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Author Topic: Mach3 and latest ESS Driver - threading now works!  (Read 3234 times)

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Offline Katoh

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #40 on: May 01, 2020, 09:15:13 PM »
Hi Roger
That's awesome if it does work!
Where can I find more information about the hookup of this? Its being a long time since I played around with things.
Could I use feedback from my servo? Sorry for the stupid questions just trying to put things in language I understand.
Cheers
Katoh
Cheers
Katoh

Offline rcaffin

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #41 on: May 01, 2020, 10:05:46 PM »
Ah, well, um.
The 'manual' has not been written yet. This thread is probably IT.
Yes, you have to use feedback from an encoder on your spindle motor.

Basically, you need the LATEST driver, an adequate encoder on the spindle motor, an input pin for what will be called the MPG A signal, while keeping the Index pulse as well. The MPG A signal is used because Mach3 can be configured to use it without any hassles.

My encoder has 512 lines: 16*32. A 256 line encoder might do. Got some doubts about going very far down from that. Well, a 100 line encoder (10*10) would work, just not as well. Better than nothing of course!

Cheers

Offline Katoh

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #42 on: May 02, 2020, 12:05:28 AM »
Quote
Ah, well, um.
The 'manual' has not been written yet.

Haha , that’s funny!

Ok I will install the newest version of the ESS software step1
On the lathe already is the single slotted disk from previous version, I keep this attached on "index pulse" step2
From my servo drive I have 3 outputs A,B and Z I connect the A+ and A- to the mpg1 input step3
On the servo drive I found two parameters I may need to alter that being the "speed output electronic gear ratio numerator and denominator values" I take it because I have a 1.25/1.0 drive ratio to the spindle. I take it that it should be 100/80 Step4
Now is the part I’m uncertain about, what is the configuration in the software to make all this happen? The other thing is I’m not certain what the encoder pir from the servo is? I take it will be quite a high value, still researching that one. I think its 2500

Thanks for your help Roger!
Cheers
Katoh
Re: Mach3 and latest ESS Driver - threading now works!
« Reply #43 on: May 02, 2020, 12:14:41 AM »
Hi,

Quote
Could I use feedback from my servo? Sorry for the stupid questions just trying to put things in language I understand.

Yes and no. You could use the servo encoder to Mach and that would allow Mach to correctly calculate the spindle rpm.
What Mach, or rather the motion controller, requires in addition is an index signal ONCE PER SPINDLE REVOLUTION.
The motion controller uses the index signal to start the thread. If multiple passes are required to cut the thread to the target
depth then the index signal is critical to get succesive passes synchronised.

As you have a belt reduction between the servo and the spindle the index pulse of the servo encoder will not suffice for
an index signal for thread synchronisation. You either have to ensure that the reduction is exactly 1:1 so that the srevo encoder
index pulse occurrs once per spindle revolutio OR you need to add an index pulse genertor to the spindle.

Craig
My wife left with my best friend...
     and I miss him!

Offline Katoh

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #44 on: May 02, 2020, 12:30:08 AM »
Hi Craig

Yes I do have an index input directly from spindle to mach3, in the form of a slotted disk only one slot triggers an opto sensor works a treat, before I went to the ESS it worked with just the BOB,s use to thread Ok not brilliant but worked.
What I just sort of noticed then is the thread cuts but wants to put a second thread 180 deg from the first one started. look at the pic. Bizzare!
Cheers
Katoh

Offline rcaffin

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #45 on: May 02, 2020, 12:46:57 AM »
A belt drive? Um, I missed that.
I agree with Craig: the encoder must be on the spindle too. There is too much room for slip and slop with a belt drive for the encoder. This does not mean you can't have a belt drive - far from it. but all sync must be to the spindle itself.

Cheers
Re: Mach3 and latest ESS Driver - threading now works!
« Reply #46 on: May 02, 2020, 01:01:36 AM »
Hi,
yes, if you use a belt drive it not only needs to be 1:1 but it can have no slip, ie it has to be a toothed 'timing belt'
type otherwise successive thread passes will result in disaster.

Just as a matter of interest how are you driving your servo, step/direction or 0-10V analogue?

I ask because if you use 0-10V analogue, which is by far the most common control methodology for hobby spindles,
then the ESS plugin for Mach4 offers a subtle but powerful advantage over the ESS and Mach3.

In particular the ESS can execute a PID control loop over the spindle motor with the PWM (effectively the 0-10V analogue)
as the controlled variable. This allows for marginally powered and/or low inertia spindles to be precisely and acitvely
speed controlled resulting in more accurate threading.

Note that this speed controll still requires a 'once per spindle revolution index signal' for thread synchronisation.

Craig
My wife left with my best friend...
     and I miss him!

Offline Katoh

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #47 on: May 02, 2020, 03:31:12 AM »
I should clarify a things first.
The spindle is driven by a timing toothed belt, absolute no give in that one.
The timing is still controlled by a slotted timing disk directly off the spindle.
The AC servo works of step and direction, funnily enough I forget certain things that I’ve done and its encoder runs back to mach already on the mpg1, when programming a speed its rock solid in the spindle.
I haven’t yet had a chance to upgrade the software but I am thinking now its something in the config settings.
I an turn the spindle by hand and get an rpm to show on the screen.

Dont know.
Cheers
Katoh

Offline Katoh

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #48 on: May 02, 2020, 03:51:24 AM »
Hi all
Thanks for all your help, just a quick update working still on the older software I managed to find some errors, my errors more than anything. I had set the ESS config to RPM setup from mpeg where I only had figures of 1 and 1 in there it was actually still getting rpm feedback from the slotted disk on the spindle (don’t know how). Turns out if I changed a few figures to what they should be it works as it should feedback from the servo and correct speeds through mpeg pulses.
I wish I knew this earlier! A quick trial produced a 1-1/8" UNF thread in some 1020, without an issue. Later I will attempt to load the latest ESS software and do a few more trails, Ill keep you all posted.
Thanks Roger, if this all goes well I maybe able to help you write that manual.  ::)
Cheers
Katoh
Cheers
Katoh

Offline Katoh

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Re: Mach3 and latest ESS Driver - threading now works!
« Reply #49 on: May 02, 2020, 11:29:18 AM »
Hi Friends
In this crazy world its amazing how quickly things change. I installed the new ESS software and it seems to be fine, quick test I cut a M12 thread in some mild steel, even cut an M4 thread into a nail, was impressive then tried a larger thread and it all went to hell >:(.
Started doing its usual starting from a random point? The rpm is rock solid, the only thing I notice is the index pulse, on the diagnostic page works well when turned by hand but anything above 20rpm fails to show the index light flash on the on the screen.
On the bob it shows every pulse flash next to its input pin but not on the mach diagnostic page only shows random flashers, could this be the issue?
Thanks
Katoh
Cheers
Katoh