Sensitive Drill 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.

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

[cfellows]

Just about finished.  All I have left is adding the lever lift assembly and drill and tap 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

[smfr]

Hi Chuck

Looks like a nice bit of work, but I'm trying to understand how it works. Does it raise the part as the drill bit works its way through, via the counterweight that I see in the second photo of your first post?

Simon

[cfellows]

Hi Chuck

Looks like a nice bit of work, but I'm trying to understand how it works. Does it raise the part as the drill bit works its way through, via the counterweight that I see in the second photo of your first post?

Simon

Thanks, Simon.   The counterweight only reduces the weight of the table, it doesn't overbalance it.  So you still have to manually move the table up and down.  The idea behind these little drilling tables is to use a pecking motion, Drilling down just a little bit, then backing out to clear the chips.  Usually what breaks a small drill bit is the accumulation of chips in the hole around the drill bit.

Chuck

[rudydubya]

Nicely done Chuck, as usual.     Will you be adding some kind of lever for raising and lowering the table?  And where did you procure the linear slide?

Regards,
Rudy

[AussieJimG]

It is a bit hard to see on eBay and I can't tell whether this is both parts of the slider but this looks a bit like the slider.

http://www.ebay.com.au/itm/NSK-LS15-15mm-LAS15FLZ-20-Linear-Guide-Rail-Block-Slider-Actuator-THK-New-NIB-/170879458586?pt=LH_DefaultDomain_0&hash=item27c9359d1a#ht_3545wt_1159

Jim

OK, ignore this, Chuck has posted a much better link

Jim

[cfellows]

Nicely done Chuck, as usual.     Will you be adding some kind of lever for raising and lowering the table?  And where did you procure the linear slide?

Regards,
Rudy

Thanks, Rudy.  I got the linear slide off ebay a number of years ago.  It came with a micrometer positioning handle attached to it.  It is 1.75" high x 1.75" wide x 1" thick and has a total travel of just over an inch.  The body and the slide are both made of aluminum and the ways are steel.  Instead of balls, it uses small rollers alternately positioned at 90 degrees to each other.  If doing an ebay search, look for linear positioner or linear positioning or positioning slide.

Chuck

[cfellows]

A little more information.  This type of slide is called a crossed roller slide.  The one I used was made by Parker and was called a positioning slide.  Here is one that is similar:

http://www.ebay.com/itm/SMI-LINEAR-1-CROSS-ROLLER-SLIDES-XRS16-24-FREE-SHIPPING-/360477842624?pt=LH_DefaultDomain_0&hash=item53ee275cc0

Chuck

[rudydubya]

Thanks for the follow-up info Chuck.

Regards,
Rudy