Tormach Plasma CNC Settings and Capabilities

I (DocWomp) took a day to assess the CNC plasma and below is my take. All tests were conducted on 20GA mild steel sheet with Fine Cut consumables, 32A and 1401PM feed (slightly modified from book values). Details and pictures for each of these tests are in the comments, but here's the TL;DR:

• Good repeatability. Reliable torch ignition. Accurate positioning. Responsive controller.
• Outside features look pretty great. Even the 0.25" saw tooth came out half descent with sharp outside corners Long thin features (12" x 0.1") are possible if considerations are met
• Hole work is a mixed bag. The larger the rounder with a considerable drop in quality under 0.25" Best to spot with a Pierce and drill them manually.
• Inside corners are just awful. The machine hard stops, creating a wave along the receiving line and blowing out the inside corners leaving a rectangle looking like a dog bone. Recommend min 0.05" inside fillets (more on future mitigation strategy plans below).
• No active Torch Height Control. Right now long cuts in thin sheet will wrap the material and the torch will scrape into it. There's simply no avoiding this atm. Might be able to figure something out in the future. The probe does a good job for large collections of small features.

Recommendations:

• All inside cutouts min 0.25" or larger
• Min inside corner radii 0.05"
• Min spacing between outside contours 0.5"
• Z zero at ~1" if thin material might wrap
• Min material thickness >0.15" between inside contours
• Min 0.1" thin features if long lead in and no sharp inside corners
• Min 0.15" lead in arc radius
• Loop outside corners with min 0.15" arc radius

Holes

Repeating hole work looks okay. The plate with 0.25" holes fell apart. Most likely because of over cutting and my not leaving enough material between features. The sliced circles are my fault too. Shape/size distortion visible. Position relatively okay. Reliable torch ignition.

Outside Cuts

Outside contours look pretty great. Minor points taken off for the blowout in sharp inside corners on the saw tooth. Minimal waveyness, because of the looped toolpath that cuts out and back to get sharp outside corners.

Thin Features

Thin features look surprisingly good. That tiny guy on top is only 0.1" across. SheetCAM does a good job with offsetting a predictable kerf during long constant velocity cuts. Not much over cutting. Sharp inside corners blown out, but that's another test.

Inside Corners

Inside corners are a mess. On bottom, sharp corners. On top progressively larger fillets from 0.025" to 0.125". Might have more luck if I can get the Fusion post to work. Specifically a feature that slows down when approaching corners or automatically adding in image corner radii.

Small Holes

Progressively smaller holes are kind of a mess. I think this started at 0.25" and dropped one thou per hole. They all look pretty bad, so I'm just going to use a different process or oversize holes that aren't location critical.