Tranny question - RC-Monster Forums

BrianG · **Tranny question -** 03.28.2006, 06:48 PM

This probably isn't the correct place to put this, but since there are no "transmission" categories, I guess this will do. :)

Anyway, has anyone though about using the planetary inline transmissions for their BL motors? They are small, and with a diff ratio of ~2.8:1 (for Revo and E-Maxx) coupled with a tranny ratio of 7:1, it would just about right and there would be no need for spurs and "traditional" transmissions and the space they consume. The motor could be mounted lower. BK has one that handles quite a bit of power. I imagine these are more for planes, but why not trucks?

Now, I know this would make it difficult for a 4WD truck, but I was thinking of making a 2WD "muscle car" type of vehicle complete with the BL motor in the front under the "hood". The RCM heatsink clamp just looks too pretty to hide, and the forward mounted weight would help keep the front on the ground.

BrianG · 03.29.2006, 10:59 PM

Hmmm, no responses about the tranny question, eh? Well, if it helps, go to bk-electronics and click on the motor looking thingies on the lower right corner. The BK 40 is what I'm talking about. It says it is 40mm diameter to fit all 500-800 motor sizes, weighs 86 grams, comes in ratios of 5:1, 6:1, and 7:1, and will handle 2800 watts continuously.

MetalMan · 03.29.2006, 11:21 PM

It could work, but they are pretty expensive - $180.90!!

BrianG · 03.29.2006, 11:28 PM

Yikes! That's not cheap, especially if "it could work". Oh well, just an idea. I just thought it would be a smaller transmission solution and more like a real car.

MetalMan · 03.30.2006, 08:33 AM

Honestly, I don't see why it wouldn't work. The only thing it might not be suitable for is a 2250, otherwise it would handle any other motor that we use in cars. 2800watts is a lot, and is twice what L or even XL motors may ever see.

coolhandcountry · 03.30.2006, 01:20 PM

WEll it rules me out. I was getting my hopes up to. Maybe one for on a center diff conversion to lower the ration down some would help with gearing situations.

BrianG · 02:07 PM

Well, aside from the price, I think it would be nice to have a relatively small inline tranny with enough of a reduction ratio to replace a traditional transmission and spur gear. However, as I mentioned previously, it doesn't lend itself well to a 4WD setup unless you use a center diff, but then the reduction ratio for the pinion to the diff "spur" might lower it too much. Maybe if you used a 5:1 model in that scenario.

I still dream of a 2WD muscle car, like an old charger or something like that, with the "motor" under the hood just like the real thing. Maybe even disguise a motor cooling fan to look like a blower outside the hood. :) It would make for a neat drifting car as well. The RCM heatsink looks sorta like the heads of a large engine, except finned. It might be a little tough for the motor wires to fit without pushing the motor too far back though. Now, I just have to find a platform that lends itself well (will require modifications I'm sure) to what I'm thinking of.

I just don't want to spend ~$180 on something that will break right away because it isn't made for the strain of the sudden changes in forces found in a car vs the propeller of a plane.

coolhandcountry · 03.30.2006, 03:06 PM

Did you ever think about making one from a tamiya. They had the one where the motor mounted up front in the orginal motor spot. It had a three speed transmission to. It was really life like. I wanted to get one cause they was awesome looking. I am not sure the name of them though. I have to search and see what I cam up with. I got a couple videos on them.

Dafni · 03.30.2006, 03:33 PM

I was thinking about a planetary tranny some time ago. And if it wouldn't make my motor any longer, I would have one on my G3R. I already have a nice project in my mind for next winter...

Definitely do-able, Brian. And I saw a BL Nemesis (Genesis II) with a planetary tranny and belt drive on a german forum not too long ago.

RC-Monster Mike · 03.31.2006, 10:00 AM

Your talking about the mountaneer/bruiser, Leroy. Cool for sure. :)

coolhandcountry · 03.31.2006, 10:49 AM

Ok. I didn't know the model of the truck. I did know they had one. Are they still in production?

BrianG · 03.31.2006, 03:06 PM

According to the tamiya website, the mountaineer is discontinued, and I couldn't find anything with "bruiser" in the search. :(

There's still some Mountaineers on eBay, along with a good deal of parts, but the fact that it's discontinued makes me worry that getting replacement parts may become difficult in the near future, especially through LHSs.

Oh well, I guess I'll have to find some type of setup that will lend itself well to this type of design. I would think a ladder-frame will work well, but nothing jumps out at me as "the ideal design", so it looks like it's fabrication time. Poo, I need to get a CNC mill. :dft004:

RC-Monster Mike · 03.31.2006, 03:33 PM

Bruisers and mountaneers were discontinued in the 80s. The Tamiya 18 wheeler has a similar tranny that some folks have used in projects, though. You may want to have a look at this. :)

BrianG · 03.31.2006, 03:43 PM

Holy Cow! The 80's. There were R/C's back then? :) j/k.

After looking at their 18 wheelers, I think I'll just have to fabricate something, or find parts from various other trucks that will fit my needs. Yup, a frankenstein! :)

squeeforever · 03.31.2006, 10:40 PM

yea, the bruisers were nice for sure. they looked about as close to a real truck as it gets. they even had leaf springs with a chassis rail style chassis.