Damaged big twist drill

[Hukshawn]

Here I took some better pictures of the hoopajooped end.



This is the part that's annoying. The shank is actually off center on the drill.



At its thickest at the base, it's 1/2". But there is a taper in the thicker part above. I'd guess probably about an MT5. If I can get this chucked up, I could do the MT sleeves idea.

 

[Hukshawn]

It says Morse twist drill & Moh Co.
New Bedford, mass.

 

[Silverbullet]

Just cut the bent short stub off. Start fresh , with a good inch or so in the new adaptor it should be good.

 

[Jimsehr]

I just checked EBay and found a nice American made 1 1/8 drill for $29 dollars shipping included. So you might see if it is worth it to fix yours.
Jimsehr

 

[Dave Smith]

Shawn--I have fixed many big MT drills that the turned down shaft is bent---first lay it in a section of angle iron and rotate it to determine which way is the bend of turned down shaft end---second clamp it in a vise so the bent section is facing front and the turned down section is at the end of the jaws---third use a heavy hammer to get a good blow to end side to straighten the bend-(you can slip a section of pipe on the end for leverage and hit on the pipe end)--forth put the bit back in the angle iron and rotate it to see if you gained---keep going through these steps until it rotates without wobbling----the next step is to carefully grind any burs off with an angle grinder flap disk so you can slip a thick walled tube over the bad section and weld it in place----since you will not be using the bit at a fast rpm it should work good again---you then can file three flats on it to keep it from slipping in chuck---this method just takes some of your time but is rewarding when you use the bit---since you were skilled enough to sharpen it nice then you will have no problem straightening it---Dave

 

[Hukshawn]

There's some really great ideas here, guys. Thank you. I acquired a few more big drills. The house I'm currently wirking on has a huge hobby barn FULL of stuff. And I mean full... the previous homeowner had lots of money and liked auctions. Mechanic kind of stuff. He's gone now and the current homeowner (his son) is just trying to clean up to make it all useable. So, I've had free reign on a lot of stuff. Most of it is garbage tho... but, some good. No machinery. I'll need to de-rust some things so I may be giving mr petes rust Olympics another watch.

 

[Chipper5783]

David, great work! Could we have a look at your MT3 holder for the tool post please?

Pretty straight forward. Most of the QCTP offerings will have the option of a MT tool holder. There are various arrangements. I have one for my CXA, which is dedicated for a morse taper - use it on my 15" lathe. I have two for my 40 position system which uses the dedicated boring bar holder and then an adapter sleeve (MT2 & MT3) - for the 11" lathe.

Of course you could make a block (square and bored for MTx) and hold it in about anything. You could make up a Gibralter style holder and bolt it down to the cross slide (this was an available option for Dean Smith & Grace also from Mazak). Several options to improve on simply a QCTP tool holder, but I assure you, the QCTP holder for morse tapers works great on drill 1-1/4" and smaller.

 

[whitmore]

Here I took some better pictures of the hoopajooped end.

If you could turn a cap for the cutting end, to engage the tailstock center,
then indicate on the undamaged circular bit, with the hoopajoop
shaftoid in a four-jaw chuck, THEN you could cut a small taper
to take brazing into a scrap of some suitable shaft bored with a
mating socket.
A munged tool with a good MT2 end would be a good find in
the local scrap pile.

 

[Tozguy]

Chipper, thanks for the pictures. I will look into making an MT3 sleeve for my boring bar holder.

 

[Steve Peterson]

Shawn that is a lot of bit for such a small diameter shank...Looks like a disaster waiting to happen...or perhaps already has. Do you think someone has already turned down the shank to fit their chuck? Or ground it down?

David

It looks to me like the previous owner ground down the shank to fit a small chuck. Must have done a bad job of it.

Steve