New cutter with problem

[Heavy D 1]

I've got a new us cutter mh-871 and it is cutting zigzag lines like stairsteps when it cuts diagonal, is this normal?  Please someone from us cutter staff help me.

[Guest manwayvan]

Good luck with that request..This has been covered in the past I believe but I don't remember the outcome..You may try searching the forum but a few things come to mind..Blade not rotating in holder easily(a little oil will help). Rollers maybe slipping the vinyl instead of smoothly feeding..Does it do it on the test cut as well

[BannerJohn 1,324]

most of the people who posted this problem ended up getting a new cutter or an upgrade to a more expensive one. General consensus was it is a defect in the cutter. Not all of them do this..mine doesn't.

Submit a ticket Monday...you might have to wait awhile...I have been told that USC receives about 200 support tickets a day...in addition to 100 phone calls. Even with a staff of 6 or so, I can imagine it's hard to keep up.

Meanwhile, try slowing the cutting speed down a bit...it might help.

[rrc1962 0]

How pronounced is the stair step?  My Refine does this to a degree on straight diagonal lines, but the steps are so small that you can't see it unless you look with a magnifying glass.  Probably has something to do with resolution.  I can change the resolution in Flexi, but haven't because it's not what I would call an issue and higher resolution consumes far more memory.  Maybe I'll fiddle with that sometime.  Funny thing is that it cuts a curved live smooth as silk.  I only notice it on text with straight diagonal lines like arial italic.

[Dakotagrafx 7,297]

read this for help

http://forum.uscutter.com/index.php/topic,22822.0.html

[rrc1962 0]

read this for help

http://forum.uscutter.com/index.php/topic,22822.0.html

I read through all 27 pages of this post and everyone having the problem has on thing in common.  They are all using Sign Blazer.  I can tell with 99.999% certainty that it is not electrical or some sort of interference.  Those problems are never consistent and reproducible.

These are stepper driven machines.  A stepper motor moves in...steps.  Each step is equal to some very small distance which depends on system settings.  A stepper motor system will never cut a perfectly smooth diagonal because minimum motor movement is limited to one step or in most cases 1.8 degrees shaft rotation.  This means that to create a 45 degree diagonal, the the X moves one step, y moves one step, x moves one step, etc...over and over very quickly which makes the cutter move at a 45 degree angle.  The amount of linear movement per step is called step resolution and depends on how the motor is connected to the final drive and what reduction ratio is used.  If the step resolution is .001 that means that for each motor step the axis moves .001.  Changing reduction ratios can increase or reduce that.

If the X and Y are timed perfectly then the motors move in unison creating a smooth line.  If the motors are out of time then you see stair steps.  Other than very high end stepper systems, you won't find many instances of perfectly timed motors.  Just the difference in cable length from the drive to the motor is enough to throw the motors out of time.  In higher end machines they use servos because servos are capable of any degree of movement defined by the encoder resolution. 

Another factor is pixel or point resolution.  At 300DPI an image has nice smooth edges.  At 30DPI you see stair steps.  I think this is where the resolution setting in Flexi comes into play.  A printer with a very low resolution will print stair steps in the same way that a plotter set at a low resolution will.  The drawback to higher resolutions is that it consumes more memory as more data is being transmitted for the same given area. 

In conclusion, if SBE is only capable of sending data to the cutter in one fixed (low) resolution, I would say that's the problem.  I guess the only consolation one can offer is that it is free.

[Heavy D 1]

Nope I am using Flexi 8.1.  I really want someone who works for US Cutter to respond to this post.

[rrc1962 0]

Nope I am using Flexi 8.1.  I really want someone who works for US Cutter to respond to this post.

How bad is the stair stepping?  Is it like the problem outlined in the above link?  Have you checked the resolution setting in Flexi?  I use FlexiPro 7.6 and my resolution is set to over 1000....1096 or something like that.  I also have the MH781 on WinXP with a serial connection.

[Dakotagrafx 7,297]

Did you really read all 27 pages? - Mader took the machine to his mothers house 80 miles away and it cut fine - with signblazer

[rrc1962 0]

Did you really read all 27 pages? - Mader took the machine to his mothers house 80 miles away and it cut fine - with signblazer

I don't buy it.  Electrical noise and RF issues are not consistent and repeatable.  It has to be either software telling the cutter to cut like that or a defect in the cutter.  This issue could just be normal operation.  Like I said, my MH781 shows a slightly rough edge on arial text, but it's not noticeable to the naked eye.

Maybe he'll post a photo of the jagged cut.

[Dakotagrafx 7,297]

But when he (MADER) Upgraded to the copam the problems went away - the copam is better shielded.  If you read he also tried another members cutter that worked great for them before and after he borrowed it but it did the same thing at his house.  This has been a known problem with a lot of the 871's - was not a problem with the prior model or the p-cuts.  Personally I believe it is a problem with RF interference and poor shielding or filtering.  I am not an expert as I only had 2 years of electronics training.

[rrc1962 0]

But when he (MADER) Upgraded to the copam the problems went away - the copam is better shielded.  If you read he also tried another members cutter that worked great for them before and after he borrowed it but it did the same thing at his house.  This has been a known problem with a lot of the 871's - was not a problem with the prior model or the p-cuts.  Personally I believe it is a problem with RF interference and poor shielding or filtering.  I am not an expert as I only had 2 years of electronics training.

