Alternative To Forbon

[AndrewMc]

Another source?

Has anyone used the Thomas Register (thomasregister.com I think?) Great palce to search for unique or hard to find materials.

[Spence]

Here's an alternative line of thought.....
Google 'Fish Paper'.

http://www.jjorly.com/fish_paper_die_cut.htm

and

http://www.oliner.com/Vulcanex/Index2.htm

are the sort of results you'll find.

[David King]

Why not use copperclad pcb? You can have it etched, cut and drilled to .001" precision and have the magnet holes and eyelets plated through. That not only takes care of your eyelets but all your magnets are grounded and the pickups mostly shielded at no extra cost. The PCB places are extremely competitive on price provided you can give them 4 weeks of lead time and get them the correct file format for your drawings.

To say that forbon sounds one way or another I find a little over the top but I suppose if you make your living selling a product spawned in the 40's and 50's you'd better believe in it to some degree yourself.

[mkat]

Why not use copperclad pcb?

Sounds ok, but I think Phil was after a material that's not so hard on tools. Although forbon may be expensive though easier on tools, pcb can result in expenses in tooling much quicker. Actually, aren't there different types of pcb, some softer than others?

[Joe Gwinn]

Sounds ok, but I think Phil was after a material that's not so hard on tools. Although forbon may be expensive though easier on tools, pcb can result in expenses in tooling much quicker. Actually, aren't there different types of pcb, some softer than others?

The key is glass fiber. The classic green PCB material is glass-epoxy or glass-polyester. In other words, fiberglass, just like boat hulls. Steel tools wear out almost instantly, and one must use carbide or abrasive tools.

Carbide drill bits are easily available, and don't cost that much. However, carbide is brittle, and one must use a drill press, or one will break far too many drill bits. There are drill presses (typically small and turn at at least 10,000 rpm) made just for circuit boards, but an ordinary drill press will work well enough.

Likewise, carbide router bits and mills are available.

There are circuit board materials made of fibers other than glass, so high-speed steel tools will work OK, but these materials are usually too stiff and brittle to be punched cleanly. One must drill and rout them. I would look at melamine-paper and melamine-linen. Some brands/kinds of melamine-paper have a nice cream color. Likewise, phenolic-canvas/linen/paper can be a light tan color. Many of these materials are advertised as not intended for "primary insulation", which means withstanding mains power. For a few volts, no problem.

Search for plastic laminates in MSC and Google.

[David Schwab]

Why not use copperclad pcb?

Why not indeed!



I didn't find it hard to work with either. I scored and snapped it by hand, and shaped it with a robosander drum on my drill press.

[dbtk44]

If you can track down some thick pieces...formica would be pretty slick. Not exactly "vintage" in appearance, but it would probably work very well for the job.

[DrStrangelove]

Flatwork comments

As mentioned, Forbon isn't sold in small amounts. LMC Plastics sells Dynos vulcanized fibre in 500lb lots or 28 sheets of .093" for roughly $1750. NVF in Pennsylvania is about the same. GRT Genesis will return a phone call.

My opinion is that you can make pickup flats from anything that is suficiently thin, strong, and not too brittle. Formica/micarta/phenolics are okay. Corian is too brittle at 1/16" (.062"). ABS, Delrin (polyacetal), and acrylics are okay. Polystyrene ages badly, embrittles after a short few years.

G20 or FR4 2oz. copper-clad circuit board is dimensionally stable and would solve the matter of solder holes and eyelets handily.

The problem with circuit board stock, acrylics, and phenolics is that they are rigid and more microphonic than vulcanized fibre (Forbon/Dynos) which is somewhat more self-damping. Wax potting fixes this.


Links:
http://www.lmcplasticsource.com/dynos.html
http://nvf.com/forbon/forbon.htm
http://www.grtgenesis.com/

-drh
--

[David Schwab]

G20 or FR4 2oz. copper-clad circuit board is dimensionally stable and would solve the matter of solder holes and eyelets handily.

That's what I've been doing. I etch solder pads in the copper and solder my coil wired to that. The rest of the copper gets grounded and becomes a shield.

The problem with circuit board stock, acrylics, and phenolics is that they are rigid and more microphonic than vulcanized fibre (Forbon/Dynos) which is somewhat more self-damping. Wax potting fixes this.

Good thing to keep in mind!

[mkat]

Great! I found the whole price list, looks really good. They say it's gray on the site. How does it look? Does it still look allright?
Can you post of pic maybe?

I placed an order with McMaster-Carr last night and received a rejection email from sales. Apparently, they don't "accept business" outside the US, except for a few "long-standing customers".

[Carey Nordstrand]

Time to stop lurking I guess...
Ok, here's my source. http://www.oliner.com
I was stumped too until I did a search for vulcanized fibre instead of vulcanized fiber.
Their minimum order is around $300 I think. I get 2 4x8 (slightly smaller actually) sheets cut into quarters for shipping every time I order.

[mkat]

Time to stop lurking I guess...
Ok, here's my source. http://www.oliner.com
I was stumped too until I did a search for vulcanized fibre instead of vulcanized fiber.
Their minimum order is around $300 I think. I get 2 4x8 (slightly smaller actually) sheets cut into quarters for shipping every time I order.

Thanks for the link Carey, I'll see how I go with them.

[Phil m]

Hey Carey, since you're a member now can we have all your pickup secrets?

[Carey Nordstrand]

What secrets? It's just magnets and wire...

[David Schwab]

What secrets? It's just magnets and wire...

It's like Italian food... same ingredients, but in different combinations!

Nice to have you here Carey.