[QUOTE=neweuser;316700]Delusions of Grandur right there nooby...if you peep sjcrss's sig, you can plainly see there the ideas. In fact, I wanted to stick a 1/8th diff in an modded FLM tranny case for years. Just never took the time to do it and Mike came out with the slipperential anyways, so there was no need for one.

thanks T, well i think enough about who did what or when...I can supply info as well as MC...... I think credit needs to go where credit is due....so here goes.....
Original Idea 1/ scale diff in FLM case...newe
1/8 scale diff in erevo tranny ( I made up theplans ect. and did all the test fitting ect.) ...sjcrss
shaft re-design's and other gear mods...ect plus new ideas for the cd design...MC
this being said everyone is getting credit where it is due.....

IMO, who cares! lol It works!

[QUOTE=neweuser;316701]It was a joke, hence the little winking icon.

I just started making my center diff. Today I ground down the center spur gear. It was suggested to me to use a nut and bolt assembly to chuck the spur into a drill press, then use an angle grinder while the drill press rotated the spur. I didn't have an angle grinder, so what I did was chucked the spur/nut/bolt assembly into a hand drill and used that to spin the spur while I ground it down against a bench grinder. Probably took longer than using an angle grinder, but it worked out fine.

Not sure if I took off enough yet, but I was concerned about grinding too much off of the outer lip and making it too weak/brittle. Is this going to be a problem if I left the modified spur like this?

http://i47.photobucket.com/albums/f1...3/P1020350.jpg

It looks ok to me, one thing i did, is I determined the cap overhang, per the gear mounted to it, but it looks good so far

Not sure what I want to do next, maybe cut and drill the Traxxas output shafts. Thinking of sourcing a local machine shop to drill and tap the holes in the cap because I don't want to screw it up and bust off a tap in the hardened steel.

are the spurs made from hardened or high speed steel?
cause i could use the lathe instead.

The Thunder Tiger spur used in mistercrashes revised design is hardened steel, which is what I am using. I'm not sure what type of steel is used in sjcrss' original Hyper 7 version.

I think it's hardened steel as well,....thats what my machinist told me at least...

I am pretty sure that all good diffs and center diffs like Ofna, Thunder Tiger, Losi, Mugen and so on use hardened steel spurs and ring gears. That CD is starting to look good simplechamp, if that lip is still too thick and you run into fitness problems in the tranny, you can take off a little more and I'm sure you won't have any problem. The lip I left on my CDs are like half a millimeter thick, it's just there to center the piece on the diff case.

I wish someone could make these gears for $5 each :mdr:

http://i177.photobucket.com/albums/w..._gear_top1.jpg http://i177.photobucket.com/albums/w...ar_bottom1.jpg

Nice mistercrash! I was actually planning on trying out just the two mounting screws instead of four, we'll see how well it holds up, my main reason was to have less holes to drill and tap. Also was debating countersinking the holes where the mounting screws go, but not sure if the material is thick enough.

You pretty much read my mind on that drawing!

EDIT: Can I get some advice on drilling the pin holes in the cut-down output shafts? What size bit is used? (I have a bunch of SAE bits, not so many metric) How do you drill the holes exactly on-center? How far from the end should they be drilled?

This is how I do it.

If you're going to have a machinist make the holes in the spur gear and thread them, maybe he/she can make the holes in your shafts also.

That's something that had crossed my mind. Probably would be the best. Do you have a measurement for how far from the end of the shaft the hole needs to be?

Modded the plastic spur tonight and it turned out well. All I have left to do is cut down the output shafts and then after the long weekend I'll call around to a few shops to see what they'll charge to do the drilling and tapping. Unfortunately I have a feeling this is going to turn into a $90 center diff, but no turning back now!