Floating Head Post Code

[beefy]

OZ has spoken!

Acourtjester,

someone seems to be going in the huff, I never expected you to be such a dick.

Members like yourself are the reason I decided to PM the OP to share my hard earned knowledge. I've suggested about this gcode learning quite a few times before and it always falls on deaf ears.

All I'm doing is giving a bit of a push for plasma cutting guys to learn a bit more for THEIR benefit. Assholes like yourself, who get all sulky and respond like that, ensure members with some decent info to give will not bother with this forum. Thanks for the reminder not to waste my time any more.

I did have a doubt when I decided to PM the OP, now you've just made me realise I made the right choice.

[AndrewMawson]

The problem is, those pearls of wisdom only go to the one individual, rather than the wider audience

[beefy]

The problem is, those pearls of wisdom only go to the one individual, rather than the wider audience

Hi Andrew,

I'll assume that comment is meant for me, seeing as it came after my last post, and appears directly related to what I said.

All that does is reinforce my intent to keep to myself. What I see as the real problem is the wrong person gets the crap. A guy tries to help with the "give a man a fishing rod instead of a fish" thing, so that he will be able to help himself now and down the track.

No one seems interested, as has always been the case with this gcode learning suggestion. Next the likes of acourtjester attack with that crap. Does anything get said to him, no. But of course the one who's been attacked then gets a complaint because he PMed the OP, double whammy.

If that's the way it works I'm happy to be the bad one.

[acourtjester]

I must say you are way off base with your interpretation of my post. I have always approached the post I have made in a positive manor, and add hope, humor and the use of emojis to lighten the mood. I have never called a poster out and was taken back when you started here. I never portray myself as the one with all the answers, or the only answer. After 2300 posts if I was a "dick" I think I would have heard about it before now. We all have different ways of looking at things and I have stated that. Learning is very important but the OP was having a problem and I did not think now was the time to tell him learn something new if he wants he can do that later. Not all of us want or need to learn everything knowing how to snoop around in G-code is important. But SheetCam does a great job of doing it for you as long as you feed it good info, part of that is the correct post processor. To help other learn I have posted screen shots so they could see what I was talking about, done searches to find thing for other. I know is not something that will be on my tombstone

[AndrewMawson]

I suppose I've used G code for so long on so many different machines, it seems slightly strange that anyone with a CNC machine wouldn't have a reasonable familiarity with it, and also want to learn the details. OK it's not essential, but hey I'm here because I enjoy it !!!!

I come from an era when you hand toggled the stuff into the control standing up on the workshop floor, and only later did I have the luxury of writing G code into a file and down loading it vie RS232 remotely. When CAM came along and a CAD file could be converted directly, you still needed your wits about you to check that the post processor generated reasonable and workable code, and if not, how to modify the post processor.

It must be said though that in general, machine generated code tends to be far less efficient than that written by a machine coder who was brought up when memory was small and expensive.

[tcaudle]

look at the G28.1 command. N0100 G28.1 Z1.18 F19.685
the Z value in the G28.1 defines the "starting point" for the touchoff. Normally it rapids to that point and then slows to the homing velicty in the MACH Homing and Linits. What happens is if you rapid height is lower than the value it will first run to that point THEN start the slow move down.
So its going to move to 1.18 inches regardless if that is below or above where you are on Z

All values in a POST are in MM. When you pass a variable from SheetCAM to the POST you will find that it applies a "SCALE" factor if its passsed in inches
so the POST varaibles internally should be in mm. There may be some literal values that it simply puts into code.

[tcaudle]

BTW the "F command In that same line does nothing. MACH uses the values you set in the Homing & Limits for the feedrate

[carlosdav87]

Hi everybody
I know this post is old, but actually I am having the same issues. when the G code sends G28.1 the torch goes down twice one i at speed given in the homing/limits speed and the goes up and down again slowly so I am loosing time on each program.

Basically the floating is making the same routing as when I am homing the machine I mean moving to the axis fast and goes back and returns slowly to sense again.

If you can support it will be much appreciated. (sorry for my English I am from Mexico)