Coring on my metal lathe

[Sheldon]

Been using a carriage mounted gun drill for years and wouldn't do it any other way.
It would be a waste of my time and energy pushing a tail stock back and forth.

Automatic feed for the win! My gun drill has the air fitting at the back, so it's super easy to align. Just put the tip in the starter hole, and line the air fitting up using a center in the tailstock. Lock it all down and let 'er rip.

 

[CuesDirectly]

Go with the one that is accurate, moving the tailstock by hand is not accurate, it's high and it may be left or right, that is why they have the lockdown. Use your dial indicator on the top of the tailstock, zero it and then lock it down, you may see twenty thousands of an inch +/-.

Expanding foaming glue with fill the voids created I guess but why not drill accurately in the first place?

Lock it down and take the time drilling 3 inches at a time and see if there is a difference.


Hats off to those who posted about their setup using the carriage, it's accurate when done right and those who posted did it right, great job.



John, if I can give one real important piece of advice, hang a bungee above your chuck, then attach your chuck key to it. The day you understand to never never never never leave it in your chuck is the day you can remove the bungee. I can see the lathe is not on but that is not the point, you don't aim an unloaded gun in the wrong direction for any reason, same with the key, never do it. Some are designed to fall out if turned on, that is why they are so loose, they are supposed to fall out before hitting the lathe bed but you can't count on it.

Great job on the last cue you posted, it looked great.

 

[JC]

Go with the one that is accurate, moving the tailstock by hand is not accurate, it's high and it may be left or right, that is why they have the lockdown. Use your dial indicator on the top of the tailstock, zero it and then lock it down, you may see twenty thousands of an inch +/-.

Expanding foaming glue with fill the voids created I guess but why not drill accurately in the first place?

Lock it down and take the time drilling 3 inches at a time and see if there is a difference.


Hats off to those who posted about their setup using the carriage, it's accurate when done right and those who posted did it right, great job.

What you say is true except the gun drill is a different animal. There is so much flex in the shaft that it really doesn't matter what's going on at the shank end (to a point). The cutting bit self centers in the wood. You could never drill a hole with a drill bit accurately pushing the tails tock for the reasons you cited.

Here is a photo of the deep end of the hole that I pushed through by hand and glued up Friday. I cut off the blind end and found my center this morning. The hole is .631" and the core is .625" and it is glued with west systems. This has not been trued up yet so the OD and ID are exactly where the gun drill cut it in the Cocobolo @13.5" deep. I ran it between centers and you can detect almost no runout at the end with the naked eye.

It may be the wrong way to do it but so far the results speak for themselves.

BTW I got the idea from a PM from this thread where the person told me one of his friends just pushes the tailstock. He wasn't recommending this, just mentioning it. So I tried it along with many other ways and it worked way better than I expected as I was trying different things.

Thank everyone for the input on this thread.

 

[JoeyInCali]

Go with the one that is accurate, moving the tailstock by hand is not accurate, it's high and it may be left or right, that is why they have the lockdown. Use your dial indicator on the top of the tailstock, zero it and then lock it down, you may see twenty thousands of an inch +/-.

The gun drill's head is supposed to go in straight following the pilot hole.
Using the tailstock is just as accurate as using the tool post.

 

[BarenbruggeCues]

The gun drill's head is supposed to go in straight following the pilot hole.
Using the tailstock is just as accurate as using the tool post.

Not contesting accuracy but if both ways work just as well and one way is much easier I will choose the easier way over working harder.

Working harder is not always working smarter. It would be just working harder.

 

[selkov]

I use my variable speed router and two drill bits. The first looks like a forstner bit but with regular flutes 1/2 deep this allow material to exit as the bit enters. The second is a regular bit .03 larger. cut slow, autofeed tool post. Apply air.

 

[JoeyInCali]

I use my variable speed router and two drill bits. The first looks like a forstner bit but with regular flutes 1/2 deep this allow material to exit as the bit enters. The second is a regular bit .03 larger. cut slow, autofeed tool post. Apply air.

What is a "regular" bit ?