In MMD 2017.02.24, Gordon Ramsey discussed the task of making rings
for pre-formed pouch fabrication, a subject I had also discussed in
MMD 2017.02.22.  In that edition, I commented on the prospect of using
a "Cricut" hobby paper cutter for producing such items and concluded it
was not the most efficient tool for the task.  This conclusion has been
confirmed with some experimentation.

I have one of the early Cricut machines and have exchanged several
emails with Spencer Chase who has also experimented with his for such
things as valve plate gaskets.  Although it is not possible with my
machine to input an arbitrary "vector" shape for cutting, there is a
"work-around" I was discussing with Spencer.  As a pre-cursor to
purchasing the necessary software, I experimented with some of the
"canned" images in the Cricut library that are functionally equivalent
to valve gaskets to judge the feasibility of the process.  Disaster
ensued.

The first issue to solve is how to anchor the material being cut so
that it does not move when subjected to the relative high lateral
forces generated by the "drag knife" of the Cricut.  The means for that
provided with the cutter are thin plastic backing sheets covered with
a "low-tack" adhesive, supposedly similar to that on "PostIt" notes.

Well, it's not low enough.  Apparently when first used, these sheets
exert a fairly high "grip" on the material.  With multiple uses, the
adhesive becomes less and less "aggressive", but my sense is that only
three or four "cycles" of the sheet (which has a maximum size of 6" x
12") would be possible before needing to be replaced -- and they aren't
cheap!

Having placed my laminated card stock on the bed and proceeded with
the cutting, it soon became apparent that this material, only 0.022"
thick, was not giving up easily.  Adjusting the cutter for maximum
knife pressure, it took no fewer than four "passes" to complete the
cut.  Then, as I pealed the material away from the backing sheet, half
of it came up and the other half stayed adhered to the "low-tack"
adhesive.

At this point, my only choice was to mechanically scrape the adhered
material away, which took the remaining adhesive with it, ruining the
backing sheet.  Starting over with a new one would have presumably
produced the same result.  Cutting any thicker or harder material would
be essentially impossible with this tool.

I have attached a video file link to this message showing my laser
cutter producing one AutoPiano valve plate gasket in about 8 seconds.
In production, this gasket "shape" would be copied and pasted to be
100 (or more) "Up", limited only by the available size of the sheet
material and the size of the machine bed, which is 60 cm x 90 cm, or
roughly 2 feet by 3 feet.

I have also successfully cut material up to 1/8" thick, like "fish
paper" and similar fiber board materials, typically used for valve
popper guides and similar applications.  Since the laser beam exerts no
lateral force on the material while cutting, the only clamping forces
on the material can be simple lead weights, which are moved from area
to area, to avoid the beam while it is paused.  If you are unable to
view this file from the MMD message, this link points to the file in my
"DropBox" account, and you should be able to view it there:

  https://www.dropbox.com/s/54r42guv51lxhwf/20170228_115726.mp4?dl=0 

You may possibly be prompted to create a DropBox account if you don't
already have one.  Basic accounts are free and provide 1 GB of "cloud
storage" space for what-have-you.  If creating an account is a problem
for you, message me privately and I'll send the file by email.  You
will need to be able to receive a file of this size (6.4 MB) and be able
to display the file format (MP4).

John Grant

 [ http://www.mmdigest.com/Attachments/17/02/28/170228_182434_Laser%20cutting%20valve%20gasket.mp4