Sovol SV06 MonoBlock Extruder Mount

Update 2/01/24

It seems that the 15.2mm or 15.3mm versions of the NEW design work best for getting the right size for the bushing holes on most printers.  I would say use the 15.2mm.  Worst case, if you have a dremel and a large sanding attachment (less than 15mm, but large for dremel tools), you can slightly enlarge the bushing holes for drylin.  Use the 15.3mm model if you like steel bushings.  

Update 1/20/24

I have had too much going on to properly figure out the nautilus 5015 parts cooler and how to add it to my MonoBlock.  It's also because I rarely ever need more than the stock parts cooling fan because I print mostly engineering material.  

Thankfully the community has remixed it, and though I haven't tried it, you now have an option!  

Update 12/12/23

I have added a new version that uses all heat set inserts.  The bushing retention grub screws on the back now require 6 m3x4 long (generic) heat inserts.  The belt tensioner requires 2 m3x6 long heat inserts (ruthex).  The extruder requires 3 m3x6 inserts.  You could also use just the generic m3x4 inserts, though I prefer the longer ones when possible.

I have included a step file so you can remix this as needed, and I changed the license to allow it, but please test what you remix before releasing it as I think we all hate a poorly done remix. 

I would still recommend a test print first so you know how your printer will print the bushing cavities.  That said, a dremel sanding wheel can help too.

The new version is the version I am using now, and it was made to look like the model I made for the Plus.  It has the same geometry as the original for the bushings.  It is taller, but will only put your extruder 2mm forward on the Y axis. Some material was added at the back to allow for heat set inserts.

If you don't have a printer to make this, I can print one for you and test/assemble it.  Message me for price and other info.

Original Post

Along with several other SV06 injection molded parts that will break/crack on you, your extruder mount/bearing carrier will likely suffer the same fate.  In my case, a random and unexplainable print head crash caused my printer to be completely unusable.

The problem, as I see it, are the molded parts themselves.  The tight tolerances with the press fit threaded inserts, the thin walls inherent in the injection molding process, and the rush to market with minimal testing (IMO) make the extruder mount very weak and prone to cracking.  

I found some slight wobble in the extruder when the printer was new, but I accepted it as “normal”.  That wobble got worse (bearings were poor) and I was getting pretty bad banding in all of my prints.  I changed to better, smoother bearings with slight change in quality.  

Then I had a random print head crash into the bed.  

It wasn't until I took a close look after the crash that I found the cracks.  They may or may not have been there prior, but I am sure they were made worse if they were.  I used some clamps with Acetone to attempt to fuse the mount back together, which slightly helped the wobble, but it was still producing unacceptable results.  

I also made sure the gantry was square, installed custom X-twist firmware, and used UBL.  All that in an attempt to remedy poor print quality.  Nothing worked because the mount was cracked and had wobble.

I am not an engineer or a day job designer, but I just couldn't let this machine sit broken.  I also did not want to wait a month or more for a replacement from Sovol only to have a new replacement of a weak part (IMO).  Extrapolating the thought of repeating that process was fuel for this project.

The Sovol .stl files for this part are basically unprintable, so I redesigned the mount using measurements I took while keeping in mind the places where it failed.  That is why I decided to not make it a split case design, hence the name MonoBlock.  

I strengthened the areas where the extruder assembly screws into the carrier/mount and made it much more rigid.  Belt removal is now simpler without having to remove the extruder.  I also made channels in the bearing holes that allow pressing out old bushings/bearings for maintenance. 

When assembled with Drylins, the weight is significantly less that the factory setup.

Results:

The Ghost on the left was one of a few acceptable prints I had with my SV06.  It was still not as good as I wanted.  I used the same file to make the ghost on the right with the only difference being the extruder mount. 

Files:

All files are named based around the bearing/bushing diameter on the model.  It is print in place (with no supports needed for ABS, but does come out better with supports) so the bushings/bearings press in.  PETG will require supports at 77 degrees overhang and a dremel with a sanding wheel or stone to remove the rough areas where the supports were.  

You can also get better proportioned bushing holes by using supports with ABS, but that wasn't needed for the ABS plastic I used on the one in the video.  I tried some other ABS and found supports really helped.  

