Anyone have a mill that can help me out

I need to open up 10 holes from 7/16 to 1/2" and it's hardened tool steel. Drill bits don't even scratch it. Only 1/4" think.

Need it done ASAP.

Guessing a mill. Or?

Robert
714-875-2414

i got a machine shop, left ya a message. need some more details before i say i can do it though.

If Dan can do it let me know and I will put you in contact with a guy I know here in Sierra Madre.

If all else fails I'm at a shop Hemet.

Ok well got it done. Will post more tommorrow.

Ok so short version. I Ordered a Tru trac (eatons Posi unit) for a Jeep JK> The JK switched to 1/2" ring gear bolts about 3 years ago from the now typical 7/16 or the for ever typical 3/8's.

The norm is to just use a step bit or a basic 1/2" bit in a small press that I have. Takes about 1 min per hole max.

BUT NO! The F#&)($ Eaton Posi has the most hardened case of ANY carrier/Locker I have EVER seen! The arb, detroit (another eaton product), trac loc, grizzly, Zip, etc... ALL are easy to drill. some a tad bit more hard but nothing bad at all.

I Tried 4 different drill bits, even indexing up & a few different unit bits, nothing even scratched the surface. NOT ONE Shaving any of them.

SO I went to a end burr in air die grinder, my last resort tool. It got about 1/8" in to about 5 holes, it was throwing sparks everywhere, but working. But after 5 holes it was shot.

The next day I picked up 3 more of these end bore bits at 21$ ea. After getting home and having 2 of them fall appart after only getting about 1/5th the way finished and not one hole fully open, I went looking for help.

I got a great offer from Vanimal. But he was far...

I remembered a buddy out in Riverside (only about 30 miles from me) and that he had a full machine shop in a hanger on his property. Not just a small one but like a hanger lol. He is a pilot and machinist, so I called him.

I got out there with the carrier and he took about 20 min to get it perfectly (well with-in .001) if centered and true in a Bridge Port chuck that he has setup in a digital 3 axis.

And he tried a end mill bit. It instantly started chipping apart a bit that he would use on anything else he does typically. He machines axles for tone rings (D44 swap in to XJ ABS rears), and wheels for hub conversions, etc. He opened a brand new end mill, and same thing.

SO I LUCKILY brought the one last new end burr and told him this is carbide and maybe this can work, he said well never had to try something like that and with only a 1/4" shank was not happy to have to try it, but he would.

After about 4 min per hole, it all worked out.

NOW WTF EATON! Why would you make a posi case that hard, when the detroit is not even close to the same hardness and more abused. Ugg...

Pictures..

OH and anyone that needs any Quality jeep work or machine work, he is for hire he said.

Detroit TrueTrack: all the install fun of a full case locker
All the traction of a LS.

Glad you got it sorted Robert.

werent people having problems with some part internally on those things wearing into the case and making the whole unit worthless? maybe they stepped up the quality of the case to deal with that. I know the boostwerks guy modified his to have a needle type bearing in the end to fix a problem with wear inside the case.

I have used a carbide burr to drill out leaf spring holes in the past. That is the only way I have found that I can drill spring steel. A carbide burr and lots of lubricant should make it work well. Sucks you had to use up several end mills, those things are pricey.

here is boostwerk's thread: http://naxja.org/forum/showthread.php?t=1062865

souske said:

Detroit TrueTrack: all the install fun of a full case locker
All the traction of a LS.

Click to expand...

SPOBI

Trutracs work fine, you just have to "know" how to work them.

Bad info? I have one in my DD!
They are *not* a locker

GrimmJeeper said:

here is boostwerk's thread: http://naxja.org/forum/showthread.php?t=1062865

Click to expand...

Yeah totally different then this one..

This looks like some soft material


I know you cant really tell my looking, but my case was all machined and LOOKED hardened.

And this this design is very different.



So they must have changed some things.

i find plunge milling to be a little hard on endmills, especially on hardened stuff with a not so rigid setup. glad you got it done, it would have sucked driving down here and back just for that.

souske said:

Bad info? I have one in my DD!
They are *not* a locker

Click to expand...

it's not bad tech, it's just different tech.

I am lost, where is the "bad info"? Who said it was a locker? And who said there was any tech?

lol

inside joke. carry on :rof:

Since we're sidetracked anyway... The trutrac provides for more capability than a clutch type LSD, thats all I meant. My trutrac was more than capable of LOCKING the front axle even when I had one front tire in the air. It is a worm gear type posi, and therefor requires torque on both wheels to lock....so if one is in the air, it spins....unless you preload it with the brakes before you get to that point. Extrememly feasible in a front axle with auto trans...or stickshift if you have three legs.

A question for you machinist types, would tapered ream work for enlarging a hole in hardened material?

Alot of variables there, is it carbide tipped, what size taper (angles), in a drill press/mill, free hand, how hard (hrc), thickness/depth, through hole/blind and I would not do it. You can buy carbide spade drills (pricey) and I would not free hand drill with it. All depends on circumstances.
But it could be done.