Ok So I was testing different settings (IPM, Lead out, overlap) and have this weird angle that makes no sense.
My first thought was the torch was not square in the X axis, but it is.
It is out of square in the Y axis and I will fix that, but that part of the hole cut square.
So to maybe make this easier to understand, I cut the holes and when done if I were to put a 11/16" dowel through the hole it would be tipped in the X axis. Plumb in the Y but tipped in the X. Just like you took a drill and Drilled on a angle.
Here are some pics but its hard to see the problem.
You ca see where there is one spot where the hole is not as round.
Being all I was cutting was holes I set speed at what I wanted for the holes. I had all 6 holes cut at different speeds. slowest was 22IPM and 26 was the fastest.
So I set it at 45 amps and increased ipm by 15%. I did not see much change in dross. I think the dross your seeing in the pics is right at the lead in and out. Everywhere else there is very little dross.
I made a couple of changes. I squared the torch on the Y axis and loosened up the bearings just a bit and change consumables and that helped with the hole being more round and little bit less angle.
Will be doing some more testing. Problem seems to be right at the lead in lead out spot.
Phil I saw a sheet cam rule applying 60% slow down for 1.5" circles. I was confused if was 1.5" circumference dim. or 1.5" diameter ? We have some parts with some slots in 1/4" mild steel for 1/2" nominal fasteners and likely need to apply a sheet cam rule to that, instructions also disabled THC for smaller profile slow downs for holes to avoid torch height dropping does this make sense?
I would recommend doing at least a 60 I do 50 percent slowdown. Yes it will disable THC for that bolt hole. I do a lot of parts in 1/4 with 1/2 bolts I usually do a .6 hole in my case that is acceptable.
Yes We were going to make some test profiles. I saw some coding where the sheet cam rule can drop THC but also saw some info that Fire control will disable THC so have to play with that I guess… Ideally we want the .50 slot wide dead nuts We were spoiled getting our work done at an outside shop with laser. We are using 12mm bolts at .470 nom OD. Planning on making some profile cuts inside CCW path (for the slots) just to see what we get in some 1/4’ flat bar scrap . I thought a small master as a cut profile would be ideal, something that has bits of the geometry including outside and inside cut dimensions to check maybe all in a single path or small snips.
We saw some weird cuts where the path was programmed for overlap but seems the torch cut off at end of cut not running in the overlap. Has anyone experienced that? I guess once you generate enough G code you know what to look for before you run it?
I am getting a divit right at the end of the cut and I have not tried removing the overlap yet to see if that helps.
Jim Colt was the one that said no lead out just overlap, but that’s Hypertherm
My overlap is so small I don’t think I could tell if the torch was turning off early or not.
I am just now starting to get the hang of setting in fusion. We don’t have fast enough internet at the shop. So I have to make changes in fusion at home and bring back and try and see if I went in the right direction when making changes.
another question i also do a start from the center of a hole smaller than one inch. Have you tried to increase lead in? i always do at least twice kerf lead out.
Okay, not sure if Fusion gives you the options that sheet cam does. I have been using Auto desk Inventor for the last last 9 years, but it cannot generate G- code. so we bought Sheet cam. If folks only run Fusion you may be more limited on tool cut path speeds for small hole slow down rules etc. but not sure. we saw some similar odd ending cuts where the torch should have moved away from the ID cut then turned off and seemed to just cut off. In my machine design work in automation machines it all happens so fast its ideal to have some video running you can look back and rewind really helps in debugging for starting up.
I have my lead in right at the center of the hole. My thinking is the lead out/overlap is the problem. I am going to set up another test where I cut 6 holes and give them all different settings.
I just cut around 300 16mm holes in a 3/16 plate for a welding table and did a bunch of testing to try to get accurate holes.
I ended up at 45amps, 35 IPM with a 60% slow down(21 IPM) for the holes, .13 pierce height, .04" cut height. Start from center, no overlap, .01" lead out. This was with an Everlast 52i and PTM 60 torch.
