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View Full Version : Is 5-thou on a 10" TS blade OK or too high



Howard Rosenberg
10-15-2021, 9:30 AM
My 10" TS blade on my Delta contractor saw is out a little more than 5-thou.

I use a small device to hold my calipers in place in the mitre slot and I checked it 2 ways -
- moving my calipers toward the same tooth at the front and rear of the saw
- feeler gauge (same tooth, front and rear....)

Is this an acceptable variance?
Or should I adjust my saw?

This all started because I want to make a TS crosscut sled and some of the videos recommended yesterday got me thinking I should check first.....

Tom M King
10-15-2021, 11:23 AM
I would want it closer than that. I'm sure the majority are at least that far out though. Certainly useable. I have an old Unisaw, that mostly by luck, is set dead on with fancy calibration equipment, and it's nice to use.

I should say though, that I'm one of the old guys who has used a tablesaw for 50 years, never used any kind of safety device on one -yes, still have all fingers, and never a kickback, or a close call. Also, I never crosscut on a table saw.

Doug Garson
10-15-2021, 1:17 PM
I think the general rule of thumb is 5 thou is acceptable. I just adjusted my General 350 and settled for 7 thou tow out ie back of blade 7 thou further from slot than front. I was trying for 5 thou but settled for 7 as it shifted when I tightened the bolts. I measured using a micrometer held in the miter slot with a simple jig. I'd say you're good to go.

Warren Lake
10-15-2021, 2:15 PM
tow out is on the rip fence if you use tow out.

You are talking mitte gauge if I read it correctly, it should be parallel. When that is correct then set your rip fence to what you want in terms of tow out.

Doug Garson
10-15-2021, 2:37 PM
tow out is on the rip fence if you use tow out.

You are talking mitte gauge if I read it correctly, it should be parallel. When that is correct then set your rip fence to what you want in terms of tow out.
Ok, tow out wrong term for miter slots and yes perfectly parallel is best, but 5 or in my case 7 thou is close enough for woodworking. 7 thou is less than 1/128". Note I didn't intentionally set it at 7 thou out, just settled for that after a couple attempts to get under 5 thou. Just tightening the bolts moved mine 3 thou.

Robert Hayward
10-15-2021, 2:48 PM
just settled for that after a couple attempts to get under 5 thou. Just tightening the bolts moved mine 3 thou.
It would take about half that 7 thou to make me happy. There are methods to stop the creep when tightening the table bolts. Been quite a while but I believe one method I used was to position the washers with the cut side up towards the table. Another method was to tighten the table bolts just a tiny bit at a time and then in a sequence. Like you would tighten a head on an internal combustion engine.

Warren Lake
10-15-2021, 2:59 PM
id cut a piece of wood on the mitre gauge and compare front of blade running to when you get to the heal, it will tell you what is going on

Andrew Seemann
10-15-2021, 4:11 PM
My 10" TS blade on my Delta contractor saw is out a little more than 5-thou.

I use a small device to hold my calipers in place in the mitre slot and I checked it 2 ways -
- moving my calipers toward the same tooth at the front and rear of the saw
- feeler gauge (same tooth, front and rear....)

Is this an acceptable variance?
Or should I adjust my saw?

This all started because I want to make a TS crosscut sled and some of the videos recommended yesterday got me thinking I should check first.....

You can try, but it is going to be hard to get a contractor saw set better, and there is a good chance you could make it worse. That is a relatively light weight saw with the motor attached to the arbor and a lot of flex in a lot of places. For reference, move the saw to a different part of the shop, crank the up and down and the bevel to max and back, and redo the measurement. You might get the same 0.005" and you might get a different number.

Being off 0.005" over 8" isn't bad for a cross cut. You probably will get more inaccuracy from the sled itself, between material flex and the needed clearance of bar in the miter slot.

Johnny Barr
10-15-2021, 6:39 PM
Sawstop have advised that 10 thou is OK which is what mine was straight out of the box. It did cut well at that setting but I wanted better. Fortunately its easy to adjust on a Sawstop so I ended up with about 1 or 2 thou although this can change with temperature. I didn't notice much of a difference other than a few less but an insignificant amount of teeth marks after rips. If you're getting good, smooth straight cuts at your current setting then leave it.

Bill Space
10-16-2021, 2:58 PM
My first thought is: What is causing that offset?

Could be the blade. Could be the arbor. Could be a bit of something between the blade and the arbor.

I think if that amount of difference concerns you, then you should look further and try to isolate the reason it is there.

Pretty sure my results would be satisfactory if using a saw with that amount of deviation from perfection.

But this could just be the view of a non-perfectionist! LOL.

Lee Schierer
10-16-2021, 6:40 PM
When I tuned up my Craftsman TS I encountered the same problem with the adjustment moving back as I tightened the bolts. The lock washers had indented the cast iron just enough that they would pull the arbor right back where it started. By loosening the bolts and rotating each lock washer so it was no longer aligned with those indentations and then hand tightening the bolts, making the adjustments and then slowly tightening each bolt a bit at a time. I was able to get my saw under .003"

I will add; that if you are measuring off the teeth, you will get errors on every check because most teeth are tapered. Use the flat surface of your blade plate for your measurements. A dial indicator from Harbor freight costs about $20 and it can be securely mounted to most miter gauges to give more precise readings.

Doug Garson
10-16-2021, 7:31 PM
I use the depth probe on my digital micrometer and yes, I put a spot with a sharpie on the blade body near the outside edge and measure to that not a tooth. I have a simple jig that holds the micrometer in the miter slot.

Bill Dufour
10-16-2021, 8:39 PM
This is a good time to learn that lock washers do not work. This has been known for about 150 years. Locktite does work, if needed. Fine threads on the bolts is probably all it needs.
Bill D

johnny means
10-17-2021, 7:33 PM
My general rule of thumb is that any discrepancies don't matter until they present themselves while I'm working. If i can't notice it from the cut, does it matter?