[Lotus23C]

Hi
I'm looking at either building a Joe's Evo or Hybrid at 4' x 4', it will be made of aluminium and steel (not MDF). I don't as yet, have the plans.
However, I have this desire (illogical possibly) to use lead screws, not racks. Mostly as it looks more straight forward and a bit cheaper.
I assume I can connect the screws directly to the stepper, avoiding belts, tensioner pullys etc...

So, are the racks that much better?
It's going to be a hobby machine and I might drive it hard sometimes, but not on a daily basis.

thanks
Patrick

[ger21]

If you purchase the plans, and get access to the forum, you'll see that almost all of the newer builds use rack and pinion, and many of the early leadscrew machines have been converted. Rach and pinion is much more efficient than acme leadscrews, and will give 2-3x better performance.
If you want to use screw drive, then you'd want to use 20-25mm diameter screws with a 10-25mm pitch.

[Halbmond]

Ofcourase lead screws are less efficient in class. Only advantage is that it is self locked. Ball screws are good choice,

[ArtHeatSign]

Choosing between lead screws and racks would depend on how much work you plan to perform and how efficient you want it to be. Since you said it's just an hobby machine that won’t do much work on a daily basis then you can go for screws just make sure you go for the strong ones.