Straight edge guide for Circular Saw

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Forum topic by Peter posted 05-14-2012 07:26 AM 23194 views 6 times favorited 25 replies Add to Favorites Watch
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15 posts in 2174 days

05-14-2012 07:26 AM

Topic tags/keywords: question circular saw ripping advice

Hi all,

This is my first post on here, I’ve been looking through the marvelous projects on here for a few weeks and reading through the forums.

After reading a post on how it can be unsafe to rip 4×8 sheets on a table saw and seeing people recommend a straight edge I took a look at them online and found they can be an expensive purchase.

My questions:

What straight edge or straight edge guide for circular saws would you recommend to someone for under $100?

Kreg has a straight edge guide, would this make a good purchase?

Thank you

25 replies so far

View Charlie's profile


1100 posts in 2256 days

#1 posted 05-14-2012 08:57 AM

BUILD one!
Get a sheet of 1/2” plywood. Cut about a 4 inch strip off one long edge. Doesn’t have to be a perfect straight cut, but do the best you can. What you’re after is that nice straight factory edge. Now cut another strip off that same side of the plywood about 10 or 12 inches wide.

Your circular saw base has what I call a “fat” side and a “skinny” side. In other words, the blade isn’t in the center. There’s about 3 or 4 inches of base on one side of the blade and only an inch or inch and a half on the other. So that wide side is the “fat” side.

Take that first long strip with the factory edge and screw it to the wider strip such that, if you set your circular saw against the factory edge, you’ll be cutting off some of the wider strip. Now do exactly that. Run your saw against the factory edge and trim off the excess from the wider strip.

You now have a saw guide. No need to measure offsets to make up for how much base you have on one side of the blade. There’s a picture of my 4 footer in this thread

What do you do with all that extra plywood? Go to the OTHER long edge and make another saw guide, but make this one about 5 feet. And another about 3 feet.

To USE this saw guide set it right on your marks on the KEEPER side of whatever sheetgoods you’re cutting.

And you’ll STILL have plywood left over for making other jigs and stuff. So get nice plywood!

View miles125's profile


2180 posts in 3975 days

#2 posted 05-14-2012 10:56 AM

Build you a supporting table around your TS so you can rip plywood sheets. Having a table saw you can’t rip plywood on is like having a car you can’t drive out of your neighborhood. :)

-- "The way to make a small fortune in woodworking- start with a large one"

View Fred Hargis's profile

Fred Hargis

4956 posts in 2463 days

#3 posted 05-14-2012 11:01 AM

Building one as Charlie suggested would be my recommendation as well. That gives you a guide that you can set the edge exactly on the cut line and get the results you want.

-- Our village hasn't lost it's idiot, he was elected to congress.

View jmos's profile


823 posts in 2339 days

#4 posted 05-14-2012 12:04 PM

I agree with Charlie and Fred. But, if you don’t want to go to the trouble, you can just use any straight piece of stock, clamp it to a board, and cut away. It takes more time to set up since you have to account for the distance from the edge of the base plate to the blade, and it can leave marks on the work from the saw, but it works fine.

Alternately, there are lots of cheap aluminum guides that have built in clamps you can pick up for not too much. They are handy, in that you don’t need extra clamps, but have the same drawbacks as listed above.

I don’t have any experience wit the type of guide you link to, but I would be concerned about them shifting slightly during use giving a wavy line. Doesn’t seem as bullet-proof as a straight edge. But, I could be wrong on that.

Now, if you decide to get into big money you can use a track saw, but they are all pretty pricey.

-- John

View Peter's profile


15 posts in 2174 days

#5 posted 05-14-2012 12:09 PM

Thanks for the advice,

I was working in the advice from this question regarding TS and sheet goods the common theme seemed to be that it is unsafe to use a TS for this type of work, only a few people advocated the use of it. Being a beginner I want to keep myself as safe as possible, after all i need my fingers for typing at work!

View Sawkerf's profile


1730 posts in 3038 days

#6 posted 05-14-2012 12:15 PM

How about guides for under $5.00 each? I use quite a bit of 1/4”and 1/2” ply for the cabinets I build, and invariably have long strips left over. I use a piece of 1/4” approx 6” – 8” wide for a base, and attach a narrower piece (~2” wide) of 1/2” to it with an exposure slightly wider than my circ saw’s base plate.

I run the saw down the guide along the edge of the 1/2” and rip away a bit of the 1/4”. When I’m done, I have a guide with a width exactly matched to my circ saw. I can mark my ply, align my guide with the marks, clamp it down and make my cut exactly where it should be.

I have guides for both circ saws as well as one of my routers. They’re easy to make, cheap, and make use of scrap that would otherwise get tossed in the trash.

-- Adversity doesn't build reveals it.

View Gene Howe's profile

Gene Howe

10383 posts in 3398 days

#7 posted 05-14-2012 12:39 PM

Charlie and sawkerf have the right idea. If you want a bit more accuracy for a few bucks more, you can build your own “track saw” wannabe.
Just start with 3/4 ply (I used Baltic Birch), rout a channel for an aluminum T-track. I got mine from Peachtree. Attach their miter T-Bar to the sole plate of your saw, insuring it is square to the blade.
With this modification, I can take plywood directly from the breakdown table to the project without needing to true up the cut on the table saw.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View Charlie's profile


1100 posts in 2256 days

#8 posted 05-14-2012 12:55 PM

That thread you referred to is good. Take this away from these conversations….

