Mimaki UJF-3042 restoration

[Smoke_Jaguar]

Make sure to put the dampers in exactly as shown in service manual. There are 9 easy ways to install them, and only the hard way actually works without letting air in. Save up a lot of obscenities as well. For the special Mimaki damper deflate tool, a bent stick works just as well.

 

[kehall]

The pumps ready to go back in the station housing.

The worst of the ink mess that was basically EVERYWHERE under the station was cleaned up (the felt pad removed, clearly totally full as it weighed a lot!)

Could do with an Ethyl Acetate pressure washer That chemical certainly makes light work of moving old sticky ink (even if it does stink to high heaven)

I believe the white ink contains titanium dioxide - and I could swear I came across little sections of reconstituted titanium metal fragments in the midst of all the mess!

The wiper section was practically welded to the main station body with dried up ink, it was pried away and cleaned behind before reattaching with the three screws, two on top, one at the side underneath.

I manually moved the "wiper" nozzle out a bit to help clean a bit more inside (and it still needs more cleaning!) Probably a little grease on the ramps either side too.

Does that wiper nozzle actually contact the heads, should it not be rubbery or something, it feels fairly hard?!!
I've seen pictures of two styles, one looks like a silicone blade, and this one which I presume is just a sucker (a bit like me for getting into this project haha )

The glue-repaired top capping cover (just leaving it to cure for 24 hours) needs to go back on the capping section and the station reassembled (hopefully remembering where all the screws go!)

I'm pretty sure the ink (CMYK at least) is still in good shape, it is extremely free flowing, not gelled (it seemed to enjoy leaking through the threads of M3 bolts I'd initially tried plugging the lines with (later with little silicon bungs)), and the photo-initiators still work fine, curing when testing stuff that dribbled out onto a paper towel with a hand held 5W 395nm UV torch.

I'm not as convinced if the white is ok given the titanium dioxide, but have two new 220ml cartridges within expiry date to try anyway.

So tomorrow may be the day we see if anything actually prints from the heads!

 

[kehall]

Make sure to put the dampers in exactly as shown in service manual. There are 9 easy ways to install them, and only the hard way actually works without letting air in. Save up a lot of obscenities as well. For the special Mimaki damper deflate tool, a bent stick works just as well.

Thanks, I found the removal quite awkward, as that rear tab prevents a 'straight up and out' approach which would have been nice. The service manual (calling them dumpers ?!) doesn't particularly say anything special that I saw about reinstallation other than being the reversal of removal.

Definitely will go through 'deflate' process waiting for a nice stream of ink from air purge port after install though. I'm hoping the damper adapters on the top of the heads are ok too (two are the old style with white top).

 

[Smoke_Jaguar]

Oldest ink I got to work was 4 years off date without major issues. Print quality was crap, but great for testing. Shook the crap out of it first of course.

 

[netsol]

i noticed a couple people refer to them as dumpers
bad transliteration program, i guess

 

[Smoke_Jaguar]

Service manuals do call them dumpers.

 

[netsol]

i guess i have no mimaki service manuals

 

[Smoke_Jaguar]

Want some? I know a guy, totally not me..

 

[netsol]

one good friend, across the parking lot in the industrial park has all mimaki now
we never got involved
tons of rolands (all price based, of course)
some mutohs & almost all my clients followed my lead & went with roland

 

[Smoke_Jaguar]

We're almost all UV printing here, less maintenance and cheaper, more fade resistant inks Also, running flatbeds. Roland's UV stuff has a long way to go. People keep bringing me samples from Roland/GSG and I just print them a copy with higher DPI settings, and they think I sold my soul to Satan or something. At 8 years old+ on the flatbeds and a UCJV300, they're still better in lots of respects. Also, bottled ink is great. zero waste in our shop, unless it leaks. Considered putting bottles on the MK1 6042, but never got it running before just replacing it with a MKII we got for a killer deal.

Mimaki needs more techs though, so I learned to fix my own. Getting trained on some models, but it just lets me work on them the boring way without voiding warranty.

 

[kehall]

I'd hope to be able to modify this one to be able to take bottles, perhaps through tweaked old ink cartridges, assuming it all gets back to action! Now for today's update...

