Acetal

[Rodent]

anybody use (or try) extruded Acetal for cutting flatwork?

if so - how does it machine with a single flute mill? does it remain stable during and after cutting? how it it's electrical properties?

any other tips based on experience would be welcome

[dpm]

anybody use (or try) extruded Acetal for cutting flatwork?

if so - how does it machine with a single flute mill? does it remain stable during and after cutting? how it it's electrical properties?

any other tips based on experience would be welcome

I use it for humbucker bobbins. It's very nice to cut, seems to like a slow cutter speed and highish feed rate, doesn't need a cutting lubricant. It's a really good material for bobbins IMO. It might work well for SC flatwork if the fit to the magnets is tight enough. It doesn't glue well and is slippery. This is how I use it - http://music-electronics-forum.com/t33263/

[David King]

Nice, the bead blasting looks awesome.
I love machining acetal but I expect there may be significant differences between cast and extruded product. For example extruded acrylic is HORRIBLE to do anything with.

Here's an article. Acetal isn't cast but can either be extruded or pressure formed and there are some slight differences.
http://www.plasticsmag.com/features....sue=May/Jun-05

It looks like Extruded is more stable with less internal stress.

[Rodent]

ok - I think I'm going to give a sheet of this a test and see how it does.

I like that I can easily find Acetal sheet stock in .06" and .09" thickness, and the price of $8/sf for a 24"x48" sheet vs. fishpaper at $30.35/sf for a 54" x 84" sheet hopefully makes this a great new product for custom flatwork. the smaller sheet is also shipping-friendly


several forums note that it can also be laser cut so long as the laser cutter is properly vented outside

[David King]

Where are you getting your fishpaper price? That figure seems way off considering that a 4 x 8 sheet of 3/32" forbon is $85 or so, about 1/10th the price.

[Rodent]

of the 15ish companies that I could find offering fishpaper, this was by far the best quote I got (either directly on-line, or via email reply)

Fishpaper - Vulcanized Fibre Sheet (FISHPAPER) Order Online

about half of the companies who don't have an on-line price didn't even bother to send a reply to my RFQ.

the sales rep from Professional Plastics has been the most helpful of all, and had I not decided to give the Acetal a try I would be ordering from them today. Professional Plastics is also the only place I found where I could do a Will Call type pickup at the warehouse, avoiding a significant cost of custom cut sheets and/or shipping

[David King]

My local laser guy charges $35 and hour. That's an awful lot of flatwork cut up, especially has he has two 18 x 24 60W epilogs.

[Rodent]

dang! if you don't mind, drop me his contact info via PM or email

[Rodent]

wound a couple sets with the Acetal, and have these observations

- cuts nicely on the cnc with a 1-flute plastic mill. I used both 1/16"D and 1/8"D bits without issue

- the product I received had a couple cracks along the edge, probably from a careless handling during shipping. given the price difference, I have no issue sacrificing 3/8" of edge as waste

- I decreased my hole diameter by .001" vs. what I was cutting on the fishpaper, and achieved a perfectly snug fit with the mag rods that didn't slip wile winding

- decreasing the hole diameter by .003" was a little too snug, and caused a couple hairline cracks on a few mags that weren't dead center when I pressed them into place

- Acetal does not reach to humidity changes like the fishpaper did, and remained relatively flat even a couple weeks after unpacking


next up is potting. I'll share if there's any issues encountered via epoxy or wax potting


overall I'm liking the Acetal so far. can't wait to see how it laser cuts