RC-Monster Forums - Takin' it to the E-side....

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- - Takin' it to the E-side.... (https://www.rc-monster.com/forum/showthread.php?t=6443)

Thanks. It can be difficult to visualize until you get into the tranny and see how it works. This would be an excellent candidate for a Flash animation so you can see exactly how it works. Unfortunately, I don't know Flash. Poo.

Me neither. :002:

I agree it would be excellent to animate! Maybe we have a graphics/media student as a forum member who might want to tackle the project????

The idea of a two speed is nice, but you really don't need it with an electric motor. The motor is going to put out more than enough torque to drive second gear from a standstill. I didn't do a traxxas vehicle, but I did do a Monster GT and I had a similar dilemma. I acutally wound up locking the tranny into first gear. By going with a large pinion and the smallest spur, I actually get a respectable top end out of it, but it is crazy wild on the bottom. Doing back flips off of walls and trees is really easy. It suppose it gets to about 30 mph, but it gets there in a couple of seconds. I considered opening up the tranny and going with second gear, but I like it the way it is.

Another thing that concerned me was the OWB. I didn't want to have to worry about it. I drilled right through it and locked the whole up. Now I do have motor breaking and reverse. I don't worry too much about the braking heating the motor up. You'd be surprised at how little braking it is that you need to stop the truck. I think I have mine set at 20 or 30%. Really, if I had it any higher, the truck would flip over.

Quote:

Originally Posted by BrianG

OK, here's a breakdown on your options:

Option 1: Keep the two speed tranny, mech brake, and mech reverse. Of course, you'll need servos for the reverse shifter and the brake. The downside to this is that the reverse is generally pretty weak and God help you if you don't come to a full stop before you shift into reverse. And you cannot use a center diff (the diff replaces the shift fork, dog gear, and second output gear).

Option 2: Keep the two speed tranny and mech brake, but no reverse. Like above, you need a servo for the brake. But this option lets you do the FOC for a simpler, lighter, and more reliable tranny. You could also go with a center diff with this setup.

Option 3: Mod the tranny for single speed (2nd gear). You don't have to, but you can remove first gear altogether for a simpler and lighter tranny. Regardless, this is the ONLY option where you can use the brake and/or reverse using the motor. Trust me.

You are right, there is a OWB for reverse, but there is also one for first gear. How the tranny works is like this: The input shaft spins both first and second gears at the same time. But since 2nd is not engaged, it just spins freely on a regular bearing. 1st gear, being in a OWB turns the primary shaft, which turns the output shaft. When the speed gets high enough, the centrifugal clutch engages. When this happens, 2nd gear is now spinning faster than 1st gear, and since 1st gear is on a OWB, it spins freely. This OWB on first gear is what makes it so you cannot use motor reverse and/or brake.

Thanks for all the info. I'm going to go ahead and lock 2nd gear. You guys have done a lot of the experimenting for me, so I should listen to the words of wisdom. I like the idea of getting rid of the mechanical brake set-up and servo anyway and I'll have reverse again via the ESC for bashing.

If you don't mind, could you post the procedure for locking out 2nd gear and is there anything I need to add or change to ditch the low gear while I'm in there? I really appreciate the advice!

Thanks!

You can remove first gear and the OWB altogether. Then, pull out the clutch assembly and remove the shift point set screw, spring, gray plastic plug, and ball-bearing. File some round "half moon" spots at three locations around the metal hub and then screw three 4mm bolts into 2nd gear. The "half moons" in the hub should fit right up to the bolts for best results.

http://www.rc-monster.com/forum/atta...1&d=1160192341

The clutch arm is out in this pic, but it really has no use now.

If you want to revert back to 2 speed, you'd have to buy a new clutch.

If you don't want to mod the clutch, b0gh0s makes a locking hub which replaces the clutch and does the same thing. His solution is totally reversible. Depends if you want to go the cheaper route.

