EMC2 Stepconf - Table Travel - Units used?

[skimask]

In Stepconf, when setting the Table Travel (i.e. soft limits), what units does EMC use?
I'm going to have to use 2 different configurations, one inch and one metric, for different setups. (my PCB program only does inches, my other CAD program does both, my machine has a metric leadscrew)
If I'm using the 'inch' configuration (as setup on the first screen of Stepconf), is the table travel in actual inches? i.e. -1 to +7 would be 8 total inches of travel? Same for metric... -1 to +7 would be 7mm of total travel...
Or is this number in motor 'steps' or 'revs' or 'micro-steps' (if applicable)??????
I'm assuming the units used for the table travel would be the same units used for the home location, but I don't have home switches installed, yet. That'll happen sometime this coming week.

Also (reference the statement above about inches AND metric), since the machine has a metric leadscrew, I have to convert the mm/rev to T/P/I. 1.5mm/rev = 16.9333333333333333333333333 T/P/I.
How many of those 3's does Stepconf recognize? Or do I even have to worry about it? Does EMC do the inch -> metric conversion for me when loading G-code?

[chester88]

You can select metric or imperial by Gcode 20 and 21.
use stepconf to set up your machine whatever way makes sense (sounds like metric).
When you want to use imperial gcode issue G20 first, for metric G21
And yes metric machine the soft limits would be mm.

[skimask]

Originally Posted by chester88 You can select metric or imperial by Gcode 20 and 21. use stepconf to set up your machine whatever way makes sense (sounds like metric). When you want to use imperial gcode issue G20 first, for metric G21 And yes metric machine the soft limits would be mm.

Ok, thanks...clears up a couple of things for me.
If the G20 or G21 (as appropriate) isn't present in the G-code file in the first place, I guess I get to learn how to properly edit G-code files now!

[cadmonkey]

Editing a G-Code file is simple - open in a text editor (not word processor...) and add/change the G-Codes you want/need. I thought it was daunting the first time too, but then realized it's the same as turning the dials on a manual machine and keeping a copy of a G-Code reference (like the section of the manual for EMC from the linuxcnc.org website) handy to sort out what the program is already programmed to do and to decide what to add in to accomplish what you need to change. My more complex programs have had more hand coded information than CAM generated. Using free/shareware/opensource CAM I am the "post processor" adding in the environmental conditions I want/need (like turning the spindle on, coolant, pauses for the spindle to attain speed, pauses to let the spindle take a break on long programs, etc.). It's really a lot less complex than you'd think. If you do something really wrong, the problem will be identified (dialog box saying something like "Invalid argument on line xxx") when the file is opened and parsed.

If your screws are metric I would stay with a metric setup rather than a lot of math conversion and then using the metric/imperial workspace environment settings as suggested above.

Greg

[skimask]

Originally Posted by cadmonkey keeping a copy of a G-Code reference (like the section of the manual for EMC from the linuxcnc.org website)

Oh yeah... You aren't kidding. Thinking about having that [FRAMED] for easy reference!

If you do something really wrong, the problem will be identified (dialog box saying something like "Invalid argument on line xxx") when the file is opened and parsed.

Sounds like an easy thing to do with a 'dry run' (i.e. no tools, spindle not on, etc,etc,etc)

If your screws are metric I would stay with a metric setup rather than a lot of math conversion and then using the metric/imperial workspace environment settings as suggested above.

If I could stay all metric, I would (even though it'll take a little bit of brain work to convert myself over to metric). The problem I have is that I use an old, moldy version of Protel 2.7.1 for the PCB artwork, and even though the main screen shows all metric measurements in it's dialog, the gerber output comes out in imperial units (at least I'm fairly sure that's what comes out).
I suppose that's where the 'dry run' is going to come in handy.

JDG

[Zig]

You ought to be able to output metric gerber with protel.

What do you do to convert gerber to meaningful isolation g code?

[skimask]

Originally Posted by Zig You ought to be able to output metric gerber with protel.

I know I should be able to do that, problem is, I'm not 100% sure it actually CAN do that. This version is really old, like vintage ~1993 Protel Advance PCB 2.7.1.

What do you do to convert gerber to meaningful isolation g code?

I downloaded the trial version of DeskCNC awhile back, generated some G-code with it, only because it was the only thing I could find at the time to handle it for me. The trial is about to run out so I'd better get to thinking what I actually want to use in the future as a permanent solution.

[Zig]

I too am using EMC2 and run with Protel to generate gerbers.

I use a pcb CAM package normaly used inpreparation and editing of phototools and solder paste stencils.
The package is called Graphicode Powerstation and it has all the tools for generation of isolation outlines and conversion of outlines to G code.

I could not find anything else that would operate at any degree of speed and performance including multiple isolation paths.


There is a package available from Galaad but it is slow and sometimes it does not generate the complete isolation path.

I have been in touch with the author who claims a new version will be out soon which will address the issues.

Collinbus have a package called coliliner they have been threatening for a year and a half to release as a stand alone apllication capable of generating G code but so far it is only an idle threat.

More upmarket T-tech who make milling machines also have a stand alone package ( based on an earlier version of Graphicode application ) .

I think their package is called Iso-Pro 2.7

You might also have a look at aproduct offered by a German company called BUNGARD.

Just a quick summary of my search.