WoW!!! how much power!!

Are you telling that the "Hot Bodies Spiral 10 tooth pinion" with the "Hot Bodies Front/Rear Hardened Diffs (43 tooth spiral ring type)" doens't resist the outrunner power??? AWESOME,

I bought a pair of hot bodies spiral diffs for my CRT because of I thought they were the best...

May I put the new 43/10 spiral ones ? or let the original 43/13 ones?

Thanks.

Actually the gears themselves are super tough and really hard stuff. IF the bearings would hold up and keep the mesh right.
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I think it should be possible to shim everything just right. That should eliminate the driveline issues.

Does your ESC have a ramp up feature? I set my HV110 to slow start and it helps keep from hammering the driveline.

Awesome power. Just awesome.

Matt

I did shim everything JUST right. It was perfect. :yes:

The spiral cut gears are punching the inside race right through the bearing.

I could lower the starting power some in the ESC setup.........I guess :whistle:

Thanks.

Ah, Sike makes his first appearance on camera! Is that grating sound the bearing coming apart? I had my stock diff revo do the same thing, the inside bearing let its balls go and it was making quite a crunching sound. I got the truck used so I have no idea how many runs were on that diff. I replaced it with another stock diff and have not had any issues yet.

Here's yet another Vid

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Ahh, good deal. Sorry, I was not trying to offend you by suggesting the shimming. I haev just seen it so many times (poor shimming) that it is second nature to mention it.

Hey, how much room so you have for a thrust bearing? I can cut a CF washer on my CNC for you. CF has a very slick hard surface that works well as a thrust bearing when there is not enough depth for a normal thrust bearing. I have done it with decent success.

Nice display of raw power. Congratulation on your outrunner setup (especialy for custom winding your 4130). It would be interesting to log some data with an eagletree: with the rpm sensor you could immediately tell what kv your custom wound motor now has. You really should get one :wink:

I wonder what would happen at startup with a jazz 55-10-32 or a MGM 9032 on 10s1p A123 with your factory wound 4130/20 (305kv). Determining the right KV of your outrunner in combination with the right voltage to eliminate cogging at startup with the right esc seems to be the most challenging/interesting part. Your setup seems to do well with a very small hicup when starting up from a near stand still.

BTW: i had the same bearing problems (spiral cut pinion/diff) with my Neu 1512/2Y on 10s1p A123 in my buggy. I changed the bearing quite often. I thought it was due to the fact that the buggy already was 10 years old when i converted it to brushless. :wink:

The bearing itself is 8x14x4mm. Each Pinion uses two of them.

How it's setup now, the front pinion tries to push into the front diff, while the rear pinion tries to pull out of the diff.

Maybe just use CF on the load bearing side and a Ceramic Nitride bearing on the free wheeling side of the pinion. Think that would work? It sounds good.:yes:

Aaah, so I'm not the only one. LOL

I've never tried a Jazz ESC, they look really good though. The MGM is said to work well with outrunners.

Yes it is an interesting challenge. Now for the diff challenge. :whistle:

hey sike, can you tell me the name of your revo vids?

You will still need a roller bearing on the pinion side. Two bearings are needed for proper input shaft support. I was wondering what teh clearance is between teh pinion and the bearing near it. If there is enough clearance there to put a CF or stainless washer there, that would work. Maybe a narrower roller bearing would provide the needed clearance.

I currently have 3 - .2mm shims there right now. It makes the mesh just right.

Here's all my vids on Youtube.

http://youtube.com/profile_videos?user=sikeston34m&p=r

You will need at least 1.5mm CF wafer to act as a decent thrust bearing. If there is any way to run a narrower bearing there, you could add a thrust washer and that would most likely work.

If the design will allow for the bearings to be placed up against each other you may be able to make enough room for the cf washer. I have a pair of the hybrid diff cases at work, I will have to take one apart and see how it looks, even though Sike needs to dissassemble the diff again to replace the bearings.

Stupid as this may sound, but would a carefully shimmed bushing resist falling apart any better? I know they are rather poor for high speed applications, but since they are a solid piece of metal there isnt anything to break as such...

Those videos really do belong on BYT, Im sure the guys would appreciate seeing how powerful BL power is when its done right- love that truck.

I'm not sure if a bushing would work better or not. We're dealing with really huge side AND thrust loads at that point.

Thanks for the Compliements.

I'm trying to reprocess on the setup actually. Is there a way to eliminate the ring and pinion? We've just about eliminated everything else with this setup.:lol:

How about a center mounted motor that spins the front and rear spider cups with a ribbed drive belt? Such as seen in alot of on road cars. I wonder how tough the belt setup is?

Hmmmmmmm.............thinking thinking

I am sure that the secondary drive belt from a harley would be able to hold up to the power, may be a bit overkill though...

You could do a chain drive, put some hardened steel spur gears on the diff cups, and use a bicycle chain, that is the correct size (would have to be smaller than the bicycle chain, but you get the idea). Then drive the center of the chain with another steel gear that mount to the motor. Only problem may be the sizes of the gears. You currently have 10/43 gearing. Finding a slightly larger steel spur for the diffs will not be an issue, a 46 would work and not be too big. But you would have to use an 11t pinion on the motor and somehow make sure the chain would stay in contact, maybe some spring loaded idlers? Sounding kind off complicated now. Maybe investigate the possibility of a needle roller bearing in the correct size?

