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Flat saw blades?

Started by D._Frederick, January 20, 2011, 07:22:22 AM

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D._Frederick

While I was aligning the miter slot to the blade with my dial indicator, I rotated the blade to see how much wobble it has. The 5 newest blades I have read from 0.004 to 0.010 inches.

My just turned saw collar measures 0.0003inches. How "true" should the blades be?

Are the $200+ blades any better?  Does this wobble effect the quality of the "cut" or does the centrifugal force hold the blade true?

The blade mfg. use flatness as a selling point.

Give me your thoughts.

Just Me

 I have never seen a blade that was perfect. I used to look for such things, till I figured out it was like a four leaf clover. Flat is good but the runout that you are talking about is well within usable limits.

My blade of choice is FS Tool. Expensive though, but they do work well for a long time and have nice big chunks of carbide that can be resharpened many times.

If I am in a hurry I can pick up Freud Industrial blades locally. These are not the blades that you will find at the Borg. They are heavy blank blades that can be resharpened a few times, and considerably cheaper than FS Tool.

I tried a Tenaru[? spelling?] blade on my job site saw recently and was impressed with it, but that was just a 10" contractors saw. Might spring for one of their bigger blades for the shop.

What saw are you working on?

Larry

D._Frederick

Larry,

I have a 1975 model Powermatic 66 that the arbor bearings went south and needed replacement.

tyb525

Did you also true the arbor nut and both washers, or does your saw not have the washers/collars?
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

Just Me

 Those are great saws, just a workhorse that once tuned will stay that way for thousands and thousands of feet.

I have one of those saws with a 5 hp 3 ph, just burned out the motor after many years of abuse running on a static converter.  Its my own fault, I had a rotary converter but never bothered to get thePM off of the static converter. I need to find a new motor for it, or a used one that someone who converted to single phase has sitting around. Hear of one let me know.

Larry

terrifictimbersllc

It might not all be from the blade, some of it could come from the arbor.  And the further the measurement is taken from the turning axis, the greater such wobble will be. If you can get a dial gauge on the arbor,  I would first check its runout by measuring perpendicular to its face near the outer edge (largest diameter).   It can be corrected by marking the low spot then inserting a shim (tape, paper, plastic) at this mark between the arbor and the blade.   If somehow both the blade and the arbor have some wobble, then you can rotate the blade on the arbor and  find an optimum where some or all of it is canecelled out.   
DJ Hoover, Terrific Timbers LLC,  Mystic CT Woodmizer Million Board Foot Club member. 2019 LT70 Super Wide 55 Yanmar,  LogRite fetching arch, WM BMS250 sharpener/BMT250 setter.  2001 F350 7.3L PSD 6 spd manual ZF 4x4 Crew Cab Long Bed

D._Frederick


tyb525

I take the movable saw collar  and put a sheet of sand paper on the saw table and "dress" the collar until it is completely bright. The nut has enough "slop" in it contacts the collar 100%.

terrific-

I only have the one table saw and am changing blades too often to try and find optimum point for each blade. If you leave the blade on the saw, you have a good idea.

If I can get the saw guide aligned to a couple thousand, I will cut a slot in a board and measure the saw kurf and see how much the wobble effect the cut.

terrifictimbersllc

Quote from: D._Frederick on January 21, 2011, 11:42:31 AM

tyb525

I take the movable saw collar  and put a sheet of sand paper on the saw table and "dress" the collar until it is completely bright. The nut has enough "slop" in it contacts the collar 100%.

terrific-

I only have the one table saw and am changing blades too often to try and find optimum point for each blade. If you leave the blade on the saw, you have a good idea.

If I can get the saw guide aligned to a couple thousand, I will cut a slot in a board and measure the saw kurf and see how much the wobble effect the cut.
Just talking about either 1) putting a few thousandths shim at one place between blade and arbor, or 2) rotating the blade relative to the arbor to find the point where most of the out-of-round cancels. Once either is found,  both arbor and/or blade can be marked to put things back together the same way again. If the mark is under the washer it won't get wiped off.

An example of the the first option: My Wood-Mizer CBN sharpener arbor was shipped with an arbor which had unacceptable runout, maybe 2 thousandths at the outer edge of the 1.5" dia arbor, which  was magnified at the larger outside edge (5-6" dia) of the CBN wheel to be 7-8 thousandths.  I just marked the extreme point on the arbor with a sharpie, and put a little piece of masking tape there.  Now there is only 1-2 thousandths runout at the outside edge of the wheel and the vibration and noise are gone.  Since I always have a dial caliper around it is no problem to find and stick a 1-2 thousandths shim of something in there at the mark when I change wheels which I do frequently.
DJ Hoover, Terrific Timbers LLC,  Mystic CT Woodmizer Million Board Foot Club member. 2019 LT70 Super Wide 55 Yanmar,  LogRite fetching arch, WM BMS250 sharpener/BMT250 setter.  2001 F350 7.3L PSD 6 spd manual ZF 4x4 Crew Cab Long Bed

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