Direct Drive to Diff E Revo Build

[sikeston34m]

Originally Posted by MetalMan

This truck has caused me to stop procrastinating on turning my MT2 into a direct-drive outrunner-powered truck. Now I have everything I need, except for the custom shaft that still needs to be made.

Thanks a lot

The MT2 looks like a pretty awesome truck. Are there aftermarket 1/8th diffs available for it also? I'm gonna check that one out a little more. Only weighs 5 pounds! I like that!

In considering other trucks for direct drive conversion, just remember what we've ran into on the cogging issue. I think that line that you can't cross is somewhere about 4 inches of roll out per turn of the motor. Vehicle weight affects this I'm sure.

But more so, I believe it also has to do mainly with the level of EMF pulses that the ESC MUST get from the motor to start properly. More on this later.

[MetalMan]

Originally Posted by sikeston34m

The MT2 looks like a pretty awesome truck. Are there aftermarket 1/8th diffs available for it also? I'm gonna check that one out a little more. Only weighs 5 pounds! I like that!

In considering other trucks for direct drive conversion, just remember what we've ran into on the cogging issue. I think that line that you can't cross is somewhere about 4 inches of roll out per turn of the motor. Vehicle weight affects this I'm sure.

But more so, I believe it also has to do mainly with the level of EMF pulses that the ESC MUST get from the motor to start properly. More on this later.

The MT2 is pure 1/10 scale, no optional 1/8 diffs. The diffs are actually a weak point on it, even with the optional hardened diffs on the 18SS kit (which are the ones I started with). However, aluminum diff housings have fixed that issue for me, in combination with the hardened diff gears.

My motor is a KMS 4120/06:
http://www.hobbypeople.net/gallery/108521.asp
I get these at a discount 'cuz I work there. It uses a 6mm shaft, so I have a 6mm steel rod that I will turn down to 5mm where the dogbone cups attach.

Only problem that I have found with the MT2 so far, is that the stock chassis is pretty narrow.

[sikeston34m]

Originally Posted by MetalMan

The MT2 is pure 1/10 scale, no optional 1/8 diffs. The diffs are actually a weak point on it, even with the optional hardened diffs on the 18SS kit (which are the ones I started with). However, aluminum diff housings have fixed that issue for me, in combination with the hardened diff gears.

My motor is a KMS 4120/06:
http://www.hobbypeople.net/gallery/108521.asp
I get these at a discount 'cuz I work there. It uses a 6mm shaft, so I have a 6mm steel rod that I will turn down to 5mm where the dogbone cups attach.

Only problem that I have found with the MT2 so far, is that the stock chassis is pretty narrow.

What's the diff gear ratio and the tire height on the MT2?

Hey, that looks VERY much like my motor. Let me give you a word of advice here. When you get the motor, remove the endbell. set it on a table and wick some RED locktight in around the stator and the bear holder. Let it sit for a day or two, then dry up what doesn't soak in. What does soak in, gets hard and creates a VERY secure bond in the absense of oxygen. Some outrunner manufacturers don't loctite both ends of the stator. This can spell for disaster if the stator breaks loose. Check it, it may already be done.

There are some outrunners that have a 5mm shaft that would be suitable, but it looks like you found a great one. I might have to give that one a try.

[MetalMan]

Originally Posted by sikeston34m

What's the diff gear ratio and the tire height on the MT2?

Hey, that looks VERY much like my motor. Let me give you a word of advice here. When you get the motor, remove the endbell. set it on a table and wick some RED locktight in around the stator and the bear holder. Let it sit for a day or two, then dry up what doesn't soak in. What does soak in, gets hard and creates a VERY secure bond in the absense of oxygen. Some outrunner manufacturers don't loctite both ends of the stator. This can spell for disaster if the stator breaks loose. Check it, it may already be done.

There are some outrunners that have a 5mm shaft that would be suitable, but it looks like you found a great one. I might have to give that one a try.

The diff ratio is 38/13 (2.923:1). For now, my tire height is 3.5" (Proline 2.2 Road Rages).

I haven't taken the motor apart yet since this brand uses snap wrings that are difficult to remove. But when I do, I'll put red loctite on it as you mentioned.

[aqwut]

This build is awesome.!.. my 3rd GST will be direct Outrunner as well..

[johnrobholmes]

What did you use for your bracket? I am having a hard time sourcing local angle aluminum of good grade and size.

[sikeston34m]

Originally Posted by johnrobholmes

What did you use for your bracket? I am having a hard time sourcing local angle aluminum of good grade and size.

In the beginning, I thought I wanted a full skid plate under the motor, so from Ebay, I ordered a 4 foot stick of 4" x 4" 1/8" thick angle.

Then I changed my mind and went to Lowes. There I bought a 4 foot stick of 2" x 2" 1/8" thick angle. It's back there by the threaded rod and the steel angle.

Everything is made from the 2" x 2" angle except for the ESC mounting plate. That's 1/8" sheet. And also the little blocks that support everything, those are made from an aluminum sheet that's 3/8" thick.

All the bolts and nuts also came from Lowes. They have a really good selection. In thinking back, I probably should have used aluminum bolts for some weight savings. That probably wouldn't amount for much though.

[Revracer]

im amazed. how about a video? this is amazing man. what speed and torque do you get with it? what run times and what is the over all price tag on the conversion?

[sikeston34m]

Originally Posted by Revracer

im amazed. how about a video? this is amazing man. what speed and torque do you get with it? what run times and what is the over all price tag on the conversion?

Thanks.

I'm gonna be posting video's with various battery setups.

I'm working on getting the diffs installed right now. I'll post data as soon as I get it, but it's gonna be good!

Oh, on the price tag thing, I'm not really sure I want to add that up!

[Revracer]

way too much for me then... can this motor be bolted on wit ha tekno kit? bolt in liek a standard motor?

[BL_RV0]

Originally Posted by Revracer

way too much for me then... can this motor be bolted on wit ha tekno kit? bolt in liek a standard motor?

no. it cant.

[johnrobholmes]

Sweeeeeet! Time to go buy some aluminum L for my 1/10th solid axle truck :D I have been using outrunners in cars for so long, seems that I should have tried this by now.

[DrKnow65]

Right on Sikes!

At some point after you've had the opportunity to play with it for a while :) would you mind giving an accurate list of parts (#'s and source) for this conversion? I almost bought a revo roller 3.3 off ebay for $285, but I had to get my 4wd Academy SB V2 Pro first. ($268 after shipping from amainhobbies with a coupon :)

I am going to sell off all my nitro stuff >done with nitro forever!!!< and start persuing the DDR, so any info is important.

Thanks for sharing the build with us all, guy's like you are what make this hobby a blast.

[suicideneil]

That is so very true. Sometimes we need to see other people try stuff out before we can decide whether its a good/viable idea or not. Sike is a trend setter; saddly the planks on noob central couldnt grasp the concept and would rather play with titans or cheapo 600 motors- their loss!

[johnrobholmes]

I am totally in love with the concept. Who needs a stinkin gearbox when you have people like Sike? The weight savings would be HUGE! (rummages for 3032 outrunner)