How should I setup these cuts?

[Marshall Harrison]

My son designed a DVD rack that I'm building for him. Essentially it has two birch ply sides that will have a series of dados that will hold shelves of luaan. I can cut the dados with my TS as my standard curf will fit the luan fine.

I'm having a problem trying to decide how to make the cuts so that they will line up on both sides and be evenly spaced. I realize now that it would have been wiser to make the dados first on a larger piece of wood then cut it into two pieces but I didn't do it that way. I was thinking of something like a box joint cutting jig with a key of something that will register in the last cut to get the spacing right. I just can't decide what to use for the key and how to setup the jig so that spacing will be correct.

Any ideas will be appreciated

[Michael Ballent]

You could use a router jig that has a edge guide that would fit into the prior cut. First dado the edge guide would ride on the edge of the plywood, move the router and put the edge guide into the previous dado and route the next one, keep going until your are done... That should give you equal the same distance for each dado.

Hope that helps :D

[Ken Garlock]

Marshall, if I understand your problem, I would proceed as follows:

Cut one piece of plywood the width of 2 sides plus 1/8". Then cut your dados across the entire width of the board. When done, rip the board down the middle. Voila(a large violin), you have your two sides with absolutely matching grooves.

As the Russian fellow said in the movie 2110 "It a piece of pie." :)

[Marshall Harrison]

Thanks Micheal and Ken.

I would rathre not use the router as I don't have a bit that small. The saw kerf from my standard saw blade is the right size so I prefer a method that would use it.

Cutting the dados on a board then riping it to create the side is the way I should have donit and I may just scrap the sides I alread cut and do it that way.

Mi biggest problem is getting the dados evenly spaced over the entire side. The luann shelves to hold the DVDs should have the DVDs evenly spaced apart. I need to cut about 20 dados evenly spaced up the entire side.

[Mark Singer]

Marshall,

Cleat them together with temporary cleats. Use a router and make a jig that moves the router the desired distance. Have a piece of masonite that registers in the first dado and sets the fence the proper distance away. Then rout both pieces in one pass. They shpuld be mirror images of each other...remove the cleats and you got it! Its better to make the piece wider and rip off any tearout. Enter the router on the good edge don't exit!

[George Summers]

Since you are using ply for the sides and thus, I assume, will use some type of edge banding on the front of the sides to hide the plys: why not just edge glue the two sides together, run your dados across the combined piece, re-rip and use a tad thicker edge banding to make up the kerf width you lose in the ripping.

George

I happened to think later (it seems its always later) that you could use a 1/8" thick piece in the edge gluing and rip it out when the cross dadoes are finished and still have the same width sides.

George

[Norman Hitt]

I was thinking of something like a box joint cutting jig with a key of something that will register in the last cut to get the spacing right. I just can't decide what to use for the key and how to setup the jig so that spacing will be correct.

Any ideas will be appreciated

Marshall, at the point you're at, I would make a box joint jig. To make the key, just take a 3/4" board about 4" wide and 18" long (for control), and stand it up on edge against your saw's fence, and set the key's width and run the board about two or three inches into the blade, then stop, shut off the saw and remove the board when the blade stops. Then lay the board down flat and set the fence for height of the key, then push it into the blade, again, about two or three inches and again, shut off the saw and remove it after the blade stops. You can then break out the key, or cut it off with the saw and insert it into the jig.

[Dave Richards]

I couldn't follow Norman's description but he's on the right track. Make yourself a box joint jig for your miter gauge. A simple wood fence attached to the face of the gauge and extending beyond the blade. Before attaching the fence, make a cut through the fence to hold a key. Then move the fence the same distance as you'll have between dados. Mount the fence to the face of the gauge.

Add an 1/8" key in the slot you just cut. This will register the plywood for each successive pass.

Since it sounds like you're using an 1/8" kerf for your dado, I'd be inclined to epoxy an old drill bit or something else that is 1/8" in diameter into the key slot in the fence. It would be safer than making a piece that small on the tablesaw.

[Ted Shrader]

Marshall -

All are viable suggestions. Thumb Rule: There are at least three ways to do every task in woodworking. This is a great illustration.

However, I like George's great idea. Add a scrap strip in the middle, glue everything back together, cut dadoes and rip apart. Goes with your idea you wish you had done in the first place to achieve the alignment. Won't have to build a finger joint jig or buy a new router bit.

Regards,
Ted

[Fred Chan]

Marshall, I'm with Ted on this one. Use a thicker piece of whatever material you're going to edge band with between the boards. After dadoing just rip the pieces and presto! pre edgebanded sides.

[Marshall Harrison]

I think I'm going to go with a combination of what has been said here.

Use the TS since the kerf is the right size and I don't have a router bit that small

Add a fence to my miter guage. Not sure what to use for a key that small but the idea of a drill bit sounds promising.

Buy some other wood large enough to cut both side's dados at once then split it. I'm going this rout becuase I've decided the 3/4 ply was a bad choice. I want him to be able to remove the luaan shelves and arrange them as needed so that he can handle double box DVD sets. That meens that the slots have to come through to the front. Can't think of a way to make the ply look good on the front and still have the slots go through.

Thanks. I'm going to have to finish this soon as I seem to be dreaming of ways to do it all night. Kinda ruins my sleep :mad:

[Jerry Clark]

I would band the front edge for clean effect and use the TS blade in the RAS and use a finger to set the shelf spacing.:rolleyes:

[Doug Shepard]

Since your pieces are already separate, here's something else that could work:
* Cut a spacer that's as wide as the spacing you want between each dado.
* Set your TS fence to put the first cut where you want it, then cut the first slot in both pieces.
* Shut the saw off
* Slip the slot on one of the pieces over the TS blade.
* Unlock the fence and slide it over. Then put the spacer on the end of your piece and slide the fence back up to it and lock it down.
* Remove the spacer. Remove your stock. Power up and make the next cut.