Reinforced plastic beams for x-axis rails ?

I am trying to think out the box here so that I can move away from using steel for the frame. Having read a fair bit, I have concluded that steel is far from ideal for cnc rails due to the following.

1. Resonance
2. Thermal stability

As a result I have looked at casting the rails using epoxy granite and reinforced plastic beams. Both of which will have excellent damping. I am waiting on the tech literature for the recycled plastic beams as I am not sure what the thermal stability of them is.

http://www.lankhorst.co.uk/hst/l18a1...K?open&lang=UK

Interested to hear your thoughts on this.

Thanks

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As a result I have looked at casting the rails using epoxy granite and reinforced plastic beams

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im assuming when you say "rails" you mean the frame or rail beds ?

i like the idea of epoxy granite, i dont like the idea of casting around the plastic I beams.... if your going to the trouble of casting a base anyway why go to the bother of using the I beams..... if its about keeping the "volume to weight" ratio down id be tempted to just cast around foam or polystyrene blocks

Quote:

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Originally Posted by blackburn mark

im assuming when you say "rails" you mean the frame or rail beds ?

i like the idea of epoxy granite, i dont like the idea of casting around the plastic I beams.... if your going to the trouble of casting a base anyway why go to the bother of using the I beams..... if its about keeping the "volume to weight" ratio down id be tempted to just cast around foam or polystyrene blocks

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Sorry, but having reread my post it was not very clear. I was thinking of

a) casting the rails using epoxy granite

b) using the plastic i beams for rails

Both a and b would then have a 50mm * 40mm machined aluminium section attached which has been precision milled to hold the linear guide rails.

The other option and I would love to explore it, would be to make the rails using composite materials. eg foam which has been layered with carbon. Carbon is super stiff and I suspect you would end up with a very stiff and light rail ?

Thanks

The plastic beams you are referring to in that link is the same thing as plastic decking. Have a look here
http://www.ebay.co.uk/itm/Recycled-s...item5adfe7aa65

This stuff still flexes but good over short lengths. Might give some a try myself.