There is a test print folder that you can use with the diagram pictures in the description to get the right size for your printer.

I also made a clip that goes over the top of the MonoBlock to provide even more support.  The whole assembly is top heavy, and I thought it could benefit from more support.  The clip is 32mm on the inside where it holds the assembly to the block.  I can change this if needed, just message me.

You will need:

Extruder Assembly Mounting:

3 M3 threaded heat inserts

AND

3 M3x8mm countersunk machine screws 

OR

3 M3x10 socket cap machine screws (If using reinforcement clip).

OR

ONLY 3 M4x10 socket cap screws to be hand threaded into the mount with the extra retention clip over the extruder (not tested).  You may need to drill out the extruder plate to 4mm for this to work.

Belt Attachment:

2 M4x14mm countersunk machine screws to thread by hand into each side to clamp down on the belt (What I did).

or

2 M3 threaded heat inserts

2 M3x14mm countersunk machine screws to clamp down on the belt.

 

Bearings/Bushings:

3 Igus Drylin bushings

OR

3 LM8UU bearings

6 M3x4mm set/grub screws if you want to or need to put tension on the Drylin bushings or have extra reinforcement for either the bushings or the bearings.  The holes are in line with the retention channels on the outer surface of either choice.  There are 3 holes for the bottom bushing.  You can use 2 of your choice (or all 3).

Test Prints:

There are test prints that you can run to predetermine which model will work best for you on your printer.  The pictures above correspond to the test print dimensions so you can take measurements of the test prints before you commit to the model that works best for you.

15mm model is the main model, if you know your printer is dialed in.  If you typically get undersized parts, print the larger test file.  If you need a modified test file, message me and I can make an stl for you.

Printing parameters:

• Temp resistant filament (PETG, ABS, etc.) I used ABS
• 0.2mm layer height 0.4mm nozzle
• 3 walls with alternate extra wall or up to 5 perimeter walls
• inside to outside print order
• 30-50% infill (I used grid)
• SUPPORTS: 77 degree overhang, 2 walls, 15% infill, concentric infill

Instructions:

Please reference above diagram pictures if needed.

1. Run a test print.  If your printer is calibrated, and you know it to be very accurate, you can print the 15mm version, but I would still run a test print first. If your printer tends to undersize models, print the larger test print and vice versa.  
2. Print your MonoBlock.
3. Press in your bearings or bushings.  There are 2 on top, 1 at the bottom.  The bottom bushing can only go in on one side. A 9mm socket will help push it to the end stop. If you require serious force to press them in, especially the Drylins, the hole is too small.  It is better to have slight to medium force required to push them in.  
4. Install set screws. Installing set screws will help with retention if needed/wanted.  Don't overtighten.
5. Test fitment on assembled X axis.  Put the X axis together and make sure the MonoBlock slides freely along the linear rods then take it off of the rods.
6. Slowly thread, by hand, the 2 M4 screws. 1 on each side, into the holes for clamping the belt. When you feel resistance, back the screw out some and then continue threading the holes. Or use your soldering iron to insert your M3 threaded inserts
7. Use soldering iron to install 3 M3 threaded inserts to the front of the mount.
8. Install the extruder assembly with either 3 M3x8mm countersunk screws, The reinforcement clip and 3 M3x10mm socket cap screws, or try the clip with 3 M4x10mm screws without inserts.
9. Reassemble the X axis and install the belt.  Tighten the 2 M4 screws down on the belt.
10. Test, Level, and Print!

If you message me needing another size, I can probably upload a specifically changed .stl for you. 

Sovol support is kind but slow, and these parts are not readily available. To make matters worse…they are unreliable.  If yours is fine, I would print one now to get ahead of this problem.

If you have had other breakages, I have other SV06 repair parts on my page.  Each part I made has been re-worked to be 3d printer friendly.  

Changelog:

10/12/23

Loading the .stl's in Prusaslicer, I noticed 616 errors that were fixed by the slicer.  I dug through the model and corrected the problem areas. The problem areas were around the relief for the baby breakout board at the top of the mounting face.  The recess no longer is chamfered.   

Prusaslicer now reports zero errors.  

I also adjusted the positioning of the bottom extruder screw hole to 90 degrees in relation to the hole above it.  It was at 89.6 on the original.