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Adjustable Stop Collar different sizes?

Posted: Thu May 16, 2013 3:21 pm
by benush26
I recently bought the Adjustable stop collar both to use on the table saw but also to fabricate an Incra like fence adjuster.

I download the pdf for the vernier tapes and had to adjusted the image to fit the 7.006" size as suggested and then laminated the piece.

However, what I found is that the circumference of my collar is 7 5/32". Which means the tape does not come close to fitting end to end. :confused:

Checking the picture, their ends are much closer to meeting than mine.

Are the collars that much different in size (older versus newer) or is the 7.006 length appropriate for the vernier tape regardless of the circumference of the collar? :confused:

Thanks for any insight.

Ben

Posted: Thu May 16, 2013 8:54 pm
by JPG
The tape lengths need to be equal to the circumference.

Note the upper one(0 - 62.5) is cut off to provide access to the set screw.

Laminating the strips will alter their thickness thus affecting their 'fit'.

So you need laminated strips that completely encircle the circumference.

Interesting that yours is 'bigger'. Are ya sure?;)

Posted: Fri May 17, 2013 1:15 am
by benush26
[quote="JPG40504"]The tape lengths need to be equal to the circumference.

Note the upper one(0 - 62.5) is cut off to provide access to the set screw.

Laminating the strips will alter their thickness thus affecting their 'fit'.

So you need laminated strips that completely encircle the circumference.

Interesting that yours is 'bigger'. Are ya sure?]

Thanks for the info

And yes, I am relatively certain it's a little bigger. :o

Posted: Fri May 17, 2013 12:39 pm
by JPG
Anyone with calipers/micrometer care to measure the od of theirs?

7.0006 is an odd dimension that has got to be taking in the thickness the paper.


I do not have 'one', but am guessing 2.25" and the strip should be 7.06".

Posted: Fri May 17, 2013 1:17 pm
by dusty
I never get the same reading twice but all of my measurements on the Stop Collar were greater than 2.24" and less than 2.27". I took measurements on two different Stop Collars but they measured similarly.

I hope this answers the question.

Posted: Fri May 17, 2013 2:12 pm
by reible
Hi,

It might be that they vary in size but what you are trying to do is divide the circle in to equal size segments. You just need to get it to fit your collar no matter what the dimension is.

I didn't find this "improvement" to be all that useful so I have no wrap on mine besides I get lost working in 1/128 of an inch....

Ed

Posted: Fri May 17, 2013 8:23 pm
by camerio
So is there any other way to use it without the tape ?
Any suggestions Ed or Dusty ?
I have not yet found on what I can print the tape yet...

Posted: Fri May 17, 2013 9:24 pm
by JPG
Printer paper. Lightly spray shellac it from the back side.????

Posted: Fri May 17, 2013 10:54 pm
by BuckeyeDennis
I've been meaning to do this myself for months now. Thanks for the kick-start!

Raw measurement data:
... The OD of my "Adjusting Nut" (short ring with the set screw) measures 2.230"
... The OD of my "Adjusting Screw" (tall ring with knurling) measures 2.244"
... When I printed the vernier tape PDF with the printer scaling at 100%, both tapes did indeed measure precisely 7.006" long.

Here's a photo of a collar with both labels attached, extracted from the "Vernier Tapes" PDF, which you can download here: http://www.shopsmithacademy.com/Tips_Ar ... _Tapes.pdf

[ATTACH]21401[/ATTACH]

And here's a link to the manual for the gizmo itself: http://www.shopsmith.com/ownersite/prod ... Collar.pdf

Analysis summary: Whoever wrote the vernier-tape instructions seems to have misunderstood the design intent. I believe that the actual intent is for you to choose either the decimal or the fractional scale (your personal preference), and then stick it on the "Adjusting Nut" (short ring with set screw) only.

Detailed analysis: The circumference of the short ring is Pi*2.230" = 7.0057". Close enough (to 7.006") for gov'mnt work. ;)
The short ring is almost exactly tall enough to fit the height of the scale, as printed. Perfect fit in both dimensions. But a scale does not fit height-wise on the tall ring, because the bottom of the scale would have to wrap around the knurling, which has an even larger OD. Lousy fit in both dimensions. Hence I must believe that the technical writer misunderstood the design intent, the mistake got published, and no one ever corrected it.

Also note that in the photo from the vernier instructions, the end of the decimal tape has been cut off to clear the set screw. And that the vernier tape on the tall ring is indeed partially wrapped around the knurling.

Personally, I have already stuck a triangular piece of tape on the tall ring as an indicator mark. All that should be left is to stick the decimal scale (my preference) to the short ring, and then I can make relative table-height adjustments, in thousandths, with ease.

I will probably experiment with a second triangular indicator on the tall ring, 180 degrees from the first, to use when the first indicator gets hidden on the backside.

Posted: Fri May 17, 2013 11:12 pm
by reible
Sometimes you have to go back to the good old mechanical days to see just how this should work. So just for those who want to know I did a sample of how this can be done.

I used a little different size then the stop collar but assumed that one full rotation = 1/16".

I started with a strip of paper taped to a plastic tube (substitute for the collar).

[ATTACH]21402[/ATTACH]

I then wrapped the paper around the tube so I could mark the length or circumference.

[ATTACH]21403[/ATTACH]

The length is from the edge of the strip to the mark and I really could care less how long that distance is.

[ATTACH]21405[/ATTACH]

I then attached the strip to a sheet of paper, you will see why in a moment.

[ATTACH]21406[/ATTACH]

Remember way back in school when you learned to bisect a line? That is what we are going to use to establish the markings. I started by using the two end points and finding the center. If a full revolution is 1/16" then a half will be 1/32".

[ATTACH]21407[/ATTACH]

More coming.

Ed