Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: jaja on June 27, 2009, 03:15:11 PM

Title: shuttle mode, step/velocity and single step
Post by: jaja on June 27, 2009, 03:15:11 PM
Forum members,

Finally installed and tested one MPG. Works super! Tommorrow I will place the second one.
Some questions in the shuttle window:
1  In single step mode, if I turn the mpg, not every click is one step, although the pause between the clicks is long enough.
   This is strange because in multi step mode every click is absolutely one step.
2  The step/velocity mode has a DRO next to it. I can not find any difference in changing its values, so what do they do? And also, if the turning speed of the MPG is slow enough, and you enter the stepmode from the step/velocity mode, the steps are all different in size.

I'm still cutting air, but cannot wait trying it for real,, must be much more fun compared with the old cnc program, which had none of these possibility's.

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on June 27, 2009, 03:36:20 PM
Your issue with the step mode not working on every click could be due to your resolution, for example if you had 500 steps per mm in your motor tuning that would be a resolution of 1/500 = 0.002mm. Now if you had the step increment set at 0.001mm then one click would have to move 0.002mm so Mach would not move it but the next clcik would mean you have asked in total for 0.02mm moves so Mach can then move as that is your minimum resolution.

Step/Velocity I dont think works and has never really worked from what I remember but Art would be the one to say for sure.

I only ever use Velocity mode and Multi Step mode and I never change the step increment, it is always set to 0.01mm, but you may find you prefer things differently.
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on June 28, 2009, 03:55:19 AM
Hood,

Thanks again for your answer, (I hoped your reaction should come quickly, and it did)
The size of the step was 1,000. The MPG has 25 clicks per revolution. So I think that every click should be one step (in single step mode).
It is also typical that it is not regular. It can make 9 or 10 clicks and move every click, and then suddenly it can make 3, 5 or even 7 clicks without moving.

But your suggestion in putting it in Multi Step mode 0.01mm and in Velocity mode, is probably the best for me too. I really don't know yet, as I have never used the program in real.
Today some more test and build up will be done.
Thanks, and I'll let you know
gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on June 28, 2009, 04:46:54 AM
If the size of the step was 1.00 then it should move every step, just wondering if you have done the MPG calibration? Not sure if that would help or not.
It sounds more like the steps are not being seen by Mach for some reason, maybe a high debounce ?
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on June 28, 2009, 05:57:12 AM
Again,, thank you Hood,

This debounce is a very good idea, going to try it directly.
Perhaps it can also shorten the time between turning the MPG and the moves of the motor, since the optical encoders have no hysterese at all, so no debounce time is needed, I think.

I have done the calibration several times to figure out which turning speed of the MPG was comfortable, so this is not the fault I suppose.
One detent (click) of the MPG in the calibration screen gives a calculated number of 4. So mach sees the 4 sides (flanks?) of the signal, which should be correct.
Don't know how the relation between this calibration and the: "count/unit" on the  Port and Pins configuration screen, Encoder/MPG's is.
Going to check it right now

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on June 28, 2009, 07:37:51 AM
The time between the MPG turning and motor moving should be almost instantaneous. Accel can affect it in that if your accell/decel is etremely slow then it may look like it is not starting right away but it would be more noticeable when stopping as the axis would decel to a stop and still be moving after you had stopped turning the MPG.
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on June 30, 2009, 03:09:58 PM
Hood,
Thanks to you, things are working good right now (but I'm still only cutting air).
At this moment I'm trying to connect some hotkey's to some buttons on the screen. It would be much more convenient.
Have read a lot on the forum, and I have also read the answer to the next question, but I still cannot find it.

I think I need screen 4 to make/connect the hotkeys, and screen 4 should be in the root of mach3 on my computer or otherwise it could be downloaded from the download page.
But I cannot find it overthere. Is it called screen 4?
Is it on: downloads>screensets ???
gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on June 30, 2009, 03:13:22 PM
its on the programme  downloads page near the bottom
http://www.machsupport.com/downloads.php

Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on June 30, 2009, 03:26:21 PM
Thanks Hood,
Going to try it right away.
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 03, 2009, 03:47:10 PM
Hood,
The mach screen 4 is fantastic! I have been experimenting with it the whole week.
But now another question appearred.
The "Part Coords." button, what is his function?
No matter what I do,,, it always has the same values as the Program Coords.
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on July 03, 2009, 03:57:31 PM
Sorry dont have a clue, when I first got the lathe setup I looked at the standard screenset and couldnt work out what half of it did so made my own, afraid I am impatient like that :D
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 03, 2009, 04:20:10 PM
Thanks Hood,

There is another topic on this item, but the answer is not so clear to me.
"normaly you should have Machine, Part and User coordinate. where part is your G54 zero point and user is an extra coordinate used for set-up or manual operation."

