Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: haley on November 09, 2011, 01:27:08 AM
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In the attachment, the box in front of 'Ang Short Rot on G0' is checked.
Is there any way to enable this order under 'Ang Short Rot on G01', maybe by upgrading?
Please help..
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Not that I am aware of. Not sure what your trying to do or why.
RICH
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You really don't want to do that with G01 as you would loose total control of the Axis movement. The G01 HAS to do exactly as commanded. The G00 you can get away with a few fudges.
(;-) TP
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I'll add that usualy all three of those settings in config have to do with indexing since the A axis steps per are degrees.
Don't do that and it can get interesting .........
RICH
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Thank you very much for all your replies.
I am trying to figure out how to command for my particular case.
We are now developing CNC machine which mostly engraves cylinder types out of material.
We would like to figure out how to engrave 359 degree first and then engrave 2 more degree to the same direction.
We do not want it to move for 2 degrees backward.
The explanation is quite weird but hopefully someone can understand this situation and help me out.
Haley
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That would be easy enough. You are not limited to 360 deg of rotation you can do any amount.
(;-) TP
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Sorry, the question was not so clear.
I'm looking for a way to turn it -359 then -360 and then -1 again..
It's the other way around
Haley
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you go to -361 to -719 or you go to -360 and reset A to 0
bill
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or you run in incremental mode and do
1
360
1
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Thank you all very much for the comments.
I guess what I'm trying to do is quite uncommon case.
Please see below if anyone can please help:
G01 X5.453 Z3.329 A715.422 F1200
X5.472 Z3.31 A716.858
X5.491 Z3.286 A718.295
(X5.51 Z3.265 A719.768
X5.529 Z3.246 A361.242)
X5.548 Z3.224 A362.746
X5.568 Z3.19 A364.25
The above data is large, more than 1MB.
So it is quite hard to modify one by one.
The problem is the contents inside of brackets().
Inside of the brackets, when A spindle is turning, how can I turn it from 719.768 to 361.242 by using closer direction?
(Not to the other way around, I need closer direction...)
If there is no current possible solution, is there any possibility to add it?
So I can decide whether or not to use Ang Short Rot On G01.
We are currently developing CNC machine and this function is very important.
Please look closely into my case and I really appreciate for all your helps.
Haley
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You may want to consider requesting one on one support to help develop your machine.
Here is a link where you can make the request.
http://www.machsupport.com/forum/index.php/board,18.0.html
RICH
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Inside of the brackets, when A spindle is turning, how can I turn it from 719.768 to 361.242 by using closer direction?
Go from 719.768 to 721.242
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Haley, I believe your problem is with whatever software you are using to produce your G-code. I ran into this same issue some years back and not having the top shelf ($$$$) software, wrote my own little app to convert flat pattern X,Y,Z G-code to X,A,Z for cylinders. I found the zero crossing is a problem that must be dealt with. One way is to limit 'A' values to the range of zero to 360 deg. I chose to test each ‘A’ and if the next move would result in a value less than zero or over 360 deg , then insert a new block with a ‘G92 Axx’, (where the new ‘A’ is the current ‘A’ plus or minus 360 as required to stay in range.). In your example 719.768 would have already been changed to 359.768 in a previous block and the move to 361.242 would be the short move that you want.
I’ll attach a copy of my app, don’t know if it will help, but might give you some ideas.
In my opinion, you must fix your G-code; you do NOT want Mach deciding when to take the short route and when you really DO want to move more than 180. Been there, done that :).
Al
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OK just to clear it up there is NO such thing as shortest rot on G1 and I would guess there never will be. It would make the machine unusable as to the A axis.
Shortest rotation on G0 does the job you just have to program for it.
(;-) TP