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Gallery, Projects and General => The Design Shop => Topic started by: awemawson on October 03, 2014, 05:03:28 AM

Title: Making Bellows - What Material?
Post by: awemawson on October 03, 2014, 05:03:28 AM

I've decided to try and make new waterproof bellows for my Wire EDM machine. Details in this thread:

http://madmodder.net/index.php/topic,10085.0.html

They are very simple in that there are no complex end shapes, just a folded zig zag of material running vertically in channels above and below.

The bellows are 113 mm tall, each fold is 25 mm long so the channel they run in is 25 mm wide, and fully stretched they are about 600 mm long. The material is 0.6 mm thick and seems to be some sort of impregnated fabric.

In use they open and close very slowly but are subject to constant de-ionised water spray.

So what material to use and more importantly where to get it ?

(I thought I had some suitable replacements as mentioned in the other thread but they proved too narrow)

Title: Re: Making Bellows - What Material?
Post by: chipenter on October 03, 2014, 03:09:39 PM

I have some dip moulded rubber bellows on my mill but they are only 14mm pleats 200 by 300 to 450 ARC http://www.arceurotrade.co.uk/Catalogue/Machine-Spares/Machine-Bellows .

Title: Re: Making Bellows - What Material?
Post by: philf on October 03, 2014, 04:38:57 PM

Andrew,

I was racking my brain trying to remember where we sourced bellows from when I was at work but couldn't and so ended up Googling and found this:

http://www.franksworkshop.com.au/CNC/Bellows/Bellows.htm

This guy made his own bellows out of thin Polypropylene sheet using the material's excellent 'hinge' property. It's also very resistant to most chemicals.

Phil.

Title: Re: Making Bellows - What Material?
Post by: RussellT on October 04, 2014, 05:28:48 AM

I have a friend who as part of his work makes bellows for the chemical industry and other applications from PTFE and other plastics.  They are turned on a lathe and alternately cut part way through from inside and outside.

I'm not sure how relevant this is to your application but it may help with ideas.

Russell

Title: Re: Making Bellows - What Material?
Post by: awemawson on October 04, 2014, 06:46:15 AM

Thanks one and all for your suggestions.

I have ordered a sheet of 0.5 mm thick vulcanised fibre board as per this link:

http://www.rhnuttall.co.uk/materials/vulcanised-fibre/

Time only will tell if it will bend as I want, but it's the nearest thing I've found to the original bellows. I've also got quotes being prepared from two firms of bellows makers, but they don't seem to move very fast in closing a sale !

Title: Re: Making Bellows - What Material?
Post by: loply on October 04, 2014, 12:56:28 PM

Quote from: RussellT on October 04, 2014, 05:28:48 AM

They are turned on a lathe and alternately cut part way through from inside and outside.

How on earth do you make bellows on a lathe?  :scratch:

Title: Re: Making Bellows - What Material?
Post by: awemawson on October 04, 2014, 12:58:43 PM

Presumably, unlike my flat ones,  they are the cylindrical type that can surround a lead screw