I'm just finishing up a Model D build and I have some questions about lead screws.
The table is 4' x 3' (working area of ~ 3' x 2'), so I have 4' and 3' lead screws. I used 1/4-20 threaded rod, and while jogging, I noticed that even at 10-12 inches per minute the 4' rods whip like skipping ropes!
My first question is, will a 1/2" rod eliminate the skipping rope on a 4' span?
Assuming I solve the skipping rope issue, I'd like to crank out more than 10 ipm. I've heard legend of similar sized D models getting 20-25 ipm which would be great. Would switching to 1/2-10 ACME lead screws improve my ipm dramatically?
Lastly, if ACME screws are the answer, are the screws with more than one start more accurate? Greater resolution? or is single start all I need?
Thanks,
Mike