Gear mesh keeps changing on XMAXX.

[WickedFog]

Well that's interesting. Something with that bulkhead is putting the assembly in a bind. But since nothing is rotating on the bulkhead, I don't see how it could cause run out.

 

[Mrgoodwrench35]

The bulkhead houses the rear diff, center diff, and the spur shaft. All of the bearings for the rotating components ride in the bulkhead. There's another plastic piece that comes with the bulkhead that caps the center diff into the bulkhead, then a cap for the spur shaft and cap for the rear diff. I have the aluminum H.R. rear diff cap and spur shaft cap.

 

[WickedFog]

Yeah, I am building an X-Maxx. The thing is though, even if the bearing journals were not concentric with each other, it won't create run out. It would only push the assembly out of square. But rotating wouldn't show run out because of that. It would need to be something that is rotating and wobbling causing the issue, and the bulkhead of course does not rotate. So I am a bit puzzled how a bulkhead swap would fix the issue. But obviously something is going on there with that other bulkhead. I just wish I could think of what the heck it could be

 

[Mrgoodwrench35]

Beats me. I've looked over both pieces of the bulkhead and I don't see it. It's definitely directly related to the center/rear diff area.

I ran 2 sets of packs through it today and didn't break anything. Motor runs at about 110, esc never broke 100. Felt good to play with it again.

How far along is your WF?

 

[WickedFog]

How far along is your WF?

I got all the chassis plastic, the heavy duty arms, the body mount set, and the RPM carriers with oversized bearings before running out of money. Oh, I also have a Spektrum 160A ESC for it. It still needs diffs, gears, driveshaft, axles, wheels, tires, bumpers, motor, and a body. All the expensive bits unfortunately.

 

[Mrgoodwrench35]

I got all the chassis plastic, the heavy duty arms, the body mount set, and the RPM carriers with oversized bearings before running out of money. Oh, I also have a Spektrum 160A ESC for it. It still needs diffs, gears, driveshaft, axles, wheels, tires, bumpers, motor, and a body. All the expensive bits unfortunately.

Nice! Sounds like you have a good start. Do you plan to use the factory center driveshaft?

 

[WickedFog]

Nice! Sounds like you have a good start. Do you plan to use the factory center driveshaft?

No, I was thinking of going with an aftermarket setup.

 

[Mrgoodwrench35]

I'm running the M2C spit center shaft setup and it works great. I broke, bent, and stripped a few of the factory shafts. I only ask because I have several NIP factory center shafts and stub adapters that I'll likely never use. I also have a lightly used rear bulkhead if your interested

 

[WickedFog]

I would almost take you up on that rear bulkhead just to get a look at it to see if I can figure out wtf is going on. But I don't want to put anything like the stock driveshaft in this after reading and watching vids about people bending them. I love building RC's, but I hate tearing them down to fix them

 

[Mrgoodwrench35]

I'm curious about the bulkhead too. I mocked it up again last night with spare parts and I still dont see the issue. I'm almost certain I can feel a binding condition with just the center diff and cap installed. Its hard to tell for sure and I dont have a way to read rolling torque on something that small. Even with the rear diff removed I get the shaft deviation at the spur. My best guess is the bulkhead is warped and causing a weird binding condition.

Now that I know the problem I see why it took me so long to figure it out. I would have never suspected the bulkhead as the culprit.

As much as I enjoy modifying and playing with these things, I absolutely hate having to tear them down for repair. The only time its fun is when I'm installing upgraded parts that will hopefully work better than the factory stuff.

 

[Lukedavis]

i only read the first 2 line of this post. you cold have 2 issues. bent motor shaft ot bearing are off as in if you measure bearing from inside shaft mount edge it will be different when you rotate bearing

and thats why you read through the full post before replying lol.