Dimensional Print Studio


SMJ1 Update

I have been using the Snapmaker J1 (SMJ1) since the first of the year 2023. It’s been almost 12 weeks.

It has had some faults. The most serious was a failed ribbon cable at the left extruder head. It had a 90 degree crease in the large flat cable that became a concentrated flex point when printing. The wiring in the ribbon cable failed open (broke) like flexing a paper clip until it breaks.

 Lots of erratic print head behavior before the total fail. A new cable with no crease fixed the issue. 

The SMJ1 has its Snapmaker “Luban” slicer which is a modded Cura. The documentation is better than Cura but the interface is clumsy as it must work with other Snapmaker products. Multi-purpose is always a compromise for a specific task. I used Cura.

I have now written my own Configuration for using Simplify 3D (S3D) with the SMJ1. I find it a far better SMJ1 print solution for my way of thinking. 

The S3D doesn’t create a pretty display picture embedded in the gcode but the files produce excellent prints for me.

The SMJ1 operating system complains about a single extruder print (telling me it is a file for a dual extruder) when I try to use the copy or mirror functions built into the SMJ1 OS. 

However, dual extruder and single extruder left or right print perfectly with my S3D configuration file.

I assume I will have to create a true single extruder S3D file for the SMJ1 with no reference to a second extruder to get copy and mirror to function. These are printer features I have only tested and will seldom use. So this is presently not a high priority to create and test.

There may also be a specific block in the SMJ1 OS to keep this function proprietary to the Cura-type format.

UPDATE: I created a 2nd Simplify3D config file, removing the script for "parking" heads. Works perfectly for Copy, Mirror, and Backup printing with the J1.


We have met the enemy and he is us.


The Facebook Snapmaker J1 forum is a total swamp. If you like to complain and accept poor advice and see unusual and unnecessary “MODS” (equipment modifications like huge and unecessay material fans) it is a place to hang.

Good advice is hard to find as the Factory Support folks rarely contribute.

One example is an issue with J1 extruder jams or plugging causing an extruder clicking noise (stalled steps) and eventual flow failure. Many cases were posted and I suffered the same issue. 

No response from factory support.

The real problem for me was a setting in the slicer that retracts far too much filament for a change between print heads when printing. Default CURA is 20mm retract. Non-IDEX dual nozzle printers do this to prevent oozing from the idle nozzle.

With the J1, excessive retraction causes filament stringing and cooling inside the extruder leading to eventual flow failure. Not the outside stringing you can see when printing. It is the stringing you see on the end of the filament when you pull a filament out the top of the extruder.

Not needed with the SMJ1 IDEX as the idle nozzle sets on a rubber stopper between print actions. Zero or standard print retract of 1.5mm is all that is needed. Again, a simple single entry in the config file in the extruder switching section fixs things.

Plugged nozzle and clicking issue solved. 

Many forum inhabitants have no idea it is retract setting totally separate from the standard (when printing) retract. The first reply was from someone clueless about this separate nozzle change retraction, but rambled on how he carefully tested every filament and temp setting and 0.8mm (not1.5mm) was the “correct” printing retract. Totally off topic.

I offered my working solution but it soon disappeared in the swamp’s quicksand of ignorance.


I have turned off the following and auto notice of activities of several (brands) of 3D printer forums on Facebook. I am not on a mission to be a 3D print super hero, saving people from their many faults and uneducated equipment mods.  I still have plenty things and mistakes to make on my own. I will come and go as I decide.

My interest is the creative design and use of modern technology like 3D printing to “make” things.

Commercial and hobby printers have hardware and software issues but not as bad as user ignorance. The forum folks certainly need the help to understand,  but that is not what I wish to spend my time correcting. The forums are there. I have a choice of to participate or not.

Future posts (and issue solutions) will be from links to posts here in my own blogs. Don’t need to live in a swamp like Pogo.

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