That is how I press motor shafts in and out, with my drill press and a 5mm flat punch.

All the New parts are on their way

RCM 4.3:1 Ratio 1/8th truggy diffs
Center CVD's
AXI 4120/14 outrunner motor

Hopefully this build will get back "in gear" when they arrive.:yes:

I will be waiting! I have a solid axle truck that wants to be converted direct drive too :D

Dont forget my hyper7 wants direct drive too :)

just got done reading the thread. Bravo Sike. Well done.

She is a beauty.

Got a little bored waiting on parts to get here. So I decided to enlist the Revo in a weight loss plan! :lol:

She went from 9lbs 8 ounces, without batteries, to 9lbs 1 ounce. When I change motors, another 4 ounces will drop to make the weight 8lbs 13 ounces. I'm thinking about maybe trying the Badlands tires/wheels, so that might shed a little more weight.

I decided to get rid of those gawdy "sideboards". I shaved them on down. This allows me to lay my Lipo's down for an even lower center of gravity.
http://i160.photobucket.com/albums/t...m/DSC06662.jpg
Ok, maybe 4 Series 10,000mah Lipo's are a bit bulky. How about 4 Series 5000mah Lipo?
http://i160.photobucket.com/albums/t...m/DSC06663.jpg
OR, if I can settle on a HV ESC that I like, How about 8S1P A123?
http://i160.photobucket.com/albums/t...m/DSC06666.jpg
I also trimmed and slimmed up the motor mount some.
http://i160.photobucket.com/albums/t...m/DSC06667.jpg
My Tower Hobbies order should be here tomorrow. The rest of the parts will be here either Tuesday or Wednesday. I'm ready to get this thing going. :yes:

This is a very cool project. It is really tempting me to try something like this... :whistle: Also, how heavy are your 8s1p a123's? I'm thinking of dumping my 4s 8000mAh and going HV...

Bye:mdr:

8S1P A123 is 1lb 6 ounces. What ESC will you be going HV with?

Do these Wheels and Tires look funky? Good for Asphalt Speed runs I think.

http://i160.photobucket.com/albums/t...m/DSC06670.jpg

I LOVE the Phaltlines!

Sike, this is coming together really nicely man. It's looks fine with the 10Ah lipo's on there... that would make for some nice runtime at that, 40 mins at least at 40 mph.

Thanks.
 

Hey Sikes thanks for sharing this project info with all of us. This thread has been a pretty educational venture. We are learning at your expense and that will help a lot of us decide how to proceed on some of our own builds. The trucks setup looks really good, and the direct drive is a unique concept for that truck. With those street wheels and tires you should be able to get some pretty fast runs. keep up the good work. We are having fun just reading through your experience.:lol:

Thanks, I seem to like the jazz controllers the 55-32-10 or something like that. I have not decided yet though... Also, those tires look great!

Off topic question, would a 63v 3300uf 85c cap be ok on my quark 125? I know its not low esr, but since its so big, would it work? I have 2 of them....(from an older bass amp:oops:)

Bye:mdr:

It not being a low ESR cap means that it is a lower quality version. It's internal resistence is higher(slow to charge, slow to drain), so it may or may not help performance. Also, the 85C rating, is it's maximum operating temperature. The low ESR versions are 105C rated.

I have a few extra 63v 1000uf 105C that are low ESR. Interested? Drop me a PM.

Parts ARE IN!!!!
 

Wooo Hooo! Look what I got!
http://i160.photobucket.com/albums/t...m/DSC06675.jpg
I got the new motor also.

I've got to hand it to Mike on this one! Fast Shipping and great service. These new diffs look beefy! I guess I better go get to work on this! :yes:

"You see a shadowed figure with an armload of parts, go into the workshop and shut the door behind him. Then you hear a whirring sound of machinery"

:yipi:

done yet? Got an hour of test time too? :D

hurry your ASS up! j/k, take your time and do a good job.

Any thoughts on a centrifical clutch setup for a direct drive brushless? It would have to stay engaged (spelling?)under braking and work at a low rpm. Wouldn't this fix all cogging issues?

