Help With A Jig

[Keith Starosta]

I've been asked to study the design of an old .22 caliber shell box, and determine what I would charge to re-create several new versions. The overall measurements of the box are 7 1/4" x 3" x 1 7/8"...

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The construction of the box itself is very basic and straightforward....merely a block of wood with the top 1/2" sliced off for use as a lid...

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My question is, what would be the best, most efficient way to drill the holes that will hold the .22 shells? I'm thinking that the use of a jig is in order, but a jig for the drill press, using brad-point bits? Or possibly a router jig, using a properly-sized collet? The smaller holes are 1/4", and the larger holes are 3/8".

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My potential client will most likely order many copies of this box, for resale at gun shows, etc. I would need to use something that would enable me to use speed, but precision as well. Being that this would be my first commission, I definitely want to deliver precision quality.

Thanks for any help you can provide!

Regards,

Keith

[Brian Vaughn]

I would use a pin offset from your drill bit, and a fence. All you have to do is place the first row of holes, then use the pin to locate each of the next ones. Because basically, you're just drilling shelf pins really really closely together. As long as your pin to drill bit line is parallel to your fence, then you're set.

[Tom Ewell]

If you have, can get hold of, or make an overarm pin router you could spend the bulk or your time making templates for the top and bottom.
Once your precise templates are complete you would be able to knock out the box fairly quickly.
Of course there is also cnc.

[Chris Fournier]

Well that is doable but it would be tedious. Sometimes tedious is what we do to make a $ or $$.

My first suggestion would be to find a fellow with CNC capacity that would do the hole drilling for you. Get a quote and integrate this cost into your cost. I know that this may not be appealling to many with the "cando" spirit so...

You will need a drill press, two drill bits of the diameter that you have specified, MDF, 1/4" ground drill rod, a two part jig, and patience!

Here goes:

Get a piece of 3/4" MDF and cut it to fit your DP (drill press) table. You'll fix this MDF to your DP from below, screws, washers or imbedded t-nuts and bolts, your choice, I'd use bolts.
Once the mdf is on your DP take your 1/4" bit and bore into the MDF, try get about a 1/2" deep hole. Now you are going to take one end of your ground 1/4" drill rod and grind it square and then put a chamfer on the end. Now cut a 5/8" to 3/4" piece off of the ground drill rod. Place the ground chamfered end of this piece up and the cut end into the hole in your MDF on the DP. You now have a very accurate hole boring machine that requires templates to make you $$$!

One thing though. How will you maintain concentricity when you take the MDF off of your drill press and then need to remount the table fixture to do another run of shell boxes? Well it's so easy to make that you can just save the guide pin and do the entire process over again or you could try to plunge the bit into the bored hole, pin removed and then fix the MDF down on that position. Likely also good enough.

Now the template. You need a template with the hole pattern for your boxes laid out to scale with 1/4" holes in it. It needs to be pretty tough to endure making many boxes. Since you're just starting out I'd say use 1/4" tempered masonite for your first effort. You can move to better more expensive materials if you end up wearing this jig out. How you lay out this masonite template is up to you. You can lay it out directly on the masonite, lay it out on paper, copy it and glue the copy to the masonite using 3M super 88 spray adhesive or you could lay it out on the computer, print and glue etc. In your lay out you will include the outline of the boxes dimensions!

Now CAREFULLY drill all those 1/4" holes on the layout. The job that you do here will be repeated on every box that you make so get it right!

Now you have a template but you need to be able to align and hold the box halves on the template while you drill. Take some MDF, pine whatever and screw it to the lay out lines on your masonite template - the lines that delineate the outside of your box. Screw these battens from the underside of the jig and make sure that you countersink the screws so that the jig sits nice and flat. If you're a hotshot you have a piston fit with your boxes and you can likely just hold them in lightly with hand pressure. To be safe you can use a DEstaco type clamp or a piece of wood and a screw set up to clamp the box half in the jig. Better safe than sorry...

Now plunk your lower box half in the jig, put the 1/4" bit in the DP and drill out your box by aligning all those holes in the jig on the guide pin in the DP table fixture and you are on your way. Of course you've set the depth stop on the DP as you require and you're sucking up all the wood chips as you go. If the bit gets clogged then "peck" the bit as you drill - in/out/in/out etc. This breaks the chips and keeps things going.

The box top is only a drill bit change away. Put in the 3/8' bit, set the depth and you're off. You'll need to adjust your clamping set up for the shallower top I guess.

Now the face of these drilled and routed surfaces is likely a bit rough. In my shop I'd pass them through the planer and take off maybe 1/32" or less to clean them up. If you want to really impress your client, then you could return to the DP and use a nice countersink, with the DP depth stop set for the chamfer you wanted and you could countersink all the holes - nice touch or over the top - your call.
By countersink I should really be saying "cross hole deburrer". Don't settle for less.

