CNCish Table saw

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Forum topic by srfrancis posted 02-17-2016 02:25 PM 957 views 0 times favorited 8 replies Add to Favorites Watch
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4 posts in 1067 days

02-17-2016 02:25 PM

Just wondering if this has been done or worth the effort. Extensive googling hasn’t gotten me anywhere. Working on a sketchup.

Had an idea to mount my contractors table saw trunnion/motor assembly onto a movable carriage, like a gantry, using linear bearings to keep things straight. Keep this whole gantry under the table with the blade cutting though like it would otherwise for a regular table saw. Make like a 9 foot cutting length with about a foot over hang to go past the cutting area. Add a linear rack/motor to the cutting axis, and motors to the height and angle axes. This gives a straight cutting axis with the precision limited to the linear rail, so say less than 1/32” along over the whole length.

Add a removable rail to one end with a incremental adjuster for squareness and adjust that to less than the same 1/32” for the whole length. Use a threaded rod for measuring length along the rail for the stop, good to the thousandth of an inch. With this you can break down plywood hands free and repeatable. Can also do thin strips as well as edge joint up to the whole length.

Place a miter gauge slot perpendicular to the cutting direction with an incremental miter gauge and fence, which can give you down to 0.05 degree precision. Use the same length adjusting system as above. With this you can do any miters and shallow angles for a full piece of plywood or any other lumber to 9 feet.

As far as electronics, put in a digital readout for the bevel and height which you can code in. Place a rotary for speed control for feeding the saw forward or back, maybe a single pushbutton for a full length cut. I suppose you could add in the motor controller for all the stop blocks and or miter gauges and automate the whole thing. Clamps to hold down pieces.

With this you can cut anything you can lay on the table repeatable and hands free. 4” depth of cut compared to CNC router, ~2’x11’ table size. Fold out support wings. I think the accuracy could be made as good or better than a sliding table saw with way longer rip capacity.

8 replies so far

View XquietflyX's profile


339 posts in 1196 days

#1 posted 02-17-2016 02:30 PM

sounds like an awesome idea. please update with pictures and info if you end up developing this.

-- You can tell a lot about your wife by her hands, for example if they are around your throat she's prolly pissed off at you...

View HokieKen's profile (online now)


7534 posts in 1374 days

#2 posted 02-17-2016 03:02 PM

Sounds like a bottom mounted track saw to me. Other than hands free, not sure I see any advantage over a good track saw.

-- Kenny, SW VA, Go Hokies!!!

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4 posts in 1067 days

#3 posted 02-17-2016 03:53 PM

Thought I had a unique idea, spent a good portion of the weekend drawing it up. Germans beat me to it….

It is like a bottom mounted track saw, except faster to recut. I thought about doing that first initially, but if you think about it, the arm you would need to hold up the track is about a foot, then add the weight of the saw, you start eating up all your depth of cut with a support structure, and it still might flex messing up your bevel and straightness.

I think I can make a lower tech version of that, ideally shorter and more compact to fit in a garage on casters, that doesn’t cost ?0,000$. Also mount a router with a lift on that gantry, storage underneath for the arms, a shop vac. Given that its just a hobby for me, going for more bang for the buck and how much I can squeeze in a small space.

View JAAune's profile


1854 posts in 2553 days

#4 posted 02-17-2016 04:00 PM

There are beam saws out there but they work above the table. I believe they also cut entire stacks. Mafell makes a powered track saw too.

Mafell Panel Saw

-- See my work at and

View MadMark's profile


979 posts in 1689 days

#5 posted 02-17-2016 04:03 PM

Spend a little coin (comparitively) on an Incra fence and cut 1/32” +-.002” all day long.


-- Madmark -

View Ger21's profile


1075 posts in 3367 days

#6 posted 02-17-2016 04:33 PM

It’s called a beam saw.
It’s a saw on a carriage that moves under the table. There’s a hollow beam that holds the sheets down over the blade, so the blade is never exposed.
Beam saws have a fence at the end of the cut, and “pushers” mounted to the beam that hold your parts against the fence when crosscutting.

They take up a lot of space, because they actually grab the boards and position them before cutting, so even a small one needs about 10ft behind the saw carriage to be able to pull 8ft sheets back, and usually have 5f tables in the front to support the cutoffs.

A small one probably needs close to 15ft x 15ft of space.

-- Gerry,

View bigblockyeti's profile


5314 posts in 1957 days

#7 posted 02-17-2016 04:55 PM

+1, what you’ve described is essentially a beam saw. Hard surface counter top fabricators use these extensively with wet cut diamond blades.

-- "Lack of effort will result in failure with amazing predictability" - Me

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1075 posts in 3367 days

#8 posted 02-17-2016 07:00 PM

We used to have one in the shop I used to work at. Could cut up to 5 sheets of 3/4” thick material at a time.
About $100,000 for the one we had, made by Schelling.
It could also automatically kerf sheets for bending, and cut dado’s.

-- Gerry,

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