Sunday, December 28, 2014

My Printer - Getting Auto Gap to work... Finally!

I have been on a quest to get Auto Gap to work on my machine.  I had been able to obtain gaps in both left and right that were 'equal enough' to not clog and give me good prints.  But, I always had to adjust the gap after Auto Gap was run,


I had assumed that the two adjustment screws adjusted the print jets themselves and affected how much each print jet protruded from the housing.  In fact I was going to use the fact that the bottom of the housing was flat to create a gauge to help me not only equalize the gaps between the right and left print jets; but, also measure their protrusion from the housing.

It was a wrong assumption leading to a fools errand.  And it didn't make me all too happy when I figured it out.  While I do have some access to people inside 3D Systems, I do NOT always have access to information that would make mine and your lives easier.  This is one of those cases.  I kept asking the wrong question and nobody steered me to the tight one!

 DISCOVERY #1 - Entire Print Jet Housing pivots

It turns out the the two 1.33mm adjustment screws adjust the ROLL of the entire print jet housing!  Moreover, the also seem to adjust the gap!   I found this as I was experimenting with loosening the screws to see if it affected the protrusion.  All of sudden it became evident that the entire print jet housing could be pivoted or 'rolled'.   Then it followed that what the screws were actually adjusting was the angle of the pivot to adjust the tips of the print jets to be evenly spaced from the print table.

So, the first goal was to alternate between running Auto Gap and adjusting the screws until the gaps were even.   This took several passes.

DISCOVERY #2 - Screws Also Affect Auto Gap Results

But, as the screws were adjusted, it was evident that the two adjustment screws also lowered the gap.  Again, repeatedly tightening the screws evenly and then checking Auto Gap eventually did the trick.  Backing off both, just an 8th of a turn and checking with the gap tool confirmed that Auto  Gap was now working very well.


For those of us having an adjustable print jet housing, the adjustment screws affect the print housing itself by controlling the 'ROLL' of the housing to position the print jets level with the print table.  Then, moving to the next step, we can use the adjustment screws evenly to position the print jet housing to improve the performance of Auto Gap.

The print jets still protrude at different amounts.  But, fixing the 'ROLL' of the print jet housings took care of any negative affects that situation presented.  While I had seemingly wasted some time creating gauges, it actually was quite beneficial because it taught me to appreciate how very precise 70 micron printing is on the Cube 3.


  1. Hi Tom

    This post is really interesting. I've had several prints ruined because the right nozzle has hit the build and knocked it off the bed.

    The instruction only talk about leveling the left nozzle so I assumed it was normal for the right nozzle to be a little lower, even though that didn't really make sense to me.

    Is there a video or step-by-step how-to for making these adjustments?


    PS. since the 1.09b FM update I've had no broken cartridge issues - YAY!

    1. The print jets need to be as perfectly aligned as possible. Hopefully, these videos are still available.

      Nozzle level:


    2. Thanks Tom! I'll check them out. Unfortunately I have to take back my excitement about FM1.09b. A cartridge clogged on me yesterday 32 hrs into a 37 hr print. Feel like I've broken down and fixed these things so many times that I could do it blindfolded. :) Best H

    3. I've finally gotten a clog in the newest printer, myself. It seems two situations make it worse, repeating very small features and 70 micron layers.

      But, I've been able to recover fairly quickly.