Z-stop Microswitch Fine Adjustment Mount by mikepcw

Last crawled date: 3 years ago

Enables easy fine adjustment of the Z-end stop height
For getting that first layer height dialled in good and proper each time!
This is intended to be mounted to this my Unbreakable Z-rod stabilizer (http://www.thingiverse.com/thing:158580)
Provided you have a fairly level bed, you should only need to check the height in the middle of the bed.
e.g. adjust wingnut and z-home the head. Tighten the wingnut to lower the microswitch (reduce print head offset), loosen to raise it. Repeat a couple of times to dial it in exactly as you want.
Required parts
M4 bolt with hex head (see photo of what I found in hardware store in Aus)
Spring (fairly stiff) and washers to go around the M4 bolt
Wingnut (you could also use this http://www.thingiverse.com/thing:13807 but i haven't tried)
Pre-installation procedure
In its virgin, as-printed state, the male and female slider parts should interfere and will NOT slide. This is intentional, and you need file the mating surfaces such that they just slide smoothly but remain snug, without any play at all. This is important since any side-to-side wobble will negatively impact the precision of the adjustment. Sorry, this can take a bit of filing.
Use some sandpaper to finish off and get the mating surfaces nice and smooth.
Installation
(colours refer to CAD drawing)
Position the Z-rod stabilizer (blue part in drawing, available here http://www.thingiverse.com/thing:158580) in the ball park level with your print bed.
Attach the male, slider rail mount (pink in drawing) via the M3 holes. Screw this down fairly tight since access is difficult once installed. The heads of both screws should be completely recessed (see photo).
Press a hex-head M4 bolt into the T-shaped slot in the female half of the mount (green in drawing).
Attach your microswitch.
Install washer--spring--washer onto the M4 bolt (photo of me holding the assembly)
Put the bolt through the hole in the flanged part of the mount, and install wingnut on the bottom.
Tip
If you find it does not slide up when you loosen the wingnut, you need to sand the mating surfaces more or use a stiffer spring.