BL Revo using Revo Transmission?

[BrianG]

Just wondering if there was a good BL motor to use with a Revo using a stock transmission with a 40T, standard pitch spur? I'd think the gear ratio would be quite a bit less than using an E-Maxx tranny and would strain the BL motor.

I like the fact that the Revo tranny sits lower and uses stock center shafts and slipper assembly. Creating a motor mount and finding a good spot for the batteries would be a bit of a challenge, but I don't want to start it unless I know if the tranny can even be used.

I've seen someone who has used the stock tranny with a BL motor before, but they used a larger spur and had to cut the chassis to allow for the larger diameter. I really don't want to do that.

anything is possible
i have a friend working on a design so he can use a t-maxx two speed tranny in his emaxx but the tmaxx tranny has a one way bearing in first gear(and i think the revo does to) so that would mean you woudnt have any brakes in first gear

[midnit]

You mean you wouldn't have any engine (motor) braking :)

Originally posted by midnit
You mean you wouldn't have any engine (motor) braking :)

correct
you would have to come up with an external brake

[maxxdude1234]

The beauty of a nitro transmission is having a disc brake. The electric brake on my lehner 2000XL is absolutely hopeless.

[coolhandcountry]

I think starscream has a revo tranny in his truck. He has also ran a tmaxx tranny. You may want to search for this.

[RC-Monster Mike]

I have a friend in France who designed an internal part that converts the Revo tranny into an "electric" tranny. It basically locks the tranny up and eliminates the clutch I think(been a while since I looked at it). I have the file for the poart somewhere and I don't think it is terribly difficult to make. I will have a look at it again. I definately know the Revo tranny can be used with the disc brakes, though.

[squeeforever]

ive been think of doing the same thing with my evo although i would reverse the tranny and use a center diff. the mgt 52 tooth spur would fit if you have concerns about gearing.

Originally posted by RC-Monster Mike
I have a friend in France who designed an internal part that converts the Revo tranny into an "electric" tranny. It basically locks the tranny up and eliminates the clutch I think(been a while since I looked at it). I have the file for the poart somewhere and I don't think it is terribly difficult to make. I will have a look at it again. I definately know the Revo tranny can be used with the disc brakes, though.

let us know if u find it

[crazyjr]

I think traxxas makes a singlespeed conversion for the Revo tranny

[BrianG]

Boss 302: Yeah, I kinda figured it was possible, I was just curious what pinion to use with a 40T spur and a good matching motor for 12 cells.

midnit: Well, I would use the stock disc brake setup. I'd prefer to use that anyway as electronic braking just reduces runtime. I;ve heard of brushed ESCs that actually charge the batts during braking, but not sure if that is available in a brushless ESC.

Mike: Those directions would be handy. That was one aspect that I was wondering about. If you do come across that file, please do post it.

Squee: How would the 52T spur fit without cutting into the chassis? The 40T is pretty close as it is.

carzyjr: actually, depending on how the gearing works, I may just keep the two speed.

I would be doing the FOC, which of course wouldn't really remove reverse as long as I do something with the OWB in the tranny. It would just be really nice and tidy to be able to use almost all stock parts (brake, tranny, center shafts, slipper, etc) except for a fabricated motor mount for the BL motor. Converting a Nitor Revo would be a lot easier that way. Plus, offering an electric production conversion kit would just involve mounting a battery tray and motor mount, not the whole chassis.

[squeeforever]

i dont think they make a single speed for the revo tranny.

im not sure on the spur clearing the chassis although i know it will fit it.

also, the brushless esc's DO recharge the batteries when you brake. so it would actually increase runtime. it would just be a ever-so-little bit harder on the esc.

im pretty sure that you can lock the revo tranny with some jb weld. i have heard of people doing it to the savage trannys.

[BrianG]

Really? I've never seen a BL ESC with the regenerative braking feature listed. Maybe Mike can confirm (not that I don't believe you Squee...). I thought it was only a brushed ESC feature. You are right though; if it did have regenerative braking, it would increase runtime. But, if the ESC simply attempts to lock the rotors when braking, that would definitely decrease runtime.

I just looked at my Nitro Revo with the 40T spur on it and there is about 1/16" clearance between the teeth and the chassis. Maybe shimming the tranny up a tad might gain a little more clearance, but not too much or the center shafts will run into the underneath of the chassis. Normally, I wouldn't care about cutting a little trough into the chassis so a bigger spur will clear, but the cut would be right on the angle and I don't want to do anything that would compromise the structural integrity.

Does anyone know of, or can measure, the diameter of a 51T Mod1 spur? The Trx 40T spur is exactly 42mm in diameter from tip of tooth to tip of tooth. Plus, using the stock spur allows the use of the stock slipper, which seems to hold up well even with larger Nitro engines. Can the 52T spur use the stock slipper assembly?

Speaking of spurs; I am using a 40T spur and a 12T clutch bell (pinion), which equates to a 3.33 ratio. When using a 51T Mod1 spur, using a 15T pinion comes out to the same ratio. If not, 14T or less should be available. Keep in mind that the standard gears of 38T spur and 15T pinion (ratio of 2.533) gives a top speed of approx 45mph at an engine speed of 50k rpm (approx). My Nitro (stock 2.5R engine) with 40T/12T gives about 30mph top speed, which is fine, so I would guess a similar 3.33 ratio would work since that engine rpm is about the same as a BL motor (actually a bit less). Here is the gear ratio chart for a Revo:

[crazyjr]

correction to my last post. I checked and there's no singlespeed conversion for the revoat this time

[BrianG]

That's OK as I really want the two speed. First gear speed for more torque at start and slower speeds and then second gear for some high speed passes.