Looking for drilling jig ideas

I've been trying various things over the last few years and I'm just curious if there's any engineering geniuses out there that have a better way to do this...

I drill thousands of holes in 1" and 3/4" aluminum square tube (1/16" thickness). The holes are mostly around 1/4". The distances between the holes are varied... Could be anything from one inch to a foot. Also, the 1/4" holes have to go through both sides, but there is also a smaller third hole on one of the remaining sides that match each of the first two holes. Because I do so many of these, I'm just looking for the smartest and quickest method possible. Multi head drills are out because many of the holes are too close. CNC would be great, but that's not an option right now. What I have to work with is basically one drill press. So far I've just tried using one master piece and then altering the distance of an end stop. That's not great because then you have to move each piece in and out, which can get tiring since some pieces are 5' long. Then I went with a template, but the templates wear out fast and it also doesn't work well with the full size bits. A smaller pilot bit has to be used first for accuracy, so then that makes it even longer to drill everything twice. Another thing that slows things down is that even the smallest amount of burst burs on the bottom have to be removed in-between each drill move, or the burs will make the bottom uneven and destabilize the piece on the next hole.

So far I'm thinking that maybe I could have a jig where there's pre- marked holes along the length of a base tube, where you could move a peg tab from hole to hole, using that as your backstop. Then the burr problem could be eliminated by having the tube sit on top of the open end of a channel, so there would be space in the middle. I don't know, that's the best idea I've come up with, but it would still mean moving each piece in and out for one set of holes. Also, the more you shift things, the more you run the risk of screwing up. After drilling about

80 holes in one piece and then screwing one up because you flipped when you should have flopped... that's when you start looking for a gun. My dream is to have something where you just lock it in and watch it go, but I don't think I can get something like that right now.


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as a first step, you might consider having two drill presses side by side, one with each size drill - drill all the small holes, then move to the next drill press and drill the larger ones. A foot operated press like was available with the older Delta presses would be nice also, or an air operated downfeed.

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William Noble

Are all the holes along the same line? If so, you could use single axis CNC!

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Put a microswitch on your drillpress quill to hold off controller movement while you drill. A linear table advances your workpiece exactly the right distance for your next hole after the quill returns to the top.

As your budget permits you can add a Z axis and a CNC controller to orchestrate things and take you out of the picture except for drill changes and workpiece loading.


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A pic or print of exactly what you're doing would help with the ideas here.

My first thought, Make a steel tube that just fits over your 3/4 and another that just fits over your 1 inch tubes. Very carefully drill all the holes in these larger tubes. Now you have a drill bushing jig. Insert part, drill all the holes, remove part.


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Karl Townsend

If the holes are always on the centerline, I would make a steel angle iron template, clamp the aluminum to the steel, drill 1/8" holes for all with a portable drill. Go back with the 1/4" or whatever bit. Drill one side only, all the burrs will be on the inside.

Templates can be color coded for different patterns or have separate templates.

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Well, you could use a multihead but drill holes 1,5,10,15, move the workpiece to the next stop, drill holes 2,6,11,16,....


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A few thoughts:

Consider multiple drill presses. I have two Harbor Freight 16 speed bench drill presses in the back of the truck (went shopping yesterday) that will join 2 more. They will be mounted on 24" high bases to get the table level where I like it. I make extension tables out of heavy laminate sink cutouts. Everything is fixtured, never have to change a drill to complete a part. At $200 each, you can save a LOT of time.

Take a look at your designs, see if you can standardize on hole sizes and/or dimensions. The object is to be able to build the minimum number of fixtures or templates to handle your product.

Consider mounting your part on a long board under the product,with it's template clamped on top. Fit your drill press with a hugely oversized table. Much easier to slide it around and get the next hole.

Your template should use drill bushings for much longer life. These are hardened steel, hold the drill accurately for 1000's of holes.

Consider a master template with all the holes you could ever want. Flip a piece of hardboard over the top with suitable notches to remind you which holes to use. Example: suppose all holes are in 1" increments and you use two sizes of drills. Fixture has the smaller holes and the larger holes in 1/2" increments with bushings. When you want a part with holes 3" on center, grab the cutout with 3" spaces on the notches. If you need the small holes, the notches are slightly different. If you want the first hole at 1", next at 2" next at 5", so be it.

Dave99 wrote:

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Drill bushings are not expensive, when you consider the use you will get out of them. Make a drill-jig out of angle or channel for each model and put bushings in them. color-code hole sizes, clamp the jig on the workpiece, and drill one size, change bits and do next size, etc. Or as Wm and Roy mentioned, get multiple drill-presses to speed up the work. At $200 a pop from Harbor Freight, it ought to give you the production gain you wish.

As for the breakout burrs, consider making a channel in the table, and put up a fence to keep the piece aligned with the channel. Deburr as a final operation, not one-at-a-time.

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Thanks for the ideas... You know, I was going to ask if anyone knew of anything like that single axis machine. That might actually work. But I guess I'd have to build a table for that.

What I used for a template before was aluminum angle. I knew the aluminum would wear out faster than steel, but I didn't realize how much faster. I was careful to try and not hit the template, but it still wore out after about 80 drillings per hole. I didn't even realize it until I started noticing some inaccurate holes, then I put the drill bit in there an realized they had gone way larger through wear. Maybe a steel one would last longer. I'm hesitant to use bushings because I've got many patterns and versions. It would probably cost about 1k in bushings.



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