Hello,
During the current 3-color printing process, I noticed that the printer has to grab the first head 2-3 times.
It picks it up, moves forward a short distance, waits briefly, re-inserts it, and then grabs it again.
The console shows the following:
I think this is software related.- Moved it there.
Am I right and you use snapmaker orca?
Maybe this is worth a try:
Surely not. Isn’t this a problem with the pogo pins not making contact properly, so it retries until they do (or it gives up)?
Yes, you are right. I missed the picture and thought about the printing process. Sorry.
Open a ticket:
https://snapmaker.formcrafts.com/u1-troubleshooting-request
and have a look at the wiki:
https://wiki.snapmaker.com/en/snapmaker_u1/troubleshooting/pogopin_contact_anomaly
I’m getting this problem too, I have not yet gone through the formal diagnostics but it’s pretty clear what the outcome will be.
Back in the 1980’s (and before), when I was doing military electronics, we had a need for high-reliability interconnect with very low insertion/extraction force, and we used a contact technology called Hypertac. The male was an ordinary gold-plated pin, but the female was a cylindrical cage of gold plated wires, shaped into a hyperboloid by twisting it. Very expensive of course, and I don’t know what the service life would be in terms of mating/unmating cycles!
Are the pogo pins and contact pads (Snapmaker seem to call them “solid pins”) gold plated? I sure hope so, but by the look of Snapmaker’s illustrations they might not be. Gold plating is essential for long-term contact reliability.
Illustration of a Hypertac contact pair, cribbed from Smiths Industries:
Clean the pogo pins with some IPA & microfiber cloth. Might help & can’t hurt
Already done that!
Worth a try. Do they need to be greased again, or would contact spray be better?
There shouldn’t be any grease anywhere near the pogo pins.
Contact cleaner is only a de-greaser, but non-conductive (reducing hazard in live electrical situations). IPA should do the job, and leave less residue. Even contact cleaner won’t work unless the contamination it is being used to remove is physically wiped away rather than redeposited when the cleaner evaporates.
Strangest thing, and I have no explanation, but this morning I switched toolheads 2 (the one that was giving me toolhead swapper anomalies) and 4. I figured the anomaly count would swap to head 4.
Did it heck. I completed a dragon print without an error report at the end (unheard of, the only time that’s happened before was the very first). So then I tried the diagnostic routine downloadable on the wiki (it’s a G-Code file which prints nothing but does 100 swaps on each head), again with no anomalies.
I have no idea why, except to suggest it is a fluke.
It was. The diagnostic file never reports anomalies (even though I’m sure there were some), but another dragon did indeed report anomalies.
I’m running a print currently, but there’s an option in the menus to check the alignment of the toolhead as it docks and you can manually adjust it to make sure its centred - just wondered if this might affect the pins being aligned properly on toolhead pickup?
I had to adjust mine as it was sometimes picking up/replacing the TH 2 or 3 times before printing with it?
How do you judge whether it is centred?
I have now had a close look at the pogo pins etc, particularly on my problematic toolhead. It all looks in fine fettle, the pins extend and retract fully, I don’t know why there is a problem (except for lack of gold plating).
There is a locating bump on the toolhead which fits into a depression in the carrier. I don’t see how there can be any misalignment, the bump guides it in, and there is at least ±0.5mm margin on the solid pin - pogo pin alignment.
You can manually trim them, mine were all off to the right - doesn’t have to be 100% precise but you can see when it lines the TH up with just in front of the main pin then you can use the controls to nudge it left/right if off centre
OMG!
I’ve done as you said and realigned the head pickup coordinates. Heads 1 and 3 looked OK (T0 & T2), but I made minor adjustments to heads 2 and 4 (T1 & T3):
It was really worth taking the photos just to see what adjustment was needed, and the misalignment was only one nudge (the smallest increment available on the controls).
The outcome was a perfect run on the swapper test file (the Fluidd console showed no retries, and the fan didn’t cut out), and a dragon print with no anomaly report at the end.
Excellent.
I still think the pogo pins and contact pads should be gold plated though.
…but only temporarily 
Damn, hoping you’d got somewhere - I wonder if a pin is getting stuck during printing?
When you swapped heads T1 & T3 did the anomalies stay on T1 or move with the swapped head to T3?
So was I, but my optimism was premature. I can’t find anything wrong with the pogo pins at all.
T3 now gives the most trouble for sure, but it’s not exclusive.
It is very difficult getting useful stats, because I never get a toolhead swapper anomaly report at the end of the swapper test print, even though retries are clearly shown in the Fluidd console, and despite the troubleshooter wiki saying:
Down and Run Toolhead swap test gcode.
After the G-code has finished running, please tap the error code and record error count message.
(complete with an illustration of the Toolhead Swapping Anomaly report). I’ve confirmed this many times, and even regressed my firmware to 0.9.4 pursuing it. I’m discussing this with support at the moment.
It seems the only way to provoke an anomaly report is to do an actual print (the dragon of course), and the report is not cumulative (it resets for each print). I suppose the data is in there somewhere, but only accessible in Snapmaker’s encrypted logs. Annoying.
Query: I’m sure I’ve seen reference somewhere to gold pins. My pins don’t look gold plated, and none of the illustrations show gold plating. Anybody disagree?
And now I know why!
In the first place, the swapper test was defective and has now been fixed. In the second place, toolhead retries do not necessarily constitute a swapper anomaly. See Exercising Toolhead Swaps - T0 Not Getting Selected (and other things) - #5 by CrazyIvan
I am now thoroughly familiar with the process (information from Support and my own deductions).
The U1 firmware monitors the electrical contact of the pogo pins during head pick-up. If a bad contact is detected, it replaces the head and tries again up to two more times. These retries are seen in the Fluidd console (as per your screenshot). This is normal.
The pogo pins are only for the control and monitoring of the part fan (fitted on the toolhead). The heat-break cooler is a separate fan in the toolhead. The pogo pins are inevitably not 100% reliable, and retries will generally overcome the small percentage of unreliability. If, however, they fail to make proper contact after three attempts, printing continues but without the part fan running on that occasion.
This may or may not be a minor inconvenience, depending on the material being printed with, but likely as not the print will be fine. There remains a good chance the fan will work fine next time that toolhead is picked up.
If there was a fan misoperation, the event is recorded as a Toolhead Swapper Anomaly, and if there are any anomalies accumulated by the end of the print, a warning message is presented and the user can inspect the number per toolhead. Note that if the fan would not have been running anyway, a failed connection is not regarded as an anomaly.
(0.9.x firmware paused to alert the user at the time of the anomaly. That meant you might come back to the printer expecting a print to have finished but in fact it was paused waiting for a command to resume, as happened to my consternation. 1.x firmware informing the user at the end is much less inconvenient!)
A few anomalies every now and again are to be expected, and serve as a warning to clean the contacts. Multiple anomalies happening every print need to be treated more seriously.