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on July 03, 2009, 04:48:19 PM
Suppose it must be something like an offset of some sort, why it would be needed I dont know.
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 05, 2009, 09:21:00 AM
Hood,

1    The whole morning I have been testing the lathe for real,, on some pieces of metal (don't know any specifications, its not to hard, that is all I know, could be steel 37).
Mach3 is so much better than my old program!
Sweat on the forehead. One mistake with the jog cycle. Made a 10mm step on the z-axis, and by mistake I also made just before on the x-axis.
So I tried to cut 10mm in one cut. The toolholder was not to tight, so it was pushed aside,,, the insert broke.
That leads to the question: is there a way of having different jog cycle steps for the z- and x-axis, so you will never use the one for the z-axis on the x-axis?

2   Also had i strange thing with a program wizard.
The program showed a F 42 value, but the feed read out showed it was in real 66 mm/min.
Could it be caused by the feed override which I did before on the manual screen? I think not, because for as far as I know, it is not possible to change the feedrate while a program is running.

3   Once I read on the forum (and I think it was your message) about the feed and speed values. Could you give me a guideline on this subject? I have been testing and trying, but it would be nice to have some sort of guideline on this. I know it depends on a lot of things like the construction of your lathe, the power of the steppers, the size of the toolholder and so on,,, but a rough guideline would be nice.

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on July 05, 2009, 10:45:41 AM
Hood,

1    The whole morning I have been testing the lathe for real,, on some pieces of metal (don't know any specifications, its not to hard, that is all I know, could be steel 37).
Mach3 is so much better than my old program!
Sweat on the forehead. One mistake with the jog cycle. Made a 10mm step on the z-axis, and by mistake I also made just before on the x-axis.
So I tried to cut 10mm in one cut. The toolholder was not to tight, so it was pushed aside,,, the insert broke.
That leads to the question: is there a way of having different jog cycle steps for the z- and x-axis, so you will never use the one for the z-axis on the x-axis?

Not as far as I know.



2   Also had i strange thing with a program wizard.
The program showed a F 42 value, but the feed read out showed it was in real 66 mm/min.
Could it be caused by the feed override which I did before on the manual screen? I think not, because for as far as I know, it is not possible to change the feedrate while a program is running.

Feedrate override will be in effect until it has been reset. And FRO can be changed whilst code is running.

3   Once I read on the forum (and I think it was your message) about the feed and speed values. Could you give me a guideline on this subject? I have been testing and trying, but it would be nice to have some sort of guideline on this. I know it depends on a lot of things like the construction of your lathe, the power of the steppers, the size of the toolholder and so on,,, but a rough guideline would be nice.

gr jaja

With a lathe it is best to use G95 (Feed per Rev) as it makes things a lot simpler as you only have to think of the spindle speed. Obviously you will need to have spindle feedback to use G95 but most do on a lathe as it is needed for threading.
Feeds I normally use are, for  roughing  somewhere between 0.2 to 0.3mm/rev and  for finishing 0.1 to 0.15mm/rev

Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 05, 2009, 11:14:33 AM
Thanks Hood,
Have made a button with an OEM code and a hot key for the feed reset, works good.
The feed/rev is not yet working on my lathe. I have not been able to mount a optical device at this moment. But I could not wait testing mach3 on my lathe!
I will use your guideline as soon as the spindle feedback is finished.

Thanks again Hood.
gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: RICH on July 05, 2009, 09:43:21 PM
JAJA,
Let me take a try at this  for you and hope i don't confuse.

