Print lines changing shortly after print starts

[Artist369]

Ok so i have my printer setup to do 8 passes, they come out about 1/8" thick. Starting this morning the printer will start out printing correctly, then the lines become about 1/4" thick and only doing a few passes. I have a Mimaki JV3 160-SP. I am only able to print about 12" before it starts doing that. Any help would greatly appreciated.

Update: Ok so i know what the issue is just not what is causing it. The printer is changing resolution in the middle of a print. No idea why.

 

[OmegaAdv]

I have that problem when print large width to say 100cm x100cm(Print and Cut) and in the some part there is a part that the print go to 10-20cm width and it get to change the passes and resolution like yours. I print with ONYX X. With Photoprint I don't have that.

 

[Artist369]

Ok, so i know someone who works on Mimaki's. He didnt know the answer so he contacted another person he knows that also works on them. They brainstormed and final took a shot in the dark and guessed, because neither of them could come up with a solid solution. Their guess was that there was dust on the encoder strip. So i took some alcohol, wiped down both sides and sure enough printed just fine (so far). If you go to do this do not use the cleaning solution for the printer. Just use 70% isopropyl alcohol. The strip has tiny hatch marks that the carriage reads as it goes back and forth. The printer cleaning solution will mess up the hatch marks, then the strip will have to be replaced. Hopefully this helps someone.