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Hesitations and Small Wobbles
« on: March 23, 2017, 03:39:21 PM »
Hello!

We have done extensive research and spoken with several people regarding the issues we're having.  We are now hoping to speak with someone from mach3 to try and figure this out :)

I'll try to provide as much information as possible, but please do not hesitate to ask for more if necessary.

We are currently working with CorelDraw X8 - Sheetcam TNG - Mach3.  We're using a 4 x 4 Spidercut CNC plasma table with Hypertherm Powermax 45 with machine torch.  CorelDraw and Sheetcam are run on a PC with Windows 10 and Mach3 is run on a pc w/o any internet connection with Windows XP.  For the past several months, we've corrected issues with corel and minor mechanical issues with the table.  We've narrowed our issues down to Sheetcam and Mach3.  We are using SVG format for all of our files and they import well into Sheetcam, though we're finding that many nodes are added to all imported drawings.  I've spoken with Sheetcam support and made adjustments to settings to give me the cleanest lines.  All is well and g code is created.  It looks good once loaded into Mach3.  We've attached a pen to the torch due to all of the issues we're having, so just drawing instead of burning for now.  We set everything up and it starts out drawing fairly clean lines, but each drawing ends up with min 2 - 6 small areas of wobbles or wavy lines and the torch head seems to hesitate at those areas for a fraction of a second - almost like its unsure of where it wants to go.  There is absolutely no indication of this in Corel or Sheetcam.  From further advice, we've unchecked all of the boxes under CV Control and set LookAhead to 200.  There were slight improvements once we did this, but the wobbles and hesitations are still present in random areas of the drawings.  Our selected post processor in Sheetcam is currently Mach3 Plasma - our THC has yet to installed on the table.

We've read a fair amount about decoding the gcode - the current file we're working with is a simple letter "R" and we gone through the gcode line by line to see if there's anything obvious that stands out.  For inexperienced users like us, we can't see anything.  I'll attach the gcode to see if someone is able to see any issues with it?

As I mentioned, please let me know if there is any other information you need from me.  Any advice or help would be much appreciated!

Jodi

Offline Tweakie.CNC

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Re: Hesitations and Small Wobbles
« Reply #1 on: March 24, 2017, 03:41:13 AM »
Hi Jodi,

Your Gcode runs just fine here so it could be that your Mach3 settings are causing an issue.

Could you post your .xml file - the one from your Mach3 folder named <your profile>.xml then your settings can be checked. Copy and rename the file Jodi1.xml before posting.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Hesitations and Small Wobbles
« Reply #2 on: March 24, 2017, 10:07:00 AM »
Good morning Tweakie,

Thank you for taking the time.  I've been looking through all of my Mach3 files and am having a hard time finding the profile for our plasma settings.  I've been able to locate .xml files and profiles for Mach3 Mill and Mach3 Turn, but nothing for plasma.  I've taken a screenshot of the Mach3 files in my computer - maybe you can shed some light?  My apologies for my lack of technical experience.

Thanks again,
Jodi

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Re: Hesitations and Small Wobbles
« Reply #3 on: March 24, 2017, 10:56:36 AM »
Hi Jodi,

Bottom right of your main Mach3 screen is the Profile: that you are using.

Look for that name.xml in your Mach3 folder.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Hesitations and Small Wobbles
« Reply #4 on: March 24, 2017, 12:04:51 PM »
Hello again!

Found it...thanks for the help.

Hope you can see something we're missing :)

Jodi

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Re: Hesitations and Small Wobbles
« Reply #5 on: March 25, 2017, 02:41:44 AM »
Hi Jodi,

In Config. / General Config. I recommend that you change your Look Ahead to 200. In addition you may need to experiment (to get the optimum performance) of your CV Control settings - This document will give you more details on this http://www.machsupport.com/forum/index.php?action=dlattach;topic=7923.0;attach=6168

Hope this helps.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Hesitations and Small Wobbles
« Reply #6 on: March 27, 2017, 09:32:52 AM »
Good morning Tweakie,

Thanks very much for taking the time to check out our plasma profile and for the link.  We've been experimenting a fair amount more this weekend and feel like we're onto something.  We've continued playing with the drawing import settings in Sheetcam and are starting to see some improvement, but still not where we need to be.  I'm not sure if when you looked at our plasma profile, you were able to see our motor tuning settings?  We have yet to change them - they are what the company we purchased our table from told us to enter.  Could the steps, velocity, acceleration and other settings be potential issues?  Can you offer us any advice on where to start making adjustments to these settings?

Thank you!
Jodi

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Re: Hesitations and Small Wobbles
« Reply #7 on: March 27, 2017, 10:26:33 AM »
Hi Jodi,

You can check that you have the steps per unit set correctly for each axis by using the Axis Calibration feature on the Settings (Alt-6) screen.

Velocity and Acceleration are pretty much a trial and error thing - increasing Velocity in steps until the axis movement is unreliable then reducing the setting by 30% then setting the Acceleration figure to 10% of the Velocity figure. From that point fine tuning to obtain optimum performance.

Tweakie.

Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Hesitations and Small Wobbles
« Reply #8 on: March 28, 2017, 10:58:59 AM »
Good morning Tweakie,

Thanks again for the info.  This has been a very frustrating few months trying to get it right.  We spent all day in the shop again yesterday playing with the velocity and acceleration as well as some more sheetcam settings.  We read through the online mach 3 installation and configuration manual and are still no further ahead.  I'm going to start one more thread as kind of a last ditch effort to see if anyone can see something we're not.  I'll post screenshots and pics to show where we're at.

Thanks again Tweakie :)
Jodi