Author Topic: How do you cut accurately on an A4 sheet that has been printed on?  (Read 2042 times)

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Micodabs

  • Newbie
  • Posts: 16
Hi guys, like the question says...

I am trying to inkjet print a logo or design on to a suitable paper and then feed it into my cutter ( a cheapie Liyu without laser) and cut accurately around the printed art.
I am not wanting to contour cut which leaves a small border, I want to cut the exact shape with no excess around the edge.

The problem I am having is the printer does it's thing accurately, all the time, as the uniform sized A4 sheets are picked up and processed, same result each time, afterall that's what printers do yeah?

But I have no way of feeding the printed sheet into the cutter which will allow me to lineup the blade and cut accurately around the printed art.

I have used Inkscape to design and print the work and then export to Signcut.
The A4 sheet also has bomb sights on to aid lining up but no matter how I align my starting point on the cutter I always get inconsistent results.
And believe me, this is after 2-300 attempts, I have no hair left lol

I have tried using the alignment process in Signcut and placing the centre of the blade in the dead centre of the bombsights but this too proves unreliable.
I have even tried cutting the shape first and then feeding the cut paper into the printer but again the printer prints slightly off and so I end up with the same result.

Just wondering if anyone has experienced this and found a way around it?

Been trawling Youtube and other sources and even asked Signcut, but cut the generic response to 'try the alignment process' and nothing else.

I'm stumped, and frustrated lol



Micodabs

  • Newbie
  • Posts: 16
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #1 on: November 22, 2014, 06:40:32 AM »
Forgot to say, I have also messed around with the blade offset position to no avail, I use it on zero normally.

crshirts

  • Hero Member
  • Posts: 2060
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #2 on: November 22, 2014, 05:48:30 PM »
print picture in center of paper,
cut with that same paper
remember the corner of paper is 0,0
not where the cutter puts 0,0
so offset accordingly
Graphtec ce-5000, 16x20 mighty press, Illy and Corel.

Micodabs

  • Newbie
  • Posts: 16
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #3 on: November 26, 2014, 05:13:44 AM »
Thanks for that Crshirts.
I seem to remember setting the cutter to it's default Home position and then placing my pre-printed A4 sheet on the feeder with the point of the blade spot on the bottom right hand corner (as the sheet sits in the cutter with you looking at it) and then feeding the sheet out to the front of the cutter until the top right hand corner is level with with the blade. Any slight alterations I made for this position were followed by feeding back to the original bottom r/h/c to make sure that both top and bottom of the sheet were level.
This way I figured the A4 sheet would be dead level and travel back and forth in a true manner as the cutter worked.

Even tried the other way by levelling the sheet as described above and then setting the cutter's home position manually.

Both methods still gave inaccurate results and that was with a blade offset of zero too.

I'm stumped, the only thing I can think of is a slight discrepancy between the cutter and Signcut (their support staff were pretty disinterested) but the system settings seem good and the test cut of 300cm x 300cm is spot on using digital calipers to check.

So the best I can hope for is margin of error and allow for this in my designs, which kinda defeats the object of having a digital machine to cut 'precisely' lol

I'm in the process of setting up a new desktop (which has it's own headaches with Windows 8.1 preinstalled *groan*) but once that's up and running I'm getting right back into this, I don't like giving up easily lol


bungy

  • Sr. Member
  • Posts: 268
    • Coast to Coast Embroidery
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #4 on: November 26, 2014, 09:17:29 PM »
I see you have done the manual home (origin) set. so disregard that part of the attached image.
But also consider that the printer may not be printing in exactly the same spot sheet to sheet, and if so will complicate you problem.
so you need to print some alignment mark/s to help you keep the image "square" and use these ,marks to line up sheet and not edge of paper.

don't assume it is solely a cutter issue.
I don't think you will find a perfect solution with your current setup, but you may find an acceptable workaround.
Also consider increasing bleed around image to allow for the slight discrepancies between sheets.

if that makes sense.

also, see attached for another idea that may help.
Software: CorelDraw X7 | CS5 Design Premium | Wilcom ES e3 Level3
Embroidery: HAPPY HCA-1201 | SWF UK/A-1204
Presses: DK20s 20x16 | DK7 Cap Press | Mug Press
Printers/Cutters: Roland SP300i | Roland GX-24 | Ricoh SG-3110DWn

Micodabs

  • Newbie
  • Posts: 16
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #5 on: November 27, 2014, 03:32:39 AM »
Hi Bungy, thanks.
Yeah, I've tried that.
The problem with just using one single origin dot is even though the blade is perfect on that, it doesn't guarantee the orientation of the entire sheet.

