My first, nearly finished CNC, actually this is the  third one. The first one was a moving gantry style but I didn't make a good job of it. It was too big for my garage workshop and didn't turn out very stable, the gantry was very shaky so I took it apart, never made a photo of that one so can't post it.

The second one was better, more robust and stable than the first one. A good clean up and a coat of paint and it would looked pretty good too. But, just as I was finishing off the Z-axis we got notice from our landlord to vacate  the premises. The idiot built a large extension to the rear of the house without planning permission and got caught just before the 4 year period before it became legal if no one had noticed it. He is in deeeeeeepppp s*&t up to his eyebrows so now he wants us out so that he can get the builders  in to reduce it down to legal size. I don't know if he has but I hope he pays a huge fine, he deserves whatever he got and is/may be coming to him.

Anyway, as we don't know if we will get another house with a garage or not I've had to change my plans again and make a smaller one, small enough to fit into a small shed maybe or even in the house somewhere. I might build a box around it to make it look like part of the furniture and use it in  the garden when I need to. Below is what I came up with.

Nearly finished, just the stepper motors and the electronics to fit after a good clean up. I might even give it a coat of paint or varnish after I tested it and done the final adjustments to make sure the router is running level with the table.

Overall measurements: 420mm (W) x 460mm (D) x 540 (H) without the stepper motors.

The working size is about 250mm x 380mm, measured from the centre of the cutting tool.

Table: 345mm x 460mm
Travel : 380mm

The drawer slides are left over from another project that never got finished,   they are temporary and will be replaced by better ones. 

Side view.


Gantry:
535mm high, 150mm bottom, 75mm top.

Z - Axis setup:
Left: 16mm stainless steel rod salvaged from a machine I took apart a few years ago and two 16mm  linear  bearings bought from EBAY sometime ago for another project that never got done.


Middle: 2mm pitch Lead screw with its own nut, pulled out of an old machine a few years ago, can't even remember what sort of a machine it was.


Right:  Stainless steel tube with it's own bushing I salvaged from an old laser printer, can't remember which one, took many apart.


I sandwiched the bearings/bushing and the nut in V grooves I cut in to two pieces of plywood. I used hot glue to keep them in place while I screwed the two pieces together and screwed another piece on top of that one. I then secured the router to a longer piece with jubilee clips and secured that on the previous one. I guess I'll find out if it'll all hold together when I start using the machine.


Measurements:
120mm (W) x 242mm (H)
Travel: 85mm

Linear bearing made out of right angle aluminium, skateboard bearings and 
20mm electrical conduit.

Bottom view.


The box is made out 70mm x16mm pine, cut from old 150mm bed slats.


Measurements:
Front and back : 70 x 420
Sides and braces : 70 x 443

Anti backslash nut.


This is how I made mine.


I used a spring to force the two M12 nuts apart and joined  the two nuts together by welding a piece of steel across them. I then welded another two pieces of steel together in a cross shape and welded that on the opposite side of the two nuts. Using two pieces of 18mm plywood as spacers I secured it to the underside of the table with two screws. 


It looks like it will do the job but will it hold? Time will tell I guess, if it falls apart then I'll have to think of something else.