Cut quality suggestions?

[tim111]

New consumables. Running a hypertherm powermax 45 with machine torch.

Cut out of 11 gauge Mild.

Sheetcam Tool settings

kerf width .06 in
feed rate 140 ipm
pierce height .15 in
plunge rate 40 ipm
cut height .06 in


Getting similar results with lower feed rates. tried 100 ipm and 60 ipm.

Any advice would be helpful; Thank you

Attached photo looks better on the computer than in real life.

[jeepsr4ever]

First thing I see is your holes should be slowed down. You should also cut holes with THC off or with an extended THC delay (enough to finish the hole). You can process those using a different operation/layer in sheetcam. Make sure your gantry is square (If you do not have a Star-Lab from mid summer that came standard with the auto home/squaring switches installed you can buy the kit in our estore). And lastly you can use 'loop sharp corners' in sheetcam for the ultimate edge on thicker material.

[tim111]

Thank you Sir,

Ok, ran one with a path rule command in sheetcam with 30% speed, helps alittle but needs improvement. Will attempt to draw insides on separate layer and slower operation.

A few quick questions:

1. How do you apply a setting to turn off the THC?

2. What is the proper way to zero the z axis? I may be having issue understanding the floating z home.

[jeepsr4ever]

3 ways to turn off THC

1. If you have path rules for thc off (small holes)
2. Use a code snippet
3. Put in a THC delay of 5 seconds

2. Z axis is set to AUTO-ZERO. But the pierce height and initial cut height are dependent on the switch offset. On proton Z's there is no switch offset and no switch. On older models about .055 or 1.5mm works fine and depending on the model of machine you have it may be in mach 3 under settings or in sheetcam under options/machine/post processor/set custom post options.

But all that being said you cannot get a 1/4 hole in 1/4 to be perfectly round.....why? Because plasma will have a trailing edge and with a small radius there is a basic rule of 1.5 time thickness is the smallest good hole. So one more thing comes into play. In the latest sheetcam there is an option for overcut. Overcut will travel a set distance you set past the end of the geometry so in a hole keep going around the circle up to halfway (rarely do you need it past .125). This gives you a hole with no noticeable lead in or lead out.

Here is an example