A bushing would not be a bad idea. It would require alot of lube and need replacement often. But, hey, a top fueller needs maintenance from time to time!

Questions???
 

You know Sikes you might be on to something. If a belt drive was strong enough and efficient enough to drive a 700lb motorcycle, then why not come up with a scale size belt for our trucks that fits the same sort of specs? It would make things quite a bit easier for the 4X4 setup of the types of vehicles we run. Just think of it. two Harley style belts that could run directly from the motor to the drive axles. Maybe using a slipper or clutch type motor drive.:lol:

I use belts all the time. They are tough enough for this application. Space is an issue, though (for the design you guys are discussing).

Your kidding right? You guys might want to check into the Belt driven RC's for idea's to make that work for you. They even have kevlar belts now for the belt driven RC's. I am possitive some of those belts are the sizes you need. and long term effect word be way better then it was 3 years ago when we were streatching out belts left and right.

Don't know how or where you would get it but a ceramic bushing would be worth considering. Ceramic has a very low drag coefficient and does not expand with heat. I.E. no lube required and it's too hard to wear out any time soon. Besides this is a "wet" diff right? So even the metal bushing would last a while right?

Hey sikes any updates?

Sorry, No updates in awhile.

I'm going to install the 13/43 Hot Bodies gearing in the Revo diffs. The Custom Wye Wind performs almost like it's undergeared on the 10/43 gearing. (which doesn't hold up btw)

So I'm gonna trade the 4.3:1 ratio for the 3.3:1 ratio. I believe the Custom Wye wound 4130 will still start just fine. And IF it doesn't, I believe the Kontronik Jazz will. :yes: I just learned that they are very smooth with outrunners.

I've really been watching/waiting for Tower Hobbies to get the 2 speed kit in the for E maxx. I was gonna put all of this into one order. BUT they just bumped the "delivery" date up to Late Feb. *Sigh*

That Sucks.
 

Yea it sucks when they do that, but we all know it is due to some delivery issues beyond their controls:whistle:. Some items go on for months like that, because they cannot get the items from their suppiers when they would like. We are all still looking forward to hearing about your testing with this one Sikes.:lol: Thank you for sharing it with us:yes:.

Well keep up the good work man! im learning alot from reading your threads :yes:

Thank you.

I placed the Tower Hobbies order for the 3.3:1 Regular cut gears.

I believe I can get this to hold up as long as I use them. They will side load the pinion bearings instead of loading them like a thrust bearing does. :yes:

Ok, it was as I suspected. The Pinion side bearings center race was punched out from the load. The other pinion bearing appears to be in fair shape.

http://i160.photobucket.com/albums/t...m/DSC06827.jpg

I have a pretty good feeling about these new gears. The ring looks alot tougher compared to the old one.
http://i160.photobucket.com/albums/t...m/DSC06826.jpg

Here's where the difference is! Notice how these pinions compare? I like how tough the new one looks. The teeth are much bigger and straight cut. I think this has a chance. LOL

http://i160.photobucket.com/albums/t...m/DSC06825.jpg

The spiral cur bearings are a good idea, they should last longer than a strait gut gear, as the teeth are in engagement more than on straight cut gears. The bearings need to ge conical like a full size car, and they need some sort of preload, like a crush sleeve. Most likely would be too big to work well in the space available.

Good luck with the straight cut gears, hopefully they will treat the bearings better than the spiral ones did!

Yes I think the spiral cut bearings are a good idea too. The only downfall is the lack of the correct bearings to work with them. (Please keep in mind that for a regular setup using a slipper, and/or a center diff, the spiral cut gears would work great)

I got the 13/43 gears installed. I took the Revo outside to give it a test spin as best I could. They are going to work! :yipi:

First I tried it on 4S. Much to my surprise it doesn't cog. It does feel like the ESC tries to run off and leave the motor if you just stab it though. (too fast of an acceleration rate in the programming I think) If you ease into the throttle, it runs VERY good. Top speed is MUCH better and the Wye Termination has the torque to pull it to some great acceleration.

Then I had to try it on 6S. The issue that I spoke of on 4S is gone. This is going to be hard to control. It's got some crazy power. I can't imagine what the top speed is going to be, But it hauls! :great: It will wheelie at speed too.

I couldn't get too much into it because it's very dark out there. LOL

I believe these gears are loading the bearings the way they were meant to be. I think we're there.

I'll try to get some video's tomorrow. :yipi:

Ok, the next weak link that I see is:

Is there a set of Revo Diff to Wheel cvd's that are compatible with the regular Hot Bodies Diff cup?

I have the RCM 6mm conversion shafts installed. These allow me to use the Revo Driveshafts from Diff to wheel.

I'm twisting them like a Barber Pole. The hardened steel pin that secures the Revo Shaft to the Diff is elongating the hole. The flat part is twisting. This will eventually give way to metal fatigue.

On 6S, I'm going to need some tough cvd's on the rear. I think the Hot Bodies diff cups may be stronger since there is more steel there. That is, IF I can locate a Revo cvd that will work with them. :yes:

I can tell you that the THS cvds will not fit the hb diff output cups. I would think that most revo cdvs would work, as they have the same size ends as an emaxx cvd. Someone here should know!