Need help identifying the cause of this cut quality

[Schultzy18]

I have tested a lot of different variables but cannot find the root cause of why these cuts come out so poor. I exported an svg in Inkscape to a dxf R12 to open in myplasmcnc that is paired with our plasma table. On MyPlasm the lines look perfectly straight as well as in inkscape but when the cut is finished I get some waves in sections that should be perfectly straight. Working with a hypertherm powermax 85. Cutting on 14ga with recommend settings from Hypertherm Cut Guide Book. Using a 30-45A fine cut consumable with little use. Running 40A, 0.14in cut/pierce height, 0.3s pierce delay, 90 cut speed and 93V. Any ideas appreciated! TIA(Pictures shown below)

[sonbakler]

It looks to me like something loose on your machine. With your system powered up your motors will likely be locked up and holding the gantry still. Put your hand on the gantry and gently try moving it back and forth and feel for any slop. Do the same on the x axis carrier And i bet you will find some slip somewhere that can be fixed.

[Schultzy18]

It looks to me like something loose on your machine. With your system powered up your motors will likely be locked up and holding the gantry still. Put your hand on the gantry and gently try moving it back and forth and feel for any slop. Do the same on the x axis carrier And i bet you will find some slip somewhere that can be fixed.

Thanks, I will definitely take a look at that tomorrow. Running on a STV CNC Sparx 4800x, do you have any recommendations of where to look?

[adbuch]

Please post the svg file that is giving you these wavy cuts so we can take a look to make sure that it isn't a software problem.
Thanks,
David

[Schultzy18]

Please post the svg file that is giving you these wavy cuts so we can take a look to make sure that it isn't a software problem.
Thanks,
David

[adbuch]

Please post the svg file that is giving you these wavy cuts so we can take a look to make sure that it isn't a software problem.
Thanks,
David

I see nothing in your file that would cause those wavy problems. I expect you have mechanical issues with your table - loose pulleys, belts, worn bearings, etc.

David

[adbuch]

It looks to me like something loose on your machine. With your system powered up your motors will likely be locked up and holding the gantry still. Put your hand on the gantry and gently try moving it back and forth and feel for any slop. Do the same on the x axis carrier And i bet you will find some slip somewhere that can be fixed.

[TJS]

I have not looked at the SVG yet. I have found the less nodes without changing the profile of anything the better. Also to the OP can you just use the SVG into your program. I know that CandCNC recommends using SVG's into sheetcam for Command CNC vs DXF's.

[adbuch]

TJ - I have heard that myplasm can do some wonky things if the file isn't correct. I took a look with Inkcape and did a cut path preview with Design Edge. This file would cut fine for me.
David

[Dirtmotor]

Might also check your torch mount and Z axis for loose screws as well as gear or pully on your motors .

[adbuch]

Might also check your torch mount and Z axis for loose screws as well as gear or pully on your motors .

[Schultzy18]

Just want to say thank you to everyone who offered advice. Looks as if I had a few gears running loose on the rails. Quick little readjustment and retightening did the trick.