doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com need help

so, I did something I knew I shouldnt have and knew what was going to happen but convinced myself it wouldn't happen to me.

Anyway, now I have a problem. I need to know who has the ability to EDM or some other tech method to get a piece of carbide drill and spring out of a blind hole.
I have tried everything. and of course I broke a drill off inside the hole . yeah, stupid is as stupid does.

the bolt is useless if I cant get the hole cleared.

We had a place called Jerry's broken tap and drill removal it was in Santa Ana CA.but you might find one near you they did a great job of fixing my self inflicted problems

JERRY'S BROKEN DRILL AND TAP REMOVAL

Machine shop in Santa Ana, California

Address: K, 1018 E Chestnut Ave, Santa Ana, CA 92701

Hours: Closed ⋅ Opens 7:30 AM Mon

Phone: (714) 836-6824

Some broken off drills can actually be drilled out themselves, but it requires a very good drill bit and just the right cutting fluid. My neighbor was helping a friend change out a mid-section on a saltwater fishing boat motor and broke one off last week. With care, he drilled it out dead center, and re-tapped the threads to the next larger size.

While I likely wouldn't try this next method myself, my m/l mentor and machinist friend did this many yers ago. He had been begged into working on a Purdey for an acquaintance. Jerry was extremely precise and careful in all his machine work but in spite of that he broke off a tap in a small hole on the Purdey. He anguished over what to do for weeks, calling people he felt were ingenious enough to help him correct the problem without leaving a trace on the gun. He finally reached a gunsmith who told him to heat the area around the hole and broken tap, lightly, and melt a tiny amount of beeswax into the flutes of the broken off tap. It was explained to him that the melted beeswax would seep into the treads between the tap and the hole. When it was cooled he was to use a very tiny amount of an acid, the name of which I cannot remember, and put it on the broken tap, a tiny bit at the time, and that in time the acid would eat away at the broken tap. The melted coating of beeswax would protect the hole itself. Knowing no other method to try Jerry proceeded and, in time the acid removed enough of the tap that he was able to remove it without a trace of damage to the Purdey.

Not suggesting you attempt this, but I thought it was so interesting that I have remembered it for some 40 years.

If you are sure it’s carbide, you are probably correct in your assumption that it will take something like EDM to remove it. It takes diamond wheels to sharpen carbide. But, if you are not sure, carbide end mills will cut most anything commonly used in taps and drills. A vertical mill be best using carbide. I tell all my friends not to use anything carbide for taps and drills when used in common operations. If they break one I can usually cut it out.

On a hobby level, if you have a dentist friend, maybe you can talk to them about using their high speed drill setup? I'd assume it's a relatively small diameter and shallow hole, might work, years ago I got a carbide tap out that way, or rather a dentist, duck hunting buddy did for me. It may also help if there's a bit of spring in there, just a little clearing out may get bits loosening if they're wedged against each other, instead of the gun part. Good luck with it.

I always wondered about using a dentist's drill for something like that. I remember years ago; I asked my dentist about his drill. I believe he said it ran at 30,000 RPMs. I guess some of the high speed drills run around 250,000 RPMs. That would be nice to have in your home shop.

I bought a set of these not too long ago. They are diamond dust coated. Big set for low money. The above posts make me wonder if it couldn't be done, very carefully and slowly, with a good Dremel tool and these. Good reviews.

https://www.harborfreight.com/diamond-rotary-point-set-50-piece-69665.html

Stan, those are only as good as the bond between the metal and the diamond. Get them too hot and that dust will peel right off. Ok for soft materials and light duty only.

The problem with titanium is that it is titanium, hard as heck and difficult to cut. I think Brian is right EDM is the answer. The question is will the cost be prohibitive? A photo of the part might help inspire a different answer or another solution. He is not the first person the have an issue like this and sometimes others have an outside the box solution for a problem. I’ve gotten a few broken screws and bolts out by freezing or using dry ice or welding a second bolt onto the broken stub. Perhaps the broken part could be removed or worked around. In extreme cases you could drill around it to cut it out and weld the hole up, then dress down and retap it.

From my experience cutting and drilling titanium, I think many grades don't put up much resistance, unless one feeds too slow Then, it gets gummy and can smoke bits in a blink? But carbide might be harder on cutting edges. My friend used carbide burs on the carbide tap, and ran through a few of them. Had the water running, but at that high rpms, it really looked pretty smooth, not too much chatter at all. He made a slot, we gave it a couple of thumps with a small punch, he made a cross slot, punched it again, and bits finally started breaking loose. Maybe lucky, it didn't look like the tap had bottomed when it broke. It worked on that sample of one, but if I'm not mistaken, you've probably got a good bit of mileage on that type of tool.