I'm picturing a clutch (old old school) that had two weights on levers that would spin out with rpm, pushing (leverage) on a clutch disc. I remember seeing them on elevators for speed brakes and at a power pland to control a turbine flow valve. Hope you know what I'm jabbering about :)

I also saw a modernized version for harley davidsons that used sliding weights that spun between two concave washers to apply force to the clutch. I'll see if I can find a photo to help you all understand.

Here's a link to the harley autoclutch, but I couldn't find any photo's of the internals.
http://www.efmautoclutch.com/

Basically there are two plates with tapered grooves (channels) from the center out (large groove at the center, getting smaller twards the outside). There are balls (weights) that are in the groves, when the rpm's increase the balls are pulled outward by centrifical force, this wedges the balls farther into the grooves and pushes the two plates apart, applying force to the clutch pack.

That's a pretty interesting design. I think there is much improvement to be seen in the "clutch" area of RC. I wish someone would design a clutch for RC that works like that.

Most "slipper" clutches that are used today are designed to "protect" the drive train, but they also hinder acceleration. It's really the fact that it never truly locks up that does this.

I'm almost 100% positive that I have the answer to the cogging. These diffs will change how everything acts. With the Phaltline tires and the 4.3:1 diffs, Rollout is exactly the same as the E maxx outrunner setup in 2nd gear. This is gonna be awesome because this is SOOOOOOO much tougher.

I got the Diffs assembled. They look great inside and out. I also figured out the CVD arrangement. Now I have to split the bulks to install them.

For all you guys taking notes here, the RD Logics CVD's work with the Hotbodies diff cup. The THS Racing cvd's do NOT work with the HB cup.

Keep good notes of this buildup for me OK Sike? I won't be able to do it too soon, but imitation is the most sincere form of flattery :) I think I'll be converting my hyper7 befor I can do the DDR (direct drive revo) but I'd like to do direct in both of them. Eventually....

Maybe I'm wrong, but doesn't a Centax clutch work like that? Or is it the balls themselves that apply the direct force on the clutch? I know that it uses balls set in a concave hole so when the flywheel spins the balls are forced outward but the shape of the hole they sit in forces them forward as well. What I don't know is if they touch the bell or touch something else that in turn touches the bell. Any thoughts?

Well I got the front end tore apart and the Bulks split. This is my first time tearing down a Revo. I'm impressed with the design. It's a tad more complex than the E maxx.

I took out the front stock diff. There's something wrong with it. It's leaking grease everywhere. When I spin the pinion, it feels like the ring gear inside is warped or something. It spins freely for about 1/3 of turn, then I feel the gear mesh and there's ALOT of drag. Hmmmmmm.........Aaah well, I'm not gonna trouble shoot it right now.

This does point toward the fact that this diff was dragging the setup down though.

The RCM diffs feel sooooooooooo smooth and spin VERY freely.:yes:

@Drknow:

Let me get this perfected. I'll show you the EXACT setup to go with and some video's. :yes:

Sounds like the inside bearing on the pinion let go and the ball bearings are floating around inside the diff. I had the same problem with my tekno revo rear diff. It only had 3 different nitro motors and 1 hour of hard brushless running! Maybe some better bearings, boca avid etc, would be the ticket. They may be expensive, but would sure roll nicely.

I am also digging this build and dieng to see the end results :)

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 :diablo: :yipi:

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

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! :yes:

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.

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.

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.

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! :yes:

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

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.

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.

3.5 x 3.14 = 10.99 (Tire Radius)

10.99/2.92 = 3.76 inches of roll per motor revolution

This configuration should work! I'm sure you will be able to increase tire size somewhat since it's so lightweight. :yes:

The AXI uses those snap rings also. I use a pair of small screw drivers. First pry the ring apart, then starting on one side, pop it up out of the groove. Then using both screw drivers, work all the way around gently prying up until it's completely out of the groove.

I don't think I've ever seen a pair of snap ring pliers that small. I'm sure someone makes them though.

I think you meant circumference:whistle:

You are correct!

Circumference........that's what I meant :lol:

Sorry about the Brainfart there. I have those sometimes.

It's been a long day already and I'm wrestling with this truck right now. lol