Best way to do square cutouts

[smorris]

I have a sheet of starboard, a high density plastic, that I need to do a series of square cutouts (1 1/8 x 6/8) in for mounting switches in the center of the sheet (3 x 27 in). How best to proceed?

At this point I made a template with turbocad. My current thinking is to use spray adhesive (tested and it sticks fine) to mount the template on the piece and use a coping saw to do the cutouts. I may grow old and die doing 17 holes... Anyone have a better idea?

[WayneJ]

Drill a hole in the starboard and use a jig saw with a fine tooth blade.Support the plastic on a piece of wood with a hole in it to clear the blade.
Wayne

[Greg.B]

Using the template you have start with a pilot hole and use a jig saw to cut. I would clamp a guide to the edge so that the jigsaw can run along it. It might take some time but it will be clean and even.

[LCHIEN]

Use a router either with a template guide or a top bearing template bit.

First make a template - I find the easiest way is to make it with butt-jointed 1x4 material, with at least one extra long member to be able to clamp it outside the router base area.

If using the bearing bit make the template the same size, if using the template guide bushing make it oversize in each dimension by the difference in bit dia and bushing O.D.

Clamp the template over the work, securing with at least two clamps. The need to be over 3" from the opening to allow room for the router base as I mentioned before.

You can either plunge into the material or pre-drill a hole bigger than the bit. Follow the template you should go clockwise around the opening. Make two or three passes moving the router quickly taking small bites rather than trying to cut carefully in a single pass - the bearing or guide will keep make the cut clean and smooth no matter how many passes you make.

You may wish to raise the work off the bench with supports so the router won't eat your table.

After you are done you may wish to square off the hole corners with a file, nibbler tool, hacksaw or other cutters.

Don't forget to make a couple of test runs in scrap material.

P.S. one last suggestion, use the smallest dia. bit so as to minimize the material you have to square off in the corners. A 1/4" spiral upcut or downcut bit with a 1/2" dia templat guide bushing would be good for the size hole you are talking about.

[smorris]

Thanks, boy that was quick. I do have a template bit for the router so that may ce an easy way to go. Thanks again. Now to go fire up the workshop.

[RayintheUK]

Follow the template you should go counter-clockwise around the opening.

Clockwise when routing around the inside of a template.

Ray.

[LCHIEN]

Clockwise when routing around the inside of a template.

Ray.

You're right, of course. when i was writing it i thought about it twice and pictured it with a table mounted router for some reason...

Corrected the original post.

I'm glad SOMEONE is reading them.

[smorris]

Well, the template is cut. Took a couple ideas and got the job done. I put the paper template on a piece of plywood, drilled a half inch hole in the center of each and used my bandsaw to nibble out the openings, I cut in from the opposing side on as I did each hole. It ended up a little floppy and I glued on some material on the edges to stiffen it up. I did end up with one opening in the center that hit the upright at both ends no matter how I swung it around so I used a straight bit on the router table to cut that one out.

Any reason not to do it on the router table as my bearing is on the end of the bit? I'll just drill a hole in the starboard for it to come up through. I prefer to use that if there isn't some compelling reason not to, like safety.

[jdschulteis]

[. . .]
Any reason not to do it on the router table as my bearing is on the end of the bit? I'll just drill a hole in the starboard for it to come up through. I prefer to use that if there isn't some compelling reason not to, like safety.

I say go ahead and do it on the table. See the posts by Ray and Loring about feed direction, though. On the table, travel counter-clockwise around the inside of the template.

[jarhead]

Since we are on the subject of feed direction, I don't recall where I read this, but I find this a great method of helping to figure out the correct router feed direction. You form a backwards capital letter "L" with your right hand using your thumb and an index finger. Point the thumb at the fence or the surface the router will ride against. You router in the direction that your index finger is pointing to.

[scorrpio]

I take it you don't have a mortising attachment on your DP?

[LarryG]

Since we are on the subject of feed direction, I don't recall where I read this, but I find this a great method of helping to figure out the correct router feed direction. You form a backwards capital letter "L" with your right hand using your thumb and an index finger. Point the thumb at the fence or the surface the router will ride against. You router in the direction that your index finger is pointing to.

Yep ... an excellent way to remember this.

But wait, there's more! Turn your hand upside down and the same trick will now work for a table-mounted router.

IOW, whether your router is right-side-up or upside-down, your hand is held exactly the same way, matching the router's orientation.