How do I cut plywood panel for different project pieces?

[Philip Florio]

Okay this might seem like a stupid question or maybe just a very simple newbie question.

I'm building a router table from some plans. I drew out the pieces on the 3/4" Birch plywood. Now that I've done that I'm wondering how I'm going to cut these pieces? I left a 1/8" space in between the parts for a blade kerf.

Using a circular saw doesn't seem practical since I might cut into another piece. Could the answer be a jigsaw for 3/4"?

Phil

[Alan Schwabacher]

One usually thinks about how to cut while laying out the pieces. Sometimes the grain pattern is the important thing, and you will sacrifice some stock to get the best appearance. In the diagram you show, if the two pieces on the right were shifted up a bit, you could rip the full sheet so as to separate the pieces on the bottom third from the others. Dividing the plywood into smaller, more easily handled pieces is very helpful.

If you do need to cut a corner to separate parts, it's probably a reasonable approach to cut most of the way with a circular saw and straightedge guide, then finish the corners with a jigsaw, cutting from each side. You will want to support the plywood so it does not shift as you cut it, either with some sort of lattice table, or on a sheet of foam insulation.

Unless you have a very well set up circular saw and guide (commercial or shopmade) you will likely find that finish cuts and final dimensioning are best done on a tablesaw after rough cutting to separate parts.

If you want to follow your diagram, how you cut depends on what you cut with. On a tablesaw a high priority is to get the pieces to handleable weight quickly. One possible pattern for your diagram would be:

1 crosscut I, I from D, D
2 Rip q,h from ABCD
3-5 rip ABCD pairs apart
6 crosscut A from A, B from B, ...
7 crosscut RQ from JH
Proceed from there with the little pieces.

However, I would increase the rough sizes of the pieces just a little, so as to have something to trim on the more accurate finish cuts.

[harry strasil]

reverse the pieces on the right end, cut the rest a bit oversize and then finish cut to size on the tables saw.

[johnny means]

No, no, no! A, B, C, D, and I should be ripped first. The rest of the parts should be able to be arranged in such a way that they fit into two last rips. This would leave you with four rips that only need to be crosscut and trimmed to size. No need for stop cuts or changing directions.

[Doug Shepard]

No, no, no! A, B, C, D, and I should be ripped first. The rest of the parts should be able to be arranged in such a way that they fit into two last rips. This would leave you with four rips that only need to be crosscut and trimmed to size. No need for stop cuts or changing directions.

That's my thinking too. Cant tell for sure from a pic but R & H look to be the same width? If so, I'd put them in the same strip then start crosscutting the rest of the small parts and rip those last if they're not all the same width.

[Chuck Isaacson]

Okay this might seem like a stupid question or maybe just a very simple newbie question.

I'm building a router table from some plans. I drew out the pieces on the 3/4" Birch plywood. Now that I've done that I'm wondering how I'm going to cut these pieces? I left a 1/8" space in between the parts for a blade kerf.

Using a circular saw doesn't seem practical since I might cut into another piece. Could the answer be a jigsaw for 3/4"?

Phil

That is a nice router table, I just built the same one. My cut up was a little easier. I was using a bunch of scraps that I had laying around, but I also wondered how to cut it all up.

CHuck

[Stephen Edwards]

You could also reduce the overall dimensions by 1/4" - 3/8" and have a little more wiggle room. If you keep the router chamber the original size, you won't even notice the small difference in the other parts of the table, IMHO.

Sometimes, plans are like recipes: you can make adjustments on some of 'em that won't have an adverse effect on the finished product. This is one that you can.

[John Coloccia]

First thing I'd do is make two rip cuts to separate all the A, B, C etc parts. The I'd use a panel cutter to make the remaining cross cuts. For stuff like this, I use the panel cutter with the fence setup on the opposite side of the blade. I setup the cut with the fence, and then move the fence away to keep it from binding during the actual cutting. All the other parts are pretty straight forward to do with a couple more rips, and some cross cuts...maybe even on a miter saw if you have one.

One trick to stuff like this is if you have a bunch of parts that have a dimension in common (say, everything is 24" long), try to cut all those dimensions at the same time with the same setup. If they all end up being 24 1/32" long, at least they all match and that's usually the important part.

[Dan Forman]

It might be helpful if you said what tools you have to work with . Do you have a table saw, and just trying to figure out how to cut the sheet down into more manageable sized pieces, or do you need to cut everything with a guided circular or jig saw?

Dan

[Philip Florio]

Thanks guys,

The tools I have are standard shop tools, table saw, circular saw, jigsaw.

