Need help with cutting 22ga CR sheet

[Pete17]

Hi everyone. Hoping to gain some insight as to what I’m doing wrong. I’m getting really poor cut quality with some dross on the top but a fair bit on the bottom. I’m trying to increase the quality while decreasing the amount of time I have to spend on clean up.

Heres the details:
Fusion 360 with FireControl
Hobart i27 Plasma Cutter
Consumables look okay with about 400 pierces.
Crossfire Table w/o THC
Used the thinner spacer for torch height.
60 Gal compressor
Aftercooler
Water Separator
Desiccant air dryer
MotorGuard M60

22 ga Cold Rolled sheet
75 - 80 PSI …varies as torch starts & stops to reposition for next cut
25 amps
200ipm
Full table of water
Grounded to work piece

Thoughts anyone?

![Front|375x500](upload://rDn

ImYjQdjCXAuD1JpuTgcHNTVf.jpeg)

[TinWhisperer]

Low speed dross?

So you’re not setting it for the full 27 amps that unit’s capable about putting out ? you’re just a hair down from the top setting?

Here’s the cut chart for the book.

According to it you’re running slow looks like they want to 200 in per minute for 16 gauge.

I am assuming you’re running the higher amperage circuit to your plasma. ( So that would be the top cut chart in the picture)

[Pete17]

Thanks for the quick reply. I was basing the 25amps/200ipm on a chart I found online. I’ll up the amps to the maximum 27 but what do you think I should try for IPM?

[TinWhisperer]

I would max out your machine and I would try 250 ipm

I’d also pull apart your consumable pack and perform a thorough visual inspection for deformities. Regardless of how much time they have on them or what state you think they are in.
Myself I never leave consumables in the machine after a cut so every time I load consumables back in I perform a thorough visual inspection.

[Pete17]

Great,thanks. I’ll try that and report back.

[mechanic416]

Air is set to high 27 amps only need about 65 psi flow pressure.

[Pete17]

Okay, thanks.

[Pete17]

Looks like a test at these new settings will have to wait as something happened to my sheet metal file. All of a sudden it doesn’t recognize most of the inside rectangles when I do a post file.
Might have to start over from scratch.

[TinWhisperer]

Are you developing tool paths in Fusion 360?

And is it “discarding contours” is that the alert you’re getting?

Could you post the f3d file from Fusion 360 that’s failing you, if it is Fusion 360.

[Pete17]

Yes developing in Fusion 360 and posting to FireControl.
I’m not getting any alerts but when I try to simulate, it only cuts one or two of the 16 rectangular cut outs then the outside perimeter.
I’ll try to post the file shortly.
Be forewarned though…I’m a novice to this and this was my first attempt to design with sheet metal rules.

[Pete17]

Heres a link to the Fusion file. Download options are limited as I don’t have the paid subscription yet.

Fusion

[TinWhisperer]

this link will walk you through the F3D export process.

This can be done with the free version .

Tool path generation fail

[ls contour 2] I couldnt get that DXF file in load I altered the format and can tell there is a few layer in here. [ls contour 1] here is a piece of that corrupted file. something missing in translation. Does that DXF load on your fusion360? you could export a *.F3D, zip and share that with us. From this menu you also can export all the layer into one DXF ( this also could create a cornuted file depending on how the layers interplay) [ls contour 3] [ls contour 4] Here you can export…

the *.F3D file also contains the CAM data which I want to look over.

[Pete17]

Okay so I was able to export it but something else happened to the file thats really screwed it up. Here is the file but I don’t think its repairable.

Sheet Metal Chimney Base v10.f3d (504.2 KB)

[Pete17]

Sorry that one was in CAM, this one i=s CAD.
Sheet Metal Chimney Base v10.f3d (483.8 KB)

[TinWhisperer]

I use the first F3D you provided.

I went back to the design workspace and turn on the flat pattern and turn off the 2nd sketch.

Return to the manufacturing space and update the current tool path. I reduced the finishing overlap and reduced the lead in and lead outs and selected a few Entry Positions. Now fusion generates a tool path.

here is a new F3D

chimney cap lf pete17 v4.f3d (486.0 KB)

[Pete17]

AMAZING, thank you so much. I’ll try it out in the morning. Cheers.

[TinWhisperer]

I never produced any G-Code with the file but I think the problem you’re having is just your lead in and the finishing overlap we’re just too big.

[Pete17]

Noted… I’ll let you know how I make out.
Thanks again

[TomWS]

@Pete17

AMAZING,

Yes, that is what we call @TinWhisperer when we need a manual from him. Other times… hmmm, well, there really aren’t any other times. We ALWAYS need a manual from him!

[Pete17]

Hahahaha…