Sensitive Drilling Table

[cfellows]

After breaking several 3/64" drill bits drilling pilot holes in my V8 connecting rods, I decided I needed a sensitive drilling fixture. Actually, it's probably more just the fun of building than actually having one, but, still, it would be a handy addition to the shop. So, while waiting on delivery of some 8-40 taps and dies for my V8 air engine, I decided to build me one.

My design will be similar to the Hummingbird Drilling Table designed by Jose Rivera and marketed through The Little Machine Shop. However, it's currently out of stock and I don't know if it's been discontinued or not.

I favored this design over the drilling table featured in HSM because the HSM model has a rotating table and you can't secure work to it for drilling. It is, however an elegant and simple design.

Simple enough to build my own. My design uses a small linear slide which has an aluminum body with steel ways and counter rotating angular rollers. I'm also using a 3/8" thick steel base for weight and stability. The rest of it will all be aluminum.

As an aside, I picked up a set of ball end hex drivers yesterday from Ace Hardware. Almost $25 with tax, but these little guys are really going to be a useful addition to my shop. Makes installing and removing socket head cap screws really fast and easy.

Chuck

 

[Don1966]

Chuck I look forward to seeing it built. I have a set of ball end hex drivers love them.

Don

 

[Mcgyver]

Hi Chuck, that HSM design above is a picture of the one i made (bob pinched it for his site).

Anyway, I would just footnote the table rotating from this users perspective is a non issue; actually never occurred to me. Likely it doesn't rotate because of the friction between post roller on the crank. If it was an issue I'd slot the shaft and loctite in a 1/16 pin, but it hasn't been an issue

What makes the design of the HSM one so great imo is balance. The little brass cylinder is moved on the rod to balance the table and work. That's what gives it such great sensitivity; that and little fiction. That Little Machine Shop designed isn't balanced is it? If not, I wouldn't build or buy one. While I haven't used it, if you're applying force to overcome gravity its at the price of sensitivity.

just my $0.02

 

[cfellows]

Chuck I look forward to seeing it built. I have a set of ball end hex drivers love them.

Don

Thanks, Don.

Hi Chuck, that HSM design above is a picture of the one i made (bob pinched it for his site).

Anyway, I would just footnote the table rotating from this users perspective is a non issue; actually never occurred to me. Likely it doesn't rotate because of the friction between post roller on the crank. If it was an issue I'd slot the shaft and loctite in a 1/16 pin, but it hasn't been an issue

What makes the design of the HSM one so great imo is balance. The little brass cylinder is moved on the rod to balance the table and work. That's what gives it such great sensitivity; that and little fiction. That Little Machine Shop designed isn't balanced is it? If not, I wouldn't build or buy one. While I haven't used it, if you're applying force to overcome gravity its at the price of sensitivity.

just my $0.02

Yes, I had seen your name associated with this table and I do apologize for not inserting your name to give you credit for it. It is an elegant design and I like it a lot. The only reason I favored the Hummingbird was that I could easily attach a small vice or fixture to the table for repetitive operations on multiple pieces (like connecting rods for a V8 ). That and the fact that I had that small linear slide laying around that I was just itching to use!

As you say, the shaft of your design could be keyed and the top could be any shape you wanted. My elevation lever will be a simple lever so adding a counterweight will be easy enough.

I'm just about finished. All I have left is adding the lever lift assembly and drilling and tapping some 1/4" holes in the top for fastening things down.

The table has about 9/16" vertical travel. I can add more if I need it, but I think this is plenty for small hole drilling.

And the glamour shot...

Kind of surprised that the little linear slide has absolutely no detectable slop, yet is buttery smooth.

Chuck

 

[Mcgyver]

Yes, I had seen your name associated with this table and I do apologize for
not inserting your name to give you credit for it.

no apology needed, I was really just establishing credentials . Credentials in having used one....to clarify I am NOT the designer; as you noted it came out the mag and it wasn't my article.

good luck with your build. if you can incorporate a counter weight it is imo a good idea; its a great feature of the little one pictured above. those linear bearings are something aren't they?

 

[Don1966]

Looking good Chuck, but where did you get the linear slide from?

Don

 

[cfellows]

Looking good Chuck, but where did you get the linear slide from?

Don

Thanks, Don, I bought the slide on ebay. I don't recall how much I paid for it, it was several years ago. If you find one, make sure it's made from aluminum. It needs to be as light as possible.

Chuck