[TT-CNC]

Hi All,

I’m building my first CNC machine... a router with fixed gantry, using a HobbyCNC PRO Kit, 305 oz-in motors, very heavy, machined aluminum alloy rails from a Cardiac Cath Lab, and two complete 36″ long, 2-start 1/2″ x 10 lead screw fixtures. I will greatly appreciate thoughts, constructive criticism, and input from anybody willing to share their knowledge… Here’s my plan:

My goal is a work area roughly 30″ x 18″ using my two 36″ lead screw assemblies for the X and Y axis. I have all the parts, but lack experience and knowledge of making and using a CNC router.

An 18″ Y-axis is really more than I need, but came up with a plan to maximize the X-axis…

If I made a work table/carriage for the X-axis with 4 linear bearing trolleys on fully supported rails, could I mount the lead nut near the end of the table to push/pull the entire length of the lead screw, and get ~30″ of travel (+/-, depending on length of the trolleys)? Hopefully the simple "drawing" attached will make this idea more clear than the description alone...

Has anybody tried this method (haven't seen a similar plan)? Are there problems inherent with this design? Any special considerations for this set-up? (I’m OK with the “wasted” footprint space in favor of simple design and increased rigidity.)

[harryn]

The setup you have is good for learning and hobby use, but will take some time to align, at least that was my experience.

As far as the lead screw, think of it like a long noodle. To some extent, the precision comes from having it under tension.