[ferrumdg]

Been trying to get some text around a cylinder (it's part of a a project I need to be done with..)... epic problem so far... thus I've tried to isolate the 4th Axis engraving operation and just use some scrap to run a few tests...

here's what the part looks like within bobcad:


here's how it looks in the simulation (that's just what it should look like)


and here's the real world output (the machine engraves text pieces over itself...) and I don't know WHY.



attached is the Post G-Code...


any input welcome... thanks!

[ferrumdg]

Addendum:

The Problem arises upon further inspection of the issue as BobCAD outputs the 4th Axis rotary angle with "plus" and "minus" values... but the 4th Axis (indexed) on my machine works with values from 0...360... so -65.5 is the same position as 65.5 (the fagor 8025m controller actually disregards the minus-Sign as far as I can tell)


Anyone knows how I can bring bobcad to actually output 0...360 values instead of negative positive values?

[Jessebobcad]

Well this should work. I believe what you will need to do is set the limits for the machine. CAM Part> Milling Tools> Default> Current Settings> Machine Definition (Be certain that the machine you are using under Milling Tools > Part is the same as the default one) then select your rotary axis. On the Rotary Axis page you will need to set your limits to 0 for Min and 360 for Max.

I have a question for you though. Is your machine absolute where it takes absolute positioning or incremental? Also if Absolute is it continuous? These will require post modifications that you will need to contact support about.

For more helpful information about Machine Definition please view the course on our website here:
Online Courses | BobCAD-CAM

[ferrumdg]

Jesse,

thanks - actually just about 40seconds ago I was able to solve the issue...
I had already set the limits for this in BobCAD from 0..360 - but it didn't work still...

then I went through the postprocessor file and found this:
440. What is the rotary output type (0=Abs Pos, 1=Signed ABS, 2=Signed Continuous) ? 0
for some reason this was defined as 1 (Signed ABS)... changed it to 0 (Absolute Pos) - and that's it...

it's working now.

[Jessebobcad]

I also found an additional area that may help:
Cam part> Milling tools> part> current settings> Multi- Axis Posting

On the bottom right under move list writer 1st rot axis angle limit can be set to 0-360

Jesse

[magicniner]

This area also needs the correct machine selecting, this looks like the solution to my problem but although seemingly vital to function curiously isn't mentioned in any basic BC setup guides.

[ferrumdg]

I also found an additional area that may help:
Cam part> Milling tools> part> current settings> Multi- Axis Posting

On the bottom right under move list writer 1st rot axis angle limit can be set to 0-360

Jesse

Well if the postprocessor is set up to use signed absolute - this will not really have much of an influence...

As mentioned, my issue has been solved by setting the postprocessor up to not use signed absolute values for the rotary axis.

[mmoe]

Well, those are interesting results. From the looks of it, the post processor would work if you were to move your text entirely on the positive side of the "0" degree mark. It appears that "BobCAD" is backwards, while "Text" is normal, which means that the "0" degree mark is probably right in between the two words. Let me know if that is or isn't correct.

Assuming that I am correct, simply moving the text so that all of it is on the positive side of the "0" mark will eliminate the problem. The other solution, if it isn't possible to reposition the text, is that somehow you will need to make the "0" degree mark the "360" degree mark. That way, I am pretty certain you can program across the center line since instead of going to "-65" degrees, you'd go to "295" degrees. I'm not entirely sure how you would set it up that way, but I'm pretty sure it would work fine if you did. If you were to make a post processor, perhaps you could have it somehow add 360 to all angles that are normally output.

Here's your test file with 360 degrees added to all the positions, done with the G-Wizard Editor. Basically, I replaced all W values with the value plus 360. For example, your first line of rotation is W5.526, which is replaced with W365.526. You are free to try it out, but I obviously will state that you do so at your own risk. I am not there to see the machine or verify the setup. If it works the way I expect, it should rotate the part 360 degrees prior to cutting, the run as normal. Obviously, a dry run with your finger on e-stop would be prudent.

[mmoe]

I usually have my setting for the forums such that I see the posts from top to bottom, with bottom being the latest. I somehow ended up backwards to the default and didn't realize you'd solved your problem. What does the programming look like now with the changes? Curious to see the output.