And how would you make *this*?

[Porter Bassett]

This seems really simple, but I'm having a hard time coming up with a good way to manufacture this.

Start out with a small piece of wood -- 3"x3"x1". On the top, I want to rout out a square recess 1/8" deep and approximately 2.5" across. But the size of that square is critical -- I need to be able to dial in to get the size exactly right. (I don't know exactly how big that square needs to be, but it's an odd size that I' want to be able to dial in.)

Ideas?

[Jim Kountz]

jig, router template.

[Greg Hines, MD]

This seems really simple, but I'm having a hard time coming up with a good way to manufacture this.

Start out with a small piece of wood -- 3"x3"x1". On the top, I want to rout out a square recess 1/8" deep and approximately 2.5" across. But the size of that square is critical -- I need to be able to dial in to get the size exactly right. (I don't know exactly how big that square needs to be, but it's an odd size that I' want to be able to dial in.)

Ideas?


I would use a router, template bushing, and a template. In addition, I would rout it on a much larger workpiece, then cut it to your final size.

Doc

[george wilson]

I'd put it in my milling machine,but that might not help you.

Make router jig.Practice and adjust till it works out. Remember which templet guide AND WHICH BIT you used with it.

[glenn bradley]

+1 on using the original to make a router template and a simple jig to reference the block the same way each time. This could be very much like a simple mortise jig except the shape would match your item.

[Jamie Buxton]

You say "manufacture". Are you planning on making a few of these? Or do you plan on making lots and lots? A router jig will do a few. But if you're going to make lots and lots, a computer-controlled router like the Shop-Bot might pay for itself.

[Porter Bassett]

I'm only planning on making one or two of these.

I don't see how a router jig would give me what I want. I'd measure and make the jig as close to the correct size as possible and rout it out, but then how would I adjust it to make just a little bit bigger? Start over and make another jig?

[Dewey Torres]

Porter,
How about telling us (or better yet showing us) exactly what you are trying to make. There is always more than one way to do things in woodworking.

[Jamie Buxton]

So your big problem is not making the hole, but knowing how big to make it.

Make a measurement device. Start with a piece of plywood which is perhaps 6" square. On top of it put four pieces of 1/4" plywood which are going to be the sides of the hole. Put the whole thing wherever it is that the eventual piece will be. Slide those pieces of 1/4" plywood around until they're correct -- maybe they touch something which sits in the hole, or whatever. Now you know the size of the hole. Make a router jig to cut that size.

[Frank Drew]

Porter,

I think George's suggestion of a milling machine is closest to what you want; you need to be able to fasten the work down and incrementally approach the final dimensions of the cutout, so the stops need to be infinitely adjustable.

For much less than the price of a milling machine, I found that my horizontal slot mortiser with three axes (bit in and out, table left/right and up/down) gave me some of this kind of precision and flexibility. The work would need to be fastened standing on the 1" edge but that shouldn't be at all difficult.

[Bill Keehn]

Rather than a jig, I'd use something even simpler.

On my router table I would clamp 4 blocks that would allow me to move the work piece around, but would limit the motion so that the cutting edge would remain within the margins of the square that I want to create. The blocks are easily movable if I need to adjust the size of the square.

Templates are good, but in this case I doubt you could make it work without double stick tape to hold the template to the work piece and more tape to hold it to the bench.

[Brian Kerley]

You could do it a few ways, but handtols might be needed. You could take a router and hog out most of the waste. Then you could use chisels or a router plane to finish it up. You need to take off a hair on one side, you can easily pare it with a chisel, unless I'm missing something. For a one off I woulnd't spend a ton of time making some complex jig, but would use a simple jig to get close and do the rest by hand.

[John Grossi]

I would make a jig as some has suggested. One side would be shimable (sp). For shims, use those post it note paper pads. I am not sure, but if each one is .005, put 4 or 5 together, make a cut, then take off 1 or 2. Sneak up on it. A little tedious, but you can get extremely close, within .001-.002. John

[Chris Kennedy]

I would consider using my mortiser.

Cheers,

Chris

[Joe Chritz]

Depends on how many. For one I would make a simple jig that looked like a box. The router rides in that box and cuts the block. Shims on the walls will let you adjust the fit.

If you are making a few a CNC or mill is a much better option and likely worth the effort to find.

Joe

[Porter Bassett]

Porter,
How about telling us (or better yet showing us) exactly what you are trying to make. There is always more than one way to do things in woodworking.OK. This is a puzzle where you try to pack ten pennies into a square that is exactly 3.374 times the diameter of a penny. There's only one possible solution:

http://mr.porteiro.head.googlepages.com/10_coins.jpg

I want it to be as exact as possible because I want the pennies to just barely fit together in that configuration, and I want them to not fit together in any other configuration.

At most, I'm just wanting to make a handful of these, so buying a milling machine is out of the question. I think I'll try making a slightly oversized jig and then shim it.

[Myk Rian]

Miter a frame where the short side is the measurement you want. Put a back on it and you're done.

[john bateman]

I think I'd just cut a block to the dimension needed. Then glue some sides on it that were an 1/8" taller.

[Dewey Torres]

John Bateman got it.

This method will allow you to dry clamp it and test fit the solution with the pennies.

[Porter Bassett]

Is it OK if I feel like a moron for not thinking of that myself?

Thank you for the help, guys.

[Jeff Duncan]

You did say you were making this out of wood right? If so, getting the kind of tolerances it sounds like your looking for will be awfully tricky. Actually, manufacturing it right won't be the problem, keeping it right when the wood moves from season to season will. Of course that will depend on what woods you use and what part of the country you live in.
good luck,
JeffD

[Lee Schierer]

Since you are only making one or two, make your router template oversize to start with. Line the inside surface with layers of masking tape until you get a profile smaller than you know you will need. Or wrap masking tape around your template guide bushing to make it large diameter. Make your cut. Then remove 1-2 layers of tape at a time until you get exactly the size you need.

[Dewey Torres]

Is it OK if I feel like a moron for not thinking of that myself?

Thank you for the help, guys.

Porter,
Just know that this thread could have been going on for days until you showed us what you were trying to do which is why I asked. When you ask a question, put out as much info as you can.

Furthermore,
If you cut these on a dependable square crosscut sled use stop blocks and once you get a satisfactory test fit you can leave your stop block clamped in place and crank out thousands of these things.

[Porter Bassett]

You did say you were making this out of wood right? If so, getting the kind of tolerances it sounds like your looking for will be awfully tricky. Actually, manufacturing it right won't be the problem, keeping it right when the wood moves from season to season will. Of course that will depend on what woods you use and what part of the country you live in.Good point. I hadn't even thought of that.

If I made the base out of plywood and then glued sides to it, would its size fluctuate less due to humidity changes than if it were made out of solid wood?

[Chris Padilla]

Plywood is more stable than hardwood. Quarter-sawn hardwood is more stable than plain-sawn hardwood.

Why not start with something cheap like MDF? This is an interesting puzzle. I found that the diameter of a penny is 19 mm or almost 3/4".

Regardless of the wood, due to the size of the project, I doubt it will move enough to cause you heartache. Start with your scrap bin and see what you can dig out.