Prints are stepping left and right on prints larger than ~46"

[iajoycecz]

Hello.

I'm having an issue with a Mimaki JV3-130 SPII. It's similar to what happens when an encoder strip is bad, except we've replaced the encoder strip and the problem still persists. Basically, any time we send a print that is 52" in size, the image begins stepping like mad to the right and left, but if I crop my print down to 44"/46", it prints spot on no problems. Because of this I feel like it isn't the encoder strip nor the reader, I can't imagine the eye would stop registering after 46" and the new strip was cleaned after installation just in case we left any prints or smudges on it. Has anyone else encountered a similar problem? I dug around the site quite a bit for a similar issue, but most are solved by addressing the encoder strip/eye, which I feel like we've done.

Any insight would be appreciated.

Thanks!!

- Ian

 

[J Hill Designs]

does it happen on a smaller image set to print along the far margin (small print, but printing in the 46"+ area?

 

[iajoycecz]

does it happen on a smaller image set to print along the far margin (small print, but printing in the 46"+ area?

So I ran a print justified to the far left per your suggestion. The print was 48" wide. It printed fine. Then I made a file with two boxes, one at 1" x 48" and another after it at 1" x 52". It printed the 48" rectangle fine, but as soon as it got to the 52" rectangle it juked out. Top bar is the 52" one, bottom is the 48". It looks like as it was finishing the 48" bar and starting te 52" bar it began stepping on its final 48" pass.



My thinking is it has something to do with printing 52" end to end, but I can't imagine what that could be. Thoughts?

 

[jfiscus]

After you replaced the encoder strip, did you run tests like linear calibration, etc?
(I've never replaced one on our mimakis, but have done a lot of rolands and that is always the next step to be sure it's happy with the new strip)

 

[iajoycecz]

After you replaced the encoder strip, did you run tests like linear calibration, etc?
(I've never replaced one on our mimakis, but have done a lot of rolands and that is always the next step to be sure it's happy with the new strip)

I did, which is where things get wacky. I ran an encoder test and it attempts to read 1680.3mm. With our last encoder strip it failed constantly around 1500mm, regardless of how well we cleaned it or how much air we blew onto the lens. So, we replaced the strip with a generic strip, I used the previous strip as a guide (I had to cut holes into the bottom so it would fit onto the track) so everything lined up perfectly. When I put it on and ran the tests on the new one it came back as failed, but instead of reading 1500mm it said E1500. I tried digging around for what that could mean but couldn't find anything. I decided to do a test at 1500mm instead of 1680.3mm and it succeeded, which lead me to try printing something at 48" instead of the 52" since it seemed to track correctly up to a certain point.

 

[J Hill Designs]

sounds like the strip has a boo-boo at 1500mm?

 

[iajoycecz]

sounds like the strip has a boo-boo at 1500mm?

I considered that, but both strips, old and new would error out at the same spot.

 

[J Hill Designs]

the only other thing I can think is that the wires to the encoder sensor 'crimp up' at that point as it rides along the carriage

 

[genericname]

I thought the printable extent of the 130 was 52", no? What size is it actually?

Is it at all possible that you have the wrong width setting on the printer? You'd probably have the carriage crashing into the side of the machine, but it's still worth looking into.

 

[iajoycecz]

I thought the printable extent of the 130 was 52", no? What size is it actually?

Is it at all possible that you have the wrong width setting on the printer? You'd probably have the carriage crashing into the side of the machine, but it's still worth looking into.

It is 52" and some change, I can squeeze a 52.5" on there if I needed to. The printer polls the media size before it does anything so I'm not sure I could tell it to go bigger then it detects.

 

[player]

Could there be something mechanically wrong with the cable?

 

[jfiscus]

If it wont even read the whole correct width of the encoder strip, then the problem points to machine failure, so at least you should be able to rule out software errors with wider files.

