Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Promech on June 08, 2011, 03:33:17 PM

Title: Help with G41/G42 lathe
Post by: Promech 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
Title: Re: Help with G41/G42 lathe
Post by: Promech on June 08, 2011, 03:35:23 PM
BTW here is the configuration screen
Title: Re: Help with G41/G42 lathe
Post by: DAlgie 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.
Title: Re: Help with G41/G42 lathe
Post by: Hood 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
Title: Re: Help with G41/G42 lathe
Post by: Promech 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
Title: Re: Help with G41/G42 lathe
Post by: DAlgie 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.
Title: Re: Help with G41/G42 lathe
Post by: Hood 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
Title: Re: Help with G41/G42 lathe
Post by: DennisF 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
Title: Re: Help with G41/G42 lathe
Post by: RICH on June 09, 2011, 07:08:47 PM
Quote
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

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

Quote
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
Title: Re: Help with G41/G42 lathe
Post by: DennisF 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
Title: Re: Help with G41/G42 lathe
Post by: Hood on June 11, 2011, 01:41:23 PM
Dennis, to be fair Mach is not CAD or CAM, it is a machine controller. Yes there are things it doesnt do in Turn such as CSS but overall it works well. If you need CAD/CAM you should really get that or just use the wizards. You paid for the controller that is Mach, not CADCAM.
Hood
Title: Re: Help with G41/G42 lathe
Post by: DAlgie on June 11, 2011, 02:53:39 PM
Yes Mach Turn is a controller, and for the most part works very well at that. For me I guess tool nose radius compensation is part of the machine control, at least in all other controls it is. Thinking that G42 should be fixed by now is not a lot to ask I would think.
DaveA.
Title: Re: Help with G41/G42 lathe
Post by: Hood on June 11, 2011, 02:58:52 PM
Time and economics I suppose. I have been waiting a long time for things to get fixed in Turn also, probably longer than most on this forum. I get pissed off every now and then as well but what are the alternatives?

Hood
Title: Re: Help with G41/G42 lathe
Post by: Promech on June 11, 2011, 04:47:41 PM
My observation is that other lathe softwares out there cost 10 times what Mach costs.  What are the differences between them and Mach?  Probably just the unsolved bugs in Mach, because Mach performs very well when not asked for ´special features´ such as tool nose radius compensation, feed/rev in CSS etc. I am sure many of us are ready to pay somewhat more for Mach if the bugs were solved. I am not a programmer, but seems to me that correcting the bugs in the lathe version is not all that difficult.  I suppose G41/G42 works well with the mill version, then have it work in Mach should not be that big of a deal because the theory is the same (just replace an end mill with a tool nose).

There are also system integrators out there that use Mach as their control software.  It would be nice if us users, system integrators, etc. could chip in a little money each, and support the upgrading of Mach 3 lathe. Then Mach would be competitive with everything else out there......

If the company that own Mach is not willing to support it properly, then they should sell it to someone who has the resources to keep it up to date......
Title: Re: Help with G41/G42 lathe
Post by: RICH on June 11, 2011, 05:01:14 PM
I just try to keep a sense of humor about it all. At least the threading got fixed.
Yes,  LT it is done, LC lathe was never fully functional or finished, and doubt if either one of them will progress more.
So if you want something more from a Cam then your off to say Dolphin or just a few others and you'll need to pay the price for the software.
There realy is nothing much out there for the lathe and frankly I would have thought that there would be after the last few years.
That to me, just says the market is not there for the effort that needs to be put forth. I see CamBam is in the beginning of a lathe module and it
currently is not at LT level. It's interesting about  LT, as we thought that after the published article on it, there would be a high interest, just didn't happen.

The redo of Mach by Brian is much more than i think he ever anticipated and hopefully after the mill end reaches some level, lathe will get it's long overdue attention.
In the mean time hobby alternatives are just not there.

Do not hold your breath and suggest users take care of themselves .....what's another 3-5 years. >:D

What say you Brian?

RICH


 
Title: Re: Help with G41/G42 lathe
Post by: DennisF on June 12, 2011, 01:14:22 PM
Hood
I know Mach is a control software and that's what i use it for now, but when i purchased my Lic it was promised that LC would come about to use for turn and mill there have been attempts by Art to address this and i am thank full for his work but it's not finished i do have Cad Cam software to use and like promech find problems with Mach in turn i found that i can only get 2.43 V to work well for turn.

Dennis 
Title: Re: Help with G41/G42 lathe
Post by: Promech on June 12, 2011, 01:49:52 PM
What is frustrating sometimes is to have things one expects to work not work and do funny things (this can even be dangerous).  I think there should be a list of the features that do not work, so that time is not wasted trying to get them to work. For example if one uses tool nose radius compensation, an alarm should come out instead of going on with herratic movements. I spent a whole day trying G41/G42 before considering, ´hey, maybe its not me, its Mach´.  Same happened with feed per rev in CSS.  Next week I will test backlash, and maybe I am for a surprise, hope not.  On the other hand I must say I have been working 24/7 for several weeks on repetitive stuff, and not a single pulse has been missed.  Accuracy and repetitiveness is excelent.  Threading, after forgetting about a high tech encoder an just installing a slotted disk works perfectly.

Jorge
Title: Re: Help with G41/G42 lathe
Post by: BR549 on June 12, 2011, 01:54:59 PM
Well there is always the DARKSIDE EMC2.

(;-) TP
Title: Re: Help with G41/G42 lathe
Post by: DAlgie on June 12, 2011, 02:04:52 PM
I have to say, that I am that confident with Turn, that I will hit the cycle start button on a new program without even looking in the enclosure, and it works every time. As reliable as a Fanuc system for me. And I have run the crap out of my lathe all this year with only one problem I can remember. But yes, instead of Mill getting all the updates, and some might say that the updates being done with Mill is stuff that isn't really absolutely necessary, whereas tool nose radius compensation on Turn is absolutely necessary. Something that could be addressed in a few days maybe?

DaveA.
Title: Re: Help with G41/G42 lathe
Post by: Hood on June 12, 2011, 06:27:27 PM
Dave, thats the thing, everyone has their priorities. For me I never use Tool nose rad comp so couldnt care if its there or not. Of course its good for it to be there but for me the most important thing was getting Front/Rear toolposts working properly. I have now modified the post processor in my CAM so that is no longer a priority for me but would still like it. Priority for me now would probably be CSS.

Sad thing is Brian is one guy, Mill/Plasma/Router guys are much more prevalent and also the part of the business that I imagine makes the money, OEMS, are probably 99.99%  Mill/Router guys. I would guess selling licences to the likes of you and me are not whats keeping Mach going, I know I have purchased a licence for each of my machines running Mach but even if everyone did that then its not a big deal, add to that you only pay once then its the volume licence sales from OEMs that keep the wages coming in to allow Brian to continue.

Just my thoughts of course so take of it what you will.

Believe me I have been wanting big changes for Turn for a long time, probably only second in length of time to Steve Blackmore. Also i have talked to Brian many times and they are not easy things to change, Rev4 should make it easier but when Rev 4 will be out is anyones guess, its been a hell of a lot more work rewriting Mach than even Brian thought.


Hood