My 520 started singing today.

[dusty]

So how far off am I as it relates to Shopsmith standards? Is the blade supposed to actually be centered or does it sit off center some?

Shopsmith uses the term "centered" but does not give any specific measurements. It is sort of up to you to determine what you consider "centered".

I will redo the table alignment. I may have pulled instead of pushed.

Pulling or pushing does not really make a big difference; the difference in the diameter of the bolts and the hole.

I am using standard Shopsmith blades.

The remaining question is standard kerf or thin kerf. Shopsmith sells both; or at least has in the past.

When I did the measurements I measured from inside edge of miter slot to the blade so the measurements do not include blade thickness.

Using your numbers and measurement technique your saw blade would be 13/64" wide (thick). I doubt that. This is why I suggested that you take all such measurements by using the left face of the blade for reference. Doing that, both measurements would be 3.508" (if you are precisely centered).

Michael

It is significant for me to say that you are already "close enough for government work" without doing any more troubleshooting..

[dusty]

So how far off am I as it relates to Shopsmith standards? Is the blade supposed to actually be centered or does it sit off center some?

Shopsmith uses the term "centered" but does not give any specific measurements. It is sort of up to you to determine what you consider "centered".

I will redo the table alignment. I may have pulled instead of pushed.

Pulling or pushing does not really make a big difference; the difference in the diameter of the bolts and the hole.

I am using standard Shopsmith blades.

The remaining question is standard kerf or thin kerf. Shopsmith sells both; or at least has in the past.

When I did the measurements I measured from inside edge of miter slot to the blade so the measurements do not include blade thickness.

Using your numbers and measurement technique your saw blade would be 13/64" wide (thick). I doubt that. This is why I suggested that you take all such measurements by using the left face of the blade for reference. Doing that, both measurements would be 3.508" (if you are precisely centered).

Michael

It is significant for me to say that you are already "close enough for government work" without doing any more troubleshooting. The thin kerf blade currently on my Mark V measures 3/32" thick (measuring the body of the blade not the carbide).

[jsburger]

So how far off am I as it relates to Shopsmith standards? Is the blade supposed to actually be centered or does it sit off center some?

Shopsmith uses the term "centered" but does not give any specific measurements. It is sort of up to you to determine what you consider "centered".

I will redo the table alignment. I may have pulled instead of pushed.

Pulling or pushing does not really make a big difference; the difference in the diameter of the bolts and the hole.

I am using standard Shopsmith blades.

The remaining question is standard kerf or thin kerf. Shopsmith sells both; or at least has in the past.

When I did the measurements I measured from inside edge of miter slot to the blade so the measurements do not include blade thickness.

Using your numbers and measurement technique your saw blade would be 13/64" wide (thick). I doubt that. This is why I suggested that you take all such measurements by using the left face of the blade for reference. Doing that, both measurements would be 3.508" (if you are precisely centered).

Michael

It is significant for me to say that you are already "close enough for government work" without doing any more troubleshooting..

Would it be fair to say that the real reason for the "rubber baby buggy bumper" is to insure that when you lower the table the blade will come up through the insert without standing on your head to adjust the alignment. It was never designed to center the blade in the slot to exact dimensions. After all there is no reason for the blade to be exactly centered. All it has to do is not rub the sides of the insert.

[dusty]

Template for Fine Tuning Quill Extension.png (14.69 KiB) Viewed 6501 times

Sure, John, that would be fair and if it does not come up through the insert you can always enlarge the opening in the insert or move either the carriage or the headstock or extend the quill. That might make it a bit difficult to keep ZCI on hand but that is no big deal either. Just make new ZCI.

[dusty]

What is depicted in the next two or three photo images is not coincidence. It is what the designer intended.

One image shows how the left face of the blade (right hand face of the saw arbor) aligns with the center line (axis of rotation) of the trunnions.

The second image shows how the plane of the table tubes aligns with the left face of the blade.

This relationship is all established by the design characteristics of the carriage, headstock, trunnion, saw arbor and "rubber baby bumper".

Carriage Stop Ring 008.JPG (152.1 KiB) Viewed 6496 times

Carriage Stop Ring 009.JPG (135.91 KiB) Viewed 6496 times

Carriage Stop Ring 002.JPG (143.18 KiB) Viewed 6496 times

No coincidence here.

[jsburger]

Template for Fine Tuning Quill Extension.pngSure, John, that would be fair and if it does not come up through the insert you can always enlarge the opening in the insert or move either the carriage or the headstock or extend the quill. That might make it a bit difficult to keep ZCI on hand but that is no big deal either. Just make new ZCI.

So if you make a ZCI that fits your saw it will always fit unless you change something that changes the blade position. It has nothing to do with the blade being dead center.

[dusty]

No, it has nothing to do with the blade being dead center but what is your point? My point is that if the blade does not come up very, very close to dead center that something is not right.

I just believe that if everything is setup as was originally intended that it will be centered. If that does not fit for you, so be it. Have it your way!

[jsburger]

What is depicted in the next two or three photo images is not coincidence. It is what the designer intended.

One image shows how the left face of the blade (right hand face of the saw arbor) aligns with the center line (axis of rotation) of the trunnions.

The second image shows how the plane of the table tubes aligns with the left face of the blade.

This relationship is all established by the design characteristics of the carriage, headstock, trunnion, saw arbor and "rubber baby bumper".

Carriage Stop Ring 008.JPGCarriage Stop Ring 009.JPG

Carriage Stop Ring 002.JPG

No coincidence here.

That may be based on your observations. That is if you get a rubber collar of the correct size. Apparently SS has been all over the place with the width. Quality control probably not the design. As you know all parts are made from a print with dimensions. I hope SS is not buying the rubber bumpers from some guy in his basement with rubber hose and a hack saw. Why do they vary in width over the years.

Case in point. I bought my first SS (510) at Woodcraft in Salt Lake City in 1994. At the time I didn't know what the bumper was for since it didn't do anything like space the blade. Three or fours years later I called SS to order something and I mentioned the bumper because I had realized what it was for. They sent me a replacement.

As I remember it fixed the problem but I don't remember if it actually "centered" the blade in the head stock. This is because I replaced the head stock with a new from SS Power Pro head stock in 2013.

So, the original bumper new on my 1994 510 is 1 1/4" wide (first picture). The replacement they sent me somewhere around 1996-97 is 1 1/2" wide (second picture). The third picture shows the same bumper on the same machine with the Power Pro head stock. The blade is clearly not centered in the insert. It is not even close to what I would publish as centered.

So what should I conclude about what the designer intended from this???

[dynabase]

That last picture (20170601_155006.jpg) is exactly how my blade sits after the trunnion change. Just a little off center. I guess the question that still needs to be answered is where is the blade officially supposed to fit - Center of off center? If "off center" how much is correct?

Michael

[dusty]

For those 'decimally challenged', the spacers are 1 3/8" and 1 7/16".

Except for Johns' which are 1 1/4" and 1 1/2".