It basicaly all has to do with offsets.The displayed axis coordinates can be Machine, Part, or Program.
Remember that what is displayed is based on what you selected.ie; if you select machine coord's in the manual screen then the DRO's will display machine coord's. So heed also whether you are in diameter or radius mode.And alos reemener this should you happen to touch off  a tool. Machine coordinates are the location of the controlled point along the X & Z axis at any time. If you were to Zero World the X and Z ( which removes any WORK offsets G54 to G5? ) and then Set Home x and Z, and then make a move, you would see the controlled point location away from home in absolute values away form home. Now if you move say to a point on the stock and can set that as part coordinates. You would see different valaue in the DRO's. Now when you open a program there are also program coordinates which are just that, namely the coordinates which are in the gcode from a X & Z zero value.
Now you can have MAchine = Part= Program coordinates on the stock, to begin with,  if you set up that way. So you are defining to Mach where the controlled point is relative to max machine movements, defining to Mach where the part is  and the program coordinates are just what they are, but are related to where the controlled point is relative to the machine and the stock via offsets.
Yes it's confusing, and you need to take the time to get it all striaght in your mind.

Probably not the best explaination as i am doing it off the top of my head.

RICH



Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 06, 2009, 10:22:44 AM
Rich,
No Rich, you made perfectly clear what part- coordinates are.
Your story explains it all.
Thanks a lot.

Now I'm going to work with it, in order to get some real "grip" on it.

Thanks
gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 08, 2009, 05:38:09 PM
Hood,
1   Can you give me your opinion about a shuttle for a lathe. Are two MPG's preferable, when you compare them with a shuttle or some sort of a joystick?
At this moment I have two MPG's installed and they work fine. So I wonder if a shuttle would give a better situation I have read a lot on the forum, but most of it handles about how to install such a device, and not what the benefits are.
2   The shuttle mode on the tab screen, what does it do? What can I do with my lathe, if I put it on (at this moment nothing).

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on July 09, 2009, 02:15:13 AM
I just use my MPG for positioning and touching off, occasionally I will use it for a cut but find MDI easier and quicker for that. I have one MPG and two (three on mill) physical buttons to change the MPG to a different axis.

I have never used Shuttle mode but I Think  it is used with the MPG as follows, you load code and have shuttle mode active, press start and when you turn the MPG the code will start running, it will stop when you stop rotating the MPG and will start again whaen you again start turning.
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 09, 2009, 09:16:00 AM
Hood,
1    suppose you want to make this item


     I would give the jog cycle Doro a value which would correspond with the stairs on the z- axis, turn the z axis MPG one click, hit the "go to Zs" button (OEM code 1017) and then change the value of the jog cycle to 1 mm, turn the Axis MPG one click, change the step value to the previous value, turn the Axis MPG again, hit the "go to Zs" button and so on.
But reading your answer,,, I suppose there is a faster way of doing this.
Ike, one could use the wizards, but I'm curious how you would do a job like this
The problem with the way I described above, is that when you forget to change the jogcycle value, before turning the Axis, you would pound your tool into the stock!

2   I'm going to try the shuttel mode,,, thanks for your explanation

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 09, 2009, 09:25:06 AM
without misspelling (i hope)

Hood,
1    suppose you want to make this item


I would give the jogcycle DRO a value which would correspond with the stairs on the z-axis, turn the z-axis MPG one click, tool does its move, hit the "go to Zs" button (OEM code 1017,, return to x= 0 and y = 0) and then change the value of the jogcycle to 1 mm, turn the x-axis MPG one click, change the jogcycle value to the previous value, turn the z-axis MPG again, hit the "go to Zs" button and so on.
But reading your answer,,, I suppose there is a faster way of doing this.
I know, one could use the wizards, but I'm curious how you would do a job like this
The problem with the way I described above, is that when you forget to change the jogcycle value, before turning the Axis, you would pound your tool into the stock!

2   I'm going to try the shuttle mode,,, thanks for your explanation

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 12, 2009, 06:07:54 PM
What is the difference between feedhold en dwell?
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on July 13, 2009, 02:46:02 AM
Dwell is a pause of a set time eg G4 P2 will stop for 2 seconds, or you may have a dwell set to allow your spindle get up to speed.
Feedhold is when you stop the code in a controlled manner and it wont resume again until you tell it to by pressing Start.
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 13, 2009, 03:29:33 AM
Completely clear Hood, thanks again.
 gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 27, 2009, 04:59:32 PM
Hood,
Did a lot of lathe work to get some experience, to get used to the machine and to make some things i never could make before I had a lathe.
Did a lot with the MPG's to be able to control things by  hand.
Here is the question:
If you work with the arrow keys on your keyboard, you can use "continuous jog, and with the "slow jog %" you can determine how fast your tool moves.
Is something like this also possible when your working with the MPG's??

