Unwanted Cut to Origin

[kzsmith 0]

I've posted this in the Mac Forum but wanted to add one here as well since this problem doesn't seem limited to a particular OS.

I'm using Signcut with a USCutter Refine 721 24" cutter on a Mac G5 Quad with 10.4.x vi USB with all updated software/drivers. The hardware completes all it's tests correctly and will cut the signcut sample but when I export a graphic to Signcut from Illustrator CS2 leaving all other Signcut settings as their default a cut is made from where the graphic was completed all the way back to the origin and the cutter is left in the down possition. (I'm actually using the pen and paper for testing)  I have set both the the machine and Signcut baudrate to 4800-baud as recommended and unfortunately get the same results.  Looking through the forums it seems some have had luck with external USB/Serial Adaptors and other sign cutting software but there seems to be little consensus on what the problem actually is. 

Has anyone been able to identify what the problem actually is and it's solution?

Thanks,

Casey

[kzsmith 0]

Wanted to follow up my post in case it might help someone else. Here's what I've discovered for my setup.

1. Get unwanted cut to origin and no weeding border using the plotters internal USB to serial converter (4800baud and 9600baud) on both OSX and XP.

2. Using Prolific USB to Serial Converter with OSX yeilds the same results. ( I got a reply from Signcut web support that

    http://www.keyspan.com/products/usb/usa19hs/homepage.spml  might work better)

3. Using Prolific USB to Serial Converter with XP works even at 9600baud!  No unwanted cut to origin and a proper weeding border.

    So having a working setup is the good news... still bummed I can't get things happy with the Mac but once I get

    the feel for thigns working properly maybe I'll try the keyspan converter and see if I have better luck.

Casey

[dgreenh 9]

I was having problems with the direct USB connection to the plotter using XP.  I was getting the cut back to origin with or without the weeding border. I installed my SIIG USB to Serial Converter and hooked up to the plotter's serial port at 9600.  This set up really reduced the number of problems that I was having, but did not completely eliminate the cut back to origin issue on long cuts 5' or so.  It seems to be a random problem.  It will cut correctly one time then it will slash the vinyl the next.  The serial connection seems to work much better and I would not go back to using the USB connection.  This is not a problem with the graphics as reported in some other posts, unless SignCut is adding layers on import.  But, it has been reported that the same problem is happening with other cutting programs so I think we can mostly eliminate this being a software issue.  I have worked in the computer and graphics industry for 28 years and this sounds like a firmware, driver or communications problem.  The knife is not getting the command to lift the blade at the end of the cut.  The frustrating part is that it is an intermittent problem.  I have been doing a lot of cutting and wasted a lot of vinyl and I can't seem to put my finger on exactly what combination of events triggers the slashing.  The cutter works very good and for the price I am pleased with the performance.  If we could get this problem worked out then this would be a GREAT plotter.

[Guest fivestar]

Yes it does it with Flexi too.  Mine has something to do with the temparture.  I got mine upstairs of the wife's flower shop where there is no air conditioning.  When it is really warm up there, it does it when it's cool it does not do it.  Also I notice static alot more when it's really warm too, so it could be static which makes sense, but I got it grounded.

I cut out 3 exatly the same graphics yesterday, 2 of them in the morning and they cut fine.  1 I cut later on in the afternoon and the blade dropped returning to the home position.  They was 118 inches, I notice mine only does it on any graphic over 24 inches long.

[dgreenh 9]

I'm not thinking mine is heat related unless the fan just doesn't move enough air to keep the main board cool.  It has been in an air conditioned room all its life.  I have the cutter grounded to the stand but vinyl just seems to generate lots of static.  I guess that could be an issue.  Static causes all kinds of weird problems with computers and printers.  I haven't had any failures on cuts less than 24" that I can recall.  Seems like most of my cutting is either less than 24" or more than 4' so I can't really pinpoint a failure length.  I don't think the complexity of the job is causing the problem because I have had it fail on 4' of 3" straight text as well as long graphic designs.  But, it has also cut those same jobs with no problems. 

I think I can round up some grounding tensil that we use on high speed printers to take the static out of the paper.  It is just a grounded strand of tensil type stuff that touches the paper as it passes through and discharges the static to ground.  It should work the same on vinyl I would think.  I don't know how long it would take to decide if this helped or not but I'll give it a shot.

[Guest fivestar]

I tried a little experiment today.  I had the plotter on and put a roll of t-shirt vinyl on the holder and gave it a big pull, the static it put off sent the blade straight down, t-shirt vinyl has ALOT more static then sign vinyl that is why I tried it with that.

I never had the vinyl in the cutter, just sitting on the stand's roll holder and just gave the vinyl a big pull and the static it produced sent the blade straight down like it does after cutting with these problems and my machine is grounded straight to the breaker box ground.  I really think it may be static build up causing our problems.  I will continue to test when I get time.

[kenimes 42]

Thank you Fivestar......we have been stumped ourselves. I have got machines in for service with the issue that I cannot recreate here.....mainly because I test with paper and the pen attachment, so no static from vinyl. This has been the most frustrating issue so far, because it is hit and miss and hard to recreate here, and now I may now why.

[dgreenh 9]

Excellent diagnostic idea!  I never thought of just running the vinyl through to see if the static creates problems.  This is probably the reason the plotters seem to fail on long runs.  They build up a nice big static charge making those long runs and when it finally has enough energy to jump the gap, it discharges and causes the problem. 

I put the grounding tensil (looks simular to Christmas tensil) on this evening.  The only place I could find to mount it so it would be in constant contact with the vinyl is under the roll of vinyl and between the rollers.  Then I grounded it to the frame where the plotter ground is connected.  I really don't have any thing long to run right now to test it though.  I have some stuff coming up but it will probably be next week before I get a chance to really test it out.  I'm a bit concerned about scratching the vinyl but the stuff is very flexible so maybe it won't be a problem. 

If we can nail it down to a static problem, grounding the vinyl will be an easy fix one way or another, maybe as easy as scraping the paint off the rollers.  I haven't pulled out my meter to see what kind of resistance there is between the rollers and the frame.  I may do that tomorrow if i get a chance.

[rrc62 0]

How about grounding the roll holders.  They sit in plastic saddles, so there is no contact between them and the frame.  Grounding them should ground the roll of vinyl.  Just take a wire and loop it over the roll holder loose enough so the the roll holder still rolls freely.  Ground the wire to an earth ground.  Maybe Fivestar can test this theory since he can easily reproduce the problem.  I haven't had this issue since I strated using Flexi, which might be coincidence.

Ross

[Guest fivestar]

Great idea Ross, I will try that tomorrow and report my finding.

[rrc62 0]

Looking at my cutter today, I noticed that the rolls are painted.  You'll have to take a piece of foil tape and wrap on of them so you can get cleam metal to vinyl contact.

Ross

[dgreenh 9]

I don't know if that is actually paint or some other kind of coating on those rollers.  I tried scraping some off with a knife and it was pretty tough stuff.  It would be hard to get those rollers down to the bare metal, plus even if you did, you would have to figure out how to ground them since they sit in those plastic saddles.  If you wrap some kind of foil around the rollers you will still have to ground the foil to the frame some how so the static will have some place to go.  I do believe static is the problem though.  It shouldn't be all that hard to figure out a good, easy method to discharge the static from the vinyl to ground.

[rrc62 0]

Wrap a roller with foil and hook a grond strap loosely over the foil covered roller.

Ross