Question about circular saw and making precise cuts

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Forum topic by TBar posted 10-17-2010 03:06 PM 5568 views 0 times favorited 12 replies Add to Favorites Watch
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10 posts in 3379 days

10-17-2010 03:06 PM

This is not exactly “woodworking”, but I know you guys will have good info for me. I recently started a project where I need to layout and cut some common rafters. I have no trouble with the layout process, but attempting to cut theses layouts precisely with my inexpensive 7.25” Craftsman circular saw has been nearly impossible. After reading a few posts here and making some measurements, I discovered that my blade is not perfectly parallel to the base, but more importantly, the alignment notch is NOT aligned with the blade.

I’m making angled cross-cuts on 2×6 boards. Does anyone have suggestions on how to improve my accuracy with this saw? I am also not opposed to buying a new saw – any suggestions for an occasional use circular saw with good accuracy?


12 replies so far

View miles125's profile


2180 posts in 4000 days

#1 posted 10-17-2010 03:16 PM

I have a craftsman that cuts just fine. As far as blade alignment, just figure out where the blade aligns and put you some masking tape there for reference.

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

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10 posts in 3379 days

#2 posted 10-17-2010 03:45 PM

Thanks, guys. I probably don’t do enough work to justify the Festool’s price. I should certainly just start with a tape alignment mark and see if my cuts improve. The Rigid might also be a decent option. I’m sure a few practice cuts on scrap lumber would help, too!

View canadianchips's profile


2600 posts in 2992 days

#3 posted 10-17-2010 03:46 PM

Make some “jigs” to help cut the angles on your rafters. Measure from the “Edge of your blade to edge of the saw”, you can use the outside edge of saw base as the mark all the time.
JUST SOME thoughts that help me !

-- "My mission in life - make everyone smile !"

View richgreer's profile


4541 posts in 3069 days

#4 posted 10-17-2010 03:51 PM

You need 2 aids. One is a short (12”) all-in-one clamp—

The second is a spacer block that is the exact distance from the blade to the left edge of your saw.

Use the spacer to precisely place the clamp. Then use the clamp as a guide to make the cut.

It may take a little trial and error to get the spacer block just right.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

View TBar's profile


10 posts in 3379 days

#5 posted 10-17-2010 03:56 PM

Do those all-in-one clamps allow you to setup angle cuts? I have used a straight edge with my own clamps in the past, but they are so time consuming (and frankly, I should probably find a short one – I’ve been using a split 8’ guide and it is just too long for this kind of work).

A spacer block is definitely a good idea. I’ve been too lazy to build up some custom helper tools, but I guess that is definitely the way to go for precision cuts.

View Sawdust4Blood's profile


404 posts in 3016 days

#6 posted 10-17-2010 04:12 PM

Find yourself an adjustable saw angle guide similar to the one here

You should be able to adjust the base on your saw to get the blade parallel. Once that’s done, all you need to know is the distance from the edge of the base to the edge of the blade to get your cuts dead on.

-- Greg, Severn MD

View Gene Howe's profile

Gene Howe

10479 posts in 3423 days

#7 posted 10-17-2010 04:22 PM

Achieving precise cuts in any material is expensive. Either in cash or time. Being perpetually short of cash and with plenty of time, I make my own jigs.
The simplest and most precise and versatile circular saw jig is one that requires no offset measurements. Mine consists of a piece of 1/4” Baltic Birch (BB) for the base and a piece of 3/4X1/2 straight hardwood for the guide.
When I made mine I started with a piece of BB wide enough to extend past the blade + the guide piece + about 2 1/2” beyond the guide piece to accommodate clamps.
Affix the guide 2 1/2” from one edge, set the saw shoe against the guide, opposite of the clamps, of course, and saw off the excess BB. You are done!
Now, you can mark your work piece, align the cut edge of the BB with your marks, clamp it down and you are good to go.
I made an 8’, 4’ and 2’ jig for different sized material. For the 8’ guide, I used an aluminum angle for the guide and 1/2” BB for the base.

EDIT: I just saw Greg’s post. That guide is inexpensive enough to meet my frugal nature and looks like a great solution, also. For framing work, I seldom need other than a 45 ,22 1/2 or 90 cut. for those, a Simpson Speed Square does the trick.

-- 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 richgreer's profile


4541 posts in 3069 days

#8 posted 10-17-2010 09:00 PM

I’m not aware of an all-in-one that you can set up for angle cuts. If I had to do a series of angle cuts I would probably make a simple jig to use with the all-in-one. It would be a board with a groove or dada cut in it that was just the right size for the all-in-one. I would set the board down over the all-in-one. The board would be cut at the desired angle on the side.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

View Fencer257's profile


15 posts in 2783 days

#9 posted 10-18-2010 01:57 AM

I cut rafters with a circuular saw but without a jig. For that reason I use a ‘left handed’ PC circular saw. I can easily see the blade AND the line so my cuts are good. I really never use the alignment notch on the front of the saw plate. I have no idea if it’s in line or not – I just never use it.

View rance's profile


4258 posts in 3155 days

#10 posted 10-18-2010 02:06 AM

To fix your problem with misaligned base, leading mark not right, and tearout on your cuts, simply cut out a nice retangular piece of 1/4” plywood that is slightly larger than your existing base and stick it to your base. Plunge through it and “Bob’s yer uncle!”. YMMV

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View cabmaker's profile


1730 posts in 2803 days

#11 posted 10-18-2010 04:53 AM

As pointed out above, while ctting rafters one needs only to watch the blade.Set deep for the birds mouth. (seat cut) Guides,straight edge, etc. will not add any value to what your doing there. Good luck JB

View TBar's profile


10 posts in 3379 days

#12 posted 10-18-2010 07:32 AM

Thanks to all for the responses. I’ll let you know how it goes.

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