Plastic recommendatioin needed......

[Chuck Keysor]

Hello Shopbot friends:

A friend wants me to make a bezel for a an electronic control box. This rectangular bezel is to be 4.5" x 6.5" inches and 1/2" thick. There are a couple of basic pockets to be milled, and threaded inserts to be clued in.

This is a prototype, and because I don't know about plastics, I said I could make the first prototype out of a piece of wood. And I said I would ask here if anyone could suggest what type of plastic would be appropriate for such an application.

The bezel mounts onto a rectangular aluminum box, that is bolted to the top of a washing machine to contain some control electronics allowing a card to be swiped that will activate the washing machine. So the plastic needs to be durable.

I think they will want me to make maybe a dozen bezels out of the selected type of plastic.

Thank you for any recommendations that you can provide, as to material, recommended bits, and speeds/feeds. Chuck

[bleeth]

If making only a few I would start by visiting my local plastics supplier and seeing what he had laying around in small piece.
For a production run I would go with Starboard.
I've got some black if you want to stop by and pick up a piece.

[tlempicke]

If you visit a plastic supply house they will almost always have "Drops" that you can buy. These are random sizes and usually sold by the pound. Phenolic is made in many different types and tough but easy to machine. Basically it is a cloth mat that is saturated with resin. You can get a piece of black, canvas filled, on E Bay but for any quantity E Bay is expensive as all get out.

[Chuck Keysor]

Thank you Dave and Tom for your recommendations. I have passed them on to my friend. I found several plastics companies, such as Laird that are maybe 15 miles away, and my friend will go there.

If I lived close by Dave, I'd stop! Thanks again, Chuck

[Sk8MFG]

As my plastics colleague would say "Anything but acrylic".


I've made the mistake of using bargain shop cutoff bin acrylic, chips and shatters very easily. I would second phenolic, or perhaps UHMW-PE or similar.

[Brady Watson]

Nylon 6/6 from McMaster is nice for this application. You can also use ABS. Both available in small quantities at a reasonable price. I really like dealing with McMaster because you can often check specs of that particular material that will help with selection & engineering.

-B

[bleeth]

Not too far Chuck-only about 18 hours or so straight through!

[Chuck Keysor]

Thanks gents for the added input! I had passed the posts on to my customer, and my suggestion that he go to Laird Plastic and talk to them, see about cut-offs, and get some sales advice.

This evening, the customer came to my shop, and he said that Laird didn't have on hand what he wanted, and he had only talked to them on the phone. They sent him to McMaster Carr, and he got today special delivery, a 2 foot by 2 foot piece of black ABS. (I think he said it was ABS.) I was shocked to see that it was badly scratched and gouged!

Where I used to work for 27 years (Dukane Corp, St. Charles) when the mechanical engineers got samples of plastics, they were flawless, and clad in plastic sheet. What my customer got looks like it could have been tossed around on a driveway! I'll try to remember to take some pictures.

Dave, as winter approaches, I am getting sadder that you are so far away! Chuck

[bleeth]

One of the biggest challenges I have in my business is customers not listening to advice, reading e-mails, or paying attention to drawings. It's a constant battle. My wife, a Realtor, has the same issue. We have reached the conclusion that damned near the whole world is suffering from ADD.

[steve_g]

Chuck…
ABS will be a nice material for your application. Unfortunately, it doesn’t come with a paper or plastic “strip” coat. Another issue is that it doesn’t take a fine finish well. When I use it I incorporate a texture of some sort. I’ll try to find some photos…
SG

[steve_g]

All I could come up with was this photo of a proto for a foot switch… The production model was better. ABS is very tough and worked well!
SG

[Chuck Keysor]

Thanks Steve for the photo. That is an interesting looking part! Much more interesting than my simple bezel. Thanks, Chuck