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Arbor run out on Table Saw

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Peter G Denmark

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I have been unable to find any guidelines to the tolerances of runout on arbors and table saw blades.

My arbor has a runout of about 8/100 of a mm (roughly 3/1000 of an inch) on the edge of the flange (diameter 75mm), which would translate to about 4-6 times that on the tips of a 10" blade. Almost 0,5 mm of wobble on that blade tips is entirely too much, so i will spend a day with a felt pen, a diamond stone and dial calipers knocking down the high areas.

But what is a reasonable target to go for, when it comes to blade wobble. I guess you can't eleminate it all together, but what is the point where it's "good enough". How much arbor run out do you have on your saws?

The bearings are ok (runs really quiet, and the deflection when trying to move the arbor up/down, side to side is around 1/100 of a mm, when assertng some force, which i think is within reason. Meaning - if i bolted a 20mm solid steel rod to a solid suface, i would be able to deflect that by 1/100 of a mm, so i don't think the bearings could do a better job.

I've spent 2 years restoring this (lemon of a) Wadkin saw, so i'm just about out of patience, and just wan't to build some beautiful furniture, instead of grinding, welding and straightening metal :).
 

Peter G Denmark

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Well - i found my answer in "Mastering Woodworking Machines" by Mark Duginske.

He says that runout on the blade tips should be no more than 12/1000 of an inch (0,3 mm), which he states translater to 3/1000 of run out on the flange (0,076 mm), so according to him i was actually within the tolerance.

I only learned this an hour ago, and had already spent the day fixing the runout on my flange using this method: http://www.forums.woodnet.net/ubbthread ... t=all&vc=1

It took about 4 hours for me, but in the end i got the runout down to 1/100 of a mm (less than 0,5 thousands of an inch). I could barely see the needle move on the indicator.

I didn't use a stone, but just marked the high areas, detected with dial calipers, with a felt pen, filed semi aggresiely on the center of the high point, and tapering the pressure of to either side of that point, making sure the file was good and squarely held against the flange.
I loosened the belts, but didn't take them of, so in between filing, i started the saw, and held one of those abrasive pads (320 grit) aganst the flange to take burs of.
Them i repeated the process until i was within 1/100 of a mm.

I've them taken my blades and put them on the saw one by one, and checked them for runout. Turned each blade a 1/4 of a turn, and checked again. when i found the spot with the least amount of runout on each blade, i marked it i correlation to a smal mark i've made on the side of the flange.
This took only 30 minutes for 6 blades, and now 2 of my blades actually has zero run out, the even my cheapest blade had only 0,1 mm, so this was a succes.

It might seem overboard to do this, but the resulting finish straight from the saw is really nice now, where before there where visible ridges. Plus - it's just nice to be able to trust your tools.
 

kirkpoore1

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I did the same thing, but stopped at .001":
http://owwm.org/viewtopic.php?f=1&t=16101

Took about 45 minutes for me, not counting the false start. I didn't mark my saw blades, though. That might be worth a look.

So, Peter, has all the work on this saw been worth it? It sounded like you were really tearing your hair out for a while.

Kirk
 

Peter G Denmark

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Kirk - let's just say i wouldn't do it again, but i was very inexperienced with cabinet saws, and when i bougt it - i felt committed. The list of faults with this machine has been pretty extensive though, so my lemon statement stands:):

Moter bracket and trunion was warped. Causing:
Binding and play in the tilting mechanism
Binding in the rise and fall
Bushing for bracket worn out.
VERY rusty table. (Actually all exposed metal was COVERED in rust)
Extension tables warped and when tightened they curved upwards.
Main table has a 0,5 mm dip.
Fence rails bent.
Fence bent.
Truss rod in fence broken.
Motor bracket retaining piece warped, and the brass set screw was stripped, and the bolt hit the motor mount.
Mitre gauge out of square with no adjustment possibilities.
Arbor run out
No arbor nut
20 mm arbor, which requres adaptors, since only small blades have 20 mm bore.
V-belts worn out
Bent motor mount
Motor burned out second time i started it.
Mounting bolts for table top hits the inside of the saw cabinet.
No riving knife or splitter
No spacers for the fence rails.
No dust collection.
Painful mixture of metric and empirial measurements

I think i have spent 500+ hours of pure work on this saw, plus a lot of time researching and waiting for deliveries for LH 20mm 1,5 rise tap, 3/4 inch reamers brass etc.

I have just welded up a sturdy mobile base for it, and got it on there, and made my first real cut on it today... I made a push stick... :). (contemplating doing a video of that project)

I've adressed most of the issues mentioned, but i can't get it perfect - that would simply be too expensive. I've taken it as far as an amateur can who only has a basic metal working tool setup. So milling has been done by gluing wet-dry sand paper on my planers beds and pushing pieces back and forth, sometimes for hours.

Will order an INCRA 1000HD mitre gauge as a celebration, from fine-tools.com.

On the upside, i think i am now an authority on Wadkin AGS saws, and i think i can compensate for the saws shortcomings, and i've gotten to know a lot of nice people in this forum, who has been champs at listening and advising. Plus - i can now use dado blades - just like Norm :) (to all you dado blade haters - thank you for worrying about my safety - i'm really glad you care. I'm going to use them anyway).
Another thing is. When you spend this much time making something work, you develop a relationship with it. My first car was a puke colored Skoda 120, and it's the best car i have ever owned, because i knew that there were certain procedures you had to do, in order for it to work (hitting the starter motor with a crowbar for example), but it got me through europe twice.

Will post some pictures in my original post with some pictures and a video link of the saw.

Thank you fellows.
 

kirkpoore1

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Holy C****, er, Pinapple! (To use the vernacular)

That's a lot worse than I thought, and 500 hours is monstrous for a restore--probably triple what I have in my worst machine. My tablesaw wasn't that bad, and it had been dropped, breaking both trunnions and the motor mount.

I would have expected better from Wadkin on some of those things, like the unadjustable miter gauge and warped trunnion. How the heck do you warp a trunnion?

I think you are an expert now. Short of a good sized thicknesser, I can't see any other machine being worse. Good work in sticking it out!

Kirk
 
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