Drilling straight holes for Confirmat scews

[David Scigliano]

I am building a large entertainment center and would like to use Confirmat scews to screw the permanent shelf in. I will be using a special drill bit for the screws and drilling from through the exterior of the side to the shelf at 90 degrees. The shelf is maple ply and 3/4 thick. How do I drill a straight hole without going through the top or bottom of the self? Are there any guides that will work? Here is my wonderful drawing.

I I Melamine side 3/4
I I
I I
I I_________
I__ I__ Drill bit through 3/4 maple ply
I I_________
I I
I I

[tim mathis]

would a dowel drilling jig work, it would be straight.

[Mark Pruitt]

Would THIS work for you?

[Jesse Cloud]

Probably the most rigorous way is to drill the holes in the pieces before assembly using a drill press. Provide some support for the verticals. Move the table out of the way and stand the shelves on end.

Another technique is to use some sort of a guide, the dowel guide mentioned above would work. Or get a piece of hardwood and drill all the holes you need for a row and use that as a jig for drilling. Once you get it started straight, it will stay that way.

If you are using a step drill for your confirmats, it probably has a minimum rpm recommendation. Be sure your drill goes that fast (most cordless drills don't). And don't forget to drill a little extra deep to make room for a screwcover.

Let us know how it comes out, we love pics.

[Ralph Barhorst]

I would drill the correct size hole in a piece of 1" hardwood on the drill press and use it as a drill guide. The hole will be perpendicular. Align this drill guide at the position where you will be drilling and then drill through the guide into the melamine and plywood.

[Steve Cox]

There is actually a jig that fits on SOME cordless drills that provides a straight hole and the proper spacing for confirmat screws. I have used it while in another shop when we were assembling carcases. It was mostly used along the edge but would work in the middle also. Unfortunately I don't have any other info right now. I'll try to find out more about it.

[Steve Clardy]

Hardwood block with a hole in it sounds good.

[Richard Wolf]

I use the General Drill guide like Mark suggested to drill holes for baluster under my balcony rails. It keeps the holes plumb in all directions. Mark's link is misleading, because the work piece does not have to pass between the bars, the whole attachment can set upon your work. Self centering pins are also included.
www.woodworker.com/cgi-bin/FULLPRES.exe?PARTNUM=946-273
Richard

[Mark Pruitt]

I use the General Drill guide like Mark suggested to drill holes for baluster under my balcony rails. It keeps the holes plumb in all directions. Mark's link is misleading, because the work piece does not have to pass between the bars, the whole attachment can set upon your work. Self centering pins are also included.
www.woodworker.com/cgi-bin/FULLPRES.exe?PARTNUM=946-273
Richard

Richard,
Thanks--I tried to find that guide at woodworker.com and I couldn't find it to save my life!
Mark

[David Scigliano]

With the above jig, am I able to drill the holes with the jig 90 degrees? How do I prevent the jig from falling to the ground?

[Steve Cox]

http://www.baerco.com/baer/servlet/C...rkProd=1496609

Here is the link to a site that has the jig I mentioned earlier. It is called a "Zentrix" system and in use it is pretty slick. It will only fit on drills with a 43mm flange. The best explanation I can give you on the flange is to look at the two drills linked below. The first has the flange, it is the silver area right behind the chuck. The second does not have the flange and would not work with the Zentrix system. If your are going to build with Confirmats I would highly recommend the Zentrix system. It is fast and accurate.

http://www.amazon.com/gp/product/B00...lance&n=228013

http://www.amazon.com/gp/product/B00...lance&n=228013

[Per Swenson]

David,

Just mark your center, measure 1/2 the width of the guide and clamp a
straight edge to the cab for the guide to rest on.

Per

[frank shic]

david, the simplest way to do it is as per recommends. you can also make a jig out of three pieces of plywood which basically looks like a !_! to allow you to know exactly where the edges are going to be and then to drill with the drilling guide as recommended by others along the center.

i've used confirmats to build wardrobe closets for my master bedroom as well as a set of kitchen cabinets. i've found that they work best for the end butt joints. i used biscuits on the kitchen cabinets for the shelves after having a couple of blowouts with the confirmats on the wardrobe closets.

if you're interested, i'll take a picture of the modified drill jig that i made to save myself the cost of the zentrix drill jig.

[Joe Unni]

Please forgive the potentially dumb question, but is it THAT hard to drill a straight hole for the Confirmat screws even without guide? My only experience that is remotely close is the Miller Dowel System. I've drilled 700+ guideless holes for the dowels without a single blowout. For those that don't know, the stepped bit for the Miller dowels is around 3 1/2" long.

Again, I've no experience with Confirmat, but is there something special about them that I don't know about? Really, I'm not trying to be a wise guy - I just don't know.

Thanks,
-joe

[Steve Clardy]

Please forgive the potentially dumb question, but is it THAT hard to drill a straight hole for the Confirmat screws even without guide? My only experience that is remotely close is the Miller Dowel System. I've drilled 700+ guideless holes for the dowels without a single blowout. For those that don't know, the stepped bit for the Miller dowels is around 3 1/2" long.

Again, I've no experience with Confirmat, but is there something special about them that I don't know about? Really, I'm not trying to be a wise guy - I just don't know.

Thanks,
-joe

Probably for some Joe. I don't have a problem usually