Problem with post for ex-trak, really stuck!

[Megan_B]

I am trying to modify the standard Fanuc post-processor from HSMexpress to work with a Bridgeport Ez-Trak system. I have gotten most of the problems resolved but I am stuck on an arc issue. Essentially what happens is that the Bridgeport will interpret any arc that is less than 180 deg and called out via a radius correctly. If these arcs are called out via I, J, (which I would prefer) I get major errors that manifest as arcs that get progressively 'shallower' (ie they are not really arcs) and/or are curved the wrong way. The problem is that when I try to output a full circle the R arc segments don't want to link (I'm assuming this is due to an arc tolerance issue?) and I get invalid radius error messages on the Ez-Trak. So basically I'm stuck with arcs that plot properly but don't link or arcs that don't plot properly but do link. All of the code generated for testing has back plotted correctly so I'm assuming that the issue is something specific to the ez-trak. I have attached the post-processor that I have so far as a txt file. Any help or guidance would be greatly appreciated!

[DMF_TomB]

need to know ez-trak version number

some are the same as a Prototrak Plus which can take some Fanuc 6m gcode and translate it to SWI format

there is a manual called the Prototrak Plus CadCam interface manual that explains SWI gcode at least for an older 2 axis mill.

there are rules on what the machine controller can accept. in particular how arcs are coded.

i was like a lost golf ball in tall weeds until i got the CadCam interface manual then it was like a light bulb turning on. it is so simple once you know the gcode rules. If all else fails read the manual

[Megan_B]

Thanks so much for the reply! I'm really beating my head against a wall.

Per your question it is Ez-Trak version 7. Is this one of the versions that uses the manual you mentioned?

[DMF_TomB]

i do not know when Ez-trak was the same as prototrak plus
.
prototrak plus 2axis mill
.
previous discussion (on 2nd page in middle of thread) on prototrak plus with CadCam interface manual explaining SWI 2 axis code , on newer machines usually it still use some gcode not exactly to the old standard
.
for instance semicolon at end of each line usually not needed for newer machines

[TheCamMan]

Megan

there are a lot of controls that don't like swinging more then a 90deg arc. So if you would like to use R the first thing i would try is changing the line
maximumCircularSweep = toRad(180);
to
maximumCircularSweep = toRad(90);

If you want to use I, J then there are 3 basic ways of defining the I and J. it could be the absolute value from your program zero, the incremental distance from the arc start to the center of the arc, or the incremental distance from the arc center to the start of the arc (basically the same number as the last with the sign reversed).

the controls for this is found in the onCircular function. the 3 basic ways of setting the centers would be.

iOutput.format(cx - start.x, 0)
iOutput.format(start.x - cx, 0)
iOutput.format(cx, 0)

I'm not sure what format will work for you but when you find out can you let us all know :-)

[Megan_B]

CamMan,

Thanks for the reply. I did try reducing the maximumCircularSweep to 90 (and less than 90, too) to no avail.

I'm thinking that I will try messing with my I,J settings in the post next. I will definitely post any solutions I find as soon as I get them.

TomB,

I took a look at the Prototrack Plus CAD/CAM interface manual and it seems to differ from the gcode that I have created to work with our ez-trak so far. The most noticeable difference is that the ez-trak does not like start and end '%' or semicolons at the end of each line. I haven't taken a look at the rest of it yet, but it appears that the set of gcodes used are very similar.

[DMF_TomB]

TomB,

I took a look at the Prototrack Plus CAD/CAM interface manual and it seems to differ from the gcode that I have created to work with our ez-trak so far. The most noticeable difference is that the ez-trak does not like start and end '%' or semicolons at the end of each line. I haven't taken a look at the rest of it yet, but it appears that the set of gcodes used are very similar.

the % sign denotes end of file (and it used to beginning of file too)
most gcode no longer uses it at beginning just the end

; semicolon is a really old use of "end of line" most controllers now read the invisible carriage return symbol for end of line (when you press enter in a text editor you are adding a normally invisible carriage return symbol)

basically SWI code uses
G100 instead of G00
G101 instead of G01
G102 instead of G02
G103 instead of G03
and X1.0 would be X1.0A or X1.0I (absolute or incremental)
after awhile it takes less than 10 seconds to recognize SWI code
the arcs center are different, incremental from ENDING POINT and not beginning point like Fanuc gcode
i use arc center absolute coordinates

but within reason if i enter Fanuc gcode into a Prototrak it will translate it usually. a really old Prototrak Plus needs ; semicolon at end of each line, can only take one gcode per line, and usually does not have a clue what to do with z axis commands.
.......on lines with a z axis command i delete the line but make sure the Prototrak will pause CR-0.0 instead of CR0.0 (goto next line)
..... you cannot have a G101 or G102 or G103 goto a position drill or rapid
at the end CR- or CR-0.0 (PAUSE)
before a G100 (position drill)
...... obviously on a manual Z axis machine it needs to stop for operator to raise and lower Z axis

[Megan_B]

TomB,

I took your advice to try switching the arc centers to be relative to the end point, rather than the start point of the arc and this seems to have solved my problem.

As for ez-trak and prototrack being the same or similar, I'm still not sure that they are. There are quite a few syntax differences, although obviously the arc callout style is the same.

At any rate, I'm still cleaning up some other minor issues in my HSMexpress post-processor for ez-trak 7 but as soon as I'm done I will post it so that others can use it.

Thanks again for everyone's help!

[cygnus x-1]

I have an older 2-axis EZTrak that I would really like to use with HSMXpress. I would be happy to test out your post when you get it fixed up.

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[Megan_B]

I've attached the post-processor that I have so far. It does work, but there are still some issues that I haven't had time to sort out. I figured that if I post it, other people can use it as a starting point and improve upon it. It would be great if everyone posts their updates to the post-processor so that we can all cooperate and have the best, most useful version collectively.

Thanks again for everyone's help on the arc issue.

Here are some known-bug notes with this version of the post:

1. The ez-trak does not seem to like it when arcs cross the axis. The easy fix is simply to position your part origin so that the entire part falls in the upper right quadrant (x pos, y pos). Needless to say this is not always convenient, so I would eventually like to correct the post so that it is not confused by the arc x,y,i,j sign changes.
2. In the intrest of time I left in a bunch of features in the post that our ex-trak does not support but which were not causing any problems. These include coolant control (we don't have it but I believe it was an option on some systems), some 3D functions, etc. It would be nice to weed these out to simplify the post.
3. There are still some features that I have not had a chance to test extensively. I'm sure that there are unknown bugs so proceed with caution when you are testing! I annotated the javascript wherever I changed something. My changes are marked with notes in capital letters (CHANGED, REMOVED, or ADDED). I didn't delete any lines from the stock post, I just commented them out so that I could easily add them back in if needed.

[cygnus x-1]

Thanks for posting your post Megan. I'm on vacation for hte next week so I won't be able to do any testing until I get back. But I'll let you know when I do.

Also, not sure if you know this but the latest release (12/23) of HSMXpress has a conversational post for the EZ-Trak. I haven't tested it yet but I did look at the generated code and it looks correct. If your control supports the conversational code you might try it.


C|

[Megan_B]

Hi Cygnus,
I just went hunting for the conversational post that you mentioned and I'm not sure which one it is. Can you give me the name of it when you get back from your holiday? Thanks!