Highly recommend doing everything mentioned in the Cheap z-axis fix with bronze bushing, washer, and bungee.
- The worm gear and adjustment arm (with orange button) is not designed for continual movement. The arm does not stay perpendicular, leading to random height changes as it flexes, and can pop out of the router body recess, leading to drastic height changes, all of which is fixed by the bronze bushing.
- The end of worm gear thread wears down very quickly, introducing slop, which is alleviated by the washer but requires constant monitoring and adjustment (increasing washer thickness as it wears down). This also adds to minor height variance.
- There are also defects in machining between the router body and the base, visible in your pic as dark gray wear marks, which causing binding and the router not going down to proper depth. This is fixed by adding the bungee to add down force.
Here’s what my setup looks like now.
I have drilling and tapped screws that hold the bronze bushing because the glue joint broke away twice. I now realize this probably happened because the bushing reduced the max -ve Z to 0.5" and I was using Fusion360 default settings that raised it to 0.6" between sections/operations. This caused the bushing to hit top extent of movement and bind. I now have set ‘Retract height’ to 0.125" above stock, and ‘Clearance Height’ to 0.125" above ‘Retract height’ which makes max Z -0.25" above stock. This also saves a lot of time as the z-axis is very slow. I do not recommend drilling and tapping unless you have a lot of patience and attention to detail as it took a long time.
If you are going to do this then you should also consider sanding the black ‘Ring’ (see pic) on inside, top and bottom, as the dimpled paint causes jerking motion on the bearings that translate to wobbled cuts.
I was amazed by the HUGE improvement in pocket cuts that these cheap fixes accomplish. Pocket cuts are now completely level even when I do not use ‘final finishing’ passes. It also improved all cuts as ‘Multiple depth passes’ always cut at correct depth resulting in much more accurate cuts.