A defect in the cutter I believe, but consistent and repeatable problems caused by "noise" just don't happen.  For that to happen and produce the results he saw, whatever noise was present would have had to been very stable and that's not what noise is.  He had his line voltage tested and it tested good.  If the issue were coming from line voltage, we would be seeing more of these problems.  He also said that he tried it at his neighbors house with the same results, which would point toward line voltage and eliminate any localized RF noise issues...Unless his neighbor had the same exact stable RF noise present, which is unlikely.  I design stepper and servo motion control systems for a living so I deal with noise issues daily.  I've never, in 12 years of doing this, been able to duplicate a problem caused by noise.  If I am able to duplicate it, that tells me that is a software or hardware issue.

I don't recall if he was still using SBE with the Copam.  I'm not a fan of SBE. 

I still say it's a resolution issue.  I'm going to play with my resolution settings and see if I can duplicate the problem.  eSpeed was also mentioned in that thread.  The poster said that he was able to duplicate the problem by changing that.

[Guest manwayvan]

I think maders problem ended up being issues with the wiring in the home or came from issues with the main power line coming in..Possibly not a true 60hz RMS wave coming through..Umm dirty power. But if the test cut cuts fine this should eliminate the issue with software, also is it 100% repeatable each cut? This would eliminate the vinyl pulling and not feeding smoothly

[Dakotagrafx 7,297]

There has been a lot of post about the problems with the 871 in many areas of the country - it is not isolated to this one.  many times the people have ended up buying more expensive cutters to solve this problem.  If I remember correctly mader even tried running it thru a battery back up device that should have filtered the incoming wave.  It could be a simple as some RF that is causing an oscillation in the control components. . .we will never know unless we could duplicate it and continue to trace it until a cure was found.  Most people are not going go thru all that, they just buy a devise and expect it to cut as it should.  These are low end starter cutters and as such have their problems.  with the old designs the cutters got people interested enough that many bought more expensive cutters down the road.  with a frustrated customer that is not going to happen

[rrc1962 0]

I still say it's a resolution issue.  I think everyone has a different idea of what is acceptable as far as the jagged edge.  My 871 is doing it to a degree.  It's hardly noticeable and only really shows up at all at angles between 6 and 10 degrees off horizontal or vertical on perfectly straight lines.  I'm OK with it considering the cost of the cutter.  If this were a $4000 Graphtec, it would not be acceptable. 

The refines step resolution is 1016 steps per inch.  That's pretty low.  Our small router is 12,000 steps per inch and our big plasma table is 4000 steps per inch.  Does anyone know the step resolution of the Copam?  If I set up a Copam driver in Flexi, it defaults to 1016, same as the Refine.  I wonder if the Copam firmware incorporates some sort of smoothing algorithm.  For the price difference there must be some substantial differences.  Both a stepper driven.

I wonder if it's an engineered issue to convince the customer that they need a better machine.

[Dakotagrafx 7,297]

The old refines (mh series) does not have a problem and the p-cut's don't have this problem - just the newer machines

[lueman 19]

I have the LP24 and was in on the original posts. I've been a technician for about 25-30 years and I  offered several suggestions including creating a simple Faraday shield and cleaning and oiling the blades. Since then in the last year I have found that problem on my machine. In my case it occurred under two different circumstances first in one case I was not using a dedicated line in both the computer and the plotter this caused a zig-zag pattern, Second it happened when my blade was out too far on some older vinyl - the dry vinyl caused the blade to drag across creating a Morse code like pattern (dots + dashes) . since then I added a UPS to the PC and I connected the plotter to a clean (dedicated)ac source. I still use the crappy vinyl, but just to test the art work & for give-away samples.

[rrc1962 0]

The problem appears to go away at cutting speeds above 36IPS and there appears to be no other difference in the cut than at slower speeds.

[rrc1962 0]

I also noticed that some text cuts fine while others will exhibit this issue.  The letter "I" in Arial italicized at a 10 degree angle will show a slight amount of stair stepping.  Deco Roman, which is a sort of artsy font, at the same angle draws perfectly straight...every time.

[Heavy D 1]

Is anyone from this shitty company going to respond to this post?

[MZ SKEETER 4,709]

if you want (need) tech support put in a ticket..., this is a forum,  not tech support.  they show up  here, when they want to.  

http://support.uscutter.com/index.php?_m=tickets&_a=submit

[Heavy D 1]

Thanks speedoggy but with all due respect I did put a ticket in TWICE and was told to come here and post my problem.

[MZ SKEETER 4,709]

WOW...  that is unreal   ;D sorry to hear that...

[Guest HowardI]

The answer is that the MH series cutter has a direct drive motor configuration. 

As noted in the early post by rrc1962: Stepper motors move in steps.

Most of the other machines have a gear down mechanism on the motors and have a much finer step size.

The one that Mader experienced was an extreme case and was definitely not the normal MH stepping.  His issue was definitely environmental.

Nobody has figured this one out yet, I doubt anyone ever will as he has upgraded to a better machine.

If the "jagged cuts" on straight angled lines is unacceptible to you then you need to upgrade.

PM me with your ticket numbers so I can look into those for you.

Howard Irwin

Support Specialist

US Cutter

425-481-3555

888-298-8143

  - Option 2

[Dakotagrafx 7,297]

The answer is that the MH series cutter has a direct drive motor configuration. 

As noted in the early post by rrc1962: Stepper motors move in steps.

Most of the other machines have a gear down mechanism on the motors and have a much finer step size.

The one that Mader experienced was an extreme case and was definitely not the normal MH stepping.  His issue was definitely environmental.

Nobody has figured this one out yet, I doubt anyone ever will as he has upgraded to a better machine.

If the "jagged cuts" on straight angled lines is unacceptible to you then you need to upgrade.

PM me with your ticket numbers so I can look into those for you.

Howard Irwin

Support Specialist

US Cutter

425-481-3555

888-298-8143

  - Option 2

no offense Howard but that is a heck of a sales pitch for the refine series.  The refine I had didn't do that.