Feed rate as it relates to material thickness and Plasma Cutter current setting

Hello,
I’m a new user. First time posting and new to cutting tables and cad/cam.
I purchased a Crossfire with XL with Z-axis. I’m using Inkscape and sheetcam. I’ve been learning sheetcam via the sheetcam tutorials. During tool set up in Sheetcam I noticed feed rate is preselected (75 ipm).
My question is does anyone have a rule of thumb for determining feed rate based on material thickness and Plasma Cutter output current? Or is it trial and error?
As I sit here writing this it just occurred to me that I haven’t tried using a different material thickness to see if that changes the feed rate setting in setup.
In any case, the feed rate should still corelate to the output current of the plasma cutter (20a, 30a, 40a). If the material is thick (within specs) and the current is set to 20 amp then a faster feed rate won’t allow the machine enough time to cut through. Any input would be greatly appreciated. Thank you.

Fernando

What plasma cutter are you using, most will have suggested set points for what material and thickness you are cutting. These are just start settings might have to tweak settings.
Make sure you have ample air supply to machine and that air is dry and clean…

Best bet is to use your plasma cutter’s cutting current and speed chart as a starting point, and tweak if necessary. For instance, the chart data provided with my CUT60 is pretty much spot on. Which plasma cutter are you using?

Welcome to the forum!

You have the right understanding of the relationship between current & speed. Material thickness is a factor as is material type (mild steel, aluminum, stainless steel).

As the others have mentioned your Plasma Cutter manual will give you starting values for current and speed for different materials & thicknesses.

In Sheetcam, you want to create cutting ‘tools’ that relate to the same factors (material & thickness), so, for example, you might have a tool called 14ga cold rolled steel and another one for 11ga. Each of these tools can be saved so after you set them up, every time you have a job with 11ga steel, for instance, you would simply select that tool for the operation and it would have the correct values. Over time you might tweak these based on your results, but, if you save the ‘tweak’, then you’ll build a good ‘toolbox’ to use.

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I’m using a Thermal Dynamics Cutmaster 40. The user’s manual doesn’t have any charts or specs on suggested settings. I was able to download a copy of the OEM service manual so I’ll review that today. Thanks for your input!

Hello Cletus,
Thanks for the suggestion. Unfortunately the user’s manual is lacking in specs. If the service manual that I downloaded doesn’t have those specs I’ll try try using the specs from a comparable plasma cutter.

Hello TomWS,
I appreciate the advice on Sheetcam. All the tips should make it easier to get familiar with the entire process.

You should have the SL60 torch on that plasma cutter. So there is cutting tips in 20, 30 and 40 amp to do your cutting from very thin the about 1/2" mild steel.

Use the Primeweld cut 60 chart that should get you in the ball park for settings.

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Hello Mechanic416,

I just received my tip order with all the tips you mentioned. I’ll look up the chart for the Primeweld Cut 60 to get me started as none of the manuals (owner’s or service) that are available for the Cutmaster 40 have any recommended settings. Thank you for your time and suggestion. Much appreciated!

Here is the Cut 60 Chart hope it helps
CUT60_user_manual Page 30.pdf (402.9 KB)

Hello T00LONGATIT,

Thanks for the chart! I thing I’m ready to start cutting!