Something to replace band saw rubbings?
Something to replace band saw rubbings?
(OP)
Something to replace band saw rubbings?
I attended some training over the weekend. As part of it there was a lecture on the importance of good band saw rubbings.
If you are in a saw mill and need new a band saw blade you take a paper and pencil and do a rubbing of a section of a few teeth of the old band saw blade. The saw blade manufacturer then uses this rubbing to make the new blade. Many of these rubbings are not clear and sharp enough.
Is there a better method to get an exact size version of a band saw blade in two dimensions whether on a piece of paper or digitally?
I am looking for a simple, readily available, inexpensive solution.
Thanks,
Tom
I attended some training over the weekend. As part of it there was a lecture on the importance of good band saw rubbings.
If you are in a saw mill and need new a band saw blade you take a paper and pencil and do a rubbing of a section of a few teeth of the old band saw blade. The saw blade manufacturer then uses this rubbing to make the new blade. Many of these rubbings are not clear and sharp enough.
Is there a better method to get an exact size version of a band saw blade in two dimensions whether on a piece of paper or digitally?
I am looking for a simple, readily available, inexpensive solution.
Thanks,
Tom
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.





RE: Something to replace band saw rubbings?
Supposing you don't want to dismount or cut up the existing blade -
- take a digital photo of blade with a steel rule next to it; import image into Autocad or whatever, and trace the outline directly into CAD lines.
- take an impression in clay or wax or "repro rubber" (basically a low-shrink silicone RTV), and digitally reproduce the image by any of the above methods.
RE: Something to replace band saw rubbings?
Similar to Btrue's first idea but use graph paper or a similar checkerboard as immediate back drop.
3D scanner. http://en.wikipedia.org/wiki/3D_scanner
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Something to replace band saw rubbings?
I've been told that the brand name "Repro Rubber" is very similar to the dental casting material; we tried to get our paws on the dental stuff and were told we couldn't get it without a prescription - not kidding, and you are probably as dumbfounded reading that as I was being told it over the phone from a dental supply house. The brand name stuff we use for doing inspections is expensive, I want to say $300 US or so for about a pint of material, but it's been awhile. There are similar casting products, advertised as "low shrinkage" available from McMaster, that would probably serve as well. For an industrial repro process, I would just make a few castings to calibrate the shrinkage, then adjust accordingly in the CAD file.
But the digital photo method I think would be quickest and easiest. Another method I've seen used for photos is to put a $1 bill against the part, obscuring the serial number, and take the photo that way. The benefit there is that everybody has a $1 bill in their pocket(*), so there's no running around to find a scale or grid paper, and there's no discussion about whether the picture was taken against 1/4" grid paper or 0.2" grid, cm scale or inch, etc.
(*)Whoops. Except me, today, just a $5.
RE: Something to replace band saw rubbings?
Interesting what you say about the dental molding stuff, I swear that's what our QA dept used back in the UK. Hard to believe it's more difficult to get here in the 'land of the free'.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Something to replace band saw rubbings?
RE: Something to replace band saw rubbings?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Something to replace band saw rubbings?
Exposing diazo paper properly takes about 15 minutes using a typical desk lamp or machine tool lamp. ... of course they must be fluorescent lamps. Sunlight works too, but it's not always found near a bandsaw.
The other limitation of using diazo paper is that almost nobody stocks it anymore.
Something else came to mind: Carbon paper. Lay plain paper against the blade, then carbon paper, then some more plain paper, and rub, say with a Pink Pearl.
Problem: Almost nobody stocks Pink Pearls or carbon paper anymore.
OR,
Lay a piece of plain paper against the blade, and spray paint the blade against the paper.
Many outfits keep _some_ kind of aerosol spray in stock.
Mike Halloran
Pembroke Pines, FL, USA
RE: Something to replace band saw rubbings?
Ted
RE: Something to replace band saw rubbings?
Mike Halloran
Pembroke Pines, FL, USA
RE: Something to replace band saw rubbings?
You would have several since you change them every 4 or 8 hours or so. You would have extras since they sometimes get beat up. Sometimes the good ones and the spares get beat up in the same shift.
However these blades are customized in the mill. They are very expensive to physically transport.
Here is the official answer from Norm Brown, Regional Manager for Simonds.
Bandsaw rubbings
Tom,it is the most accurate form of duplication available with the least
amount of complexity or tools, any one can do it with a sheet of paper
and a dirty finger. We do have other ways available like the VariDesign
program that is free to every one , it is on the Armstrongblue website.
We discussed scanners etc. but the rubbing is easy and we (Simonds
convert to DXF
So Simonds does it this way because some of their customers like doing it this way.
There was a discussion at this meeting of mills that want blades to last forever and that want filers to repair wrecked blades. Other mills are more careful of staff time.
The big problem is that the steel only holds up so long. We can make ceramic tipped saw blades but they would still need to change saws every so often because the saw plate does not hold up.
Tom
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.