UJV55-320 -- Print Registration (X-Axis)

[Isaac_K]

Major print registration issues on our Mimaki UJV55-320. Affecting all colors and consistently bad from start to finish within a print session. Y-Axis registration seems to be fine. We've had techs stop by earlier today and they are saying that heads are deflected. I question that as there have been times where we were able to get this to work using the feed compensation. Additionally, the head test prints are not showing skewing anywhere near as bad as live runs. Photos are attached here - any idea what could be causing this?

Second picture shows the first print is off immediately after matching feed compensation.

 

[Smoke_Jaguar]

Head deflection can be caused by all sorts of things, head strikes, dirt, voltage, misalignment and so on. I believe the UJ55 uses 6 Gen5 heads, so they are pretty bloody robust. Run alignment checks, maybe flush the heads and go from there. Might be a good idea to look over the underside the print carriage as well, look for damage, buildup, etc. UV ink can become a gunky mess, even with daily cap cleanings and the like.

 

[Isaac_K]

Head deflection can be caused by all sorts of things, head strikes, dirt, voltage, misalignment and so on. I believe the UJ55 uses 6 Gen5 heads, so they are pretty bloody robust. Run alignment checks, maybe flush the heads and go from there. Might be a good idea to look over the underside the print carriage as well, look for damage, buildup, etc. UV ink can become a gunky mess, even with daily cap cleanings and the like.

Interesting. I never imagined voltage could be a factor. As stated in OP, I have my doubts it is a head deflection but I'll have our operators take a look as suggested. Thanks.

 

[Smoke_Jaguar]

If you have a service manual, will help a ton in doing deflection tests, different head checks, voltage tests, aligment tests and all that.

 

[Isaac_K]

If you have a service manual, will help a ton in doing deflection tests, different head checks, voltage tests, aligment tests and all that.

Would you happen to have it for this machine?

 

[Smoke_Jaguar]

Nope, unfortunately not. Looking forward to more right to repair legislation to pry service programs and manuals out of Mimaki's hands.

 

[Solventinkjet]

I don't have any experience with that model but I do work on a lot of Mimakis. The value on you print feed adjustment is extremely high to me. It should be closer to the 10's rather than 100's. Now that could be because this machine handles the feed differently than I know but in most cases it indicates your print feed is being affected by something abnormal like bad pinch rollers or possibly a failing motor. I would check to make sure your pinch rollers are actually being fully pressured onto the material. Sometimes the handle that drops the rollers down gets caught just enough to trip the sensor into thinking they are all the way down when they really aren't so it slips and causes issues like this.

 

[Isaac_K]

I don't have any experience with that model but I do work on a lot of Mimakis. The value on you print feed adjustment is extremely high to me. It should be closer to the 10's rather than 100's. Now that could be because this machine handles the feed differently than I know but in most cases it indicates your print feed is being affected by something abnormal like bad pinch rollers or possibly a failing motor. I would check to make sure your pinch rollers are actually being fully pressured onto the material. Sometimes the handle that drops the rollers down gets caught just enough to trip the sensor into thinking they are all the way down when they really aren't so it slips and causes issues like this.

We've never had to go this high on feed adjustments and thought this was odd as well. We've had to go as high as 1200 to get this to adjust properly.

From what we've seen there very few people with any experience on this particular model - even within Mimaki.
This model has 3 separate motors for the feeding/takeup process:
#1 - holding the roll material behind the machine (most units don't have this motor. I assume it's on this one due to the larger rolls)
#2 - "x-motor" where pinch rollers are feeding material
#3 - take up roller at the front of the machine.

Some more context:
- Overall, the "feed registration" is all over the place. It will improve and worsen on its own as it's printing.
- cleaned all of the pinch rollers and removed any debris in the general area - no change.
- tested a strip of material to see if the weight of the roll could be the difference. seemed to work better but still seems somewhat inconsistent.
- tested with automatic feed turned off. again, seemed better but still somewhat inconsistent.
- found #1 and #3 motor are the same - swapping made no difference..
- we are now seeing Y registration issues and getting SYSTEM HALT (2) - ERROR 509 HDC POSCNT
- cleaned encoder strip to see if it makes a difference, checked for any scratches

We're thinking the X-motor replacement is the next step but it's on backorder.

Do you happen to have the service manual for this machine? I doubt the answer to this is in there but it's always nice to have.