If you have a large shop and you can afford the real estate necessary to construct a proper setup for ripping 4×8 sheet goods, then it can be done safely, even by just one person. You need a LOT of dedicated space to pull that off and have the sheets properly and safely supported both on the infeed and outfeed sides.

My shop is only 18×16 feet. That’s it. No extra for storage. Everything has to fit and be useable in that space. I can’t afford the permanent table space for large infeed/outfeed. This is where it becomes necessary to break things down on a cutting table (even a temporary one like mine) . In my case I also have to factor in my age and a couple of physical limitations.

The simple edge guide I referred to allows you to cut about as accurately as you can measure. Set the edge on the line and go. No having to measure the offset of your saw base and then set your guide back “x” number of inches from where you actually want to cut. Set it on the line, clamp it, and make your cut. It really is that simple.

And the money you save can be put towards more wood or tools! :)

View dhazelton's profile


2756 posts in 2266 days

#9 posted 05-14-2012 12:55 PM

That Kreg unit looks like it might wobble with such a short leg that rides against the outer edge. I bought the aluminum clamping rails from Rockler when they were on sale. They’re nice, adjustable, and come with a lifetime guarantee from Emerson (I think it’s a different Emerson). But I’ve already noticed that the clamping pawl leaves a nick in the steel rod that runs the length of the rail. I could see if these get heavy use that it might present a problem down the road, but with a lifetime guarantee they SHOULD send you a new rod if you ever need one. They offer a saw plate and router plate for these as well, so one rail and many options.

View SnowyRiver's profile


51457 posts in 3450 days

#10 posted 05-14-2012 01:18 PM

I use a straight edge similar to the picture below. I use a 50” one. You can get these longer like 100” but I find once I cut the sheet shorter I can manage it on the table saw. This straight edge simply clamps on the edges of the plywood. It works well.

They cost about $50

-- Wayne - Plymouth MN

View patron's profile


13600 posts in 3311 days

#11 posted 05-14-2012 01:34 PM

in job site situations
i have used the side straight edge
(whether straight ply
or a guide like snowriver’s)
and just cut into a piece of scrap
and make two blocks of each

one set for the inside of the kerf
the other for the outside of the kerf
and use them for setting up the guide offset
just don’t get them mixed together
as they are very close in size
and can make the cut off of parallel

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Peter's profile


15 posts in 2174 days

#12 posted 05-14-2012 03:07 PM


That is pretty much what I took from the article as well as the TS for sheets is also a more experienced woodworker task. I do only have a small 2 car garage to work in and right now I don’t even have a workbench (that will be the first project). I’m going to make the workbench be an outfeed table for the table saw and also use the off-cuts to make a smaller pedestal for my router table.

Dhazleton, thats what I was wondering when I was looking at it, that it didn’t look supported enough and also looked like if too much force was applied it would twist slightly.

Gene that seems like a good modification of the basic plywood straight edge and would help when I get a router instead of the router table.

I would like to try and make some plywood straight edges but I think they may have to wait, I’ll try and get one of the clamps as per SnowRivers post. The reason for this is that I have to get sheet goods delivered as I only drive a small family car (I know, I know I need to upgrade to something else). I had already ordered the two sheets I needed for some built ins and a workbench top when we ordered some drywall and insulation for the basement reno we are doing right now, therefore the money isn’t there to have any decent length of wood delivered just yet.

Patron, I understand what you are saying with regards to inside the kerf and outside the kerf, but I’m not understanding the application of this? Should the edge not always place the kerf to the outside of the desired length i.e. into the excess? can you explain further for me?

Thank you all for your feedback, I wasn’t expecting such detailed responses!

View RussellAP's profile


3103 posts in 2256 days

#13 posted 05-14-2012 03:16 PM

You could use an 8’ level as well, I use mine all the time for this. just don’t clamp it too tight.

-- A positive attitude will take you much further than positive thinking ever will.

View 404 - Not Found's profile

404 - Not Found

2544 posts in 2939 days

#14 posted 05-14-2012 03:17 PM

Before I took the plunge and bought my plunge saw (aka track saw), I got by using a home made zero clearance saw guide which I read about on Lumberjocks.

I made mine with a slight difference, the left side is for the saw, the right side has a zero clearance for a 12.7mm router bit in my 1/2” Dewalt router.

Making one is easy, it’s very accurate and cheap (in fact it didn’t cost anything as I made it out of scraps). Getting the first straight edge is the the difficult part, you can make one any size you want as well for ripping or crosscutting.

This guide is made with the wide part of the saws’ base plate running against the straight edge, to help it from tipping at an angle.

View bandit571's profile


19768 posts in 2653 days

#15 posted 05-14-2012 03:20 PM

well, for one thing, see IF the place where you are buying the plywood will offer to cut it to a size you need. Most “Yards” will do the first cut for FREE!

Next, I have on some jobsites added a 1x to the sole of my circ.saw. I used to have a couple holes in one, where I screwed a 1x in place for a LOT of cuts. I have also “C” clamped a straight 2x to some plywood sheets. failling to find such a thing as a straight 2x, or even a 1x, I have grabbed some angle iron, and clamped it down. I mark a line with the chalk line, measure for the “offset’ to a fence, mark for the fence, and ripped away. Did a LOT of concrete formwork, and somedays, the “ready-made” stuff ain’t gonna do it. Then I’d have to bring out the plywood, and make my own forms. Dock leveler pits were the main culprit, odd sized openings to form up. 2×4s and 3/4plywood, cut to size, installed and ready to pour in a morning’s work. Not bad when it is just a couple, gets a might grumpy when there 20 to form and pour that day.

-- A Planer? I'M the planer, this is what I use

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