Unisaw help - replacement parts

[Nick Mazzino]

I was doing a miter cut last night on my Unisaw with a piece that had what I thought was a hairline surface crack. The piece got stuck and I could tell was going to kickback, thus, I pushed a little harder and unfortunately the piece just about exploded and my blade somehow hit the metal throat plate. I am very thankful I did not get injured.

Obviously my blade will need to be sharpened at a minimum or just replaced. Unfortunately it was a Tenyru Gold Medal blade.

My worry is now that I have ruined something in my table saw. I checked the blade with a magnetic dial indicator. I had it set to the blade and turned the blade several revolutions and there was less than 3/1,000ths of an inch play which is what it was when I recently bought the saw a few months ago. I also connected the dial indicator to my miter gauge and ran it along the blade. Same readings. So, I thought everything was fine.

I have a good cross-cut blade on my miter saw that I put on the table saw and was not getting smooth cuts like I was before the incident. You can see blade swirls in the cut.
Could I have possible bent the arbor shaft?
Any other ideas? If so, is there a place/site I can purchase replacement parts from other than eBay?

Thanks for all of the help.

[Matt Day]

If it were me, the first thing I would do is put a dial gauge on the arbor flange and spend it by hand to see the run out, then do the same to the arbor itself. Then go from there.
In other words, take the blade out of the equation. If everything checks out, then your blade is to blame.

[Cary Falk]

My first thought is that the blade is causing the issue. Take the blade out of the equation out of the equation as Matt describes. If you need any parts OWWM is probably your best source.

[Nick Mazzino]

I took the blade out that was on the saw when it happened and swapped out for my cross cut miter saw blade that is only about a month old. Tried a cross cut on the table saw and was still not getting a flush smooth cut. The cut was definitely better than with the affected blade, but still blade swirls in the cut.

I will have to pick up a more versatile dial gauge. Mine only has one arm and one pivot point and can't reach the arbor properly.

[John TenEyck]

Measuring at the perimeter of the blade helps magnify any run out in the arbor or arbor flange. If you measure 0.003" on the blade perimeter it might only be 0.001" at the arbor or flange. The actual value is likely different, but I think you get the idea. If you measure the run out on the blade in between the same two teeth at both the front and back of the table it will eliminate any run out in the blade itself. Doing this won't tell you if the measured run out is with the flange or arbor, but it will tell you the magnitude of the issue.
Also, note that some blades cut better in some saws than others. I have a blade that cuts great in my TS but not in my RAS. Another that cuts great in both. Have you tried cutting on both sides of the blade you are using? If it cuts better on the other side maybe the table got shifted out of alignment when it went bang.

John

[Carlos Alvarez]

I use this to keep my Unisaw in perfect alignment, and test runout: http://www.ptreeusa.com/shop_brand_inline.htm

I would bet the blade you had on there when you had the problem is bent now. The fact that a new blade is having minor issues could be just that blade isn't in great shape any more. Or it could mean your saw is misaligned and always was.

[Nick Mazzino]

Thanks everyone.

I checked the arbor flange and arbor with my dial indicator. Arbor flange doesn't move at all. Under 0.001". Arbor varies bye 0.002". Would 2/1,000ths cause this problem?

I am going to take my blade to my local woodworking shop and have them sharpen it and test it. I assume they can also test for runout or see if the blade is bent. If the blade is bad I will buy a new one and test with the new blade.I assume it has to be something with the saw since when I put my crosscut blade on it was still having this issue. Then I tested that crosscut blade on my miter saw and it was fine.

This is only my first month woodworking :(

[Bruce Wrenn]

Rather than local sharpening place, I would send it to Dynamic Saw. Explain what happened and have them check blade. It could have a couple teeth that were knocked out of alignment. Top could have shifted on saw also.

[Carlos Alvarez]

This is only my first month woodworking :(


Ooooooohhhh...then I'm 98% sure I know what the root problem is. Have you tuned the saw? I think not, since you said you don't have the tools for it. "Tune your tools, then tune them again" is something I wish I'd been told early on. Getting my Unisaw to less than 1/256" error in any direction has given me perfect cuts even with lesser blades, cut out most noise, and cut out ALL drama no matter what I'm cutting. When everything is perfectly neutral and nothing binds, your cuts will be amazing. Look up a tutorial on doing this, and get that dial indicator tool.

[Nick Mazzino]

Have you tuned the saw?

I did not tune the saw when I got it. I checked the blade run out and it was less than 1/256" and the top was flat within 1/256" as well.
I went and bought a higher end blade and it left the edges of the cut like glass.

I was able to check the runout on the arbor flange and arbor. Both Under 1/256". So I am at a loss now? I am going to get my blade checked today and potentially purchase a new one if this one is ruined and I guess try that.

I definitely want that dial indicator tool, but this is an expensive hobby to get into all at once.

[John TenEyck]

So I'll ask again. Have you checked the cut quality on both sides using the blade from your miter saw? I'll bet one side is good and the other isn't. If so, your table is not aligned properly with the blade. They are rarely perfect coming from the factory.

A dial indicator from HF is cheap, but you don't need one to check table alignment, or fence alignment for that matter. A simple piece of wood clamped to your miter gage and with a screw in the end of it works just fine. Google something like "How to align a tablesaw blade".

John

[Nick Decker]

Listen to John. Aligning the blade to the miter slot, then aligning the fence to the miter slot is your first step. Worrying about arbor runout is silly without first doing that. Not doing it will not only leave you open to less than clean cuts, it's unsafe.

[Nick Mazzino]

I have not checked the cut on both side of the blade yet. I will definitely check that when I get home tonight.

Thank you for your help, I really appreciate it.

[Carlos Alvarez]

Nick, the "tune" I was talking about is the process of squaring up all of the surfaces on your saw. Forget runout, you can't control it. A saw tuning process is where you make sure the blade is perfectly square to the table in both axis, to the fence, to the miter slot, etc. It makes a huge difference. Read up on it here: https://www.google.com/search?q=table+saw+tuning&oq=table+saw+tuni&aqs=chrome.1.69i57j0l5.7903j1j7&sourceid=chrome&ie=UTF-8

[andy bessette]

Align the miter slot to the blade before testing crosscut results.

To avoid similar problems in the future, trim the faulty workpiece on the bandsaw, first, leaving only a slight finish cut to make on the table saw.

[Jim Morgan]

There is a lot we don't know here. OP says he was cutting a miter (crosscutting at an angle with the blade at 90°), but I'd bet that he was actually cutting a bevel, ripping with the blade tilted. Was he using a splitter or any sort of anti-kickback device? Regardless of how well the saw is aligned, cutting a piece with internal tension may cause it to pinch the back of the blade, causing kickback.

A tablesaw that is aligned with the blade at 90° may not be aligned with the blade at 45°. The first alignment is accomplished by rotating the table, the second by shimming the table.