Blade/table alignment issues

[dusty]

This may sound like it coming out of left field but here I go.
When I teach some of our students in our retirement community table saw techniques I play a trick to prove a point. I show them how to check the table saw for proper alignment and show them how to make a right angle cross cut which never turns out right. Then I joint one edge and make another incorrect cross cut
Then I make another cross cut without doing anything else which will be correct. Why the difference? The second cut was made with the jointed edge against the miter gauge and it was square but not was not square to the opposite edge because the opposite edge was not parallel to the jointed edge.
This lesson was on how to square up stock for a project.
Flatten one face of the board, then joint one edge with the flattened face against the jointer fence, then rip the second edge on table saw so it is parallel to the first edge and finally plane the stock to thickness.
You should get good 90' cuts across the stock.
So, are the edges of the stock parallel to each other? You should check. My students never realize that I flip the board or that I intentionally taper the board very slightly before the instruction.
Bill V

I also never really thought that this could be a problem as I was just using scrap plywood...

Without having to chew up my jointer blades on 3/4” plywood edges, shouldn’t I be able to have a decent 90° cut IF I rip a really clean straight cut through my plywood, then place that edge on my recently aligned miter gauge?

In my head I don’t see why I wouldn’t be able to get a near perfect 90° cut where the two cuts intersect,


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Even with scrape wood, if you have a piece with a straight edge and you place that edge against the face of the miter gauge, the cut should be square to the "straight edge".

[wa2crk]

Yes you will. BUT some people will check the cross cut angle from the edge that was not against the miter gauge fence. If those two edges are not parallel to each other then there will be problems. Rip a straight edge on the table saw and then turn the board around and make another rip cut and you should have two parallel edges and when you cross cut at 90 deg it should not matter which edge you check the cross cut angle, it should be square to both edges.
Bill V

[tbolish]

This may sound like it coming out of left field but here I go.
When I teach some of our students in our retirement community table saw techniques I play a trick to prove a point. I show them how to check the table saw for proper alignment and show them how to make a right angle cross cut which never turns out right. Then I joint one edge and make another incorrect cross cut
Then I make another cross cut without doing anything else which will be correct. Why the difference? The second cut was made with the jointed edge against the miter gauge and it was square but not was not square to the opposite edge because the opposite edge was not parallel to the jointed edge.
This lesson was on how to square up stock for a project.
Flatten one face of the board, then joint one edge with the flattened face against the jointer fence, then rip the second edge on table saw so it is parallel to the first edge and finally plane the stock to thickness.
You should get good 90' cuts across the stock.
So, are the edges of the stock parallel to each other? You should check. My students never realize that I flip the board or that I intentionally taper the board very slightly before the instruction.
Bill V

I also never really thought that this could be a problem as I was just using scrap plywood...

Without having to chew up my jointer blades on 3/4” plywood edges, shouldn’t I be able to have a decent 90° cut IF I rip a really clean straight cut through my plywood, then place that edge on my recently aligned miter gauge?

In my head I don’t see why I wouldn’t be able to get a near perfect 90° cut where the two cuts intersect,


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Even with scrape wood, if you have a piece with a straight edge and you place that edge against the face of the miter gauge, the cut should be square to the "straight edge".

Good..at least I’m not completely losing my mind. I remember the first time o forayed into shopsmith ownership about 10 years ago that the table saw was the completely pain in the ass weak link for me.

Now that I’m revisiting it since I have such a small workshop space I’m afraid it’s all happening again....hate to admit but I really miss my old dewalt 744 job site saw, as it sadly was easier to make accurate cuts with. Really disconcerting, although I only paid $400 for my current SS + jointer, bandsaw, dust collector, etc...I just wish the damn thing wasn’t so apparently fickle with setting up.

I know people on here can get accurate results, but I also know a lot of other people struggle like I am with the saw aspect of these machines...I get the feeling that I’m probably missing something or my machine is defective.


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[reible]

So I see you have a Chicago location. Perhaps someone in Chicago would be willing to stop by your shop for an hour and take a look at what you have.

I live out in Aurora but don't venture into the city. If you wanted to pack up your machine and bring it out on a nice day I would be willing to go over it with you.

I have and a shopsmith since 1976 and have been well pleased with it. I get accurate cuts and they stay aligned for a long time and even when they need alignment it not a tough or lengthy job.

I can see only a couple of things that could be issues but which ones that might be causing you problems is pretty hard to guess. If you have had problems before then it is quite possible that it is something you are missing about the procedure.

Ed

[wa2crk]

I agree with Ed. Once these machines are set up they hold tolerances for a good long time unless they are bumped real hard. My machine is a 1983 frame with the 520 table upgrade and the Power Pro headstock. I do check the alignment periodically but I don't find anything wrong.
I had a neighbor who asked me to cut a piece of plywood for him and I asked what side of the line he wanted me to cut on. After a short discussion I told him that I would leave half of the line to which he replied "show me". I actually cheated because he drew the line with one of those heavy carpenter's pencils. So I made the cut and sent him home mumbling to himself.
These machines are accurate when set up and aligned properly.
Bill V

[RFGuy]

tbolish,

Have you checked your miter gauge with a larger square? I am including your picture below. It is hard to tell from a picture, but to my eyes it looks like you have the long edge of the square snug against the blade across its entire length. However, the short end of the square looks like it is contacting the outside edge of the miter gauge, but on the inside edge where I drew a red oval around it looks like there is a small gap which would explain why your crosscuts are off. It might be worth a second look at your miter gauge to check for square. Possibly use a larger square if you have one, or try flipping your square around so that the long end reaches across more of the miter gauge face. You could also use the square directly on the miter gauge to set the face square to the miter bar (rather than checking miter gauge<->sawblade). Just some thoughts...

square2.jpg (208 KiB) Viewed 10240 times

[dusty]

I can't tell from these pictures but the one expanded image from RF Guy does seem to reveal a gap (out of square indicator).

The attached image shows how I do "quick checks" of my miter gauge.

20200518_064109[1].jpg (1.26 MiB) Viewed 10227 times

The aluminum block (one of several) was originally milled to be a setup block for a piece of precision equipment. It is as perfectly square as will ever be required for me. Anything similar that you have would work for this purpose.

[rpd]

I sometimes get uneven cuts when crosscutting, especially with longer pieces, waxing the tables helps to reduce drag so the work doesn't pivot away from the face of the miter gauge.
I really do need to make a cross cut sled one of these days.

[wa2crk]

My post disappeared. When I first looked at RF Guy's reposted pic I thought it was a gap also. But now it looks to be a reflection from the polished face of the miter gauge. The camera is a bit past vertical revealing the face. There is a VERY slight gap at the extreme right end of the square's handle but I would think that it insignificant.
Bill V

[dusty]

My post disappeared. When I first looked at RF Guy's reposted pic I thought it was a gap also. But now it looks to be a reflection from the polished face of the miter gauge. The camera is a bit past vertical revealing the face. There is a VERY slight gap at the extreme right end of the square's handle but I would think that it insignificant.
Bill V

I would not argue about that BUT a square with a leg that extends all the way across the face of the miter gauge would increase reliability of the measurement. Even my method is questionable.