Homemade Router Insert for Powermatic 66 Table Saw

[Steve H Graham]

I have been going over threads about router inserts for table saws, and I thought I should go ahead and post a few questions.

I just bought an old Powermatic 66 with 50" rails and no extension; there was a homemade extension on it when I bought it, but it wasn't exactly a prize, so I discarded it. When I was rationalizing the buy, one reason I gave myself was that I would be able to get rid of the huge router table I was building. I intended to put the saw where the table used to be, and I was going to move my Woodpeck Plungelift to an insert on the saw's top.

I wonder if I could get some reactions to what I'm planning to do. I want to get some 3/4" MDF and make an insert--not sure of the size yet. I will cut the saw's rails to fit it, because I can't tolerate a 98"-long object that fills half of my garage. I figure I can attach some hardwood braces underneath the MDF to keep it from sagging, and then I can soak it in Danish oil to keep the humidity from warping it. I have an MDF template from Woodpeck, so I'll use that to make the router lift hole. I guess I'll have to put two pieces of hardwood under it, parallel to the rails, so I can screw the insert to the rails.

Will this work, or will my garage explode in flames as the wood nymphs punish me for stupidity?

The router is heavy. It's a Bosch 1619 which will never leave the table. But I think braced MDF will be okay.

I have a big scary 12" sliding miter saw I might want to plop on this thing for occasional use, but it's heavy, so maybe I should put legs on the extension.

Okay, let me have it.

[Myk Rian]

I would put the braces perpendicular to the rails. That's the long distance and will be more prone to warping with that big router in it. Baltic birch ply braces might give you better support than hard wood.
I saw your other post on the saw. Nice catch.

[Steve H Graham]

Will I be able to get away with screwing down into the side of plywood, or will it split?

[glenn bradley]

I used doubled 3/4" BB ply on edge as 2-1/2" tall ribs to support my RT extension. As long as you pilot hole them appropriately, they will not split. I drilled through-holes and screwed the top down from underneath, through the ribs.

My MDF top had sag when supported as supplied from the maker; only the edges, even though the unsupported span was only 20". I now have it heavily framed with the longest unsupported span being the long dimension of my PRL lift plate. Even with that beast-of-a-lift and a Mil 5625 hanging from it it has remained dead-flat.

Pardon the crude diagram but, its something like this: http://www.sawmillcreek.org/attachment.php?attachmentid=71637&d=1189464141

[Steve H Graham]

Okay, so I guess you glued and clamped the pieces of plywood together before drilling?

I'm wondering if I should just make the insert out of plywood, since I'll have to buy a big piece of it in order to get the ribs.

[Chip Lindley]

You never said how much less you wish to make the table than the 36" as supplied with a 50" fence! Like 20"??? I survived a long time with a 20" extension. If your fence is the biesemeyer-type, and has both front and back angle iron rails, the table should bold to them without any other support.

I made an ext. table of this sort hung off the side of a Rockwell CS for years. But, I had a *tricycle* mobile base with the single swivel wheel beneath the ext. side of the saw. It worked out jusFine. You have much more weight in the PM66 to counterbalance your puny 3hp router. Go for it!

Perhaps you might consider laminating your ext. table with formica?? It looks snazzy and lasts forever. I am not sure how smooth an MDF table coated with Danish oil might be. This table is hooked up with a PM66!!! Don't skimp!

[Steve H Graham]

You have to realize, I have no idea what I'm doing. That is where we should begin.

My guess is that a router insert should go maybe 24" past the end of the table. I'll have to fool with it and make a decision. I have room for up to a 78" tube, or 20" shorter than the current setup. If I cut the existing rails down, I suppose I can customize the length.

I got the MDF idea from Pat Warner's site and video. I used to think MDF was worthless cardboard, but apparently it's strong and stable, and it's easy to work.

[CPeter James]

Here is my setup Because of the overarm blade guard, I route on the inside of the router fence most of the time.

http://home.metrocast.net/~cpjvkj/ts.jpg

CPeter