MFT Jig for Cutting Plywood Sheets

Qwas

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Topics on jigs, and cutting plywood got me to thinking. Why make a new table when we have a perfectly good table? This is what I'm thinking of.

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Let me start by saying I already have several methods for cutting plywood sheets. And I realize two tables put together will work better than this and I realize there are many better methods to accomplish the same thing. I'm thinking this may be handy for those with very limited space.

You tilt the table down to rest on the 2x4s, slide the plywood into place against the 2x4s, and tilt the table back up. The guide rail gets lined up with the center of one 2x4 for support during cutting (you will have to remove or slide the front rail clamp out of the way). One 2x4 to the right for support of your cut pieces. And a configuration of 2x4s to the left to support the plywood. You can add a leg to the end of this configuration to give additional support. This leg could be mounted on a hinge so the leg folds up during storage.

Cut 3 2x4s to 48 inches. You can bevel one end to 30 degrees so the table can rest on them when you tilt it down. Drill some holes to accept some pegs that fit the tabletop's holes. I drilled these off center of the 2x4 width so I won't have to worry about hitting them with the saw blade that will be cutting down the center. I found it easier to put my 2x4 in place, clamp it, and then drill from underneath the table into the 2x4. You only need to drill about 1 inch deep into the 2x4.

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Cut another 2x4 52 inches long for the diagonal support. Put a 45 degree miter on one end and a compound 45 degree miter and 30 degree bevel on the other. Attach it to one of the other cut 2x4s and then drill a hole for a peg in it. I used the left front hole for this peg.

Cut another 2x4 to 44 - 62 inches for the horizontal support going off the left side of the table. I used 44 inches and it gives me support for 6 1/2 feet across the table, leaving 18 inches of plywood unsupported. Attach this board to the top of the board that has the diagonal support on it.

I tried using 3/4 inch aluminum tubing for my pegs. After tilting the table a few times, the pegs were slipping in the holes allowing the 2x4s to separate from the table. I think it needs something that fits the holes better. For those with access to European 20 mm PVC used by electricians, I think that would be ideal.

I'm also thinking a small block wood attached to the 2x4s at the 30 degree bevel to make a lip would hold the plywood while tilting the table up.

Anyway, I'm running out of time to play with this project. Too many other jobs pending. I figure before I go any farther, I would see if there is any interest. For those that want to build it, I'll try to help work out any details or problems that I can.
 
Another nice idea, Steve.  I was thinking of doing something like this--my latest MFT is 1m front to back so a 48" sheet would only overhang by about 11" after accounting for the fence on one edge.  Thank you very much for figuring out the details--well done.

Regards,

John
 
On the MFT-1080, it is only about 18 inches overhang front to back which isn't a problem. The main problem is going to be the 8 foot length. But I think by adding a leg to the 2x4 sticking out on the left will take care of that issue.

I was going to throw a sheet of foam over the 2x4s when done. I figure that is enough support to get a decent cut on the plywood wherever I want to cut. I was planning on moving the guide rail and it's rear clamp across the rear and right side to make cuts. Since the guide rail is missing a front clamp, I planned on marking my cuts and aligning the rail to the marks. Worst case, it is easy to throw clamp on the rail and hold it if need be.

This might make a nice project for the May contest. Either way, I'd like to some pictures when done. Good luck and feel free to post any questions that come up. More than glad to help.
 
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