There you go, finish, hinges, invoice!

Good luck.

[Josh Rudolph]

I would make a single jig that used a router and a bushing. The bushing would register in the jig holes and then plunge route to depth. Change to the other size bit and reuse the jig on the other side.

[Chris Fournier]

Double posting.

[Keith Starosta]

Thanks for all of the suggestions, guys. I've got some noodling to do...and I've gotta do it quickly! His next show is in 3 weeks.

[Brian Vaughn]

okay, I'd like to change my suggestion to match Tom and Josh. You need to take the time to make a very good template, then just use a plunge router and bushing setup, using 2 different sized bits (But the same bushing!). Some double-sided tape (ala The Woodsmith Shop) Flip the template over for routing one side or the other, and you're set. Then, it's just the time involved for all the plunge cutting....

[John Coloccia]

I always do this sort of thing on the drill press. I do it slightly differently than Chris, though. I put a piece of MDF on my drill press table, a bit larger than the table, and then screw/glue a little frame all around the bottom of the MDF such that it captures the table. So when i remove and replace it, now it will index on the table the same way every time. This makes it easier to realign as all I have to do is twist the table until the bit is centered, far easier than trying to realign in x and y direction. To align it simply put a square against the pin, and turn the table until it's flush with the drill also. It takes me about 1 minute to setup the whole system.

The other thing is that you don't necessarily need the pin to be the same size as the hole you're drilling. I typically use a 3/16" dowel as my pin. Just make the hole in your pattern the same size as your pin and you're good. I use this for a lot of different things but always with the same pin unless I have a compelling reason to change it.

For the drilling template, I've done like Chris and used stops on the template, but I've also just used a little piece of double sided tape. I think I single handedly keep the double sided tape industry going as I seem to use it on everything!

Anyhow, that's just some additional ideas. There are so many good ways of doing this.

[Tom Ewell]

Just to add to my pin router thing.
You could actually use the finished box you have to make a template but you'll need to unhinge the box to do it.
Double face tape the outside face box to a sacrificial piece then your template material to the sacrificial. (or you could make up a frame to secure the the layers and use the same frame for production)
Use a 1/4" pin and bit for the 1/4" side of the box and a 3/8 pin and bit for the 3/8 side the trays can be plowed out at the same time.
Lay the box hole side down over the pin and lower the router to cut the template.
Once the templates are done reassemble the finished box to original condition.

[Greg Urwiller]

It would obviously be more expensive than a home made jig, but you might consider something like the HF 5" drill press milling vise. $70 but you could use one of the 20% off coupons to lower the price, and you can always use the vise for other projects. Anyway, with the cross vise capabilities it would be easy to mark the scales to your drill point coordinates and have excellent repeatability. Position the lid and base the same spot all the time and everything should align. I believe this particular vice has 7" x 8" travel. Nope, don't have one of these, so I can't tell you for sure how accurate it is. One thing you might have to test is backlash when reversing directions. Greg

[Erik France]

I've used a drill press doing something similar. I needed a grid of holes spaced 3/4" O.C. I ripped several long strips of mdf on the tablesaw 3/4" wide and then crosscut them into shorter pieces. I kept a few 12" strips too. I put 3 strips between my workpiece and fence and set my fence for the first row in back. Then I placed 9 short strips on one end of the workpiece and set a stop block to align it for the back left hole mark. I'd drill a hole, remove a short strip, slide it over, drill the next, etc. After the front row is done I would remove a long back strip and put the short ones back, and have at it again.

[John Coloccia]

I do this exact thing all the time, for drill bridge pin holes for example, and I do it exactly as you do. I carefully thickness a piece to what I want, and then either remove or add one until I get to the last hole. This is another fine accurate way to do it.

I clamp an old framing square to my drill press. That indexes the back and the side of my workpiece and shims (I don't have a fence).

[Garrett Ellis]

I've used a drill press doing something similar. I needed a grid of holes spaced 3/4" O.C. I ripped several long strips of mdf on the tablesaw 3/4" wide and then crosscut them into shorter pieces. I kept a few 12" strips too. I put 3 strips between my workpiece and fence and set my fence for the first row in back. Then I placed 9 short strips on one end of the workpiece and set a stop block to align it for the back left hole mark. I'd drill a hole, remove a short strip, slide it over, drill the next, etc. After the front row is done I would remove a long back strip and put the short ones back, and have at it again.

x2. You could even make an L shaped fence (or a framing square as John points out) so you could make spacers for both the side and back. I think this would be the simplest jig to make and the fastest way to do it. All you have to do is rip strips of wood/MDF to match your center to center distance(s).

Some of these other jigs are good ideas too, but seems like you would spend way more time designing and making the jig to be perfect than it would be worth for a few boxes. If you are making a LOT of these boxes... Well, CNC would be the way to go.