How to cut straight lines with a circular saw

[atomic1]

I love jigs.  They can make ordinary tools even better. 

This jig enables me to make cut straight and accurate cuts with my circular saw.  All I have to do is align the jig with my cut marks, clamp it down, and make the cut.  I have a decent table saw, but I use this jig when breaking down large sheets of plywood.  It is just safer and easier. 

Here are some pics that show how it works (I made an 8 footer and 4 footer).  If you want to build your own, there is a pretty good guide on Popular Mechanics website.  If you do build one, I would recommend using 3/16 hardboard that can be found at one of the big box stores.  To glue them together, I used liquid nails. 

[pwhitlo]

These work great for cutting plywood.  I never use a table saw on plywood since I found out about these.  Easier to use too.  Cuts are so straight you can't tell from the factory edge.
 

[johninthecamper]

festool makes a guide rail that the circle saw(s) ,router(s)& jig saw slides on. 32 ,42,55,75,106,118,197 inches( not typo 197 inches).they also fit together for "custom lengths".
add parallel guides for precise sheet  goods breakdown. hooked up to a dust extractor, your saving time and materials waste is less because its cut right the first time.
festoolusa.com
DISCLOSER: I use festool,but I sell festool from a brick and mortar store.

[Evan]

Great jig! 

[Sundog]

Great jig!

Which one, and go Wings!

The beauty of this type of jig (OP) is that it is created by the saw and/or router you use so it is very exact and easy to clamp onto the work piece.  I use a 24’ version I made for cutting off long boards.  Because the run-in and run-out extends past the work piece, the corners come out perfect.  I cut one side with my circular saw, the other side with my router.  Love it!

 

[Evan]

I was referring to the homemade one but the Festool product is nice too.

Another benefit of the homemade jig is that there is ample room for clamps. 

Great cabinet.  Nice detail on the stiles.

[uncle paulie]

Yaaa, Those Festools are sweet... I'd own a bunch if I could get the family "Discount"! Nice simple cutting jig-BTW!

pv

[Chaffyn]

Here's what I do:

[johninthecamper]

Yaaa, Those Festools are sweet... I'd own a bunch if I could get the family "Discount"! Nice simple cutting jig-BTW!

pv

only way to get a discount is to become part of the festool family,which is what I did.nation wide price fixing,no undercutting the completion.you must distinguish yourself from the other dealers with service.if you want a reconditioned tool,that can be up to 30% off.example: of2000= 193.50 which is the older version of  the of2200. the new 2200 sells for almost 900.00.it was made for festool by mafell.the Recon sale happens about once ayear.they are offered with a unlimited 1 yr warranty instead of the standard 3.



discloser:I sell festool

[johninthecamper]

one thing about homemade jigs.metal will last longer than phenolic,which lasts longer than hdf or mdf,plain wood is not very repeatable,exact wise.not stable,and is "soft"

[Sundog]

Hmm… let me think.  Spending hundreds of dollars versus using a few scraps of wood already lying around my garage and making a perfectly accurate guide without the need for any offsets, measurements or calculations.  A little wax or paraffin along the edge and running surface and its slicker than snot on a doorknob.  And when I’m done, I can throw it away if I want to.  I’ll need to think about that, for a nanosecond or two.