Apparently, at 1500+mm SOMETHING gets out of whack.
What is there that can go wrong?
Cables? bad connections, pinch in wire?
Track? dirt on track inhibiting carriage movement, un-oiled rails?
encoder eye? faulty eye, wiring, overload?
other?

It seems like your original "problem" of the encoder strip was not the problem after all.

 

[iajoycecz]

If it wont even read the whole correct width of the encoder strip, then the problem points to machine failure, so at least you should be able to rule out software errors with wider files.

Apparently, at 1500+mm SOMETHING gets out of whack.
What is there that can go wrong?
Cables? bad connections, pinch in wire?
Track? dirt on track inhibiting carriage movement, un-oiled rails?
encoder eye? faulty eye, wiring, overload?
other?

It seems like your original "problem" of the encoder strip was not the problem after all.

For sure.. there are a lot of variables to consider. I'll be trying some new things throughout the day and if I fix it or figure something out I'll report back. Really appreciate all the feedback from everyone, thanks guys.

 

[Techman]

have you reset the nvram?

 

[iajoycecz]

have you reset the nvram?

That sounds outside of my technical range, but my Googlefu tells me this is a Mac process, which we don't run (we're all PC). Im curious though, do you think it could be something coming from our PC?

 

[Samurai_Screwdriver]

Here's another few things you could investigate:

1. Check for skipping belts/pulleys.
- Push the Carriage all the way to mechanical stop (like all the way to the right) then with a sharpie mark a line on the belt and on the pulley at the exact same place. Do this for the motor pulley, and the upper and lower part of the double-drive pulley.
- Run the printer until it fails and then bring the Carriage back to the same stop point and then check the markings you made. If everything is working correctly they should still match up, but if any of them are no longer aligned then you've found the belt that is skipping. Maybe it just needs more tension or perhaps it's started to stretch

2. COMP Y setting no longer correct
- Go into the #PARAMETER, then SYSTEM PARAMETER menu and find COMP Y (it's Parameter #1 I think). Note down the number and then try changing it by a few whole numbers. Run your tests again and see if this makes any difference.
- I've noticed that as machine age you an start getting into problems where they will no longer print in bi-direction (encoder loses position before making the return pass) or you get stepping. I've never been clear on why tweaking this setting fixes these problems but I fixed a number of glitchy machines this way.

3. Check the HDC Cables inside the Chain
- Encoder signals are carried on one of these cables (don't ask me which!) so as someone else mentioned you may have a break in the cable that only appears when it flexes at a certain point.

I'm intrigued to know what finally fixes this!

 

[iajoycecz]

Here's another few things you could investigate:

1. Check for skipping belts/pulleys.
- Push the Carriage all the way to mechanical stop (like all the way to the right) then with a sharpie mark a line on the belt and on the pulley at the exact same place. Do this for the motor pulley, and the upper and lower part of the double-drive pulley.
- Run the printer until it fails and then bring the Carriage back to the same stop point and then check the markings you made. If everything is working correctly they should still match up, but if any of them are no longer aligned then you've found the belt that is skipping. Maybe it just needs more tension or perhaps it's started to stretch

2. COMP Y setting no longer correct
- Go into the #PARAMETER, then SYSTEM PARAMETER menu and find COMP Y (it's Parameter #1 I think). Note down the number and then try changing it by a few whole numbers. Run your tests again and see if this makes any difference.
- I've noticed that as machine age you an start getting into problems where they will no longer print in bi-direction (encoder loses position before making the return pass) or you get stepping. I've never been clear on why tweaking this setting fixes these problems but I fixed a number of glitchy machines this way.

3. Check the HDC Cables inside the Chain
- Encoder signals are carried on one of these cables (don't ask me which!) so as someone else mentioned you may have a break in the cable that only appears when it flexes at a certain point.

I'm intrigued to know what finally fixes this!

Great suggestions. I've managed to get us limping along at 50", haven't had a chance to really try these out but as soon as we catch a break it'll be my first move. I'll report back with the results!!

Thanks!