Alt-BEAM Archive
Message #04774
To: beam@sgiblab.sgi.com
From: Peter Low peterlow@fletcherspaght.com
Date: Tue, 22 Jun 1999 10:00:18 -0400
Subject: [alt-beam] Re: Summary of various plastics.
If I recall, carbon fiber also has the property of being directional: the
fibers all lie in parallel. In order to get strength in all directions,
you have to layer with an offset. Fiberglass, on the other hand, is
typically woven: no need to layer.
I agree that the advantages of carbon fiber are in higher strength and
lower weight (if you use good construction design), and that, for most BEAM
applications, such advantages are not needed (plus carbon fiber costs more
than fiberglass).
By the way, you probably want to use the same precautions given below if
building with fiberglass. I would add that for both you probably want to
wear some kind of mask and work in a _very_ well ventilated area.
At 09:46 AM 6/22/99 +0100, you wrote:
>
>
>
>
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>HEALTH WARNING re carbon fibre
> Be very careful the fibres are very very fine shards and have the habit of
>impregnating
> the skin and ending up who knows where in the body so wear rubber gloves if
>handling the raw woven cloth or strand.
>
>Never sand the stuff without using a lubricant such as soap to pick up the
>waste
> , in dust form its like asbestos, not nice for the lungs.
>
>
>If you intend to do any moulding again where gloves cos contact with the epoxy
>resin can cause dermatitus.
>
>to be honest the use of carbon fibre is overkill on the strength front given
>the
> weight and loading our little bots take,
> fiberglass would be a more practicle alternative ....and is cheaper.
>
>Rob D
>AKA "powerbuilder"
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>"Slip" on 22/06/99 01:05:30
>
>Please respond to beam@sgiblab.sgi.com
>
>To: "Beam Mailing List"
>cc: (bcc: Robert Draycott/FS/CPL)
>Subject: Summary of various plastics.
>
>
>
>
>I'v been collecting these posts and just thought I'd put them into a single
>message to make things easier. Here are the materials which look to be
>usable for prototyping:
>
>-Carbon Fiber(a bit rough to work with though)
>-Lucite, aka plexiglass
>-Acrylic-stuff that fishtanks are made of and can be found at hardware
>stores
>-Expanded PVC or Foamboard
>-Plastistruct-similar to Foamboard
>-FRP(fiber reenforced panel?)-my dad told me about this one. He said it's
>used on walk-in freezer walls
>
>Thanks for all the responses everyone! I'v learned that there's a local
>plastics plant a very short drive from here. If the list is interested I can
>go down there and make up an in-depth price-vs-quality article. Maybe it
>could be put into a FAQ somewhere.
>
>-Jamie
>
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