3 Box Joint Jigs in a 3/4"x24"PVC pipe

[air force 1]

I was having coffee this morning and had a brain storm.

You see all them jigs in your shop, what if you could put three of them in a 3/4" PVC pipe about 24" long? And mount them on the side of your router table.
Go down to the hardwear store and buy three square rods, 1/2" - 3/8" and 1/4" (or the size box joints you need), cut them the leignth of your router table (you will have to figure the size) and drill a hole, say an inch from the end,and drill matching holes in the router table top,at the bottom you will need a hole for each size, it will povot at the top hole. Before you drill the bottom holes,mount each size and adjust for that size from your router bit. Then put machine screws with wing nuts to hold them in place.What do you think?

Joe

 

[Ray Martin]

Joe,

Could you sketch this up and post? That would help me understand your concept.

Ray

 

[Gotcha6]

I see what you're doing here, I think.
1. The 1/4" square stock would have to have a small(10-24 +-) screw to hold it on unless it was attached to a larger end.
2. As you progress up in size you'd want to use incrementally larger screws, offsetting them and staggering them so they wouldn't be too close together in the router table.
3. After you've registered the locations, you'd probably want to avoid any further adjustment and use something like c/s screws to maintain alignment.
4. Guides would have to be aligned to the miter fence so the joints would be square through the board.

Am I on the right track?
:eusa_thin

 

[air force 1]

Here is that drawing, I think this will help. You will need to do this for each size. You keep the same pivot point. But at the bottom you will have 3 holes, one for each size (if you need them). Joe
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[gator]

Neat idea. One question, what would you use to make sure you feed the workpiece square to the guide bar? I'm thinking maybe a 6" block with a dado the size of the bar to use a push block to push the work piece through?

George

 

[Sully]

Ahh, now I finally understand how this would work!

Correct me if I am wrong. The picture is a top view from above the router table. The idea is to use the guide bar (on the left of the bit) as your reference for making equally spaced cuts for the "pins/tails" in the box joint. Is my interpretation correct?

Why not just use a single size reference bar? The pin/tail spacing is only set by the reference fence to bit distance and the bit size. Provided you can smoothly and accurately reference the workpiece on the cross-bar you could cut any size you wanted with one reference. Of course the reference would have to be narrower than the diameter of the smallest bit you would use.

This is similar to the reference bar on jigs like the Woodsmith version.

Just a thought. Not trying to discount your idea, I like it. I've never seen someone try it that way and I think it could work.

J

 

[Joe Lyddon]

Don't forget... the space controlling pieces (rods) DO NOT have to be the same distance high... in fact, if too high, they could prevent you from using box joints on some stock... Like 1/2" box joints on 1/4" thick material. The height really only has to be no more than 1/4"... just enough to control the cutting distance from the bit.

The rods do not have to be very long either... after all, you're always cutting into the ends of pieces (for box joints).

I would be concerned about any flexing... that must NOT happen.

Just thoughts off the top of my head...

 

[Joe Lyddon]

Neat idea. One question, what would you use to make sure you feed the workpiece square to the guide bar? I'm thinking maybe a 6" block with a dado the size of the bar to use a push block to push the work piece through?

George

There is one nice thing about using routers on router tables.

The bit is round and just goes around in a small circle.

Keeping things Square to the bit, like a table saw, is not that important on a router table.

You can have a fence with a pivot at one end and merely move & clamp the other end to control distance between fence & bit.

In cutting box joints, it's more important to have the spacer fence stable so it does NOT move during the cut... and your workpieces should be straight up from the table (90* vertically square to the table) as you are cutting the edges. Your distance between your spacer fence & bit is also critical for box joints.

One thing I have done, that works great for me, is to use a good block of wood, say about 6" long, to get a good grip on, 4x4 with the ends square. I just use it as a "Push Block"... it keeps the end pieces square as well as provides a backer to prevent tearout.

The fence merely must be firm and stable at the bit and straight. The fence can be cross the bit from anywhere around the table as long as the above is done... and you will get the same cut, regardless.