Finished cleaning of the station assembly and fitting of newly serviced pump heads, the glued capping top plate is holding together for now!

Reassembled capping station in situ

Will source some of the oil spill sorbent material Smoke_Jaguar has suggested to replace the (now missing) piece under the capping area.

New dampers fitted and ink lines reattached (careful to get the right way round), not sure of the precise routing/order of the lines clipped around the side of the head but it seems reasonable:

Blimey those dampers are ***$*(" awkward to fit with that silly tab affair at the back. there's barely enough space to tilt and get the back 'nozzle' of the damper into the requisite hole of the damper adapter on the head! I'm half tempted to trim the size of the tab to make it a bit easier to handle in the future. Quite why they designed it like that as opposed to a 2nd screw at the back is beyond me - it would have been so much easier! I guess the newer models are improved.

I fabricated a crude damper deflate tool and set about purging air, however I have a feeling I need to have the printer in 'ink fillup: air pg' mode as even after a good 2 minutes of waiting, no ink flowed (I suspect valves on the cartridge side not open perhaps until commanded).

Unfortunately ink set LH-100 MCYKWW is showing Expire (2M) so it's locking me out I don't want to remove the battery to reset the date back in case all the other data is lost and I get stuck in an ink fillup procedure that may require wash cartridges (I have none), so am going to have to look at other options...

So still not found out yet if the repaired heads are working, but it's soooooo close!!!!!!!! The anticipation is getting unbearable LOL

I'll get onto cleaning the UV lamp now (and maybe some glass polish as it's pretty faded/cloudy and nothing seems to clear it up), and renew the UV coolant (got some PC liquid cooling stuff which will be just fine I'm sure).

so, once again, to be continued!!!

 

[Smoke_Jaguar]

I am both amazed at how clean you are getting that and traumatized by the flashbacks of dealing with my MK1 at the same time. My slider board was greyish-purple and coated with a good 1mm of old ink and the retainer tabs for the head were all snapped as well, but looks like you lucked out there.

 

[kehall]

Well... it's gone midnight here now, but I just got back home after 4 hours at the unit... Damper deflating now I managed to get into INK FILL (air pg)... Checked ink lines as didn't see much coming out, just a bit of the flushing solution I left in the heads and nothing more..... More damper deflating... got nothing from Magenta and Cyan... Got a bit from one white with some fresh white so now knew ink was getting in, which encouraged me to go back to Magenta...

Nothing, even after about 3 minutes. Tried Yellow, got some muddy Yellow starting to dribble... nothing from Black. went back to White, all good (that I could tell)... Back to Magenta, nothing. Looked at a new damper, decided I probably wasn't pressing it firmly enough. Adjusted the tool to get a bit more 'push'. Still nothing from Magenta or Cyan... Checked the ink at the cartridge outlet at the top... all ok. Black started to flow when I next checked that one.

Then thought ok great. I guess I should try a print test before spending the rest of my life trying to get Magenta out.

I went to test menu and nozzle check, selected black only, and positioned the start point. Started the test and flashes of almost blinding blue UV light as the head wizzes about. Then realised I hadn't lifted the table . The piece of paper had lots of little black specs on, so I knew something was happening though

Corrected the height of the table.... Ran the test again. This is the first 'real' print I got out of it, haven't done any 'head cleaning' other than the obligatory head wiping and suction from the pumping it seems to do before the test print (and a squirt of ink into the caps).

Well it may look ugly but given everything else, that seemed very promising to me! I then went onto Yellow, just to see.

Wow even better! I went back to trying to get some ink from Magenta and Cyan again...

Wedged the deflate tool in place in Magenta damper, firmly pressed but not crazy... looked away and came back and started seeing Magenta flow, yay! Same with Cyan.

Tried another test, Pattern 100%, CMYK and it was flying about so quickly the draught shifted the paper! I quickly pushed back and then hit end to stop it (I needed to fix paper down, vacuum doesn't seem to do anything - plus even if it did, all the holes are clogged!), so now have a bit of test pattern cured on the table but the block of ink put down seemed pretty solid, nothing like the gappy nozzle check first done).