Phil

[Tony Bilello]

The first thing I would do is shift your sketch to the right and leave the small cut-off on the left. Then you would not have to worry about your saw kerf thickness. If you cut as original sketch shows, then kerf would be a major factor and a slight error in one of your cuts and you would have to recalculate and recut all of your other pieces.

Having said that, my first cut would be to cut off II from DD. I would give myself some extra room and cut this with a skill saw and then clean it up on the table saw. This would be the safer way to do this in a home shop. Here is another place you can get into trouble and that trying to salvage the little scrap cut-offs into a larger piece. It can be done but your thriftyness can cost you a whole board some day.

My next cut would be rip cut to separate QH from ABCand D by making one long cut from one end of the board to the next. This would keep the dimensions of ABCD consistant by getting it all in one cut. Do your math and give yourself a little extra slack if possible on both sides of this cut so that the saw kerf width calculations does not have to be right on and any slight wavering in the long plywood would have some room for clean-up.

Next, I would go for manageability (if there is such a word). I would cut AA from BB. Then cut BB from CC and CC from DD.
Now you can set up your table saw to get ABC and D to the exact same size by ripping apart the A's then the B's and the C's and D's all with one saw set-up.

Next I would separate II from UU and then cut them up into final dimensions so they wont get confused with o the scraps.

Next I would separate QR from HJ leaving a little extra scrap to the left. The go ahead and final dimension those two pieces.

Next I would separate H from JS in one long cut. Then cut H to final dimension.

Next I would dimension J to final width. Then set up a cut-off block and cut all of J to final size.

You should now have enough leftover wood still attached to S so that it can be safely cut to dimension on the table saw.

[Matthew Hills]

If you've got a good infeed/outfeed setup for handling full sheets of plywood, rip away.

Otherwise, I'd get out some chalk and make some adjustments to the cutting plan so that I can start with a cross-cut between B and C using a circular saw and straight edge. I mark that edge with chalk, as I try to avoid using my circ saw cuts as my reference edges later.

With the weight split up, I'd then proceed with the rips

Matt

[Darrin Davis]

I use Cutlist Plus for figuring plywood cuts out. It will optimize your plywood and say $$$$. I think that it is free to try and it is easy to use. I bought mine so you'll have to check into it to see if it is still free. Probably the handiest program I every paid $50 buck for. Might be higher now, I've had it for several years.

[Scott Schwake]

Cutlist is free here:

http://www.delphiforfun.org/Programs/CutList.htm

[Chris Tsutsui]

A router table should be built with the best possible tolerances.

I would never use a jig saw to make straight cuts. Circular saws also should only cut straight through with this project.

One cut list strategy is after adjusting your table saw to one size, you make ALL of the cuts that need to be done at that size. Make things easy on yourself and get 2 sheets to lay this out though.

Keep in mind that beginners (like me) run a high risk of a cut error and with a tight configuration you will have no margin for mistakes. Cut error with a circular saw will most likely be a panel that doesn't turn out to be square.

One additional detail is the factory cut edges are more than likely going to either be rough, painted, damaged, or been exposed to air a long time. A fine cabinet builder won't use a factory edge as a part of their cut and will cut an inch or so off a sheet before ripping to size. This way all edges of the sheet are freshly cut and there will be a lesser chance of warping and a clean edge all the way around.

I made my RT cabinet out of 3/4" MDF since it is heavier, has better damping, and is highly stable. The top is 1-1/2" MDF.

[sean m. titmas]

A router table should be built with the best possible tolerances.

I would never use a jig saw to make straight cuts. Circular saws also should only cut straight through with this project.

One cut list strategy is after adjusting your table saw to one size, you make ALL of the cuts that need to be done at that size. Make things easy on yourself and get 2 sheets to lay this out though.

Keep in mind that beginners (like me) run a high risk of a cut error and with a tight configuration you will have no margin for mistakes. Cut error with a circular saw will most likely be a panel that doesn't turn out to be square.

One additional detail is the factory cut edges are more than likely going to either be rough, painted, damaged, or been exposed to air a long time. A fine cabinet builder won't use a factory edge as a part of their cut and will cut an inch or so off a sheet before ripping to size. This way all edges of the sheet are freshly cut and there will be a lesser chance of warping and a clean edge all the way around.

I made my RT cabinet out of 3/4" MDF since it is heavier, has better damping, and is highly stable. The top is 1-1/2" MDF.

Chris,

you made some very excellent points and that shows me that you know what you are talking about. your skill level seems to be higher than you give yourself credit for.