[ger21]

If you need 62" of travel, than it's unlikely to work, but depends on the design of the machine. On my machine, I get 46" of travel from ~66" screws.

No.

No.

Machine deflection is more likely than the screw stretching, which is what would probably have to happen. If using plastic nuts, then heavy loads could cause the nuts to have some play.

Be aware than most acme screws have a tolerance of ±.009/ft, and could be off as much as .045" in 60" and still be within their tolerance. This is very unikely, though. If you want extreme precision, you need to buy more precise screws.

Can you tell us what you'll be doing and what precision you're looking for?

[dlpaul]

Gerry,

Thanks for the quick replies. Solidworks is showing me 62'' of travel with the weight of the gantry dead center of the carriages. I've attached jpgs and as you can see the x axis is fully supported, so I don't think machine deflection will be an issue. I have 1/2-10 5 start precision rods from Mcmaster-Carr and will be using dumpster anti-backlash nuts. I'll be using the machine to cut molds for rc sailplanes -- some MDF, but mostly tooling board.

Thanks again,
Paul