Stealth Trans w/Gear Diff

[XLR8]

Glad to hear Sally is leaving. We are still deep in smoke here, enough that i am not working in the shop at all.

That case is looking great! Really nicely done!

So, the final step is to drill the screw holes for mounting the case to the chassis and the top brace plate and its spacer.

This is where I ran into the most trouble- that massive diff gear is right where my screws want to be. Well, couple that with the fact I really wanted to have both sets of holes in case an A stamp was being used, or a C stamp that lacked the countersinking on the 6 gear holes.

Thanks Jeff.

Given a choice, I'd rather have a hurricane than those wild fires. We're in north Alabama and far enough from the coast that hurricanes typically don't create much trouble for us; just rain and a little wind.

So, yeah keeping the screws from crashing into the diff gear is tricky. The key is that the front screws are spaced farther apart than the rear ones.

For instance, when viewed from this angle, it appears there is interference with the front screws...
side view.jpg
...but they are actually spaced farther apart than the width of the gear at this location so there is ample clearance.
top view.jpg

Also, screw length cannot exceed 3/8" or there could be a problem.

Ah, I see what you mean Jeff.
I've just assembled a new B6 gear diff and the housing is wider than the B4's by about 2.4mm.

In addition to requiring a wider trans case (with bearing bores spaced farther apart), the added housing width will effectively limit the length of the front chassis mounting screws to about 5/16" max. As it is, the standard 3/8" long screws will interfere with the diff housing. Unfortunately this will reduce screw thread engagement to around 1/4" but I guess it is what it is; there's no way to use longer screws without raising the diff or moving it aft and this will only create more problems.
I will revise the printed case design to accommodate the wider B6 diff. It could still be used with a B4 diff if 1.2mm wide shims are installed in the bearing bores to keep the diff housing centered in the case. I will include these shims with the printed cases.

[Chewbacca]

I have been following this thread very interested. NICE WORK!!

I thought I found the ideal ball diff for you, unfortunately it also is discontinued. It is a Losi and uses 46T instead of 45.

Part number: LOSB3594

Maybe you can find one in the US. That would pretty much solve the issues of the diff height. Perhaps the outdrives would fit into the AE 45T gear?

Since I am planning my own gear box, I was also looking for diffs with 45T or smaller. I stumbled upon the Schumacher Cougar Laydown diff, which is available as gear and ball diff.

That diff only uses 38T, so quite a bit smaller than the standard RC10 stealth. Can anyone here confirm, that Schumacher also uses 48dp gears in their transmissions?

Thanks, Tony

[guitronics]

I've also been following this thread....nice work, gentleman. I want!

[XLR8]

I have been following this thread very interested. NICE WORK!!

I thought I found the ideal ball diff for you, unfortunately it also is discontinued. It is a Losi and uses 46T instead of 45.

Part number: LOSB3594

Maybe you can find one in the US. That would pretty much solve the issues of the diff height. Perhaps the outdrives would fit into the AE 45T gear?

Since I am planning my own gear box, I was also looking for diffs with 45T or smaller. I stumbled upon the Schumacher Cougar Laydown diff, which is available as gear and ball diff.

That diff only uses 38T, so quite a bit smaller than the standard RC10 stealth. Can anyone here confirm, that Schumacher also uses 48dp gears in their transmissions?

Thanks, Tony

That's interesting Tony. I've never even considered using another manufacturer's diff. It seems like the Schumacher 38T might be a good unit to consider. Please let us know how this works out for you?

Anyway, regarding my gear box design, I still want to load the CAD model in Inventor, make some adjustments and final clean-up then send to Shapeways for a test print.
Not sure when I'll get back to this one as I'm currently chasing many other projects.

[Chewbacca]

Quote:
“That's interesting Tony. I've never even considered using another manufacturer's diff. “

As soon as I get confirmation that Schumacher uses 48 dp I might go forward with my project.

[radioactivity]

Quote:
“That's interesting Tony. I've never even considered using another manufacturer's diff. “

As soon as I get confirmation that Schumacher uses 48 dp I might go forward with my project.

