Need Help Gerber plotter issues - cutting too large

is the file been sent to cut the right size?

 

not sure i remember how to do this.
what software are you in?
what com port?

lets send a 3" square to the plotter
x3d
y3d
x-3d
y-3d
<enter>

see if the x axis is actually 3"

 

Is there any scaling or forced length happening in the Omega Plot software? Not in Composer but in the file output window that pops up. Settings are under layout>layout

 

tattosleeve is right.
it has to be a scaling issue
we use flexi these days & i forget how things work in gerber software

 

Not necessarily, I just thought that might be an area to check and make sure the settings hadn't accidentally gotten changed in there. Personally I wouldn't mess around with scaling in that window for sizing jobs. To me it was someplace to check because it could easily get overlooked if they were wrong. Might be worth trying to force to 17.675w and see what happens though. Might bring it back to the proper 18" to at least get this job sorted out in the short term. Might have to troubleshoot the exact forced length amount because your stretch might not be the full .375 from the smaller start length.

Our Summa was cutting long for a while and it was a problem with the calibration settings on the plotter but you mentioned you already looked into those so I wouldn't know where else to look.

 

I have been using a Gerber sprocket feed plotter for the last 20+ years fairly trouble free, however over the past few years I have noticed the same problem that you are experiencing. After much tearing what’s left of my hair out I believe that I have finally figured the problem out. The problem is not with your plotter. The problem lies in the spacing on the holes punched in the media your feeding though it. I have found that some rolls of mainly 3M material, inexplicably have the holes punched with a slight difference in spacing when compared to other rolls (others as well as other rolls of 3M) I’ve always believed this to be a standard followed by all manufacturers however if you lay one sheet of product on top of another you may find (as I have) this not to be true. Could be a Quality control issue...don’t know. I have found that when comparing one manufacturer to another that the hole can easily be off by 1/2” in 4’ off material meaning that as it is being pulled through the plotter by sprockets it will automatically self lengthen or shorten as it feeds. Might sound crazy but check it out sometime for yourself. Makes registration among different colors a Pain in the A#%.

 

i am not sure that's possible.
are your sprocket holes torn or distorted on the vinyl, after advancing?
the whole point of sprocket feed is accuracy and repeatability

 

I’m saying new material right off the roll PRIOR to being fed into the plotter, laid on top of a competitors product. Try comparing a few rolls of 3M or more specifically Gerber hp220 to Arlon or Oracal. I’ve found HP220 to be very inconsistently punched.

 

Just got the worst roll of specialties material 15 in punched HTV left side fine right side was bad - how can quality control not see it ? Hanging dots and miss punches everywhere- got to check if vendor punched or supplier punched either way the machine needs help