BL Revo using Revo Transmission?

[BrianG]

Where are the pictures?

Actually your design was somewhat of an inspiration to do mine the way I did. I just didn't like the motor as far out on the side. As far as the angle mount flex goes, that can be greatly reduced with a simple rear motor support.

[TypeR #126]

Hah! I was thinking the same thing. The engine brace from the 3.3 also helps a good deal.

The new Vantage CF chasis for the 3.3 is extended in both the front and the back. That might be enough to give an XL motor clearance. :)

Hey guys,

Couple of thoughts.

1) To use the stock transmission means using a chassis mounted motor as far as I can tell. I really looked at ways to try and mount the motor to the gear box but I don't see an easy and sturdy way to do it. Love to see ideas on how you guys did it with the stock tranny if you figured it out.

2) The mount I designed could be redesigned to be pushed forward by just over .25 inches if the spacer wasn't used, I don't know however if this makes enough room to clear the larger motors, and it would require even more redesign to accomodate smaller gear ratios. It can be done but I frankly don't have time to do it unless I know there will be enough people buying them (just too many projects in the que and regular work has been killing me)

3) I looked at other ways to try and mount the motor towards the center of the chassis but it puts the motor up higher if you go over the shocks for example, and it will be difficult do this in a way that makes it sturdy.

4) I am open to ideas but to effectively machine something for these bigger can motors, I need the gears and a bigger motor. If there is a popular motor (or standard size and gear), I could work something up if there is enough interest and someone who could lend the motor/gear for a few weeks.

I welcome any comments, ideas, or thoughts.

[BrianG]

I personally don't have an extra motor laying around, but the XL size can is almost 70mm long. The standard diameter seems to be 36mm, except for the Neu motors. The wires (if they come straight out the back) can be made to fit if the motor is rotated so they are on top.

I don't have any measurements for the mounting height of the motor since I did mine by eye (scientific, eh? :)). But I do have a couple of pictures that may help you get an idea by looking at the relationship with other components.

As far as gearing goes, the Revo has three Mod1 options: 36T (38mm Diam), 38T (40mm Diam), and 40T (42mm Diam). Popular pinions seem to be 14T (16mm Diam) to 16T (18mm Diam) Mod1. You have to subtract 2mm for the mesh when you measure the two gears together. I also have V1 of my motor mount I can donate for sizing purposes. It's not pretty, but it's the right size.

[rchippie]

Brian your truck looks great. Are you using the revo center diff ?.

[BrianG]

Thanks!

No, no diff yet. I bought a center diff from Squee that's basically a custom buggy diff, I just haven't put it in yet.

Lol, I just noticed there are two of the same pics above. I'll have to fix that!

Brian, thanks for the offer. I just don't feel comfortable selling anything that I can't actually fit and test with an actual motor. I'd like to think that most people wouldn't be comfortable buying something built on measurements and theory with not actual testing.

I'm confused on the length issue, my motor is 72mm in total length and I get ZERO interference with the suspension and my wires didn't have to be routed in any way shape or form. Is my chassis different somehow? If I moved the whole mount forward by .25 inches, it would easily clear any wires or anything on the back of the motor this length.

That said, the only thing I see needing to be changed to use different gears is really the amount of "throw" required to get the motor closer to the spur and accomodate smaller gear center to gear center distance for smaller gears.

Brian your motor sits visibly farther back than mine, you sure it's only 70mm in length??? :)


TypeR, thanks for posting pics and comments. If you have any issues let me know.

Interesting idea (whoever suggested it) in supporting the motor on the hind end, trying to figure out how to do this. Could be tough since motor diameters seem to vary quite a bit probably need something that adjusts....

I haven't noticed any flexing once I bolted the motor down but maybe I just didn't beat on mine hard enough yet. :D

I liked the idea of getting the motor centered on the truck and getting the batts stradled on each side, but I just can't see to visualize a way that won't introduce a ton of flex and part complexity (making the cost higher).


I apologize TypeR, and the rest, but the motor mount *is* the most expensive cuz it takes the longest to machine. Unfortuneatly, I can't seem to get it simpler. The vert piece requires a 2 decking operations, a finishing op on the lip, and three tool changes to complete before hand finishing. The lower takes two drilling operations with different jigs, 6 taps, and finishing. It takes me well over an hour for each one individually, not to mention machine wear, finishing materials, and the screw hardware/materials. There are more than 300 lines of Gcode involved in making just the motor mount and I spent about 35 hours in total getting it to be a repeatable reproduceable part (including two prototypes which are in my recycling bin).

I am not complaining, as I told brian, I make very little on these and do it mostly for the enjoyment of the hobby (cars and machining) and to cover the costs of making stuff. It also helps me show just enough income on my business to keep the IRS off my back.