dual drive x-axis?

[fasteddy]

Hi Hiltonsteve..

Thanks for the advice... To answer some of your questions... I want it as accurate as I can get it using the cheapest, nastiest materials I can get my hands on.. from what I have seen on the net, if you get the design right then a mortgage is not necessary to make a reasonable CNC.. This is why I am picking everyone's grey matter on design and sourcing of electrics..

i intend, once this machine is built, to make the next one on it.. Will be using a lot more ally on the next one so if I can get the prototype rigid and sturdy enough, this should not be a problem... Might even just upgrade the prototype using the prototype..! Its all a bit of an experiment, will be using a lot of the suck it and see methodology..

As for leadscrew, have found Marchant Dice (ebay) do a 16mm x 4mm pitch trapezoidal one that seems cheap enough, although I am not sure about getting the ends machined, might look at knocking up a couple of weldable reducers.. Also got to locate cheap nuts for this thread...

I agree that expanding the gantry sides and extending the bearing rails will eliminate a lot of yaw, but I am trying to utilize as much of the work area as possible, also with a 48" y-axis, the potential for yaw while machining at the extreme ends of the y-axis is increased..

Really try to utilize design as much as possible to avoid having to win the lottery for this one.. More expensive materials, ballscrews, motors etc will overcome most of these problems, but cost is a big issue at the moment.. If the first one comes out ok, I will no doubt put more funds into the next one.. But for now, cheeeeeap!!!!

Am using angle ally and skate bearings for the runners...

[John S]

As for leadscrew, have found Marchant Dice (ebay) do a 16mm x 4mm pitch trapezoidal one that seems cheap enough, although I am not sure about getting the ends machined, might look at knocking up a couple of weldable reducers.. Also got to locate cheap nuts for this thread...

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Doesn't he do the nuts ?