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: Hood on July 27, 2009, 05:17:28 PM
Dont think so, I never use the keyboard on my machines and very rarely use the MPG for actual cutting but think its only possible to have the MPG in velocity, multi step or step mode. In Step you can I think set the speed but thats not really any use, maybe it also works in multi step mode though, so that could possibly work.
Hood
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 27, 2009, 05:36:37 PM
Thanks Hood,
So I suppose you always use a wizard or a program to do your turning?

If I set the speed when I use the MPG's, there is always the danger of making to many steps.
I turn the MPG one click to much, and the tool doesn't stop on right place,,,, argh.

gr jaja

Title: Re: shuttle mode, step/velocity and single step
Post by: RICH on July 27, 2009, 06:25:23 PM
JAJA,
I have used my MPG's to do some cutting on the lathe. The stuff i was doing was small, and additionaly i was
looking throught a microcsope when doing the work. I mainly use my MPG's for positioning, and they are "calibrated for movement"  based the feel of turning the MPG wheel. Turn them fast and the axis moves quickly , just barely turn them and i can move at a crawl in very fine increments.
RICH
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 28, 2009, 04:28:27 PM
Interesting Rich,
Calibrated for movement,,, in what mode have you putted them?
1 velocity only
2 step/ velocity
3 single step
4 multi step
I think it must be velocity only,,, but then the smallest step you make is not so small at all
Step/velocity is confusing for me, no matter what value of the DRO next to it is, it does not make any difference (perhaps I make mistakes).

And the other lathe work you make, is it mostly done with a program???

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: RICH on July 28, 2009, 10:41:57 PM
JAJA,
I am usualy using them  in velocity only.
To get the movement i mentioned just fool with the counts / unit along with velocity settings in
CONFIG>PORT&PINS> ENCODER / MPG'S
Think my encoders are 2048 , just note  that i use them as stated and as such they are not truly callibrated.

Almost all my code for the work i do utilize wizards, Lazycam Turn along with LazyTurn  to generate the code.
Once in a while some other programs. Manual coding only when i need to edit or manipulate the Gcode.

PS: I am not exactly nuts about using an MPG to do actual machining .....just one slip on the wheel and .......
could be bad news!
RICH
Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 29, 2009, 05:00:31 AM
Rich,
Thanks for your answer.
I am going to play with the MPG configuration you mentioned. It seems a good idea.
My MPG's do 25 clicks or counts per revolution.

Have read everything about lazyturn. As soon as I am more self-confident with my lathe, I will use this program (and buy it). But for this moment, using the MPG's and connecting the wizards together is more than enough.

Another subject:
When I bought this lathe (with an old Atari computer and a totally different, very simple cnc program) all my friend advised my not to buy it. "You will never need to do tapers, arcs or fillets" they said, "and you will never be able to do some proper turning on such a device,,,much,, much to complicated". Now they ask me to do some work they can't do on their own machines (like a tooladapter with tapered backend). ;D

gr jaja
Title: Re: shuttle mode, step/velocity and single step
Post by: RICH on July 29, 2009, 07:51:30 AM
jaja,
A CNC lathe lets you machine stuff that would be very difficult to do on a manual machine.

If you looked through the LazyTurn manual, then take a look at the manual for LazyCam.
I just posted an updated version of it which includes a Lathe section and uses the same file
from LT's manual / section 5.

There are two problems a new user must address when using cnc with code generated from any software:
1. Tool application to the piece you want to machine along with defining the machining steps and order of machining

2. The basic prepratory lathe setup and also proper start and return of the tool

LC Turn can do some things that are not yet implimented in LT and the license for LC Turn will be honored for
LazyTurn ( as i understand it ). They are two different programs! That said, you will not find a lathe program anywhere for the License price, for what you get, even within the limitations of both. 
RICH

Title: Re: shuttle mode, step/velocity and single step
Post by: jaja on July 29, 2009, 04:57:37 PM
Thanks for your reply Rich.

You are right about the money. I think that programs like mach and lazy cam or turn, should be payed for, as a sign of respect to all the people who worked on it.

I do not understand your remarks 1 and 2,,, tool application- you mean which tool you use for a specific part you are turning?
And the basic prepratory lathe setup????
I know there is still a lot to learn for me.

I will read your manual, perhaps it gives me some understanding of the subject

gr jaja