ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Laser Cuttable Forbon Subsitute

:

3/21/2005 8:55 PM

Laser Cuttable Forbon Subsitute

Hi Guys,

I am trying to find a forbon subsitute that has the following properties.

a) Does not warp, or has low warpage, due to drying and atmospheric change

b) Has a matte or fibre finish

c) Is both CNC and laser-cuttable.

Phenolic is OK, but fails on b) and c) - I tried laser cut some yesterday and no joy.

Apparantly Seymour's SSL series of strat pickups use an alternative material that fits the above criteria, does anyone know what it is?

Andrew

3/21/2005 11:44 PM

Dr. Strangelove

After a few web searches, I realized that 'Phenolic' has been around so long that NEMA specifies a couple dozen different grades.

The old XXX circuit board stuff made from paper and resin is at the bottom of the heap.

The linen fabric phenolic may be worth looking at since it cuts cleanly, has a semi-gloss finish, and comes in black. It is spec'd as NEMA types 'L', 'LE', and 'LB'.

A web search on "phenolic sheet", or "micarta" turns up thousands of vendors.

-drh
--

3/22/2005 5:25 AM
Andrew C	Thanks Doc, I can't find info as to whether there is a laser cutable version of phenolic. My local laser guys tried it and said "No way we are putting that in our machine again!" Forbon creates a lot of smoke in the laser machine that they aren't too happy about either but seem to be willing to live with!

3/22/2005 8:05 AM

Dr. Strangelove

quote:
"I can't find info as to whether there is a laser cutable version of phenolic. My local laser guys tried it and said "No way we are putting that in our machine again!""

I'm guessing that phenolic smokes AND stinks fairly horribly while Forbon is only burning paper.

Have you asked the laser mill guys what plastics they wouldn't mind cutting? All plastics stink when they burn, IMO.

The alternative may be to punch out the plastic shapes, or have flats CNC routed/cut by a signmaker, then drilled by a machinist.

-drh
--

3/22/2005 6:59 AM
Joe Gwinn	On 3/22/2005 3:55 AM, Andrew C said: [QUOTE]I am trying to find a forbon subsitute that has the following properties. a) Does not warp, or has low warpage, due to drying and atmospheric change b) Has a matte or fibre finish c) Is both CNC and laser-cuttable.[/QUOTE]I would consider Nomex: http://www.dupont.com/nomex/. Nomex is a high-tech replacement for Forbon in transformer manufacture.

3/22/2005 7:57 AM
Sheldon Dingwall	I've not tried it, but what about Corian? It's way easier to CNC than Forbon, FR4, Paper or Linen based phenolic. It might be a little brittle though.

3/22/2005 8:23 AM

Dr. Strangelove

quote:
"I've not tried it, but what about Corian? It's way easier to CNC than Forbon, FR4, Paper or Linen based phenolic. It might be a little brittle though."

Yup, it's brittle enough that DuPont won't sell sheets thinner than 1/4" thick.

Since Corian is acrylic filled with aluminum oxide, it may be outright toxic if burned by a laser. If you use bimetallic bandsaw blades and carbide drills, you get good tool life.

I've cut Corian to 1/16" thickness in a bandsaw, and while it makes a good guitar pick, you can't make an interference fit with the magnetic pole pieces as you would with Forbon or other plastics. Holes need to be +.001, -.000 for things to stay in one piece.

It glues well with any non-water adhesive.

-drh
--

Page 1 of 3