Where to find thin walled plastic tube?/What plastic?

Discussion
1

I’m working on a project (electronic bagpipes) and am looking for some plastic tubes, but am really struggling to find anything good. I know suitable tubes exist, I just can’t find them anywhere.

I’m looking for something roughly 14mm ID, with wall thickness of 1 or 2 mm ideally (3 is definitely too large), in a plastic that is reasonably machinable. It’ll be cut into 250mm lengths and needs to be reasonably straight and rigid enough to hold it’s shape. All I’ve found is acrylic which is a nightmare to machine. I know suitable tubes do exist, but I have tried and tried and tried to search with no success and wondered if anyone had ideas?

Many thanks
Calum

2

What machining do you need to do? I managed to cut acrylic tube in the laser cutter with the rotary attachment, saves all the faff of drilling / cutting and worrying about cracking / splitting…

Acetal is a great plastic to machine, though I don’t think comes in tubes, rods perhaps? You could wait for the lathe to be up and running…

1 Like
3

I need to cut a few stepped holes in it - think similar to holes in a whistle but they’re ideally a bit oval… I have access to a cnc that can cut them but it’s v melty with acrylic. Aye I’ve heard a lot about acetal and it sounds brilliant - lathe access is more problematic but I’m hopeful… Is it easy to drill a hole through a rod so that it has thin walls - say drilling a 250mm deep hole 14mm ID in a 16mm rod? I don’t have much experience of drilling long holes with lathes and if it’s v challenging would be good to know as long drills are fairly expensive.

Cutting acrylic in the rotary attachment of the laser is very interesting - did you just do a really slow engrave or manage to configure it so it would cut as well?

Many thanks for the help!

4

ABS or PVC should machine ok, both available as tube. Certainly can’t cut PVC on the laser cutter, though.

5

http://www.ema-models.co.uk/index.php/abs-tubes-fittings/one-piece-extruded-tubes/vessel-tubing-14-3mm.html

1 Like
6

Looks like ABS is the plastic of choice for manufactured woodwind instruments:

http://www.pslc.ws/macrog/polycons/woodwind.htm

1 Like
7

That site is absolutely brilliant, had never thought to look up model makers so had just found plumbing pipe etc - looks excellent! I really like the idea of using ABS but am really struggling to find it in black (ideally) or other funky colours…

Butyrate on the other hand looks perfect colour/size wise - do you know what it’s like to work with? I’ve done some googling but not really finding anything on working with it - thinking fast feeds and low speeds to keep the heat down but don’t know how melty it is/if it’s as bad as acrylic…

Thanks very much!

8

Was going to suggest delrin but acetal is the same thing

this guy has a few insights on cnc machining plastics