Long circular saw guide

[Darrell Jones]

From an earlier thread where I was complaining about my flimsy aluminun guide you guys showed me how to make my own. WOW, I did and I love it. Lay it right on the line and that is where the saw cuts. No more trying to measure 1 7/16th " for the cut line. I used 1/4" ply for the base and 1x3 oak for the guide. It works great for 4' and under but what do you use for an 8' sheet? Can I make one for 8'? Do you have to splice the plywood to make it longer than 8'? Sorry for the long post. Thanks so much (again) for your input. :) DJ

[Art Mann]

I haven't built an 8 foot long saw guide, but I don't see why it wouldn't work just as well as a 4 foot one. Of course, it is a little trickier to get an absolutely straight 8 foot piece for the "backbone". Ripping hasn't been as much of a problem as cross cutting sheet goods for me because I have a long outfeed on my tablesaw.

[Jim Becker]

Unless you want to spring for a very expensive piece of 10' sheet goods, you're somewhat limited to making your longer shop-built guide about 8' (it will often be about an inch longer if you use MDF) Joining two together "accurately" is not the easiest thing to do, although not impossible. The commercial guides, with their precision machined slots do allow joining for very long cuts that are still accurate. There have been some interesting pictorials of that in action posted online.

[Rod Torgeson]

Darrell......Here is what I use to cut down 4 x 8 sheets. http://www.pennstateind.com/store/ps.html
I got it about 5 years ago or so and have used it extensively in various projects(cabinets). The base plate is attached to your circular saw and then the plate rides along the "L" shaped guide on ball bearings. Mine came with two "L" aluminum angle pieces, one for the 8 foot length and one shorter. Very easy to use. Hope this helps.

Rod<---in Appleton, WA

[richard poitras]

Darrell, if you are making a guide with ¼’’ ply and a solid piece of wood for the saw to run against and then you cut it the first time to trim the ¼’’ ply and then use it to line up your saw to the new cut line every time it doesn’t not matter if you put two pieces of ply together as long as you use a piece of wood as long as you want the saw guide to be, reason being is that the saw runs against the long piece of wood not the ¼’ ply. All that is used for is for laying out the cut line only so you can do 8 ft sheets.

[JayStPeter]

It's pretty simple really. You need something straight and longer than 8' as the fence. For the saw base piece you can keep it at 8'. As long as you position it carefully you can get a full 8' cut. You really just need enough fence sticking out the ends to keep the saw straight as you enter the cut. My choice for the long fence was a commercial guide that I used carpet tape to stick to a piece of 1/4" masonite. It worked fine because I actually clamped the guide down and not the masonite. But, you can probably splice two wooden fence pieces together in the middle by clamping them to another straight piece on the guide side during assembly.

Jay

[Art Mann]

Jim brings up a good point about using 3/4" MDF for the thicker backbone. The stuff I get is 97" long and the factory edge is always very straight. I just despise cutting that stuff because it is so messy. I would think 1/4" ply or masonite that is 8' long would be good for ripping an 8' sheet.

[David Gross]

I made an 8' guide with 1/4" plywood for the base, and an 8' 2x4 piece of doug fir for the guide. I simply ran the 2x4 through the jointer to create a flat edge, clamped it to the 1/4" ply, and made a cut with my circular. Then, I screwed the 2x4 in place. Works great.