Feed rate Issue

[vittonej]

I loaded two cuts today, 3/16 material, and 10 ga, material , I load the post processor for each material, but when I run them they automatically start at 150 IPM, then run for about 2 to 3 inches at I50 then jump down to the set speed. could this be because the plunge speed is 150 IPM and should I change these in sheet cam, or is it something in Mach, that I am missing but it never fails something doesn't cut out because of the speed is to fast in the start.
Any Ideas would Help.
Jay

[acourtjester]

Mach changes speed when it is told to if you see speed changes it is in the G-code when you did the operations planning.
Speed in the G-code is stated with the F and a number, so in a command line that has a F and a number at the end is where each change is made.
you could run the whole G-code at one speed but there are many places where the speed changes like Z home (slower) pierce height (medium) cut height (medium) then cut speed (faster) and sometime changes for cut rule commands at a percent of cut speed.

[vittonej]

well I did some more digging with my issue, If I change the plunge rate that is the setting it cuts at in sheet cam,(the start of the cut and all the tool sets have 150 for plunge rate) so this is a sheet cam issue, maybe I don't understand plunge rate, but if I set the plunge rate to my feed rate I won't have an issue, this just don't seem right? But if it works I will do it to cut the parts I need to cut for now. And then in the G code it starts every cut with F150 then 3 lines down it slows down to feed rate speed, Mach is new to me, so not sure.

[acourtjester]

When you make changes is the tool setting in SheetCam save the new toolset with "Save toolset with" and give it a name you will remember. Then be sure you load that toolset each time you run SheetCam or load an old job to be sure you are using the setting that you found work. You could put a date in the name so you know when you made the changes. If you make changes change the date so you always use the newest toolset. Another trick is to put a funny named tool in so it is a quick way to see if the good toolset is loaded and ready to use.