Transfer Case goes Kablooey!!

[dna4engr]

I took my scx10 II on its first trail run today. It was going great and performing awesome.

Then I came upon a rock obstacle. It had a little ramp but I couldn't crawl it. Got a little momentum and flew up it. While under throttle, the rear tire caught some tracking and pop something went. Driveline was locked up!!

Got home and here is the damage.





Blew out all three tcase gears. Looks like the smaller ones are the same and they're the old top gear from the scx 1 trans. I have a couple hardened ones I can use. However the one bigger 26t gear is new. It still has teeth left on it so I may put it back together with those...we'll see.

Hope HR is coming out with a hardened gear set soon.

Btw. It has a 27t HH torque master on 3s and stock kit gearing.


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[Bry73]

That is a lot of missing teeth. I better keep an eye on my tranny then too running it on the course at work. Yeah Axial list them as being powdered metal construction.
None of those parts were yet available the other day when I placed the order for SCX 10 II parts. They are now available so I will have more stock replacements soon.

[Stormin2u]

Typical low kit quality regarding the gears, remember the XR10? So she ran well other than that so its not all bad, after all the XR10 survived its bad teeth.

[dna4engr]

I'll have it running again Sunday. Going to use one of the damaged gears and get 2 of the small ones that are out of the old trans.

Yea Don, I was at robins run when it snapped. The unique gear is still kind of in one piece. The other two I have one and Derek might have one.

Since HR already makes the smaller gears for trans hopefully they'll come out with the bigger one soon.


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[Col_Sanders]

Somebody had to be the first.

[SCREAMER]

Sorry about your bad luck. Yeah, I finally went ahead and assembled the new style trans last night just for something to do and I immediately recognized those top shaft gears from the stock SCX10 and Wraith trans. I really am at a loss for this new trans design. We now have three slightly different versions of a Yeti trans and all three are bigger than a two speed trans out of a Summit for crying out loud. Do they really need to be this big? No. And don't try and tell me it's for scale this and that. It's backward, off center, not attached to any kind of scale engine so it's just a tranny going nowhere, and has a huge electric motor hanging off the side. Scale is out the window folks.

[new2rocks]

Congrats on drawing first blood. I'm sure it won't be long before someone (HR, RRP, anyone else) releases a hardened gearset for the transfer case. Until then, I'll have to try to be gentle with mine, lol.

[mikemcE]

Are we talking these ?

http://www.rpphobby.com/product_p/hotyet1000tc.htm

T case gears are 32 on mine

[SCREAMER]

No, those are not for this new transfer case. The new transfer case has two top shaft gears from the old SCX10/Wraith trans and an entirely new gear.

[dna4engr]

Originally Posted by SCREAMER

No, those are not for this new transfer case. The new transfer case has two top shaft gears from the old SCX10/Wraith trans and an entirely new gear.

Correct. I was hoping the yeti gears were the same so I could steal them from my yeti. However the parts book comparison showed they aren't.

It'll be just a matter of time I'm sure.


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[Bry73]

All stock SCX10 II transmission gears are now in stock at Hub in Little Canada.

[fr8cture]

Why not just go to the standard scx/ax trans?

[CM9000]

typical castings. crack under pressure. and kabloooeey.

I plan on selling off my trans, body and tires from my new kit. just not... into them.

[dna4engr]

Originally Posted by fr8cture

Why not just go to the standard scx/ax trans?

I actually like the new trans. It's nice and quiet. At least mine is. Plus it adds some scale points....if I ever run a sorcca event lol

Originally Posted by crawlingman9000

typical castings. crack under pressure. and kabloooeey.



I plan on selling off my trans, body and tires from my new kit. just not... into them.

The gears are actually powdered metal. A cast gear might actually be stronger but would likely need some post machining to work well.

I took the rig out at the break wall in two harbors mn after the comp and it ran fine even when bound up the gears were holding.
It now has 1 stock, 1 hardened, and the original output gear with some filing on the chipped tooth.

Axial has another set headed my way.








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[SCREAMER]

I think it's great how every story of missing, incorrect, or failing parts is always accompanied by, "Axial has parts on the way". I had the same experience with a bad ESC in my first RC ever, a Wraith Spawn. The guy at Axial was more than courteous walking this newb through troubleshooting and we got it narrowed down to a bad AE5. They didn't have any of those in stock so he sent me the nicer, and more expensive AE2. Customer service is a huge deal breaker for me and it's clear the guys at Axial get it.

[luckster]

Originally Posted by SCREAMER

I think it's great how every story of missing, incorrect, or failing parts is always accompanied by, "Axial has parts on the way". I had the same experience with a bad ESC in my first RC ever, a Wraith Spawn. The guy at Axial was more than courteous walking this newb through troubleshooting and we got it narrowed down to a bad AE5. They didn't have any of those in stock so he sent me the nicer, and more expensive AE2. Customer service is a huge deal breaker for me and it's clear the guys at Axial get it.

I had a similar experience with my Yeti on the wheel hubs. Boom the new upgraded parts were in the mail. Great company to deal with.

[CM9000]

so as in powdered metal do you mean sand cast? I don't think cast would be any stronger than your set you have.

[Killa-Cotton]

+1 for me. LOL

[CaptMatt15]

Originally Posted by crawlingman9000

so as in powdered metal do you mean sand cast? I don't think cast would be any stronger than your set you have.

Powdered Metal is actually a Sintered metal part - Not sand cast. Parts made by this process start out as literally a powdered metal mixture that is formed into the final shape, then basically heat treated to harden it. The part doesn't typically require much finished machining to hold the type of shapes we're talking about here.

Sand cast would be a typical molten metal casting process, where liquid metal is poured into a sand mold. Sand casting would require machining afterwards as the part would have flash on the edges, like a plastic injection molded part we see in our kits, and wouldn't normally keep the accuracy you need for small gear teeth, even with a metal die instead of a sand mold.

I'm in Quality Engineering in Automotive Parts Manufacturing (Automatic Transmission, actually). I manage our supply base's quality, so I deal with processes that range across tons of materials, including Sintered Metal parts.


Edit: Sintered metal parts can be known to be somewhat fragile or brittle, even as a finished part. Machined gears are definitely the way to go for ultimate durability in this type of application, but for cost/durability for most people the sintered parts work just fine.

[STANG KILLA SS]

how the hell did the plastic driveshafts survive?