Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: M250cnc on December 07, 2009, 02:13:55 AM
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I am using the latest Lockdown 032 and have just tried using ccs
As i haven't got a spindle that revs to infinity i reach my maximum speed long before the x axis is at zero.
As soon as i reach my max speed the feed per rev progressively slows down as such it will never reach X Zero.
I then tried slowing the ccs speed down and running the code again.
At the diameter that i start, i am running too fast due to the minimum speed of my spindle at this point the feed per rev is showing double what is commanded the FPR slows as it reaches the commanded CCS then back to slowing as i max out at top speed
Is anyone successfully using CCS ?
Thanks
Phil
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I have used CSS a couple of times and it worked fine for me, are you setting a max spindle speed?
Hood
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Only in the cam (ONEcnc)
The only lines produced apart from moves are
G95 F0.10
G96 S250
I will try removing the maximum speed in the cam to see if there is a difference
Phil
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Put a G48S**** and that will limit the speed that Mach will attempt to run the spindle at, so if you wanted a max of 1000 RPM you would put G48S1000 after your G96 line
Hood
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Yes, and don't forget to program G97 S____ to cancel the CSS
I use CSS a lot on my lathe. Mainly for parting and grooving operations in metals. But I use it with G94, since I want the mm/min feedrate stay constant through the operation and not increase as the tool approaches the centre and RPM climbs. This helps to reduce stress from my little lathe.
Daniel
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Hood the G48 fixed the per per rev being too high at the beginning
So now at the beginning of the facing the CCS shows as being too high, the commanded feed per rev (.1mm) stays at 0.9 all the way to the point where the spindle runs out of speed to what is commanded before it ran double FPR .2mm
From this point the feed per rev progressively drops to 0.02mm per rev
Surely it should be better than that ?
Dan13
Thanks already done in the PP in cam ;)
Phil
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Just a couple of further points i am using a SS
I can see the slowdown in the feed
Phil
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Phil,
Try to use the CSS with G94. That's the only way I've been using it and have never had problems.
Also, where do you read the CSS rate from? I am not sure the display is correct... I have not paid attention to this one, but I do know for a fact that the Strue DRO shows nonsense in CSS mode.
Daniel
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Just tried on my lathe and the feed per rev does alter and it is well screwed in that if you feed from X low to X high it is fast and the other way it is excruciatingly slow.
Now where does the problem lie? I had issues a while back with CSS and I asked around at the one or two that were using it with the PP and they said it worked fine, in later versions of the SS plugin I thought it was sorted but have only used it a couple of times and I was thinking it correct but obviously its not.
So as I said, where is the problem, SS or Mach?
Does anyone have a lathe on the PP that could test? I am SS, you are and also I think Daniel is.
Either way I think it will just have to be lived with for now or use the F/Min as Daniel has said, tested here and I get the same results as Daniel. Brian is going to be looking at Turn but when I dont know and I certainly wouldnt be holding my breath and Greg seems to be up to his ears as well so not looking like he will be having a look at it any time soon, sometimes its a bitch to be in a minority :(
Hood
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Hood Thanks for trying, at least i know it's not me this time. ::)
Maybe it's Rich's fault he's been mucking about for ages with screwcutting/threading, why hasn't he sorted out CCS ;D
So if you have a lathe and a SS and you want to use CCS, add your name here and maybe we could get a delegation over to Art/Brian's or Greggs to get it sorted ASAP. 8)
Those router boys can wait for a change. ;D ;D ;D
Dan13 Thanks for the suggestion but i want it all.
Phil
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Phill, sorry to say the Mill and Router guys have a louder voice than the Lathe guys and then of course there are the OEM guys. Brian will eventually get round to Turn and the work he is doing on Rev 4 will make things better for us and also easier for him to do the work on Turn. We will hopefully get a Christmas present of a new Turn but dont look for it this Christmas, maybe next LOL
Hood
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Hood
Thanks for the bad news
Is it definitely working in PP as i may change over
I went SS so as to use a laptop
Are there any solutions
Phil
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Phil
Dont know regards the PP, I never had a servo on the spindle when I used the lathe with the PP , the speeds were controlled by a gearbox with electromagnetic clutches so only set speeds. When I put the servo on I was already using the SS and had problems with CSS so I asked here and a couple of people said it worked fine with the PP so I presumed it was an SS issue only.
