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Re: My Newest Toy

Posted: Thu Sep 01, 2016 3:11 pm
by sehast
If I wanted to confirm the specs claimed I would lay the disk flat and use a straight edge/feeler gauge technique to measure flatness. If a .002" gauge is the largest one to fit under the straight edge anywhere on the surface of the disk then it meets spec. This eliminates any errors introduced by the arbor or drive shaft.

Re: My Newest Toy

Posted: Thu Sep 01, 2016 3:27 pm
by dusty
sehast wrote:If I wanted to confirm the specs claimed I would lay the disk flat and use a straight edge/feeler gauge technique to measure flatness. If a .002" gauge is the largest one to fit under the straight edge anywhere on the surface of the disk then it meets spec. This eliminates any errors introduced by the arbor or drive shaft.
That would work extremely well IF I had a plate that was known to be "flat". The surest thing I have to a "flat plate" is my work bench with 2" of MDF for a top or a large mirror out in the shed.

For the moment I am going to trust that the set6up plate is flat to within specs.

Re: My Newest Toy

Posted: Thu Sep 01, 2016 3:48 pm
by sehast
A good 12" rule out of a combination square would work pretty well. Certainly better than mdf or your bench.

Re: My Newest Toy

Posted: Thu Sep 01, 2016 5:30 pm
by reible
Well if it were me I would mark a high spot on the disk while rotating, as in the one that extends farthermost in-board side of the table. Then the out-board side.

Next loosen the disk and while keeping the arbor from turning rotate the disk 90 degrees and see if the spots move.

If you wanted to rotate by 45 degrees, or even 30 degree increments you would have a pretty good idea if the movement is due to the disk being an issue in that all the marks are occurring at the same place or the shaft/adapter/other unknown at this point issue with the marks move with the disk rotation.

The more marks the better. You may even find a place where the errors coincide give you either a max or min deviation.

By marking inside and outside a warp might show itself.

Ed

Re: My Newest Toy

Posted: Thu Sep 01, 2016 6:41 pm
by dusty
sehast wrote:A good 12" rule out of a combination square would work pretty well. Certainly better than mdf or your bench.
I have a couple good 12" rules from Products Engineering (PEC). I can't get a .003' feeler gauge under the ruler anywhere. I did not do an exhaustive test but did check in about 50 different locations on both sides of the setup plate.

I can slide a .002" feeler under the ruler in several locations.

Like I said, not an exhaustive test and definitely not a scientific test but I am satisfied that the setup plate is at least as flat as any of my saw blades.

It is also much more rigid so I am not likely to get a flex while doing the tests on the Mark V.

I am not yet ready to recommend this device as being any better than a saw blade or the sanding disk for doing alignments.

Re: My Newest Toy

Posted: Thu Sep 01, 2016 8:22 pm
by jsburger
dusty wrote:
sehast wrote:A good 12" rule out of a combination square would work pretty well. Certainly better than mdf or your bench.
I have a couple good 12" rules from Products Engineering (PEC). I can't get a .003' feeler gauge under the ruler anywhere. I did not do an exhaustive test but did check in about 50 different locations on both sides of the setup plate.

I can slide a .002" feeler under the ruler in several locations.

Like I said, not an exhaustive test and definitely not a scientific test but I am satisfied that the setup plate is at least as flat as any of my saw blades.

It is also much more rigid so I am not likely to get a flex while doing the tests on the Mark V.

Since you are experimenting have you tried this?It will fit on a 5/8" SS arbor.

https://www.amazon.com/MasterGage-MP-1- ... B00006RGLC

I am not yet ready to recommend this device as being any better than a saw blade or the sanding disk for doing alignments.

Re: My Newest Toy

Posted: Thu Sep 01, 2016 10:53 pm
by superpop
I get that you are looking for very tight tolerances but I think you are about as good as you are going to get for woodworking and particularly with a shopsmith. The variance you are chasing will have no impact on the accuracy of your cuts. The first time you deploy the castors and move the unit it will probably fall back out of the tolerance you have. Just my 2 cents.

Re: My Newest Toy

Posted: Fri Sep 02, 2016 5:32 am
by dusty
superpop wrote:I get that you are looking for very tight tolerances but I think you are about as good as you are going to get for woodworking and particularly with a shopsmith. The variance you are chasing will have no impact on the accuracy of your cuts. The first time you deploy the castors and move the unit it will probably fall back out of the tolerance you have. Just my 2 cents.
You are not alone with that sentiment. I have been told that several times and in several different ways.

Understand that I am NOT DISSATISFIED at all with the accuracy of the Shopsmith or with the alignment that I currently have.

However, I do disagree with your position on what happens when you drop the Mark down on its wheels and roll it around. That is a myth perpetrated by those who do not want to spend their time doing an accurate and complete alignment.

Re: A Whole Lot of Coincidences

Posted: Fri Sep 02, 2016 11:13 am
by dusty
The more I work on my Mark V the more I find that this machine was designed to be simplistic while being precise.

Re: My Newest Toy

Posted: Fri Sep 02, 2016 12:02 pm
by sehast
dusty wrote:
sehast wrote:A good 12" rule out of a combination square would work pretty well. Certainly better than mdf or your bench.
I have a couple good 12" rules from Products Engineering (PEC). I can't get a .003' feeler gauge under the ruler anywhere. I did not do an exhaustive test but did check in about 50 different locations on both sides of the setup plate.

I can slide a .002" feeler under the ruler in several locations.

Like I said, not an exhaustive test and definitely not a scientific test but I am satisfied that the setup plate is at least as flat as any of my saw blades.

It is also much more rigid so I am not likely to get a flex while doing the tests on the Mark V.

I am not yet ready to recommend this device as being any better than a saw blade or the sanding disk for doing alignments.
Looks like you confirmed that it meets spec. From what I have read the setup plate from Amazon won't be any more accurate and costs more. I have a new shopsmith 10" sanding disk I keep for this purpose but I have not bothered to measure its flatness. I will measure it and let everyone know how it compares with the Infinity disk. Personally I use both the sanding disk and saw blade to set the table miter slots parallel to the blade. First with a digital indicator and the sanding disk and then confirm it with the single tooth saw blade technique. After all the saw blade is what you want to run true to the miter slots and fence.