Having the right spring tension on your Wade’s extruder can be the difference between a useful part and a broken part.

Troubleshooting print quality issues can be a difficult problem, with a large number of variables to consider. In printing the X axis parts for an LM8UU linear bearing Prusa I stumbled across a significant factor – the spring tension on the idler block in a Wade’s extruder.

The first time I printed the parts I had my springs as loose as they would go, as I had become tired of tightening them and thought The springs are strong, how much difference could it make? Well, quite a lot as it turns out!

The extrusion was very patchy, which is particularly noticeable on the walls where what should be a straight edge waves in and out due to the inconsistent amount of plastic being pushed into the extruder.

This was particularly worrying for the thin-walled parts around the LM8UU bearings. Delamination looked inevitable…

…as indeed it turned out to be. The infill wasn’t the nicest quality ever either.

It didn’t meet the edges, and the layers beneath are visible through the top layer.

Contrast this with the same print, tightening up the springs by about 7mm:

The vertical edges are smooth and straight, the perimeter is full and even and the infill is neat, covering the lower layers.

The moral of this story? Err on the side of high spring tension. It might take forever to tighten the nuts and been murder on your fingers, but as long as your stepper motor isn’t complaining it makes a huge difference to your print.