Repairing a jacked cat-40 toolholder

Feb 15, 2011 17 Replies

Awl --



An unremovable setscrew left me doing the unthinkable: I ground the goddamm thing out with an 4.5" angle grinder, so there is like a gash half-way into the nose of the 3/16" toolholder. If you held the toolholder in the vertical, the ground-out region would be in the horizontal.



From previous responses, the whole holder is hardened, so drilling/tapping another hole will be semi-futile. If I *could* do this, this would work, even with this gash, as the tool would still be substantially supported.



So I figgered I'd mebbe weld this gash up with some soft rod, or even braze it, then drill/tap it. I thought I'd stick some old 3/16 carbide in the holder, to keep anything from "spilling" too far inward, and pray that nothing sticks to the carbide, or that nothing warps so bad I can't get the carbide out.



This toolholder doesn't have to be superstrong or super accurate, as it will doing lite stuff -- after all, these are only 3/16 tools, some engraving, etc.



Any tips, caveats in pursuing this? Best fill rod? Brazing better? Combo??



Heh, the good news is: At this point, I got nuthin to lose!!!


Your time is obviously quite valuable..

Maybe you can use it for a doorstop.

EA,

Have you gotten advanced B.Coli again??

Take a look here for a brand new one...

formatting link
It cannot be worth the time to Futz with, except for a hobby, recreation.

Just get a new tool holder, and go back to making Product! Nobody will pay you to fix that tool holder, only for shipping product.

Now back to work!

I forgot to add. For a small tool like a 3/16" you want a nice tool holder. Runout is always more and more critical the smaller the tool.

So, it ~might~ be worthwhile for a larger toolholder. a bigger tool can tolerate more runout without being hurt. For the small tools, only use good toolholders.

formatting link

If you had used an old carbide endmill running fast you probably could have drilled it out. You would need a green wheel or a diamond wheel to sharpen the enmill to a point like a die drill.

John

I'm not even a machinist, and even I know that you've rendered your toolholder useless. Like you said, you've got nothing to lose, but at this point I think you've got very little to gain by trying to save it, especially by weld bead.

To restore it to functionality would be more expensive than just a replacement toolholder; retire it. Maybe put it on your bookshelf and label it, "Don't Do This."

Good Luck! Rich

Like others have said, this one is ruined. But they can be machined. The first 50 thou is hard as glass and will dull damn near anything. After that regular carbide tooling works fine.

I've bored the top 3/4" out of several CAT40 holders so I could add an insert converting the holder to NMTB40. To do this, I took a stone in a die grinder to get rid of the top layer, then a quick boring job in the lathe.

This sounds like you have already close to cut the holder in half?

You could press fit on a sleeve and put a longer set screw in the sleeve.

-jim

That is a very *elegant* -- even slick -- solution!! My only hesitation with that would be the increase in diameter of the small nose, which comes in handy in some ops.

Also, I think this should weld up perty easy, if the material is not too exotic, and then it would be the same drill/tap fix. My only concern would be warping and/or sticking of the weld material to any carbide I stick in there as a kind of shield.

To Cross Slide: Heh, if I get this fixed, this will be my most productive effort in about 3 months!!! Goodgawd..... Ahm like *inches* away from fame, fortune, riches, and bevies of wimmins with nice big asses..... but those few inches are filled with 4140 plate.... and hardened 4140, at that....

Too bad you cain't perfume up bein broke..... well, I guess you can, if you consider beer a kind of parfum, and a saloon a salon......

Ever hear of "brazed Carbide"?

In what way was it "unremovable", exactly?

Stress & warp.

OTOH perhaps you could have hit the set screw with a torch .....

Yeah, I shoulda done that from the gitgo, but then given the events that preceded the grinding fiasco, heat wasn't an option. It will be, tho, on future occurences of stuck set screws.

In the way that a fukn *allen wrench* then broke off in the set screw, and then, while trying to mill alladat s*it out with carbide, the *carbide* broke off in the hole. I'm sure had I had a diamond tool, this too would have just continued my miserable luck.

Inyway, I'll use the softest weld rod I got, see what happens. Altho Jim's idea is certainly tempting....

Existential Angst wrote in rec.crafts.metalworking on Tue, 15 Feb 2011 18:32:25 -0500:

make sure you use set screws that are long enough that you can weld on a nut.

It will warp and be just as useless as it is now. Ebay a used one. or buy new.

It does have a small value as scrap steel.

Thank You, Randy

Remove 333 from email address to reply.

Snip usual drivel

ROFLMFAO

HTH, PaulS

Should have been able to get the broken allen wrench out.

Good case of the chatters, eh?

Or just weld the end of the welding rod to the screw & turn ....

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required