How to cut sorbothane?

First, I doubt that what you purchased is exactly the same material as Herbie's Big Fat Black Dots. I have them and they are somewhat stiffer than most sorbothane I've felt.

However, being a DYI tweaker myself I'd suggest you find a supplier of leather-working tools like Tandy. They carry hole punches for belts and leather projects and may well carry larger diameter hole cutters.

I just did a search and although most of their punches are small diameter you could use a strap end punch to cut half of the circle at a time. Here's a link:

http://www.tandyleatherfactory.com/products.asp?DEPT=206&Page=3

If you decide to go back to 1 5/16" circles, you can probably find an "arch" punch at that dia. or something close. McMaster Carr or MSC Industrial Supply would have them. It is just a heavy duty version of the pipe and already sharpened for use with a heavy hammer. You can also have a rule die made (sharpened steel blade set in a wood base), but that would be better if you have access to a small arbor press. You can also cut the sheet on a laser. If you have a sign making or trophy making shop around they could very well have a low power etching laser that would work.

And when you decide that is all too expensive and too industrial - tin cutting shears. Lots of leaverage to cut through the polymer. MSC or McMaster or local industrial supply. The HD or Lowes versions wouldn't be as sturdy.

Jim S.

Grant, The best and probably the safest way to cut your circles is on page 2165 of the McMaster catalog (#112). Alas, the cost is ~$29.

11-15-06: Jgiacalo
First, I doubt that what you purchased is exactly the same material as
Herbie's Big Fat Black Dots. I have them and they are somewhat stiffer
than most sorbothane I've felt.

Thank you for the leather tool suggestion. It appears to be
similar in principle to the arch punch suggested by Stilljd. Do you think
the manufacturer of sorbothane makes a specific product
for a small boutique audio tweak company? I'll bet you any amount of
money McMaster-Carr stocks precisely the same sorbothane used by
Herbie. I may not have purchased the same durometer rating
sorbothane used in the Big Black Dots, but McMaster-Carr carries about
all the various sorbothane made as far as I can tell...durometer rating
(40, 50, 60, 70...), elasticity rating, etc., and in a wide variety of
thicknesses. Herbie has done all the work though, so he's entitled to
charge whatever he likes for his product. Most knuckleheads wouldn't
choose to go through the research, cutting etc. that I've done to make
their own and save $50. I don't blame them for buying Herbie's product
or the discs sold for audio use on E-Bay

Thanks Stilljd and Ronnjay for your suggestions. The arch punch is
EXACTLY the right tool, but at $39 for a 1 1/2" version
purchasing one negates the advantage of buying the raw material versus
the pre-fashioned discs offered on E-Bay and by Herbie's.

I am not sure what diameter you are looking for. How about a bulb (tulips, etc.) planter. They even come with a nice handle.