Screw extractor - Pilot hole size and which size extractor to use

[dusty]

If you have enough material to survive drilling and tapping an over sized hole, that is the way I would go. But, I would do that only after attempting to drill out the captured screw WITHOUT over sizing.

I understand that you already have an off set hole created in an attempt to drill out.

I would clamp everything in place, attempt to recenter the hole without going deep and then go from there. Good Luck.

You could also just drill out the holes, fill them with epoxy (JBWeld) and redrill and tap new holes. The epoxy serves only one purpose - to allow you to redrill without having the bit forced off line. Theoretically, you would end up using the original hole after this process is completed successfully.

I have seen this done several times but it was done using a milling machine and not a drill press.

If you try this you may only get one shot at it so use a good tap and start it with the tap chucked in the drill press (power off) without moving the work piece after drilling it.

Good Luck

[JPG]

Now that Dusty has mentioned a milling machine in to this fracus, I repeat what I said earlier: 'Get an end mill'(bit).

It will chuck up nicely in the jacobs chuck. You will need to rig up a secure/accurate way to hold/position the 'workpiece'. Until you posted pix I had not a clue if this might be possible(holding possible).

Don't be impatient and let the bit work slowly.(both rpm and feed) With an end mill, the offset hole can be serve as a chip sump. Seriously it won't cause the bit to wander(if feed rate is good).

The end mill bit needs to be slightly smaller than the tap drill size for the threads in the hole(that is why secure/accurate is important).

You can find end mill bits at any convenient store(with gas pumps and karo syrup).

[mickyd]

If you have enough material to survive drilling and tapping an over sized hole, that is the way I would go. But, I would do that only after attempting to drill out the captured screw WITHOUT over sizing.

I understand that you already have an off set hole created in an attempt to drill out.

I would clamp everything in place, attempt to recenter the hole without going deep and then go from there. Good Luck.

The off center hole is probably going to cause me a lot of grief with attempting the oversize / re-tap approach due to the mating hole in the guide bar, yet it is on my list of possibilities. The "Mr. Originality" voice in my head however is pushing this approach down the list, possibly off all together.

You could also just drill out the holes, fill them with epoxy (JBWeld) and re-drill and tap new holes. The epoxy serves only one purpose - to allow you to re drill without having the bit forced off line. Theoretically, you would end up using the original hole after this process is completed successfully.

I have seen this done several times but it was done using a milling machine and not a drill press.

If you try this you may only get one shot at it so use a good tap and start it with the tap chucked in the drill press (power off) without moving the work piece after drilling it.

Good Luck

I like this idea and have pondered several variations of this approach. To my advantage here is the fact that I have a good amount of clean virgin threaded hole under the bottom of the screw that if kept intact, will allow me to insert a screw from the bottom of the hole and have it extend up past the top surface after I hog out whatever I need to to get the original screw out. I could then JB Weld around the temporary screw to fill up the pocket and once cured, remove the screw. I wouldn't even have to tap the JB Weld. If the formed JB Weld threads don't come out well, I can just use a larger screw. I'd probably use a longer screw anyway.

Thanks for the input.

[dusty]

If you have virgin thread that is accessible from the back side, can you tap from that side. If you can, it would almost quarantee perfect alignment.

If so, I would hog out the intereference, fill with JBWeld and go from there. Taking care NOT to inject JBWeld into the area of the virgin threads Run a screw into it while doing the JBWeld.

[mickyd]

Now that Dusty has mentioned a milling machine in to this fracus, I repeat what I said earlier: 'Get an end mill'(bit).
.......
You can find end mill bits at any convenient store(with gas pumps and karo syrup).

You mention repeating what you said earlier?? You must have said it in your head because I sure don't see it here on "paper", at least not in this thread. (Or did you mean earlier in your life? )

I do like this first suggestion of an end mill though. Glad you finally brought it out of the closet. Will consider for sure.

jpg's reference to the karo syrup needs explaination.... I stopped at two full serve gas stations on the way home looking for kerosene. Neither of the attendants even knew what it was. One was guiding me down a food aisle, thinking it was used for cooking......thinking......karo syrup was kerosene. I gave a friendly smile but a snort came out accidentally.

[mickyd]

~$16.00 for an "square end" end mill (square end = axial and radial cutting abilities). Too much $$ unless I have to. On the list but now low.

[johnmccrossen]

mickyd, Is there enough room on the back side for using a small angle drill? You might be able to make (or buy) a drill bushing (threaded or plain) that would allow you to accurately drill through from the back. Good Luck, John McCrossen

[mickyd]

mickyd, Is there enough room on the back side for using a small angle drill? You might be able to make (or buy) a drill bushing (threaded or plain) that would allow you to accurately drill through from the back. Good Luck, John McCrossen

I'm not sure John. I think it's too close on the sides facing the width of the extension table. Good suggestion though. I don't have a right angle drill in my arsenal of power tools however. I guarantee you that my next pilots are much closer to center. I didn't take the time I should have, not to mention the mediocre lighting I was working under. Throw some aging eyes in an I am lucky I even hit the screw at all!! It sure looked closer to center when I tapped the center punch. I'll use the circle center finder threadthe next 4 times I have to do this.

[lv2wdwrk]

I don't have a right angle drill in my arsenal of power tools however.

Mike - you can get a right angle adapter for your drill. HF has them for ~$20.

[JPG]

Mike - you can get a right angle adapter for your drill. HF has them for ~$20.

That makes the end mill cheaper!:D Maybe my 'previous' mention of one was in a PM???

FWIW how much does not getting all these done cost???