage the spur gear as I go up and down in pinion sizes. Am I wrong in thinking that?

I don't think so. The motor don't have to slide on the same axis as the gears, as long as there is sufficient travel room for proper mesh. My Bolink Diggers slide the motor on an axis above the axle.

The only thing that I see that might would limit you is the chassis itself or the lug on the transmission. But its hard to judge by a couple pictures.

[coxbros1]

that is very nice machine work! ....F

[jwscab]

Keep the motor low as possible which it looks like you've done. Plenty of adjustment range. Tie the motor into the transmission somehow. A bracket on top or something. Any flex there will kill pinions and spurs.

[PhilV]

Small update. No progress on this project unfortunately. Works been crazy. But I did get an older all black chassis Rustler roller that I am going to convert to a Bandit. I wanted to give it a try with a rear motor configuration so I can have a reference for how it reacts on the track when I do complete my mid motor Bandit. And I’ve got just about everything I need to make the switch, so I can see the track a lot sooner than waiting until I finish designing and making parts.

[rc10nick]

Great build so far! I'm jealous of your excellent machining, I couldn't machine something that nice to save my life. Can't wait to see your progress.

[PhilV]

Update!
Had some free time today and got one little piece done. I’m honestly less than enthusiastic about it though. I don’t really like the design or the idea of the entire rear suspension relying on one small contact point. Not sure who at traxxas thought this was a good idea. I made it really snug so it doesn’t wobble, but still I think I might have to figure something else out. At least I can get an idea of how the rear suspension should fit together.