Locking the revo in 2nd gear to use motor braking/reverse

[thetick]

Thanks offroader, now I just need to figure out where to get those FOC pins.

[thetick]

I'm having a really hard time finding more transmission screw pins for this mod. Does anyone have a part number? Thanks!

[BrianG]

You might want to try to give Traxxas support a call. They may be able to send you a few once you explain what you are doing. Or, they can maybe supply you with a part number just for those pins.

[thetick]

I'll try that. Thanks

[thetick]

Just talked to Traxxas and they said that the tranny screw pins are not sold seperately. Which means I would have to buy the entire gear to get the pin. So 3 pins at 7.50 a pop is a bit pricey, but I'm willing to do it if necessary.

[BrianG]

Well, that's crappy. When I modded mine, I used the two pins that came with the FOC for the intermediate shaft, and the two old pins for the input shaft (the older ones are a little weaker I think).

You might want to talk to your LHS to see if they might have something from a different vehicle that would work.

Or, how about taking a regular screw and dremeling off the threads on the lower part? You'd want to make sure there are enough threads left, but that would be a cheap alternative. Off the top of my head, I'm not sure what size you'd need for this, but probably 2mm.

[lincpimp]

I used a hardened pin, most likely one of the tamiya wheel pins. Held it in place with a grub screw from a pinion (set screw). A hardened roll pin would work too. Only issue would be to get it back out after the pin is pressed in. I hope it holds up!

[thetick]

Thats a good idea lincpimp. I'm gonna see if mcmaster carr has anything.

[thetick]

Ok...http://www.mcmaster.com/ carries all sorts of rods. I'm thinking either titanium or tungsten carbide. Not sure if my dremel will cut through tungsten though. Then I'll just use a set screw to hold it in place. Hows that sound?

[thetick]

Spent way too much time looking at rods, pins, screws on that site. Titanium and tungsten rods are not worth the money. They make many different steel rods in different strengths. Still not sure which one is right.

[loa]

Hello,

I've read this thread all the way through and I'm planning to transform my tranny using option 4. One question though.

The FOC is already installed, so I'll need to use the motor for reverse. But on the other hand I'll be using the mechanical brakes.

Is there another (less destructive) alternative than option 4?

Thanks

Loa

Originally Posted by loa

Hello,

I've read this thread all the way through and I'm planning to transform my tranny using option 4. One question though.

The FOC is already installed, so I'll need to use the motor for reverse. But on the other hand I'll be using the mechanical brakes.

Is there another (less destructive) alternative than option 4?

Thanks

Loa

Option 4 is the only way I know to lock into second. Using the FOC and locked in 2nd, I don't see any good way to use motor reverse, and mechanical brake. I suppose you'd need to use a 3rd channel on the TX for brake. Might be a bit cumbersome.

J.

I have also read this thread and I've got to say, it all seems too complex for most users. Does anyone (hint hint RCM) make a "kit" which includes the modified parts?

I don't have a Revo yet but I'm considering one. I think I'll use mechanical brakes because they are already there...is there some very simple way to lock it into 2nd if I don't want to use motor brakes? The Tekno site seems to suggest that there is a very simple way without tearing it all apart and grinding this and that.

One more bonus question for all you Revo wizards - is the revo really up to a brushless conversion? Is it strong enough? What breaks? What should be replaced before use? Anything that must be done to the tranny to keep it strong?

Thanks guys...

Originally Posted by MacII

I have also read this thread and I've got to say, it all seems too complex for most users. Does anyone (hint hint RCM) make a "kit" which includes the modified parts?

I don't have a Revo yet but I'm considering one. I think I'll use mechanical brakes because they are already there...is there some very simple way to lock it into 2nd if I don't want to use motor brakes? The Tekno site seems to suggest that there is a very simple way without tearing it all apart and grinding this and that.

One more bonus question for all you Revo wizards - is the revo really up to a brushless conversion? Is it strong enough? What breaks? What should be replaced before use? Anything that must be done to the tranny to keep it strong?

Thanks guys...

its actually easier to understand once you are working with the parts, and usually diffs are the weak points with RC cars, evrything else is up to the task, also changing to a high torque single steering servo is a plus

[BrianG]

Like azjc said, it sounds more complicated than it really is. Once you get the tranny in-hand, it's much more clear. Option 4, while sort of "destructive", is reversible by just getting a new centrifugal clutch and putting it in.

As far as durability is concerned; it is pretty tough. The only other tranny mod to do is maybe use different pins that hold the gears to the shaft. The stock ones are kinda weak, but there are instructions in this thread as well.

Diffs are gonna be the next weakest link. But, a set of aluminum cups can be a fairly cheap way to extend their life. Or, get Mike's 8th scale diffs.

Another possible weak spot are the shafts, particularly the one going from the diffs to the wheels. Because they are subjected to a lot of torque, the ends may twist over time. A set of CVDs helps this, or turn down the torque setting a little in the ESC.