Torch diving in to table

[Fastyankee13]

I was just trying to cut a piece of 3/8 thick steel and the torch would start burning for about an inch than dives in to the material. I ended up cutting the piece by hand out of frustration.

AJ
www.outlawchutes.com

 

[Dnmeistr-LECS]

Take a look at this video that explains Arc Voltage: http://torchmate.com/university/tmu-3-avhc

 

[Fastyankee13]

Dnmeistr,,
I had all that set and I have been using this machine for about two years with AVHC with Ohmic sensing. Every once in a while it will dive in to the metal repeatedly and I re-check all my settings and they are set right on. The repeatability on these machines is very poor from my experience. I solve one problem run a few jobs than it starts doing weird stuff. Very frustrating when your trying to run money jobs.
Thanks
AJ
www.outlawchutes.com

 

[Dnmeistr-LECS]

Doesn't matter if Sample Voltage is on if you are cutting at to slow of a speed and the plasma is searching for metal it will dive into the material as the arc stretches and Current Voltage increases. Voltage, Amperage and Speed are 3 points of a triangle if one changes it affects the other. If you are not using Sample Voltage and you are adjusting Set Voltage yourself then the torch diving into the metal is a result of the value set to low, raise the Set Voltage. A good way to determine Voltage after determining the best speed is to change your Distance to Corner to 8.0 under Machine Settings. Cut a small coupon in Auto mode to observe what the Current Voltage is reading, this will lockout the height control for 8 inches and not adjust for voltage during that delay. Once you see what the Voltage reads, change your distance to corner and adjust your Set Voltage.

 

[Fastyankee13]

I usually set the settings from the chart supplied by Hypetherm . But like you said the best thing to do is make some sample cuts on the material thickness I most commonly use and keep notes on the best speed and voltage from those test. So would you do a line speed test with sample voltage on for each material thicknesses.
Thinking about it now the book had a very slow speed listed for 3/8th's steel. It might of been to slow I was also using the shape file for the this cut I was having trouble with.

Thanks
AJ
www.outlawchutes.com

 

[Dnmeistr-LECS]

Line speed test is done in manual mode, you want the height to be a constant not a variable as it is adjusting for voltage. Once you have determined the best speed then run the voltage test, this has to be run in Auto mode but you also need to adjust your Distance to Corner to 8 or at lest longer than the line you are cutting. Reason being is VMD will not display voltage in Manual mode will only display voltage in Auto mode but again we want the height to be a constant. So if you set your height to be .08, while it is cutting at that distance off of the material it will display the voltage at that distance, and changing your set voltage to that value the torch will try to remain at that distance when cutting in Auto mode and the Lockout light is off.

 

[Fastyankee13]

D,
I will try and do that hopefully I can get that figured out. Is there a vid of this process out there.

 

[Fastyankee13]

Just seen the link you sent me earlier!
Thanks

 

[No Class]

The video is excellent but it doesn't mention the dampening or gain settings and what each does. These are new settings to me compared to my blue screen avhc system.