Ok, I have been seeing this pop up on youtube woodworkers channels a lot lately. Basically some people say that you can use a table saw to do the same job as a jointer by laying a long level up against the table saw fence, and by sliding the level along the saw fence with the wood, instead of having the level stationary it magically becomes a jointer.
Here's my take:
You have a fence that's straight as an arrow, and set up parallel to your blade. Any wood you run through that setup will have a newly cut side that's parallel to your fence. If you take a level that has two sides that are parallel to each other, and rest one side against your fence, you now have a level that is parallel to your fence. You've just extended your fence out X inches by using a level. If the level slides, it makes no difference. With a jointer you are cutting an edge that is parallel to the working surface. That's why you now take that piece over to a table saw or planer and put the cut edge against your fence or planer table because you are referencing off a plane that is flat and true.
I'm on medication that makes it harder for me to think clearly. Am I crazy here? Does sliding the level along with the wood make the table saw a jointer?
Refence this video from about 5 minutes to 7:30
https://youtu.be/Y8vw1kp_G_8?si=AUL6BTV9aquBGKhW&t=298
I bought my 6" Rockwell jointer off Marketplace for $50.
Why mess around?
I started with machining metal and moved into woodworking. Woodworkers do some goofy stuff at times. Lots of them are scared of radial arm saws but do freaky stuff with a tablesaw where you can't see the blade most of the time.
In reply to DrBoost :
I'm with ShawnG on the "just get a jointer" train, but I do think I see the logic (even if I'm not sure how practical it is, and I am sure how much I want to do anything dodgy with a table saw, which is a negative number).
I believe the crux of the idea is this: If you slide a board along your fence, it may rock, it may run off the end of the fence, and it may generally change its overall angular relationship with the fence and blade, which in turn means the cut side won't be straight. By anchoring the board to the level and then having the level trace the straight fence, the board, should, theoretically be sent on a straight, unrotating path through the blade, and you should get a straight edge. I believe it's roughly the same idea as a sliding table saw, but terrible.
I'll take the jointer, thanks all the same.
I think he's getting a bit fussy, but wood guys tend to do that. I can see the point, but I think you can do the same with some care and wood selection. If you are trying to turn a propellor into a straightedge, all the levels in the world ain't gonna help you.
I have a jointer, and a table saw. I just want to know if this is the woodworking equivalent to "engines meed back-pressure to run right."
i think it is. Laying a level down is just extending your fence.
A couple of things after watching part of the video. "make sure your level is level" Nope. What is important is that the level is straight and has parallel surfaces. Second, why a level? I assume because he has one handy. Seems it would be better if you didn't have to keep the straightedge and stock aligned with your hand.
In one of my first jobs as a cabinet maker (1976) we had no jointer in the shop. We used a shop made sliding gizmo that fit over the saw fence and used that fence as a guide. Imagine a three sided box that was 10' long, closely fitted to saw fence with a stop at one end to capture the board. Load board with crown to blade and slide it through. A straight-edging tool. Later a chain guided straight line rip saw which sped things up considerably.
You can accomplish the same by tacking a straight board to bowed one or use a straight edge guide and a skilsaw. A tracksaw can do the same. Funny thing, I have never even considered doing what he shows and wouldn't use my expensive spirit level that way. In his method, your stock length would be limited to level length.
Not my jam. Too many things to go wrong and I've learned to reduce my risk when it comes to power tools that cut flesh and bone. It's just not worth it.
Edit to add: if your stock has a twist or warp, this method is almost guaranteed to produce some white knuckle moments, so there's that!
I find that woodworkers really get into minutia.
When I started in hand tool woodworking, guys would post about the hours and hours they have in just getting their plane sole lapped perfectly flat. Then I see an instructor from one of the woodworking schools saying "I have prints of Roubo's books and nowhere does it say to make sure your plane sole is perfectly flat. Pick up your plane and get to work."
Guys get freaky obsessed with sharpness, buying incredibly expensive Japanese water stones and crazy stuff. Paul Sellers, who's work is in The White House among other places uses sandpaper taped to a board for his sharpening. He says "People that obsessed with sharpness shouldn't be around sharp objects".
You can spend crazy amount of time making lumber flat. Then it rains a week later and your stock isn't flat anymore.
DrBoost said:i think it is. Laying a level down is just extending your fence.
that's exactly what it's doing, and as others said, works, but jointers are cheap
In reply to carbidetooth :
Would this goody thing accomplish the same thing as a jointer, or the same thing as a table saw fence?
Well, your fence should be 90 degrees to the table.
Take a pass through the saw, and you have one face that is parallel to the fence. Flip 180 degrees, you should have two faces parallel.
Flip 90 degrees you should have a face that is square to the table. Flip 180 degrees, you should have another two faces parallel.
Providing your saw is set up right. I've seen a lot of guys who are completely mystified about how to square up a tablesaw.