I got Mike's motor mount and a few other goodies in the mail today. I have to say, the motor mount is a very nice piece of machining. I can't wait to get going. I also picked up my Spektrum system yesterday, (reciever 1 is going into my E-Maxx tonight) so I have enough stuff to get a good start on my conversion. Next month I'll get the motor and ESC.....decisions, decisions, decisions....:027:

Well, I got started with the conversion this weekend. I'm doing a bare chassis rebuild, I got the rear clip and Mike's motor mount done. I had to clearance the roll bar slightly but a little Dremel work took care of that (last pic). I like the mount, I can't wait to get a motor in it. Here are a few pics.

http://i128.photobucket.com/albums/p...irstSteps1.jpg
http://i128.photobucket.com/albums/p...irstSteps4.jpg
http://i128.photobucket.com/albums/p...irstSteps5.jpg
http://i128.photobucket.com/albums/p...irstSteps2.jpg

Funny - Brian mounted the rear brace the same way. The rear brace(latest versions have two rear braces - one for a smooth motor and one for a Feigao "c" motor) has a recess milled into it so it rests on the lower plate. While I am sure the screws will hold the motor just fine, the idea was to have the rear brace only held in position/adjusted by the screws(one screw would be plenty) with the recess over the lower plate. Basically, the rear brace is backwards, though I am sure it will work fine(my fault, as I did not include any instructions). :)

Also, on the test truck here, the mount just clears the roll bar. It may rub, but I was able to mount it without any use of the dremel. :)

LOL, that makes sense. :)

So, it should look like this:

(I borrowed and edited your original pic Cajun; I hope it's ok...)

Quote:

Originally Posted by RC-Monster Mike

I'll swap it around before the motor goes on. :013: Thanks for the heads up. Nice job on the mount, Mike, it goes on easily and fits perfectly. I set the front plate and the base with lock-tite and left the rear brace screws lock-tite-less for now. I'll adjust and lock it down when the motor is in place.

I could have probably forced the mount on without notching the roll bar, but figured I didn't want to start forcing stuff already. I don't think it lost much structural stability, it doesn't seem to flex any more than before I notched it and the motor mount slides right on.

Thanks again for all the help. I'm sure I'll have a ton more questions. Now I just have to decide on a motor and ESC combo to run in it. Any suggestions?

Oh and Brian, I'm going ahead with the batts to one side. It makes sense with the way the chassis is made. 14 stacked fit's just behind the steering servo with room to spare to the suspension. Thanks for the info on that one. Now I just need to build a couple of sub-c bricks. :027: I'm going to make sure I can accomodate a 4s lipo pack in the tray as well for later use. Tanks again for all the help!

Cajun

As soon as I posted the fixed image, I literally ran downstairs and fixed the rear motor brace. :)

If you go with a single stronger steering servo, you can ditch the one in front of the batteries to make room for your receiver box or whatever (don't forget the Proline Al steering arm if you do this). The way I have my tray made, I have room for 14 cells or 5s1p 10Ah maxamps lipos.

As far as a motor goes, you should buy my 10XL so I can get a Neu. ;) Seriously, if you want to save some $$$, I'd say use the MM and a 9XL on 14 cells or 4s lipo. If you want hi-end, the Quark 125 and a Neu. Eventually, I want to get a Neu for this beast.

Quote:

Originally Posted by RC-Monster Mike

Also, on the test truck here, the mount just clears the roll bar. It may rub, but I was able to mount it without any use of the dremel. :)

Yes mine clears the roll bar, only just.
http://i118.photobucket.com/albums/o...s/IMG_0924.jpg
The motor isn't bolted on. I just set on the mount.
http://i118.photobucket.com/albums/o...s/IMG_0926.jpg

I think it depends somewhat on how you have the stock Nitro mount situated. I had mine as low as it can go and it rubbed a little. I just muscled it in though. :)

BTW: your Revo looks nice (but wayyy too clean :))! I take it you are keeping the 2 speed tranny and using mechanical brakes? I'm sure you know this, but you won't be able to use reverse with the stock tranny without mods...