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Author Topic: G76 Lathe Theading Problem  (Read 15047 times)

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Re: G76 Lathe Theading Problem
« Reply #20 on: December 08, 2014, 07:17:44 AM »
Somehow I totally missed the part about threading being disabled in Demo mode.  Looks like that should fix me up, thanks fellas!
Re: G76 Lathe Theading Problem
« Reply #21 on: December 20, 2015, 09:32:54 AM »
Somehow I totally missed the part about threading being disabled in Demo mode.  Looks like that should fix me up, thanks fellas!


Not long after this I purchased a license and everything has been working great.....until yesterday.  Actually, I don't know when it started but I just noticed it yesterday.  It's back to doing the same thing again.  Any thoughts on why it would start doing that???

Thanks again for all of your help guys.

Offline RICH

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Re: G76 Lathe Theading Problem
« Reply #22 on: December 20, 2015, 11:02:29 AM »
What is it doing again?

Post you xml file again and the gcode file you tried.
Are you using the simple threading wizard to generate the code?

I am guessing you are new to using Mach3 Lathe.
I strongly suggest you have a read of the Manual. Also have a read of Threading on the Lathe write up which can be found in Members Doc's.

RICH
Re: G76 Lathe Theading Problem
« Reply #23 on: December 20, 2015, 01:36:12 PM »
Not new, been using it for about three years.  I used the wizard to generate the code originally.  I have read the manual.

It is doing exactly the same thing as before - first pass is ok but all other passes are at the maximum machine speed.  I'm trying to tune in my tool offset because I have production parts to make (already programmed).  

I'm not at the shop now but will get the xml the next I'm there.  Why would that have changed???
Re: G76 Lathe Theading Problem
« Reply #24 on: December 23, 2015, 09:54:46 AM »
What is it doing again?

Post you xml file again and the gcode file you tried.
Are you using the simple threading wizard to generate the code?

I am guessing you are new to using Mach3 Lathe.
I strongly suggest you have a read of the Manual. Also have a read of Threading on the Lathe write up which can be found in Members Doc's.

RICH


Here is the xml file.  The code I'm using is this:

%
G30 U0. W0.
G90 G95 G54 G48 S2000
T0707
G97 S402 M04

G00 X2 Z0.3
G00 X0.65
G00 X0.625

G76 X0.5568 Z0.700 Q1 P0.0556 J0.005 L45 H0.0141 I29 C0.025 B0.0001 T0

M5
G30 U0. W0.
M30

%








Re: G76 Lathe Theading Problem
« Reply #25 on: December 23, 2015, 09:59:24 AM »
Something else to throw out: my PC is old and I have to hit F1 to get through BIOS.  That throws my date off to sometime in 2005.  Even if I change the date in Windows the threading still doesn't work.  Could this have something to do with it?

Offline RICH

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Re: G76 Lathe Theading Problem
« Reply #26 on: December 25, 2015, 09:34:04 AM »
jamie,

First a number of comments:
- You are using version 66, suggest you try 62. I am not sure if there are problems with 66.
- You are using a screen set that i am not familar with.
  So, to make things simple suggest you use the generic lathe screen so we can be on common ground.
- Set your spindle speed manualy for threading and not automaticaly.
  So reconfigure Mach.
- When you use the Simple threading wizard click the "calc number of     
  passes" to see if your vel and accel is ok.
- G30 X value Z value, NOT U or w
  G48 - dosen't exist
  G97 -   "       "
  You need to look at Gcode definitions in the Lathe Manual for Mach.
  Two replies were posted informing you about the commands.

- Check that your index is working. You should should see the mode go
  from G94 to G95 when threading.The rpm should be stable within +- 1
  rpm as shown in the DRO when running. If you rotate the spindle by hand you will see the index turn on and off in diagnostics.

All of the above will bring you back to a basic configuration and eliminate spome things that could have an affect and simplify us trying to finding out what is going on.

RICH
Re: G76 Lathe Theading Problem
« Reply #27 on: December 25, 2015, 10:37:53 AM »
Thanks for the response!!!  I'll give you some insight to see if this helps better understand my situation:

- After I purchased a license this was working great.  It was only in the last month or so it reverted back to the issues I had prior to using a purchased version.  Why would v66->v62 fix this?
- Again, could you please explain why the screen would make a difference?  This is a custom screen that has always been used with this machine, I don't think I've ever opened anything else.
- The spindle only works automatically, there is no manual control on this machine.
- I made the code using the wizard initially and only changed the H variable (was 0.021 I think) just to see if that would help, no change.
- G30 with U and W is what works on this machine.
- G48 is used to clear the tool offsets just as good programming practice.
- G97 is what I want, not G96 CSS
- Index works fine, at least from what I can tell.


I guess what still has me scratching my head is why it work then stop all of sudden?  Something must have changed, but I know wasn't my test program.

I'm going to change my CMOS battery to see if that helps.  I'm still wondering if the system date/time could be the problem.  I'll post the results after I try that.

Re: G76 Lathe Theading Problem
« Reply #28 on: December 25, 2015, 12:40:58 PM »
- Index works fine, at least from what I can tell.

Ok, well, I thought it was working!  Your comment got me thinking so I double checked - lo and behold I'm only getting one index pulse every 2-5 seconds at 1000rpm.  I'm guessing my sensor is bad.  There are no markings on it so it's going to be interesting finding a replacement.

Thanks again for all of your help, hopefully this is my problem.

Offline BR549

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Re: G76 Lathe Theading Problem
« Reply #29 on: December 25, 2015, 02:24:08 PM »
(;-) THAT is not telling you if the Sensor is working correctly or not. The screen led cannot keep up with the pulse rate and will just flash randomly. LOOK at the actual spindle RPM is it stable or does it vary a great deal. IF the RPM is not stable then the threading will not be stable as well. It is trying to follow the RPM.

Most people do not use the latest Version(066)  as it appears to be unstable and they may have broken more than they fixed. Most use a much earlier ver for turn and threading. Do a search and you should find the info.

(;-) TP
« Last Edit: December 25, 2015, 02:27:48 PM by BR549 »