1st Build, Second machine

[JAZZCNC]

Hi Micheal,

First depends what you intend to do with the machine regards the plate thickness. I've made various differant Z axis but only one that was made with thin plate. This had a long 220mm travel and was mainly intended to cut soft materials like foam,plastics etc. It was made with with cast off's and scrounged parts that the owner and me between us gatherd (Hence thin plate was used).
It's not ideal for cutting hard materials but the guy does cut every thing from foam to Ali with it. . . It's a belt driven machine as well, very quick and accurate.!! . . I love this little machine "The Cavemill" was so much fun to make and resonably cheap being made mainly from scrounged bits. Attached a few pics of the Z axis and some stuff it's cut.

I love making "Junk yard dog's" I'm just finishing off another I'll post a pic of.

Personaly I dont like to use anything below 19mm for a Z axis that is intended to cut hardwoods or Ali. If your using profiled rail and intend to cut datum points and slots for screw etc then you really do need the 19mm else your weakening the structure. Again depends on intended use but for hardwoods and Ali using Profiled rail then 19mm is minimum IMO.
Also I wouldn't recommend using 1 carraige per side no matter what thickness material, it's false economy because it will flex badly and you'll end up making it over again.! . . Esp at the travels your wanting.
Imo the Z axis is one if not "THE" most important parts on the machine, remember doesn't matter how strong you build the rest of the machine if the Z aixs flexs you'll have BAD results.!! . . . It's also one area everybody new under estimates.

Regards travel most of my Z axis tend to be between 120-150mm the one in the previous pics had 150mm if I remember correctly.??

Attached a few pics of Zaxis made all ways. All built depending on machine and material requirements. Hope these will help you design something to full fill your needs.

Cheers.

PS: The upstands on the junkyard pics are temps just for affect to give idea too intended owner and have since been made lot shorter.

Edit: Added Cavemill pics of stuff cut.