Well, don't like bearing bad news but...
In regards to the V3 Ball Diff KD / Laydown / KR and similar gear diffs Mark Marshall @ Schumacher Racing stated "It is 36d.p."
Great idea, keep hunting. Wish I had an alternative.

Chuck

[XLR8]

Quote:
“That's interesting Tony. I've never even considered using another manufacturer's diff. “

As soon as I get confirmation that Schumacher uses 48 dp I might go forward with my project.

Well, don't like bearing bad news but...
In regards to the V3 Ball Diff KD / Laydown / KR and similar gear diffs Mark Marshall @ Schumacher Racing stated "It is 36d.p."
Great idea, keep hunting. Wish I had an alternative.

Chuck

I could tell from the CAD images in the exploded view that the pitch for the internal gears was different from the spur gear (larger teeth).
36 dp, wow, that's bizarre.

I read somewhere that Axial SCX10 transmission is a direct fit for the RC10 (same bolt spacing). Not sure if it's true. Anyway, I'd like to experiment a little with running a spool on my loose dirt track. Yeah, it's crazy but what the heck.

[Chewbacca]

DAMN!

My CAD is almost ready. The size of the 30T idler compared to the Traxxas Bandit idler already had me wonering.

......

[GoMachV]

I read somewhere that Axial SCX10 transmission is a direct fit for the RC10 (same bolt spacing). Not sure if it's true. Anyway, I'd like to experiment a little with running a spool on my loose dirt track. Yeah, it's crazy but what the heck.

I picked up an Amazon Chinese knockoff trans to check this a while back. The hole spacing isn’t correct- one set of holes is too close to the other, so a pair of holes would need to be drilled in the chassis. For a $17 transmission it’s pretty cool but definitely not stealth quality by any means- but if you don’t need a diff these might be a cheap way to keep running

[Chewbacca]

thanks for the input.

I don't want to hijack this thread any further, I will start a seperate topic over in Temple's RC10 Tech section.

[Nige55]

Did this project get any further? The idea of having a geared diff in something that still resembles or looks like the Stealth box is so appealing. I'd buy a couple for sure.

[XLR8]

Did this project get any further? The idea of having a geared diff in something that still resembles or looks like the Stealth box is so appealing. I'd buy a couple for sure.

Not yet.

I’ve been running printed transmission cases in the Optima Mid for a few weeks now and I’ve had some problems keeping some of the screws tight – specifically, the rear shock and suspension pivot plate screws. These are self-tappers and they are simply backing out (the holes are not stripped). The shock tower was easy to fix. I just through-bolted the plate to the cases and added nylock nuts. The suspension plate screw holes, however, won’t accommodate a nut so I must check the screws every few runs to keep them tight. So far, the remaining transmission screws haven’t backed out.

That said, for the RC10 cases I’ll probably design them for pilot holes, then I will thread the holes with a tap to ensure maximum thread engagement. With full engagement, I should be able to increase torque for the screws so (hopefully) they won’t back out. I’ll also want to pay special attention to the bearing bores so they are sized correctly for a press fit and thus avoid post-printing machine work that could alter the bore’s center locations.

Anyway, I’ll get back to this eventually. I have too many projects underway at the moment.

[juicedcoupe]

Perhaps consider using helicoils and machine screws, or larger brass inserts.

With plastics, I typically use CA glue in the hole. It lubricates the coil during installation and then locks it in place.

[XLR8]

Perhaps consider using helicoils and machine screws, or larger brass inserts.

With plastics, I typically use CA glue in the hole. It lubricates the coil during installation and then locks it in place.

Another thought I had was to add a drop of blue thread lock to the underside of the screw head so it bonds to the aluminum plate.

[juicedcoupe]

Perhaps consider using helicoils and machine screws, or larger brass inserts.

With plastics, I typically use CA glue in the hole. It lubricates the coil during installation and then locks it in place.

Another thought I had was to add a drop of blue thread lock to the underside of the screw head so it bonds to the aluminum plate.

Just be careful to keep the thread locker away from the plastic. It will attack and soften it, at least temporarily.