SV06 Adjustable Frame Mounted Z Stop, Clip Version (Easy Install)

Some SV06 printers have frames that are sufficiently out of square that the built in "Auto Z-Align" function cannot work well enough for the ABL system to perform properly. These models add frame mounted adjustable positive stops to correct this. An alternative is to use shaft collars on the lead screws instead, though a frame mounted solution may work better if upgrading to flexible motor couplings on the Z-axis (can help with layer lines from lead screws that aren't perfectly straight).

This version is quick to install, but if you'd rather something more subtle in appearance, check out the glue (and/or screw) version. I chose orange to help visibility in the pictures, but obviously a more subdued color might go better.

Required Hardware:

Two ¼-20 nylon locking nuts and two ¼-20 x ¾" bolts

OR

Two M6 nylon locking nuts and two M6 x 20mm bolts

Printing:

To simplify printing, versions with different clearances for the hex nuts are provided. The range is large enough to accommodate most M6 or ¼-20 nuts. Use the included hex nut sizing gauges to quickly find out which to use. You want a snug fit, but not one so tight that pressing in the nut might damage the print. All the forces are in compression when in use, so you just need to keep the nut from falling out. Make sure to use the same filament and print settings for the size gauges as you will for the actual print. Supports are not required. Use enough walls that the clip has no infill.

A bit of glue on the nut is probably a good idea. I designed the system to use nylon locking nuts, but it can also accomodate a double nut approach, if desired (tighten the second nut down to lock the stop bolt's location, be careful not to accidentally turn the bolt when doing so).

Step models of both the right and left Z stops are included to facilitate customization.

Installation:
 

Press and glue the nuts into the 3D printed parts, being sure they sit flush, and thread the bolts into the nylon locking nuts (start from the metal side) to create the threads in the insert. Then remove the bolts again.

Bend onto the blue Z-axis end blocks, starting at the outside and pulling towards the inside (see picture). Note that this will require a reasonable amount of force. Once clipped into place, slide the part back against the frame, this aligns the bolt with a hollow space in the original SV06 part. If you accidentally mix up the right and left parts, you can tell which goes where by the horizontal alignment tab, which should go backwards towards the frame (see picture).

Now screw the bolts back into the prints.

Adjustment:

To save time, adjust each stop bolt so they are just shy of the built-in stops mounted on the SV06's frame. Then you will only need to turn them slightly further to get to the final position.
 

1. Align your X-axis using your preferred method (I like this one).
    
2. Using the built-in move command, move the X-axis upwards until it is just short of the built-in stops on the frame. If you accidentally hit them, it will skew the X-axis and you will have to start over, so go slow. Note that if you used home on the printer, it will stop the X-axis from going up high enough, so power cycle the printer and try again to override this.
    
3. Now that the X-axis is in position just shy of the stops and aligned with the bed, gently lower each bolt until they just touch the X-axis end stop pieces. Be careful not to go too far and move the X-axis, as that will change its alignment. Don't be too paranoid about this, though, it just needs to be close enough taht the ABL system can work. if you find that's not the case later, it's easy to adjust the bolts a bit.
   
   If you used nylon locking nuts, you're done! If you elected to use the two-nut approach, gently tighten the second nut against the one pressed into the 3D printed part to lock the stop bolt into position. Be careful not to accidentally rotate the bolt when doing so.
    
4. Now verify your setup is working using the standard bed leveling procedure, starting with the printer's "Auto Z-Align" function and print a first layer test model.