Carriage Drilling Adapter

[Hawkeye]

A friend of mine made one of these a few months ago. I thought he meant something you attach to the carriage so you could drill sideways through the work held in the headstock. Turns out, it is intended to hold a chuck or tapered-shank drill bit on the carriage so you can drill longitudinally into the work spinning on the headstock. Confused yet?

I started with a block of steel 3" x 2 1/2" x 2" and notched it to mount in the four-way toolpost. Then I drilled and bored it to hold an R8-to-MT3 adapter I had on hand.




Two comments at this point. First, if you don't have a boring head, consider getting one. Normally used on a mill, they can be useful on a lathe. Second, if you are boring into a piece on the carriage, or using the drilling adapter, you will need a crossfeed lock. If you don't already have one, add one. It can be as simple as replacing one gib screw with a setscrew that can easily be tightened and loosened.


Once the block was bored to a snug slip fit for the MT3 adapter, it was drilled and tapped to take two 3/8" SHCSs. Then on to the horizontal mill to slit in to the bored hole.


The drilling adapter is used as shown to hold a tapered-shank bit ...


Or a chuck - anything on an MT3 shank, including the boring head.


Now, if you're wondering why bother, when I'm drilling a really deep hole through stock held in the spindle, it takes a lot of cranking to move the bit in and out of the work to clear chips and add oil. The crank on the carriage is a lot faster, plus, I can now use power feed when it's appropriate.

 

[Sharky]

Nice work.
One question: Why clamp the taper, the taper should be self-locking like the tailstock?
-Just a little extra precaution?

 

[Hawkeye]

Read back a bit. The taper is inside the R8-to-MT3 adapter. The outside of that is parallel. The part I made clamps around the adapter with the two cap screws. The MT3 shanks are, as you say, held only by the taper fit.

I could have done an MT3 bore directly into the block, but I had a perfectly good one already made, so I used it.

 

[Sharky]

Duh.... I guess I missed the R8 part....
Still, nicely done, I think I need to swipe that idea,
Sure would beat moving the tailstock back and forth for deep holes!

 

[Hawkeye]

When I was making my threading dial, I was already wishing I'd made this adapter. And, of course, I stole it from my buddy, who has a commercial machine shop.

 

[george wilson]

Dean Smith and Grace lathes have a drilling adapter built onto the carriage. But,they are exceedingly heavy duty built machines. Even their 13" lathe is very massive. I'd urge being careful to not put excessive pressure on the carriage(which will try to twist it),when using it to power feed drills.

It could also be very hard on your feeding mechanism. I can't say what the maximum drill diameter should be,but for example,maximum drill diameter used on a Bridgeport milling machine on the power down feed is only 3/8". Drilling puts a great deal more strain on the lathe's components than ordinary turning operations. You are cutting TWO very wide chips,and the very center of the drill is not a very effective cutting tool if you look at it and think about it.

Be careful you don't jerk the face out of your quick change gear box,or bugger up the power feed gears. They really rip you for spare parts.

 

[itsme_Bernie]

Dean Smith and Grace lathes have a drilling adapter built onto the carriage. But,they are exceedingly heavy duty built machines. Even their 13" lathe is very massive. I'd urge being careful to not put excessive pressure on the carriage(which will try to twist it),when using it to power feed drills.

It could also be very hard on your feeding mechanism. I can't say what the maximum drill diameter should be,but for example,maximum drill diameter used on a Bridgeport milling machine on the power down feed is only 3/8". Drilling puts a great deal more strain on the lathe's components than ordinary turning operations. You are cutting TWO very wide chips,and the very center of the drill is not a very effective cutting tool if you look at it and think about it.

Be careful you don't jerk the face out of your quick change gear box,or bugger up the power feed gears. They really rip you for spare parts.

Thanks for the tips George, I hadn't thought of that at all. Lucky you posted this before I did any more...

Bernie



Bernie

 

[Hawkeye]

All good points, George. When I said "when it's appropriate", I was already wondering if it would ever be appropriate. Maybe drilling plastic.

 

[george wilson]

I'm not saying it should not be done at all,just urging caution when using the kind of light lathes most hobby guys have. I don't use my Bridgeport clone for power downfeed drilling at all. It seems to be a very nice machine,but being not the real thng,I can't be sure of how rugged the internal parts might be vs. a real Bridgy. I'd hate to have to find parts for it since it was made in 1986. Even newer Asian made machines are often big problems for the makers to identify their OWN products.

You can see the mill beside me on my left in the avatar. That's a Deckel fp1 sticking its head up in the back ground. When I got it,the power feed was not working. I took a chance on it as the guy owed me money(and that was the only way I could see getting it BACK!!).Turned out to just be a sheared off soft steel pin way down in the bottom of the column(which is just FULL of gears). The pin was about 1/8" in diameter,and made to shear off. I have seen 2 lathes with their QC gear box faces jerked off,though. One was jerked off because someone sheared the pin,and replaced it with a STAINLESS STEEL one!! It was a 9" South Bend. The other was back in the 60's and I can't recall the make.

I had a Sharp lathe at work that needed a tailstock part. I could not get the makers to correctly identify their own product. Ended up making the parts myself. And,that is a good Taiwan brand.

 

[itsme_Bernie]

George!

You have a Deckel?! I saw an MKII Deckel FP1 in person once, and have never gotten over it hah hah. Just an incredibly well appointed machine, and looked like such a prototyper's machine. My gosh

Bernie