I agree with what you said about the printer not producing each sheet exactly the same as each sheet is prone to be drawn into the printer's friction feed mechanism slightly differently, you can actually see each sheet moving slightly as it starts to slide in at the start of a print.

That is why I then draw (on Inkscape) a perfect A4 sheet line and centred the image in it, sent it to the printer and then took that printed sheet to the cutter and tried using the printed A4 sheet corners to align the cutter using it's default origin.

As you say, I'm gonna have to settle with 'as close as' and the workaround is as simple as making printed internals for a design a bit smaller so they aren't cut by mistake.
An example is a black circle with a red letter inside it.
I will have to make to red letter smaller so it is not printed close to the edge of the black circle but the problem with that is once the black circle is cut, due to the variances of the cutting accuracy (not because of the cutter itself, but the nnaccuracy of the process I use) the red letter will look off-centre in the black circle.


In the end, I was trying to do this to avoid cutting and layering vinyl which is very time consuming and very difficult with weeding intricate designs.

I have successfully just printed an entire black sheet, and then sent to the cutter and cut a sheet of black circles which comes out successfully, but then I have to layer small bits of cut vinyl into the circles, which apart from bringing me back to time consuming work, leads to material differences and affects the look of the finished product.  :-[

In summary; if I print an entire A4 sheet with a sheet-wide pattern, like wallpaper lol, then cutting accuracy is not such an issue, I can cut 5 or 6 items from that sheet and each one will be slightly different, I guess that's ok if each customer wants a slightly unique item.
But if I get a customer who wants 6 identical items, then I can't print; it must ALL be cut vinyl.

That's as good as it gets lol

Micodabs

  • Newbie
  • Posts: 16
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #6 on: November 27, 2014, 03:37:24 AM »
I forgot to mention.

Regardless of where or how I set the blade origin to, when the cutter is instructed to commence, the blade moves over and feeds the sheet a bit to the point where it sets down onto the sheet.
This is what is causing me problems.
If the blade just set down onto the sheet at the origin point to begin cutting there, then I would be satisfied but I can't stop it doing that.
I have tried measuring how far over and down it goes and then printing an origin point and a 'set down' point too.
Still inccurate :o

Micodabs

  • Newbie
  • Posts: 16
Re: How do you cut accurately on an A4 sheet that has been printed on?
« Reply #7 on: November 27, 2014, 08:54:24 AM »
Ok, update and conclusion.
Firstly, my issue with the blade moving away from the origin point before dropping to start cutting was my own forgetfulness; I sorted this a few weeks back but haven't vut since then lol
I simply removed the weeding frame option in Signcut and the blade drops exactly at the origin point to begin cutting WHEN I USE AN A4 FRAME in the design.

Mainly however, I will have to put up with the slight deviation of the blade from the intended, printed outline, as previously said by Us, the printer will not perform consistently enough in its feeding of sheets and inking, unlike the cutter which will perform identically, time after time.
In addition to this, for anyone who may be struggling with similar issues; if you have a HP printer, their designers are stupid.
They have the option change paper sizes from US Letter to A4, but no matter how often you save A4 settings in user defined preferences, the poxy printer ALWAYS defaults to US Letter even in the settings you saved earlier.
I have googled this and numerours suers of all HP printer/scanners around the world have had the same problem.
HP ignore it, so they lost my business, I will be going back to Epson and some other manufactuer in the future.
That one issues alone cost me several head banging days in my little studio, even the poor dog clears the room now when I approach the printer lol

Anway; hope this covers and clears up anything for current/future searchers.

If you want to save on vinyl labour-time and print on media instead, then offer it to the cutter to cut perfectly around the printed design, be prepared to compromise accuracy and consistency in order to alleviate labour.

Clever/dumb balance and all that.

Over and out (and back to weeding with magnifying glass).
 :thumbsup: