why is my Summa D60, not cutting the correct size?

[Simon Clayton]

Is it not the off set?
If you add 2% to 196.5 you get 200..
Put in 0% off set and see how you go.. but i could be wrong

Simon

[MJ Designs]

That’s the first thing I looked into but the offset is set as.45mm rather than a %age.

[Rodney Gold]

The offset is not a “size” thing , its to do with how the blade is manufactured.
I have the same thing on my soljet digital printer – on a 2.5 m plot it was out 15mm and required a scaling factor of 99.4% in one direction only , I dont think these devices are made to be precision , tho the specs quote 0.3% accuracy or 3mm for every meter plotted.

I have compensation factors that can be programmed in as constants on my lasers and CnC machines , but have to do it in corel maually or in the driver as a scaling factor.
I would work out a scaling factor based on measurement in both dmensions and apply it as a given in critical applications.

[MJ Designs]

OK, thanks for that, that’s what i’ve had to do for now.

The annoying thing is i’m sure it didn’t used to do this, as i’ve said above, i’ve never had a customer complain of this in the year or so i’ve been making the dials except for the few i’ve had in the past few weeks.

Whilst thinking about this I have had another thought also. I cut a lot of smallish stickers for car windows advertising web sites etc. I will cut them in batches of about 30+ & they’re usually about 250mm x 15mm. I will lay them out so they cut in rows of 2.
Recently the top row has been cutting really bad, i.e. the cutting isn’t accurate at all, O’s look like eggs & t’s & j’s etc. aren’t straight. All the other rows are perfect except the top row & sometimes the second row.

Could this be related?

[Rodney Gold]

Check the pinch rollers and the feed system , perhaps the rollers have gone oval or there is crapolla on the system or something else , sounds like a feed problem if the long dimension is incorrect (x axis) the Y axis doesnt rely on the feed mechanism at all so should be accurate – if both dimenstions are out , it’s different story.
Im not sure whether the Summa has closed loop feedback positioning or steppers – close loop has an optical encoder that knows exactly where the cutting head/feed is , steppers can lose steps and cannot correct as they work on a move up 2 and along 2 system and if they miss a move its never compensatred for whereas closed loop servo systems will say “where am I , and if Im not in the correct position , this is where I should be and lets go there”
Most stuff I or you do on machines like this is not critical and small innacurcacies might not be noticeable either that or your machine might have developed a problem ?

[Kevin Flowers]

Gareth
do you adjust your settings via the summa program on your computer or via the lcd panel. Either way i am sure you can reset all settings tio default it may be you have adjusted something without noticing. i’ll check my summa for accurracy tomorrow & let you know the results but i use Flexi. Also have you got a scale feature within the driver software if so is this set to 100.% etc. What blades do you use i only use blades from Edward Mathias and the offset for them is 0.48 original is what you have set. Best of luck let us know how you get on

Kev

[jon vital]

I had a similar problem with stuff at the top cutting bad. It was a problem with the bearings in the blade holder I think. This was on a Mutoh though.