DrBoost said:In reply to carbidetooth :
Would this goody thing accomplish the same thing as a jointer, or the same thing as a table saw fence?
Yes, because the board travels with the jig and only uses the fence as a sliding guide. Same principle as shown in video, but we typically did 8-10' stock. You could liken it to moving a jointer over board instead of moving a board over a jointer. But don't try that, it would be pretty clumsy!
I think I get what you're asking.
The video is talking about making a square edge when you don't have one to start with. He uses a level so that the rigid beam spans the non-straight edge, thus giving it a straight edge.
Visually speaking....
So let's say you're trying to square up this masterfully-crafted, MSPaint graphic yellow board. Since there is no straight/square edge, you do THIS:
Rest blue straightedge against the fence to span the inconsistency of the piece.
Funny, I imagine I could demonstrate that quicker on a tablesaw than I could draw it in Paint!
He is cutting the crown off of the board using the straight edge against the two ends to make the widest possible straight edge on the board. You can use a strip of plywood or aluminum straight edge and screw it onto a board for lengths up to 8 feet or longer. Then you flip the board over and set the fence for the narrowest board width at the middle of the board.
carbidetooth said:Funny, I imagine I could demonstrate that quicker on a tablesaw than I could draw it in Paint!
I'm 51. I could probably draw it on a napkin, photograph it with an SLR, develop it in a darkroom, and run it through my scanner faster than I could set up a camera, video the process, and upload it to tiktubes or instawebz.
In reply to VolvoHeretic :
Exactly.... he's extending the fence, so to speak.
If I was trying to straighten the MSPaint graphic yellow board I'd clamp a straightedge to it and use a circular saw to get a reasonably close straight line. Then I'd flip it over and run my new nearly straight edge against my table saw fence.
A jointer won't straighten that. It would "ride" up and down the "humps" and make a curve.
I have an 8" jointer, but rarely use it.
The level idea would work to straighten that wonky piece, but it does so at a risk. You'd be trying to maneuver 2 separate things at once through the table saw (the board and the level). Good way to insure that you can only count to 9.
Jointers don't just straighten. They also make sure the edge is perfectly square to the face (which a properly set up table saw can do), and also makes perfect glueable surface on the edge (which a table saw can't do).
A better jointer-less hack would be this... use the straight edge and circular saw to cut it straight, then make a 2nd pass using a straight edge and a router with a straight bit in it.
I think I get it. My issue was the straight edge was extending the fence TOWARD THE BLADE but, given a long enough level, he's extending the fence parallel to the blade.
I can see that.
I still don't like it. The level is not supported at the two ends, like a table saw fence is. That scares the heck out of me. Now you can have kickback from either side of the blade, and a 4' piece of aluminum is included in that kick back.
I have a jointer and a planer, so I wasn't going to do this ever, but now I understand it. Thanks.
In reply to DrBoost :
That's why when I helped a friend in his one man custom cabinet shop one winter, we would screw a strip of plywood onto the very ends of 5/4 boards to cut them straight. We also ran the boards through a jointer afterwards. He had a planer and shaper for raised panels and cutting splines. He built #2 knotty pine custom cabinets, doors, and tables for Lake Tahoe area homes.
In reply to DrBoost :
Yes, the level extends the fence parallel to the blade. But it also reduces the humpy roller coaster ride on the edge of a crooked board.
Picture a 3' long crooked board with a 3/4" crown in it. If you set a level against the edge it touches both ends and has a 3/4" gap in the middle. If you push it through the saw with the level, the board remains straight and parallel with the blade because the "fence" moves with the board. However, if you approach the table saw with the same board against it's fixed fence, the blade tries to follow the curve. The cut will start off straight, but when you pass the halfway point, the trailing corner of the board will start pushing the board away from the fence and into the blade. It won't cut straight- the cut will be curved. (Note this can also happen with a jointer with a short bed).
I still don't like it.
In reply to SV reX :
SV reX said:In reply to DrBoost :
Yes, the level extends the fence parallel to the blade. But it also reduces the humpy roller coaster ride on the edge of a crooked board.
I still don't like it.
Yeah, I get that now. In theory you wouldn't have to move the level with the stock, assuming the level and table top was long enough.
In reply to DrBoost :
True. But at that point it's just an expensive fence extension.
How about using a couple of spring clamps to attach some Unistrut type channel to the fence? Assuming it's straight. It would also help keep 4x8 plywood aligned while trying to rip it.
HomeDepot.com: 10 ft. 12-Gauge Half Slotted Metal Framing Strut Channel in Silver Galvanized
Unistrut would work. I have some leftover aluminum I-beam that was surplus after a sunroom installation. They were the "studs" for the walls. Since they're 12' long, I can true up some pretty long lumber with them.
A similar process is used as a DIY lumber mill. People will screw a straight ladder to a log and make a track for a chainsaw. The ladder spans the dips and humps to make straight cuts.
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