SV06 Adjustable Frame Mounted Z Stop, Glue and/or Screw Version (More Subtle Appearance)

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 is the more subtle (and arguably more attractive) version, but if you'd rather something quicker and easier to install, check out the clip 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. If you plan on using screws to attach the stops, make sure to use enough walls that there will be material left after drilling to size. After printing, drill through the thin bridge above the nut to make room for the bolt.

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 accommodate 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.

Do a test fit by inserting the 3D printed stops vertically on the inside edge of the blue Z-axis end blocks (see picture). They have features designed to line up with cavities on the bottom of the SV06's parts, so can only insert one way (this also prevents mixing up the left and right parts). This aligns the bolt with a hollow space in the original component.
 

If they fit well, you can attach them. If going only with glue, apply some to the top of the 3D printed parts before pressing them back into position and clamp until the glue cures. Optionally, you can remove the original printer parts first to make gluing easier.

If you want to use screws, you'll have to remove the Z-axis end blocks from the printer and drill the pilot holes on the 3D printed stops through the original parts to create the size holes required for screws you intend to use (sheet metal of wood screws should both work, but you could use small machine screws and bolts if desired). You can install the new stop blocks while you have the original parts removed from the printer. Then reinstall the Z-axis end blocks.

When done, screw the stop bolts back into the nuts.


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.