I use the mgt 46t mod1 gear and a 20t/22t pinion with my maxcim setup. I am also using the center diff I got from ebay along with rear brakes :cool:
I'll have to post pics of the rear brakes when I can. Its a simple design really. I also use a micro servo for braking. I've found that rear brakes really don't require a large servo.

I am also using my tmaxx tranny on my G2R. I am working on mounting a center diff in it as well.

46T and 20T?! That's a 2.3:1 ratio. I'd like to see a picture of the spur/slipper assembly if you have one. Are you using the stock slipper, or something else? Also, did you have to cut into the chassis a little for the spur to fit? How do you have your brakes set up since they are disc?

I'm not going to be racing (at least not competitively) so just the stock braking setup will be fine for me.

Hows it running with the Tmaxx tranny? And are you running it the same as the Emaxx you had?:cool:

Transmission Conversion
 

I posted the following at the Traxxas forums, but don't seem to be getting any responses, so I'll see if the good people here have any input:

I'm trying to figure out if it is possible to convert a Revo transmission for use with brushless motors. It might be easier to refer to the transmission exploded view (http://www.traxxas.com/products/nitr...evo_tranny.pdf) while I go through this.

The goal is to have a transmission that will do reverse via the motor, and not by using a shifting servo. To do this, I have to find a way to replace the three one-way bearings with something equivalent (2 x #5121 and 1 x #5393) so the tranny is locked both ways. This would also allow me to use the motor braking feature if I decide not to use a disc brake.

I believe I can replace the two roller bearings (#5121 6x10x8mm) on the output shaft with equivalent regular bearings. The output gear (#3982) would then roll freely on the output shaft, but since it is coupled to the dog gear, which drives the splined part of the shaft, it should work.

However the first speed gear (#5386) is coupled to a special roller bearing (#5393) that is attached to a hex adaptor of some sort. I don't think I can find something to replace that assembly. This isn't a big deal really since I don't need first gear. So, I could simply do away with that gear and special bearing and replace them with some bearings/shims as a spacer. I realize this would create a single speed tranny stuck in second gear all the time. If there is a way to replace this bearing with a non-one-way version, I could keep first gear, but I don't think that's possible.

So, if I remove first gear, I then have to find a way to lock the two-speed clutch (#5390) so it always engages the second speed gear (#5385), which is coupled to the primary gear (#5396) through the shaft.

I think I have the solution planned out, but was hoping for someone else to take a look to see if this sounds right. I'd hate to go through all this and realize I forgot something. :)

There are not three one-ways in a revo tranny. the two needle bearings on the output gears are standard needle bearings

You can either have first or second if you want reverse and no servo's. Anthing else and it will be a grind, literaly

you may be better off using the two speed because first may be too slow and second may not be able to pull the truck

These are my opinions based on what i know from working on my Revo tranny. Starscream has the experience from doing it and i would wait and see what he says, because he might know something I don't

The emaxx tranny is the easiest and most effective way to accomplish the forward and reverse you are looking for.

The Revo tranny is ideal for the automatic 2 speed. Due to the mechanical aspects of the one way bearing design, you will not be able to use a motor for reverse. Locking the Revo tranny in 1st or 2nd gear, with reverse, will be much more complicated and more work than just using the emaxx tranny.

I really like the revo tranny but if you want reverse, use the emaxx tranny.

carzyjr: OK, I assumed the two roller bearings (#5121) were one-ways simply because the exploded view specifically says to orient the writing on the bearing a certain way. That makes things a little easier. So now I can either lock the tranny in second or find some type of replacement for the other hex bearing (#5393).

Starscream: Yeah, I figured it wouldn't be easy, but it's a challenge. As I see it, it's just a matter of replacing that odd hex one-way bearing with a locked one. I can see that being complicated. The rest of it seems simple enough. I think if one person can come up with a solution to allow reversing that uses some easy-to-find parts, it will make for a nice conversion. At the very least, it should be relatively simple to lock it into second gear since that gear is up against the primary gear (which goes to the output gear). I guess I'll just have to pick up a tranny and experiment.

Thanks for the feedback!

OK, I picked up a tranny from Ebay. I then installed a FOC conversion and the wide ratio gear set. I can see where you can't have an autoshifting tranny while locking it so reverse and braking work.

So, I removed the first gear and bearing altogether. Then, I removed the shifting tension screw, spring, and ball from the clutch and put a 4mm screw in its place. I cut the head off so it will fit in the second gear cup. I figure this will give the now locked clutch something else to grab onto instead of just the single clutch arm. I had to file down the threads on the screw a little so both the clutch arm and the screw shaft were against the pins at the same time.

While the clutch arm was held open and positioned on the "grabber" pin, I filled the entire area with plastic epoxy. If that isn't locked, I don't know what is!

http://bgosselin.home.mchsi.com/e-re...evo_tranny.jpg

Looks good. I hope you got a motor that will pull the wide second gear, because it will be high geared. In that instence i would've used the close ratio. Good luck

Actually, in second gear with the wide ratio set, the revo tranny ratio is 2:111 (38T/18T). The e-maxx in second gear is only 1.722 (31T/18T). The ratio for the revo standard ratio set is 2.29 in second gear - so it's even less.

Emaxx: 2.846 diff x 1.722 tranny (gear 2) x 51T/14T spur/pinion = 17.852958:1 total reduction ratio.
Revo: 2.846 diff x 2.111 tranny (gear 2, wide) x 40T/14T spur/pinion = 17.16544:1 total reduction ratio.

So, what does the motor mount look like?
All you need now is a center diff to finish the tranny:027:

Well, I haven't started that yet. :dft001: I'll have to work on that once I get a hold of a BL motor, but I suppose I could use a cheap brushed motor to at least get the design worked out. I have no clue yet as to how I will implement it, but I'm shooting for using parts of the stock Revo motor mount and working from there (because it already has an adjustable mount for changing spurs and pinions). The final version will probably have to be machined for accuracy, and I don't know where I'll get that done.

This started because I was waiting for my tax refund and now for my order from Mike to arrive to finish my current E-Revo, so I started thinking about how to use a Revo tranny to allow braking and reverse. Once my current E-Revo is done and working, I want to build another lighter one of a different design and see which I like better. I also want to use more stock parts (like center shafts) so I can pick up replacements at my LHS instead of trying to order or fabricate something that'll work. The only other part I have right now is a chassis. I should be able to move most of my existing E-Revo parts to the new design and maybe sell the one I don't like as much. The next design might even use Lipos.

I don't plan on ever using a center diff. I don't race so it's not needed IMO. I seem to enjoy building these than driving them, but unfortunately cash is not over abundant in my household.

cool. I don't think that far into my projects

Well, when you're stuck looking at unfinished truck because you're either waiting for parts or cash for some parts, you have time to think. :)

OR you can think of ways to make more money:)