guess what i broke

[C.B.]

View attachment 708


i cant wait till theres a better fix for this


the upgrade is a down grade from stock with the pins rob has


this isnt my picture but mine broke the exact same way

 

[str8jailbird]

View attachment 708
i cant wait till theres a better fix for this


the upgrade is a down grade from stock with the pins rob has


this isnt my picture but mine broke the exact same way

I feel you brother! I sent an estimate into a machine shop to see what that would cost to make out of titanium. Arm and a leg I am sure. I also sent in a request to Python motorsports. I emailed Rob and they are trying to come up with a solution, he is going to talk to FLM as well. The problem is that there aren't enough to make it cost effective yet for aftermarket cups. I did stumble onto something though. When I used a diamond engraving bit in my dremel to mod the stock cups for the upgraded pin to fit it must have tempered the steel somewhat because the cups I modded have been lasting a LOT longer than the upgraded cups. It's not a permanent fix because I did snap one but they have been holding up longer than the others.........

 

[C.B.]

im thinking its better to just order stock with the stock size hardened pins

 

[mooman007uk]

then the pins snap


the best fix would be splined shafts and gears like the fg ones.

 

[C.B.]

good point moo

 

[str8jailbird]

Well I am happy to say that after 2 tanks of hard beating neither of the dremeled cups gave out. It has got to be the heat from the bit tempering the material. I beat the truck today harder than usual and the only issue was a front CVD pin backing out. Some red thread lock and back in the saddle! I agree Moo, it would be nice to have splined shafts and gears. Think the FG ones would work with ours? What about MCD diffs? Use the MCD pinion and diff or won't they fit in the Ramp housing???

 

[kryptonite]

im glad your cups are holding out. mine are too. havent broke one.. but if i may ask? i thought that heating up hardened metal made is softer. thats just what i always thought. wasnt certain you could "double temper" with just a dremel..

 

[C.B.]

maybe it makes it a little softer so it doesn't shatter thats what mine looks like it did

 

[str8jailbird]

im glad your cups are holding out. mine are too. havent broke one.. but if i may ask? i thought that heating up hardened metal made is softer. thats just what i always thought. wasnt certain you could "double temper" with just a dremel..

Rob from Rampage Hop-ups can explain it better as he is the engineer. Here it is in Laymen's terms. "Hardness" as defined by the Rockwell method is basically surface hardness. If I am correct I believe that it is measured (origionaly) by dropping a steel ball and measuring how high it bounces. I think the definition is basically the ability to resist scratching and marring of the surface. Basically a longer wear ability. Tempering refers to the internal "strength" basically. When a metal is hardened it becomes brittle to a point so sometimes it has to be tempered to give some flexibility to the material to take some of the brittleness away. I am not sure where the line is when the material is hardened vs tempered to where you get the best of both. It seems that the diff cups have been hardened but not tempered enough and this makes it difficult to temper not knowing the exact material it is made from to get the proper temperature to temper it. Yep, I have been doing a little research (plus the younger brother was a machinist as well as my uncle). hope this helps. And that concludes today's lesson! Sprint and Rob feel free to add/correct any mistakes I made.

 

[Piranha2]

I say go cold-drawn forged not this cast crap.

 

[str8jailbird]

I say go cold-drawn forged not this cast crap.

AMEN to that. Why not hammer forge like a rifle barrell????????? I know that would work but man would it be expensive! I still like Moo's idea, splined diff cups into spline gears.

 

[mooman007uk]

well i bust another diff cup shaft today after 10mins of running ...rear left side...one that wasn't dremelled out...so i got a new one from the upgrade kit i just bought and heated it well beyond steel grey so over 700F and let it cool. We'll see now if this works or not.


The fg shaft is the same diameter and would fit but the spider gears are smaller...bummer could have been the true bulletproof fix.

 

[speedyd]

mine were made from hardened tool steel, but my breakage was in a different spot.the cup split.

 

[IMADMAN]

mine were made from hardened tool steel, but my breakage was in a different spot.the cup split.

Were those the ones offered from Nitro pit hobbies?

 

[speedyd]

yes they were. has anybody else broken those?

 

[str8jailbird]

You guys mean Nitro pit Hobbies has made some aftermarket diff cups? I may have to try some out. I am still waiting for some estimates from some machine shops. i know it's gonna be expensive. I actually am going to talk to a teacher pal today and see if his Vo-Tech kids may be able to make it a project. If so, I am really going to try and see what the heck the strongest stuff available is to get some to have diff cups milled from. There has got to be something.

 

[speedyd]

i don't know where you will get them i have left a public post and shot them a pm, so i could get a replacement, no response.

 

[mooman007uk]

I think nitro pit only made one batch, i read somewhere that he only had a few left (a while ago) and after that there'd be no more

 

[speedyd]

it is very possible that my cup split due to dog bone angle. it seems as though this is an in demand part maybe we could beg and pleade with them to make more!

 

[str8jailbird]

Still no response from the machine shops. Well, maybe the Vo Tech will be the answer. I am going to actually visit the local shops Wednesday when I'm off, maybe they'll give me an answer in person.