Arcs/Tool change output lathe

[nperry]

Hey guys - I'm a first timer posting here, and I've had similar topics with no true resolution posted on Mastercam.com and PM. Hoping some of you gurus might be able to give me a hand. Running Mastercam 2017. 

First issue (sorry, I don't believe this is post related) is with arc values on about 4 of my (old) lathes. 

N205 G03 X22229 Z77554 I0000 K-0156
N210 G01 X22428 Z77454
N215 G03 X22520 Z77344 I-0111 K-0111

Simply put, there's that .0001 difference in my K address that will lock up some of my machines. In the control def I changed my tolerances for NC precision, General math function and Max. deviation in calculated arc endpoints to 5 places behind the decimal. This seemed to clear up some of the discrepancies, but not all (if I change the radius of the insert it may post out okay, but may not). Is there any way to tighten this up?

 

The second issue I'm frequently seeing for some of those same lathes is that when I put together roughing and finishing operations with the same tool, I'm having tool changes posted out without selecting the force tool change option. I wrote a program recently where I'm using 6 different grooving cycles to cut off 6 pieces on one program, and it's posted out to come in and rough, return home, drop offset, pick up offset, then return to finish/cut off, return home, drop offset, pick up offset, go to next rough, etc. I figured this is something related to the null tool change in the post, and I've tinkered with it with no luck thus far. 

 

If I need to send up a post processor or display some additional code I'm more than happy to oblige. If these topics have been covered I'm sorry that I missed them in the forum, and a redirect to the proper thread would be appreciated. Thanks so much everyone. 

[ahaslam]

That's a pretty in-depth request. For the arc thing, their will always be a small amount of error between the actual and the definable. What is the control you are using on your machine? What is the error you are getting? You could try breaking arcs as a temporary fix but it will potentially affect your surface finishes. I'm not much of a lathe guy but that might work.

As for the tool change issues. It would be hard to really get to the bottom of this without knowing more about the post. Where did you get it? I could glance over it if you want to PM me the post but no promises. Have you contacted your reseller about the issues?

[nperry]

Hey, thank you for your reply! I'm having issues on 4 lathes - 3 of them are 70/80s vintage Mazak with Fanuc 2000c control, plus 1 Cinturn with Acramatic 900TC. I feel like I might be able to increase the range for error on the Cinturn, but I'd say the Mazaks are stuck. The error I'll get will be something along the lines of "End point of circular interpolation is out of admissible range". 

 

I will PM you with one of the posts and some more information. Thanks again.

[ahaslam]

I looked over the post. First off, this is a pretty old post. There is nothing wrong with that, it's just a little harder to work with and is lacking a few of the newer features. I see that Axsys was the post writer and they had modified it last year. Have you had the chance to bring this up with them? I hope they would be able to fix the tool change thing without throwing more money at it. I'm not seeing anything that is jumping out at me on it. When you post multiple tool paths, do you see an M98 P2? As for the arc issue, are you using a wear comp for the post? The G41/G42? I'm curious if the mazaks are having issues with arc length under comp. If so, would it be possible to remove the G41/G42 and just use the T0101? Again, not a lathe guy so I'm kinda swinging in the dark on this one.

[nperry]

I've sent my reseller a few emails and made a couple different phone calls...been kind of difficult getting a response from them for my post processor issues.

I don't use wear comp for programming my lathes, only computer. And I've never seen the M98 P2 with the Mazaks or Cinturn. Here's the whole program:

 

( T#0202 M407 .0313 RAD )
N5 G50 X120000 Z145000 S1500
N10 G00 T0202
N15 M08
N20 G97 S1092 M38
N25 G04 M03 U2000
N30 G00 X22746 Z138600
N35 G96 S650
N40 G99 G01 Z77358 F120
N45 G03 X22820 Z77188 I-0376 K-0171
N50 G01 Z39487
N55 Z-1020
N60 X24234 Z-0312
N65 G00 Z138600
N70 X20492
N75 G01 Z137294
N80 X21832 Z134794
N85 G03 X21860 Z134688 I-0398 K-0107
N90 G01 Z113757
N95 G03 X22175 Z113387 I-0355 K-0370
N100 G01 Z77654
N105 G03 X22378 Z77579 I-0190 K-0366
N110 G01 X22578 Z77479
N115 G03 X22820 Z77188 I-0292 K-0292
N120 G01 X24234 Z77895
N125 G00 X120000 Z145000 M09
N130 T0200
N135 M01
 
( T#0303 M407 .0156 RAD )
N140 G50 X120000 Z145000 S1500
N145 G00 T0303
N150 M08
N155 G97 S879 M38
N160 G04 M03 U2000
N165 G00 X19550 Z138616
N170 G96 S450
N175 G99 G01 X21549 Z134884 F80
N180 G03 X21560 Z134844 I-0151 K-0040
N185 G01 Z113780
N190 G03 X21875 Z113544 I-0099 K-0236
N195 G01 Z77600
N200 X22008
N205 G03 X22229 Z77554 I0000 K-0156
N210 G01 X22428 Z77454
N215 G03 X22520 Z77344 I-0111 K-0111
N220 G01 Z38300
N225 X23934 Z39007
N230 G00 X120000 Z145000 M09
N235 T0300
N240 M01
 
( T#0404 M408 .0156 RAD )
N245 G50 X120000 Z160000 S1500
N250 G00 T0404
N255 M08
N260 G97 S278 M38
N265 G04 M03 U2000
N270 G00 X61875 Z-1000
N275 G96 S450
N280 Z-1046
N285 X18400
N290 G99 G01 X21783 Z0646
N295 G02 X21875 Z0756 K0111
N300 G01 Z37446
N305 X22901 Z41424
N310 X24901
N315 G00 X120000 Z160000 M09
N320 T0400
N325 M30
%

[ahaslam]

Huh, I'm kinda stumped. It's hard to tell what is going on with this post because they are constantly overwriting variables manually. This is a little more in depth than I am really able to tackle on my free time right now. I'm going to follow this post and maybe in a few weeks I can dig into it a little more. If you can create a zip2go file then pm me the file I can try and debug on my end later.