This is an attachment that I made to connect my 7 1/4" circular saw (Black and Decker 11 Amp) to a bench and work it like a cutoff saw. I needed to save space in my shop and money, so I made this from scraps and pieces and did most of the work with the angle grinder cutoff seen elsewhere on this web site.
With the use of fiber composite metal cutting wheels, the circular saw has been used for many a hand held cut and it was finaly time to make if work for me. I like the hand saw fashion of free hand for plate, but for about 95% of my cuts, this cutoff saw memic will be great.
The base is an up-side-down standard rail tie plate (the piece that protects the tie from the track). This base is of convienence as much as passion for turning railroad "arn" into useful art or tools. This tie plate weighs more than the saw and the pieces on it ... good stability.
The parts were cut by sight measurement to fit the tie plate and the saw. I used what I had in the shop as with most projects expedient that I do.
For that reason, I intentionally left out the measurements as you may not have the same junk box as I, or the same saw.
SIDE NOTE: I saw many similar projects (converting powertools to other service) in a Christmas present, a "1968 Popular Mechanics DIY Encyclopedia". One such project used a circular saw as a sidewalk edger. I could not resist completing this cuttoff saw project as I have been ponderin it for some time. My nephew's gift has started paying off. I took me almost a week to thumb though most of the books. Now I have to go back and really read them. Wish me luck. With any luck, you might see more stuff like this here.
Cost: Nearly Nothing. The saw I had, the parts were in the shop and the only things that I had bought new at some point were the nuts, bolts and the hinge. The whole thing might have cost about $3 if I had to buy those items. I dare not guess if I had started out buying everything. The angle iron might have been about $0.35 a foot, I only used about that much too. But that is why I scrounge and make things fit the materials that I have ... to save money and it is a lot of fun.
Legend - Circular Saw - Cutoff DIY
* - The base could be lighter if you are fastening this to a table. Also in the Angle Grinder cutoff method, use plywood and top it with a metal skin ... I used 16 ga aluminum on top of two layers of 7/16" wafer wood (OSB). Top it with something that is non-flammable. Be careful with spark build up ... it can concentrate some heat. (Been there done that!) How big. As big as you need or as big as what you have. The small standard tie plate is about 7.5" x 12". It is narrow and not in the way, and still wide enough for a stable platform for the saw. I added a "foot" to the back edge of the tie plate because it was tippy when the saw was brought to the up position. This was due to the taper and the "ears" on the tie plate that hold the rail in place. The 3/4" spike holes were not used in this case. Might find a use for them sometime.
A note about tie plates. The come in dozens of shapes and sizes. I have some that are for switch tracks that have parallel tops and bottoms. I use one of these for the top of the table that my anvil is one ... and my post vise is attached to the other end of that. This is an 8" x 24" x 3/4" piece of steel with 3/4" square holes in it ... great for holding and hammering and lots of blacksmithing stuff.
Substitute liberally. Try what you have and you should always be able to return and modify this when you get more or better/different parts. For example, I didn't have the correct length of screws/bolts so I started with 2" long bolts and only needed about 3/4". Nothing hurt. Also, 5/16", 8mm, 10mm, 12mm, or 1/2" bolts would have worked. The ubiquitous 1/4"-20 or 6mm botls seems way too small for this project. Some sort of a fast acting lever action device would work to ... if you have it or can make it.
(#2) The 1" x 2" channel could be anything that holds the saw at a good height and does not sway.
"At a good height" - I choose to make the bed of the saw at a height that allowed the cutoff wheel to just touch the table with the saw "deck" level. This might be affected by the work clamp/vise that you are going to use. E.g. where with the bottom of the work be and how does that affect the height of the saw/blade.
(#4, 5, 6 & 7) The piece that holds the saw could be channel or a block with a machined groove and tapped holes. I do not have a mill or a lathe to cut such a part and welding worked in my situation.
Part #8 might be useless, but I wanted to have something that supported the saw other than just the edge of the saw "deck" squeezed in some jaws. The pipe and rod seem to be the best way to accomplish this and avoided putting the saw on a movable/hinged plate and further reducing the effective depth of a cut. This is the problem with making a saw in the first place. At the best there is some part of the blade/cutting disk that will not be used because the saw or arbor housing is in the way.
This entire project could revolve around a motor to double sided pulley ... that is another design from PM DIY Encyclodedia.
The truth, I had though on this project for about a year or more and one day I jumped into it. It took about 4 hours to get the basics done and get to cutting with it. Most of that time was spent working on the pipe to get a 1/2" rod to fit in it and I gave up and that is why I used 3/8" square ... it fit the pipe.
I will consider putting a Plexiglas shield in front of the saw also.
I am pondering an automatic guard mover ... I will ponder that for a while.
A spring to hold the saw up out of the way until I need to cut.
A stand off or stop to stop the saw from cutting into my vise!
A holder for a wrench to get lost when I need it to take the saw off this contraption.