I was wondering what is the advantages of using leadscrew on z axis?

3D Printing
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1

I was wondering what is the advantages of using leadscrew on z axis? My prusa mod is still using m5 rod with no z wobble or any complaints. Thoughts?

2

Interesting question- so are you using belts for the z?

3

@Ted_Huntington ​ no, direct from motor to rod using coupler, standard prusa i3 style

4

oh ok so you are comparing threaded rod versus lead screw- yeah I wonder what the difference (besides more $ for lead or ball screw) really is too- people will say accuracy- but I wonder if it could be noticed.

5

There is a lot of variance in threaded rods. Some are quite good, some are just bad. Some wear, some wobble, and some work great. Guess you have a great one.

6

My old Mendel had no z wobble too, because I chose the straightest parts of the rod for the Z drive. That said, even then I could have probably gotten better results with proper leadscrews. The questions are: How hard is it to convert, how long can you do without your machine, and how much better will the results be.

7

where 3d printing is concerned, there’s not much difference between the two, as long as you use them properly. threaded rods should be de-coupled from the rest of the xz axis carrier, and lead screws should be used with radial and thrust bearings.
if used correctly in both case you should not be getting any z-wobble or accuracy issues.

you would get a stiffer system with a leadscrew used correctly, because it’s like have 2 linear shafts on both sides (remember threaded rods should be de-coupled). on my test machine, where i have a leadscrew properly constrained both top and bottom, i have once printed without the linear shafts at all (had a problem with the bearings), it printed replacement parts just fine, i don’t think any setup using threaded rods would be able to do that without a noticable difference in print quality or total failure.

the main advantage lead screws have over threaded rods is mechanical longevity and less noise, though that would be noticable mainly during homing. for a print when you only move a z layer every once in a while, it shouldn’t be noticable.