Re: [CAD_CAM_EDM_DRO] re:Cnc router help

> Wilfrid,
> SNIP
> Lastly, did I understand you are going to have a 3 foot Z axis!!? Be
> careful here! The moment loads (especially on a gantry style machine)
> add up quickly! Most people don't REALLY NEED the "large Z axis
> travel they think they do... Especially since it often costs so much
> in machine stiffness, which is felt at ALL positions...
> I suggest the shortest Z you can "get away with", and a move-able
> bridge or table structure...
>
> Hope this helps.
>
> Ballendo

I had the opportunity to visit Les yesterday and look at his machine. We
discussed the problem of long Z travel, which I also plan for my router.
Our tentative solution to the problem is simple. Build the gantry for about
six inches table clearance (good for 99% of the work I will do). Attach it
to the railcars in a manner that allows you to install riser blocks if more
travel is needed.

The loss of rigidity with riser blocks and long Z-axis overhang won't be a
problem for me. The only time I will need them is when I am cutting foam.
The rest of the time I will have the stiffness needed for milling aluminum
sheet.

Doug