Question about working with Delrin?

[Mark_Paulus]

Hi all,

I want to make a mount for my 2D flashlight that will allow me to use it on my bicycle.

My idea:

Think about a fishing reel handle/mount. Has a long T shape that is rounded, and slides into 2 round screwing clamps.

Ok, I'm thinking of something similar: 2 rounded flanges that run along the body of the flashlight, 3/16" thick or so, and a groove at each end to allow a T-Bolt pipe clamp to lay in it, and go around the flashlight.

In the middle, I need a flat spot to mount the quick release plate. I am going to use the quick release bracket/spacer from a Cateye HL-500 as shown here: http://www.cateye.com/store/parts.php?cid=2_23.

I was thinking of doing this out of delrin for weight and durability purposes. It needs to not be so fragile that when I dump it, it'll crack, but not as heavy as what I have now (You don't want to know, really you don't).

My question is, how workable is Delrin with common tools? I have a file, sandpaper, a drill, and a bench grinder. Can I do something like this, or do I need some specialized tools?

Is there another polymer or material that would work better for this application??

 

[artin51]

Hi Mark,
Delrin is known for excellent wear resistance as far as polymers go, and has some inherant lubricity , which would make it ideal for the application. I have machined alot of delrin and it machines/drills extremely well. If you have access to a mill or a lathe you can make something very professional looking. You could also work it with the tools you have on hand, not sure that the bench grinder would be of any use (depending on the wheel you have on it). Hope this helps.

 

[kromeke]

I love working with Delrin. It is like aluminum only easier. But I'm using it from a machining standpoint, with mills and lathes and the like. It should be as easy to work with (maybe easier) than a common hardwood. I prefer delrin for a machining point of view over all other polymers I've dealt with (nylon, HDPE, Teflon, acrylic, polycarbonate). It can chip if you take too big a cut with it, but it isn't as brittle as acrylic. It doesn't leave large burrs like nylon, HDPE and teflon, it machines very cleanly. It is also tough stuff. Very nice material.

 

[mahoney]

The grinder won't help you much with delrin, but regular hand saws, files, drills and taps should work fine.

 

[gadget_lover]

Bandsaws and other woodworking tools will work with delrin. I use them frequently.

Instead of a grinder, you may find a belt sander works well for shaping. I have a small one with a 1 inch belt that works nicely with small delrin parts.

You will find that you can also use sandpaper and files to provide a fairly nice finish.

Daniel

 

[scott.cr]

The only issue I can think of, if you can call it an issue, is I find it difficult to get an attractive surface finish on Delrin with anything other than a sharp cutter. I've tried sanding and such (to get a high polish) but all I end up with are scratches.

BTW, another suitable material, the generic version of Delrin I guess, is UHMW plastic. (It stands for Ultra High Molecular Weight.)

 

[cmacclel]

I agree Delrin is very hard to get a nice finish unless you have a sharp cutter. Even when using a fine scotchbright the finish looks horrible.

Mac

 

[Mark_Paulus]

Thanks for all the encouragement guys.

I checked my local Plastic Supplier here, and they wanted $45 ( :sigh for 2 pieces of 1" x 2" x 6" cutoffs. I said "thanks but no thanks", and decided to look into another route. So, I'm still planning on doing this, but it'll take a bit longer to source the materials.

Since it's going to be on the underside of a light, on my bike, finish isn't quite as important, so that doesn't concern me, so much as structural stability, and the durability of the material. Which seemed VERY durable, when I picked up the blocks at the plastic shop.

 

[gadget_lover]

A "brushed" finish looks OK,

Tap Plastics sells it, and some hardware stores too.


Daniel

 

[matrixshaman]

Some specialty shops are over the top in pricing things like this - others may nearly give away a small piece. Have you done a Google search or tried eBay? There's probably some online source that will be cheaper.

 

[Lyndon]

I don't have Delrin, but I do have black HDPE (High Density Polyurethane) in 3"x10"x0.5" sheet (approximate dimensions). I've been selling them on an electronics forum for $1.50 each + shipping.

If the 1/2" thickness will work for you I have lots of the stuff. Easy to work with hand/machine tools.

Thanks for all the encouragement guys.

I checked my local Plastic Supplier here, and they wanted $45 ( :sigh for 2 pieces of 1" x 2" x 6" cutoffs. I said "thanks but no thanks", and decided to look into another route. So, I'm still planning on doing this, but it'll take a bit longer to source the materials.

Since it's going to be on the underside of a light, on my bike, finish isn't quite as important, so that doesn't concern me, so much as structural stability, and the durability of the material. Which seemed VERY durable, when I picked up the blocks at the plastic shop.