[matthew79]

I have been lurking here for a while and I finally think that I have learned enough to start the design process of my first CNC router(CNC anything really). I want to be able to make larger wood projects so I am thinking about a 4x8, and I would like to build it out of wood to begin with. I put together some preliminary plans in sketchup and wondered if anyone would care to critique. Right now the linear slides in the plans are of the aluminum angle and skate bearing variety but I am trying to figure out a better method as well as a way to make the bearing assemblies adjustable for level and preload without relying on the precision of the cuts. This is designed to be built with a table saw a router and a drillpress and a 4ft+ carpenters level as the only "beyond basic" tools needed.[IMG]

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From CNC

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[DonFrambach]

Have you looked at the kits available from CNCRouterParts.com?

http://www.cncrouterparts.com/machin...eeb4d94baf81ed

[ssutton]

I am going to second the vote for CNC router parts. I did not order my linear drives from them but scratch built them instead, in retrospect, I would order all of my linear motion parts from them. The time that you would spend designing and fabbing your own would probably not be worth the effort.

[matthew79]

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November 28, 2011

[/IMG]Thank you for the links, they have given me some new things to think about. I can't afford to use high dollar slides at the moment but I am trying to design my machine to be as upgradable as possible in the future so they are something that I want to keep in mind. My idea is to build a sturdy torsion box table and a base to support it then make the rails bolt on so if they fail either mechanically or in performance they can be upgraded. I have started thinking about using 1.5 dia exhaust pipe for the rails. I believe it will be strong enough when supported and I can purchase it in 10 ft lengths from a wholesaler straight out of a bundle so it should be very straight. Has anyone else had experience with this? I have also designed a way to make the bearing trucks adjustable for this application. I am also considering a belt drive on the x & y axis. Does anyone know where to get belt stretch and strengths online, SDP, Shepard and McMaster don't seem to have them on there websites. If anyone is interested in the design drawings I am more than happy to share, although I can't guarantee they will be worth much they are to scale(more or less).

[piperpilot]

You might want to also look at plans here:

Rack and Leadscrew~Solsylva CNC Plans

Its a little smaller than what you are looking for (2x4 cutting area) but might give you some other ideas. I'd say going with a proven design will save you a lot of time, effort and probably money.

[RossMosh]

Look into the Blacktoe 4x8. Then read the forum and see if you can get some reviews from people who have been using them for more than a minute.

In the end, you're either going to need to shrink your cutting size or increase your budget if you want a good hobby machine. If budget is a concern, I'd suggest looking at a Joe's CNC which is cheaper to build than a CNCRouterParts machine. It's not quite as nice, but it's still a nice machine.