If you have multiple accurate holes to drill, a drill fixture with hardened steel drill bushings is the way to go.  There are a couple schools of thought on the best way to locate the drill bushings in reference to chip removal, but drilling into wood you have a little more latitude than with metal.

I am at least eleven (11) years behind in making this type of drill fixture for the DeStaCo 225U toggle clamps I have installed on various fixtures for different woodworking operations, turkey box calls, etc.  On my napkin holder project, I used four (4) DeStaCo 225U horizontal toggle clamps for pattern routing the foot profile and the front opening of the napkin holder which saved a tremendous amount of sanding.  I also used a couple of the DeStaCo 225U clamps on my serving tray hopper fixture.

What prompted this latest drill fixture to drill mounting holes in wood for the DeStaCo 225U type horizontal toggle clamps and/or look alike (clone) clamps was the recent mortise jig I built using a design created by router guru Pat Warner who took using a router to the ultimate level of perfection in my humble opinion.  I have several of Pat Warner's books, CDs, instructional materials and products he offered for sale on his website.  I met Pat during a visit with our Son, Bill, Jr. and his family in Vista, CA in 2008 and had Bill drive me to Pat's home and workshop in Escondido, CA and was a fantastic and educational visit.  I snapped a quick picture of Pat catching him off guard, of which I will link here.  Pat died on July 28, 2017 and is certainly missed by his family and loved ones, the woodworking community and myself as well.  Pat Warner was a perfectionist for sure and produced First Class All-American made products!  His work was flawless to say the least.

HH225D CLAMPS

I recently modified the mortise jig and needed to make several spacer blocks to go underneath the DeStaCo 225U horizontal toggle clamps, however I replaced the DeStaCo 225U clamps with a look alike clamp sold by the toggle clamp store on line, of which has a little different mounting hole layout on the longitudinal axis, but their HH225D clamps are much smoother with less binding action in my humble opinion and have a longer adjustable spindle hold down.  Their HH225D will be my go to horizontal toggle clamp in the future; not to mention they are at least 1/2 or more in cost cheaper and the quality is as good or better than the DeStaCo 225U in my humble opinion.  The toggle clamp store provides excellent fast service as well.

PERSONAL SAFETY AND LIABILITY ISSUES

My goal will be to keep Safety paramount because hand and power tools can do serious bodily harm and death if not used properly, therefore these pages are solely for entertainment purposes only from a personal liability standpoint.  Please read the Legal Stuff page for additional information concerning liability issues before going any further.  Safety glasses and hearing protection is a must, however many times I forgo the usage of hearing protection; my bad!

MATERIALS NEEDED

I had a piece of scrap aka unallocated aluminum bar stock that was 1 x 2 x 8 +- inches and ordered four (4) hardened steel drill bushings: 1/4 inch I.D. and 13/32 inch O.D. x 3/4 inch length.

I used my smaller bench drill press to drill the holes into the aluminum bar stock, however one of the holes was too far off center to use without "buggering" one of the holes in the clamp base and had to regroup and start over.  I transferred the layout pattern fairly accurate as far as you can go scribing a reference line using a dial caliper which should be accurate enough for the hole pattern for the clamp, but something went a miss somewhere.

I decided to use my larger floor model drill press and an x-y table which should secure the bar stock and position the drill press chuck centered where I needed to drill.

I used a drill for drilling into plastic that had a very sharp point to index the table into position and centered the aluminum bar stock where the hole was to go.  I used a 120 degree countersink and several other drill bits working my way to the final drill size of 13/32" which is around .4062 inches for each hole with some run out by the quill/chuck.

A milling machine with digital read out would be the ticket for this drilling operation.  Afterwards, I found that my drill press table was not completely square with the drill which is definitely human error on my part.  Not out of square enough to ruin the project though!

There was six (6) drill bit changes for each hole, 24 total....whew!

Blue layout dye would definitely be an asset for seeing your scribed lines, but too frugal to order some just for this project.

I used a small cheap Harbor Freight arbor press to seat the drill bushings which were .406 inches in diameter.  I didn't have a reamer to open the 13/32 hole up, but the little press got the bushings in with a good amount of brute force applied.  I used this little press to seat frets in musical instruments.

I went as low tech as I could as far as using the drill fixture SN 71.  Pix below:

Just clamp the fixture in place and drill away!

I drilled some test holes in scrap material and they were close enough for Gov. work.

The above pix is the bottom side of the material edge guide that will have the toggle clamps affixed to.

Mortise jig with the new walnut edge guide member in position for a test fit.  I removed the edge guide clamp member from the Plexiglas platform and then holes were drilled into the member using the drill fixture and a battery operated drill with a 1/4 inch dia. drill bit.  I used a couple Irwin SP11 vise grip clamps to hold the drill fixture into position onto the edge guide member. 

The walnut guide/clamp member is attached to the mortise jig Plexiglas platform that holds the toggle clamps were drilled using the above drill jig and the 1/4 inch diameter holes were enlarged to 23/64 inch using three different drill bits.  EZ LOK brass threaded inserts were screwed into position.

A 1/4 inch diameter drill bit was used to center the drill press chuck, wood clamped to the drill press table at each end and then the hole was enlarged to 25/64 inch.  Each of the eight (8) holes were enlarged using the same locator/drill technique. 

Once all eight (8) holes were drilled to 25/64 inch, the EZ LOK brass threaded inserts for 1/4 x 20 bolts were ratcheted into the holes drilled.  The inserts were "tighter than two coats of paint." 

The stainless steel flat head socket cap Allen screws can easily be removed when adding spacer blocks underneath the  toggle clamps for holding down thicker stock.  Of course you need longer mounting screws too.  I originally set the DeStaCo 225U clamps for 3 inch maximum thickness stock and used a couple pieces of 15/16 inch thick scrap material as spacers between the toggle clamp spindle hold down and the square stock I was about to mortise.

The flat head socket cap Allen screws works much better than a hex head bolt and does not have interference with the sides of the clamp. 

Mortise jig with the new walnut guide member in position for a test fit. 

There was plenty of aluminum shavings from the drilling operation.

MORTISE JIG AFTER THE MODIFICATION

The next fixture/jig that I make, it will be easy to drill accurate mounting holes for screws and/or holes for the EZ LOK 1/4 x 20 brass threaded bushings.

Web published by Bill aka Mickey Porter on 03-11-19.