compensate for backlash on Z axis

What are the techniques everyone uses to deal with Z axis backlash?

The only time the Z axis changes direction is after homing out and then running the first layer which ive had alot of headaches from. The first layer prints fine but layer 2 sometimes just drags across the top of the first layer and then the third layer starts to get better but its usually layer four when everything settels in nice and smooth for me. The only thing i can think of is to cut a hole in the plate so that the nozzle sits below the plate when at home position. Then set a move in the slicing software to raise Z axis up to the level of the plate before moving X and Y and printing.

I had to fit the anti-backlash nuts and springs on my Prusa to fix it. All my other machines gravity is sufficient. I assume the Prusa axis was a bit stiff because it it hard to align the Z rods to be parallel. One of the reasons I designed Mendel90.

---

[www.hydraraptor.blogspot.com]

You could try putting weights on the ends of the X axis.

---

[www.hydraraptor.blogspot.com]

I might try some weights on mine, im always game for an easy fix. I love your Mendel 90 design, thats the simplest design ive seen yet.

If you are using Repetier-Firmware you can use

#define Z_BACKSLASH 0.2

for a 0.2mm backslash. You need the latest version for this. The option was added for a printer with large backslash, but is not offical part of the configuration.h yet.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

Slic3r has a z lift parameter that will lift Z before it moves to the XY start point to print. I think with some tweaking and tuning this also could be used to get out of the backlash area on the Z axis for the first layers. I probably will try it but it will take some fine measuring to get it correct.