Hood
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Phil,
Never even tried CCS. Have both PP and SS available but have been using just the PP since i got the new computer. The VFD and motor is "holding down the floor" as i just set the speed with belts and all turns out just nicely. One day i will get sophisticated, but until then, think i'll just make some stuff for a change.
Now on the bright side of things, i must say that I have been using your lathe screen and like it. Need to have you put a few indicators on the screen showing what is active.
Sometimes it's just fun to have some fun making something. Heck, a few more days and the nodel will be done.
I remember Brian saying that he would have the lathe stuff up to snuff by March. I think he just got the year wrong! ;)
RICH
BTW, The SS was to have backlash done a year ago. Since then built a new lathe and bought a computer to fix the problem. Sometimes things just ain't worth waiting for , life is short, if you know what i mean! ;D
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Phil,
Never even tried CCS. Have both PP and SS available but have been using just the PP since i got the new computer. The VFD and motor is "holding down the floor" as i just set the speed with belts and all turns out just nicely. One day i will get sophisticated, but until then, think i'll just make some stuff for a change.
Rich i cant believe you or anyone else doesn't see the benefit of CCS. Think of it as screwcutting across the face of a job, or a mill guy saying i do all my jobs at one cutter speed
Phil,
Now on the bright side of things, i must say that I have been using your lathe screen and like it. Need to have you put a few indicators on the screen showing what is active.
I am humbled, what indicators are these then ?
I remember Brian saying that he would have the lathe stuff up to snuff by March. I think he just got the year wrong! ;)
Lets hope its this decade ;D
BTW, The SS was to have backlash done a year ago. Since then built a new lathe and bought a computer to fix the problem. Sometimes things just ain't worth waiting for , life is short, if you know what i mean! ;D
I can understand Greg's reluctance to do feedback comp when there is a new revision of Mach Imminent :o that supposedly has comp built in
Phil
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Phil,
I can appreciate the value of CCS since i mimic it on the larger lathe by varing the speed when doing facing or turning down larger stock. The cnc'd lathe is a 6" converted Atlas and most all the things done on it have been rather small. In fact I have yet to finish it completely so all the assessories can be used.
I'll post the lathe screen additions and if you get a chance maybe you can add them. The original lathe screens can drive someone bonkers. I liked yours since it is more usable and retains the original such that if a user were to have a question you can relate. I will post what I think should be added and you can be the judge.
RICH
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Guys, where can I find this screen set?
Daniel
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Phil,
It would be nice to know the current state in turn at a quick glance. So if the indicators can be added to
the screen it would be benificial. See attached.
RICH
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Dan...This it ?
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I am finishing up a lathe retrofit using parallel ports (2) for control. It uses servo motors on the axis drives. It has an 8 station turret which is actuated by a stepper motor. Pneumatic lock.
I have gotten it setup to use constant surface speed and it works quite well. It definitely gives the VFD a workout!
I may be able to post some movies of it in action if there is any interest.
The idea of a touch screen is next on the to do list. Looks good to me.
Jim
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Updated screenset here http://www.machsupport.com/forum/index.php/topic,12686.0.html (http://www.machsupport.com/forum/index.php/topic,12686.0.html)
Version 18
Phil
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Just an update.
Looks like it is Mach that is screwed on this rather than the SmoothStepper, asked a few people on the Yahoo group and Steve Blackmore said it works fine in the old version of Mach he uses with the PP but Simon Daykin has tested again using the PP with a newer version and it does the feed per rev funny things that we are seeing with the SmoothStepper.
Hood
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Hood, thanks for the heads up.
I did try with no luck clicking the speed reduction dro while facing, made no difference.