Mimaki CG100-SR2 Service Mode

[infamuz]

Hey,
We've got an old but bulletproof Mimaki CG100-SR2 plotter, and recently we've noticed the cut length is varying from what it should be, when cut from the feed direction.

It's an old machine but very reliable and has paid for itself thousands of times over, so it still graces the studio. But this issue is the only one we've had, and I would expect it with what we're doing.

We have some 1150mm strips to cut, but need to cut them from the feed direction rather than width (left/right). So by the time it's cut the 1150mm, and we measure, it's more like +5mm. They are fairly accurate too as they're part of something else.

Anyone know, or have any experience of this?

On our CJV30-130 we can get into Service mode with Function+Remote pressed whilst turning it on and I am told there's a "500mm Square" option you can run but can't see this on the CG100-SR2 (nor boot into Service mode this way).

I know I can cut them width-ways on a larger machine to probably counteract it, but curious on the feed direction tolerance and service mode mainly for this CG100-SR2 at present.

Thanks.

 

[Headstrike]

Most likely the pinch rollers and the grip bar underneath are worn out and need to be replaced.
Practically the media slips on them during the feeding process.

 

[infamuz]

Most likely the pinch rollers and the grip bar underneath are worn out and need to be replaced.
Practically the media slips on them during the feeding process.

Thanks, I had inspected them prior to this and they seem to be good condition - in the scheme of things this plotter has had an easy life, although I did notice the pressure is unevenly set on both rollers.

Surely replacement is a little extreme, no? Nothing else is out, only this 1150mm length over the entire course. When cutting horizontally, cuts are more accurate like they should be.

It cuts fine when mark detect is used on pre-printed sheets, but cut-only without mark detect is what is causing the issue (on a long length)

I am going to try adjusting that pressure on the levers, and am awaiting Mimaki replying to me too.

 

[Headstrike]

The pinch rollers must have the same exact pressure and grip on the media otherwise it doesn't feed consistent and it also starts skewing in some cases.
The bar with the grips doesn't need to be completely flat before replacement.
You lose grip way before that.

 

[infamuz]

Thanks. I just tried cutting the 1150mm length anyway again, made no difference. It's 5mm too large. That's with the media coiled out to save drag too. The pinch rollers were actually set right, I had adjusted them for a 3-pinch roller job, but it was back to using 2 high setting pinch rollers for the thinner media I'm cutting.

Is this not something the square setting would compensate for? Surely over any long feed length you'd expect a variation so compensation must come into play?

I'd just like to try other things really if they're available to my disposal before looking at the bars/pinch rollers.

I print and cut some 2.5m sheets with mark detect (and one section is a metre square), and they cut fine, within 1mm of where they should do. So some compensation is obviously passed to the machine prior to cut, after mark detect, when it spools the sheet through to check? So surely something like this would be counteracted with the Square 500mm setting or such on this machine? (or whatever it is on the CG100-SR2)

 

[Headstrike]

Normally the plotter specs say that a 0.3% error is to be considered in specs. However out of 1150mm, you should be below 3.5mm error.
Try cleaning grip and rollers with alcohol.
Also, that media doesn't have a slippery backing, does it?
If you can pull the media forward by hand without a lot of force, that means it slips.

 

[infamuz]

I have cleaned all the rollers and grip bar with IPA just before your first reply, and checked the pinch rollers again, looks like I can further increase the pressure on them so will run another test again now. Missed that the first time!

Cut is actually 1172mm that it needs to be, and was 1178mm when I weeded it out.

The media doesn't pull out easily at all on the high grip setting, it's fairly tough and doesn't feel like it's slipping.

The media is Metamark MD5 I think, with an uncoated back so should be as grippy as can be. Assume that's where you mean?

Thanks

 

[balstestrat]

I don't know but summa has length calibration to resolve this. Mimaki doesn't?

 

[infamuz]

Yeah that is what I am hoping. Just done another, high pinch settings, 1172mm (x 60mm deep) comes out at 1178mm again.

I have used the machine for years without issue, this is by far the biggest "cut only" without mark detect I've done. Like I said, I cut 1000x1000mm decals quite a lot with mark detect and they are accurate, but this just feels like it needs some override/length calibration to resolve it. I appreciate stuff wears, but from the feel of the tugging of the vinyl, it seems taught and like this is just too much uncoiling for it to get right without some sort of calibration

 

[infamuz]

Right, found a Distance Compensation setting buried on the tool settings. Giving that a go now. It plots a 1000mm sheet out and you measure some bits up and re-input it, and it recalculates. Just done it, and now re-plotting the 1172mm sticker it as we speak. Doesn't seem to have made a difference. Not sure if the inputted measurements it requested are for actual MM or .1 of a MM? It essentially plots a line and a compensated line, and asks you to input the difference. So one side (right) is 2mm longer (1002mm), left side is 3mm longer (1003mm). So I've input "2.0" / "3.0" in the compensation setting and saved. But do we think this should be "20.0" and "30.0" (0.1mm increments)? See attached PDF snapshot of what I'm looking at..

(I'm redoing the test sheet with a view to editing the measurements to "20.0" and "30.0" and seeing if that changes things)

EDIT: Changed the settings to "20.0" and "30.0", and whole thing came out about 20mm too short. So that says to me the measurement needs to be in millimetres, like one measurement. So my setting of "2.0" and "3.0" should have worked from first time round, but don't seem to have taken any effect. Retrying a 1500mm piece now and seeing how that is. Result: Right: 3mm too long, Left: 2.5mm too long. Reinput and will run again to see if decal is scaled correctly.

Result: 1175mm instead of 1172mm. So it's getting closer, but I guess this is "tolerance/allowance" which is just about there. I'll just have to suck it up and run it width ways on a wider machine for this particular decal.

 

[Ian Stewart-Koster]

Can you put a fake figure in. I mean tell it it is out by 5 and 6 mm, instead of 2 and 3 mm, and see how it compensates for that?

 

[infamuz]

Can you put a fake figure in. I mean tell it it is out by 5 and 6 mm, instead of 2 and 3 mm, and see how it compensates for that?

Yeah, nothing stopping me doing that, guess I didn't want to keep having to test time after time and not having the correct figure for where the measurement should be. When plotting stuff up to a metre ish, generally it's ok. Seems to mainly be this 1172mm piece.

Anyway I'll plot this on a wider plotter today hopefully and issue resolved, but the length compensation needs to be finetuned definitely.

 

[Ian Stewart-Koster]

I'd be guessing maybe there is gunk on the rollers, that makes them minutely oversized, hence X number of rotations, moves the vinyl a bit more than precalculated.
Can you put masking tape through, stick-side down, and feed it or pull it back and forth, to sticky any gunk out of the grit rollers?