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Author Topic: Help with G41/G42 lathe  (Read 9916 times)

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Help with G41/G42 lathe
« on: June 08, 2011, 03:33:17 PM »
Hello,

I am attempting to use tool nose radius compensation for the first time in my lathe, but I am getting a strange behavior.  When tool nose radius is set at 0 everything works fine, but when a typical value such as 0.8mm is entered there is a strange behaviour (please look at graph in attached photos). Anyone out there knows what can be happening?

Thanks,

Jorge
Re: Help with G41/G42 lathe
« Reply #1 on: June 08, 2011, 03:35:23 PM »
BTW here is the configuration screen

Offline DAlgie

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Re: Help with G41/G42 lathe
« Reply #2 on: June 08, 2011, 09:26:37 PM »
You bring up a good question. I have also tried G42 with no luck. However, with G40, no compensation, the control does in fact take into account the tool nose radius, at least on internal corners it does. On external corners, say, to add a chamfer, nothing seems to work right. I just muddle past it I guess. A Fanuc OT isn't perfect either in this regard, but works for basic shapes.

Offline Hood

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Re: Help with G41/G42 lathe
« Reply #3 on: June 09, 2011, 04:23:00 AM »
Never used it but I think it is screwed from memory. Graham Waterworth would be the guy to tell you as I think he worked with Brian a bit on things like that probably for Rev4..
Hood
Re: Help with G41/G42 lathe
« Reply #4 on: June 09, 2011, 07:08:57 AM »
Hood,

I understand lathe is not the priority as the user base for lathe is small compared to the applications where XYZ are used (mills, routers, plasma, etc).  But, do you know if there is a reasonable estimate as to when Rev4 for lathe will be available? So far I have two problems which I consider important:

1. Feed/rev does not work in constant surface speed mode.
2. Not being able to use tool radius compensation, which is necessary for cutting accurate shapes involving tapers and arcs.

One can get around both of them by making compensations inside the part program, but its not the way it should be.

Jorge

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Re: Help with G41/G42 lathe
« Reply #5 on: June 09, 2011, 09:15:34 AM »
Jorge, you possibly have a G3/G2 issue there, just looked at the pic you posted from earlier.
DaveA.

Offline Hood

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Re: Help with G41/G42 lathe
« Reply #6 on: June 09, 2011, 11:32:29 AM »
Hood,

I understand lathe is not the priority as the user base for lathe is small compared to the applications where XYZ are used (mills, routers, plasma, etc).  But, do you know if there is a reasonable estimate as to when Rev4 for lathe will be available? So far I have two problems which I consider important:

1. Feed/rev does not work in constant surface speed mode.
2. Not being able to use tool radius compensation, which is necessary for cutting accurate shapes involving tapers and arcs.

One can get around both of them by making compensations inside the part program, but its not the way it should be.

Jorge

Not a clue I am afraid, I was to be screaming at  Brian to get some work done on turn  (his words) but afraid I have been ill for the last while and not really up to doing any testing.

Hood
Re: Help with G41/G42 lathe
« Reply #7 on: June 09, 2011, 12:25:03 PM »
Jorge
Join the crowd i have been waiting for turn for over 5 yrs now LT was supposed to come out and fix turn but now that's not coming when i bought my Mach LIC i bought it with the intention of using it for turning and was tolled then turn would be out in 3 month's LOL.

Dennis

Offline RICH

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Re: Help with G41/G42 lathe
« Reply #8 on: June 09, 2011, 07:08:47 PM »
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LT was supposed to come out and fix turn

Not really, it is a replacement for the Turn Module in LazyCam, wish Art took it a little further

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i have been waiting for turn for over 5 yrs
Dennis, hope your a young gent and have plenty of time left ;) :D ;D :)

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bought it with the intention of using it for turning

Mach Turn works quite well, yes there are a number of things needing fixing, but, with the right gcode most things you would want to do are possible.

I am ony going to guess that some day Brian will surprise all of us, but ,must be carefull on what i say since Brian is a young gent and should / will have  have plenty of time
to work on Turn. ???

RICH
Re: Help with G41/G42 lathe
« Reply #9 on: June 11, 2011, 01:27:32 PM »
Rich
Nope i think 5yrs is long enough to wait LT was supposed to be in LC which is now dead LT is not finished and dose not work well beyond rouging i am just using Mach for mill mostly now.
 Brain was the one who gave me the promise on lathe.

Dennis