Arizona 550GT / Acuity HS Printhead alignment.

[Simon Peach]

Hi all.

I was looking for some advice?

After a head strike last week, I think one of our heads has 'popped out' of its position. - . - I'm aware the head is only clipped in and not secured with screws. - Our engineer said to power off the machine and push in the centres of the printheads until it clicks. - I have done but no joy, I couldn't find any mention on the bulletins either.

Any suggestions on where I can find the sweet spot? - I'm clumsy so conscious of a slip & cracked printhead housing


I have attached a couple of images below.

 

[AlsEU]

When the head popped out, shims could fall off, so after pushing back it may not be in the same position. Regardless of this (I don't know if you have your printer shimmed or not), you need to check the software calibrations, as the physical movement of the head always affects it. Scanner (not each one, unfortunately) and special software are required. Not a simple task.

 

[Simon Peach]

Thanks for getting back to me.
Will inspect about the shims. - We do have the specific scanner here but I'm not familiar with the process. I'll run a few other alignment test prints. - Any specific ones?

Sorry to bombard with question's, we've not had the machine long so still getting to grips with it.

 

[oel10]

On head strike make sure to manualy clean print head often times upon a strike a film of residue from material gets stuck on print head

 

[Simon Peach]

Hi. - Thanks for the reply, done plenty of cleaning. - Getting a really nice test drawer! - Ive attached some images of the alignment draws.

 

[AlsEU]

All pictures show just one alignment - head alignment gantry direction. Seems that you have K3 not in line with K2 (which is a reference head for mechanical adjustment). You need to adjust each colour's first head to the K2 then each second head from each colour to the first one (except black channel, you adjust K3 to K2 in the first step). Then you do the timing alignment (basic and fine), then adjust the density balance for the colour, which was moved. For the timing alignments the calibration software is required.

 

[levakbob]

Hello, maybe I have a similar problem.
Can I ask for help? We installed two new printheads (both black), were purchased on digiprint-supplies and were delivered without bracket.
The service engineer never changed the print head like this, he always had only the original, where the print head contains a holder. He is not sure if shim head alignment will help.

There is also a significant difference in printing when only one-way and two-way printing is printed.

Uni and bidirectional black printing only are attached. If we print, then these stripes. And printscreen printhed angular

Can I ask for your opinion?

 

[AlsEU]

First of all - what was done with the heads before the installation? How the holder was positioned? That may affect quality.
Second - shim installation is obligatory, even if the printer has no shims installed. After shimming (even one head) "carriage angular" calibration shouldn't be done anymore. Instead of this 'printhead angular' should be done (sometimes it requires an upload of the new calibration test to the machine - "scanner alignment angular - shim test - CMYK only").
If you replaced both K heads, definitely the whole calibration should be checked and verified, as K2 head is a reference for all other - so all colours now are not in register, I suppose.
And at the end density balance should be verified and changed, if necessary.
Calibration software told already, that the change of the shims is required for all colours except white. That's the first step of the mechanical calibration, the software must say 'alignment status: good" before the next calibration steps may be performed.
Generally - all calibrations should be done from scratch, but essential is the answer to my first question - how the holder was applied to the head? Manually? With any kind of the tool? Precision here makes the whole job, with head in the wrong position in the holder may be difficult to get correct results.

 

[levakbob]

Hello
The heads were placed in the holder manually without using the holder. Is there any product that would help to position the head exactly in its position? Or some procedure to achieve this?
Calibrations were performed from zero. Currently we only print UNI-Dir and it is quite usable.

 

[AlsEU]

I know that some kind of a tool to position the head in the holder was available on the market, but I'm not sure if it was for the HS heads. For sure it was for the old Arizona 250 heads. There's no official procedure for positioning the head in the holder, as the Oce supplies heads in holders only.