Ran the nozzle checks again on K and Y, followed by M and C now with paper taped down...

Starting to feel really good about this!

Then spent about 30 minutes trying to find something to print white on (as couldn't see on white paper, given best efforts). Tried some plastic bag, but was fighting with !Work high issues, so then tried some brown kraft paper. Couldn't really tell there either, only JUST about see, the 2nd white head was printing nothing. I then realised I mustn't have deflated that one, so it must have been printing clear flushing solution Deflated that and found a better way to tape half a plastic bag down to the table without Work High errors.

Final print before coming back to update this thread:

Probably still a bit of flushing solution left in the 2nd White nozzle channels, I'm hoping... I've got some black card so will do some more testing tomorrow maybe

It has an interesting way to print those patterns, like does half the head, for a section, then a gap, some more, then fills in the bottom half on the reverse pass, probably just the option I chose at the time (didn't care too much)!

I'm amazed it functions with a good 2" section of teeth missing still on the belt. I heard the UV coolant fan come on a little bit and then go off again so things are looking to be fairly functional there too.

Before I came away I had a quick look at the error log out of curiosity (had meant to check the other day). Prior to my first bootup test on May 31st, the last error it had was on June 17th 2021 which was SLIDER FPC H (the same I got when first powered up).

So it's been sat around for 3 years! A quick scan through was showing error 707 HD heater break errors at least going back to Sep 2020 too, so it would appear that the head flex micro-soldering performed indeed fixed the main 'fault' of this machine (aside to the FFC cables!) before it was retired.

Next on list then is:
Do some further nozzle flushing and testing, perhaps just a few cleaning cycles...
Check alignment, other service/maintenance items etc
Swap the belt
Investigate the vacuum table cleaning out the holes
Swap the coolant
Clean/polish the UV glass (although seems to be curing ok!)
Check the keyboard as the enter key is loose and half disappearing into the panel
Swap the broken mains IEC inlet
General cleaning of dirt and dust and grime
Lubrication
Replace a few missing case screws
It is missing the front 'cover' but I guess people remove that and wedge something into the switch on the left to make it easier to do stuff? I don't think that's too important.
Find a suitable Rasterlink RIP for it though to test from a PC.
Test printing onto various plastic (ABS) - maybe find a good way to hold substrate down other than tape, not sure the vacuum would be strong enough.

Thanks must go to Smoke_Jaguar for all the support and encouragement with this!

... to be continued

 

[kehall]

The little job over the weekend was to take the table out and clean out the holes, and work out why the vacuum fan was not operating... Well the first thing was that the UV lamp had an 'extender' to shift it a bit further away from the heads, which meant that the service manual's instructions about removing the table didn't include the removal of the UV unit (it obstructs the straight up lifting out of the table). The second thing was that the fan was disconnected, which would point to one reason it wasn't working!

A 1.9mm drill bit was hand spun in each hole (some were completely obscured by ink). A flat razor blade was used to remove all the ink that was overprinted on the table and a polish up with 0000 steel wool. The fan was tested on a bench PSU and worked nicely up to 24VDC drawing the rated current so all good there... A vacuum cleaner was attached to the table exit hole where the fan mounts to in order to help clean out debris before replacing the fan. The table looks much better shape now.

Fished out the other end of the fan power connection which looked like it had some pretty dodgy repairs going on, not sure why, possibly got trapped? There was a ton of spare cable in the board area so was tidied up a little and reconnected with enough slack for the table to reach max height and down to min height without contacting the X belt.

Attention was then focused on the Y belt replacement, as it was missing a massive stretch of teeth and some others were breaking off.

The left and right end covers were removed, and could see a ton of rubber dust caking the drive gear:

The carriage was also very noisy ('pingy'), but at first I couldn't see how the belt could easily be removed from the slider/head assembly. Thankfully the obvious was pointed out that the ends 'hook' onto the slider and can be removed once the belt tension is taken away.

