Quote Originally Posted by jonbabbz View Post
Hi all,

I just wanted maybe a more experienced builder, to have a look at my design and see if there is anything obvious that might hold my design back before I commit. I posted on cnczone and took all comments on a previous design on board and have now come up with this one. Figured it would be more beneficial to be a member of a UK forum. I am already a CNC owner too so not a complete noob, although it would be naive of me to say I'm not still learning.

The goal was to create it as cheap as possible but try and keep rigidity. I've used 12mm multi-start trapezoidal lead screws on x, y and 10mm on z. Fully supported 16mm rails on x and y and 16mm round rail on z. My main concern is the lead screws on y and the 16mm rail. I used that size because it is easier to implement with the size of aluminium profile I'm using. The machine is 1500mm x 1000mm at the rails, ignore the length of z as im going to shorten it anyway. I designed it with a view to implement a fifth axis at a later date. I will be cutting MDF and PLY only.

Any advise would be greatly appreciated. Thanks

Hi The Y axis looks like it is set on one side; if it is, this will jam as the axis drive needs to be central or with two stepper drives simultaneously operated one on each side of the machine. I would also consider widening the Y axis bearings so the machine has less Y wobble. As you are only cutting MDF and Plywood accuracy is not an isse here that design is good enough. If you can squeese a bit more out of your budget, go for the linier bearings as in the photo.
Click image for larger version. 

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ID:	5909 These are far more accurate and rigid and will increase rigidity and production speed. Keeping this design square in the X & Y plane is going to be dificult.