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View Full Version : Looking for a reliable cheap linear system pls



psiron
07-06-2010, 12:43 PM
Hi everyone,

I have just started (with a friend) building an 8x4 router to cut basic shapes from plastic sheeting. As our sheets are quite large we thought we would go all out and try a larger 8x4 bed rather than the smaller 4x4 or 4x2 type.

We are looking for a cheap but reliable rail system which will span the 8ft distance. The best I have come up with are the 25mm supported rails from Zaap but really would like to save some ££ if possible by using a cheaper method. I certainly dont expect things to all go to plan and not sure if its a wise move spending so much on rails for a first project.

Anyone have any experience on rails for such a large run please? I am constantly searching but really not sure about reliability?

Any advice would be very much appreciated. I must say this is a great thing to be involved in, very exciting even though I dont have that much of a clue!

Cheers guys :)

irving2008
07-06-2010, 01:09 PM
Welcome,

I suggest you look at the designs for the blacktoe 8x4 (http://buildyourcnc.com/blackToe4x8.aspx), they have addressed many of the problems of the larger size, and its not as simple as scaling a 4x4 design. 2.5m long leadscrews are very big, heavy and have lots of inertia therefore other methods (rack and pinion, belt & chain drives) need to be considered. They also do a kit of the major parts if you dont feel like cutting them yourself.

psiron
07-06-2010, 01:28 PM
Hi,

I have looked at the blacktoe design and found mixed responses due to the MDF used in the build. I really dont know that much about MDF contracting and expanding but was a little hmmmmmm at some of the responses. I think the site is brilliant and we would definately complete the build quicker with this type of kit. Ill keep looking around anyway and not rule out the blacktoe if we cant find a reasonable alternative.

We have been looking at the build at www.automatedwoodworks.com (http://www.automatedwoodworks.com/) that machine seems ideal to what we are looking for but the rails again are very expensive. I think I would rather build an all steel machine if possible too.

Wobblybootie
07-06-2010, 04:18 PM
Look at www.mechmate.com for a machine big enough and man enough to to what you want and look carefully at the way they do their linear guides ...