The belt tensioner was at its max limit fully screwed in (which felt a bit strange but maybe was done as a 'get you by' fix given the stretch of broken teeth). A new Y-belt at Mimaki prices seemed to be over $650! The one I'd ordered in, a 5m long roll, enough to replace it twice, was about $30! Some serious markup there...

 

[kehall]

The belt tension was reduced and the right hand side indeed unhooked from the slider without too much difficulty. What then proved a problem was trying to pull the belt through the Y-bar hole with the retaining metal piece still attached, where it gets hung up on internals in the Y-bar!

Should have removed the metalwork 'end' first. Now after much swearing and poking with a long stick (getting that stuck too in the process ), managed to get the belt back through to remove the end piece.

The UV unit had to be removed (again! - getting good at setting the 2mm gap required now!), and the left hand belt side was unhooked from the post it hangs onto.

The old belt was interleaved with the new belt to get the same number of teeth (although possibly not hyper critical given the tensioner adjustment available), cut with some strong, flat bolt cutters and the left hand end was attached to the belt.

The other end was 'posted' through the Y-bar channel opening to eventually reach the other side (the dust was also cleaned up off the pulley/gear after this photo was taken).

Belt end ready to be fitted with the right hand side retaining metalwork:

The end was then looped round the idler/tensioner pulley and fed through back to be hooked onto the slider carriage. Tension was then applied by tightening two screws which applies spring pressure to the tensioner pulley. Tightened leaving about 8mm gap to the tensioner max distance and felt sufficient tension along the centre of the belt (in absence of a proper belt tension specification using a "spring" gauge). We can always increase the tension later if needed, but was happy with the amount provided.

Manually slid and then ran a few test prints - the Y motion was soooooooo much quieter and smoother now! Feels really good to have sorted that one out!

The old belt pretty much ready for the bin:

The LED UV unit glass was also cleaned with some 0000 wire wool and alcohol, the cloudiness (mainly at one side) is now gone and is clear.

I think there may be some air getting into the Cyan head (or perhaps a lower ink level could exacerbate that), as am getting a good portion of nozzles missing (mostly at the ends of the head), unfortunately I don't have a spare bit of 4.5 x 2.5mm tubing to block off the damper inlets to try a syringe vacuum leak test from the negative pressure testing ports that connect to the peristaltic pumps however so I'm not able to test that (which would also check the capping).

It may be worth just trying the air purge (damper valve squeeze tool) process a few more times on Cyan first though.

 

[Smoke_Jaguar]

Air in the heads from a poor bleed or leak can be the main cause, as well as dampers not snugly in place. Sometimes the seals in the damper ports on the head can creep out as well, or jump out when you're not looking.

 

[netsol]

I am both amazed at how clean you are getting that and traumatized by the flashbacks of dealing with my MK1 at the same time. My slider board was greyish-purple and coated with a good 1mm of old ink and the retainer tabs for the head were all snapped as well, but looks like you lucked out there.

yes, it is amazing
all my machines work fine, but, none of them look like that!

 

[kehall]

Air in the heads from a poor bleed or leak can be the main cause, as well as dampers not snugly in place. Sometimes the seals in the damper ports on the head can creep out as well, or jump out when you're not looking.

Ta, I was almost coming to the same conclusion of taking a look in that area, with a bit of reluctance, I must add!

 

[kehall]

yes, it is amazing
all my machines work fine, but, none of them look like that!

Interesting to see how this one will look after a year of (ab)use I've seen a bit of dribbling around the outside of the caps, white mostly (probably the most visible), I guess that's one area ink can work its way outside the designed captive system... When the sorbent matting arrives, I'm pondering putting a custom shaped layer of it around the caps, I believe newer models have such a thing... I've ordered some 2.5mm thick stuff, I can pile up 4 lots to make up the 10mm thickness underneath by the pumps, and hopefully 2.5mm won't get in the way of anything in the capping area, if it does, well it'll just have to get more dirty over time!

 

[Rebelious1]

Hello Gentlemen,
This refurbishing is awesome! I went on to see if anyone had a good source for UJF-3042 Slider Boards. I have two slider boards that are not allowing the black/yellow to fire correctly. Is it better to buy new ones or try to repair the two that I have?