On Monday 30 October 2017 22:58:06 Chris Albertson wrote:
> On Mon, Oct 30, 2017 at 7:13 PM, Gene Heskett
wrote:
> > On Monday 30 October 2017 19:52:00 Chris Albertson wrote:
> > > I think I see a reason why advice about PIDs used an axis and a
> > > spindle might differ. The axis servo will ha
Andy,
Thanks, Will research STMBL.
I think now that any protocol that puts data for all axis inside the same
packet has to work.
One question: So I have a LinuxCNC system writing (X,Y,Z) to ethernet at a
nominal 1,000 points per second. That is one point every 0.001 seconds.
What is the effe
On Mon, Oct 30, 2017 at 7:13 PM, Gene Heskett wrote:
> On Monday 30 October 2017 19:52:00 Chris Albertson wrote:
>
> > I think I see a reason why advice about PIDs used an axis and a
> > spindle might differ. The axis servo will have a huge about of
> > gearing so the motor will run fast and the
On Monday 30 October 2017 19:52:00 Chris Albertson wrote:
> I think I see a reason why advice about PIDs used an axis and a
> spindle might differ. The axis servo will have a huge about of
> gearing so the motor will run fast and the controller will see a lot
> of edges per PID loop interval.
>
>
On Monday 30 October 2017 17:07:28 Nicklas Karlsson wrote:
> > A real time host is still needed for CNC coordinated motion with
> > Ethercat slaves. Ethercat does no change this at all. Laptops will
> > work in some circumstances but can cause troubles with multiple ms
> > real time delays when do
On Monday 30 October 2017 15:26:06 Chris Albertson wrote:
> From what I know of control theory you are right. You will not find a
> set of gains that work for both gear ratios. The gears are doing
> their job and changing the apparent momentum of the spindle and
> available motor torque by quite
I think the difference between position and velocity is how the error
signal is computed. After you have that. I don't think a PID algorithm
cares if it is controlling temperature, heading, airspeed or position.
Originally the algorithm was invented for steering ships at sea on a
constant headin
On 30 October 2017 at 23:52, Chris Albertson wrote:
> I think I see a reason why advice about PIDs used an axis and a spindle
> might differ. The axis servo will have a huge about of gearing so the
> motor will run fast and the controller will see a lot of edges per PID loop
> interval.
The big
I think I see a reason why advice about PIDs used an axis and a spindle
might differ. The axis servo will have a huge about of gearing so the
motor will run fast and the controller will see a lot of edges per PID loop
interval.
If Gene is using a gear tooth sensor on an 80 tooth gear and running
Yes, velocity control.
There are two basic ways to go. Decide what you are going to measure.
Decide based on how fast the motor runs at lowest speed and the the PID
loop period.
Method #1. Count the number of encoder ticks. Every PID loop interval
your error signal is the courted number of ti
On Mon, 30 Oct 2017, Gene Heskett wrote:
Date: Mon, 30 Oct 2017 18:44:49 -0400
From: Gene Heskett
Reply-To: "Enhanced Machine Controller (EMC)"
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Spindle pid problems
On Monday 30 October 2017 15:20:35 andy pugh wrote:
On 30 Oct
On Monday 30 October 2017 15:20:35 andy pugh wrote:
> On 30 October 2017 at 17:49, Gene Heskett wrote:
> > Which is computationally less cpu usage 1, a 6 pack of mux2's, or
> > another pid with separate settings and just one mux2 to select which
> > pid gets sent to the spindle servo?
>
> PID is
> This seems to be a very nice design although he points to possible
> improvements.
> https://github.com/DieBieEngineering/DieBieSlave
>
> The firmware is here. It seems to be under active development as the last
> change was two months ago.
> https://github.com/DieBieEngineering/DieBieSlave-Fi
On 30 October 2017 at 21:18, andy pugh wrote:
> This is where it gets complicated. I have certainly seen ten of them
> in one place at the same time. But I think that if you want a lot, you
> need to make them or have them made at the moment.
Here are some in action:
https://www.youtube.com/watc
On 30 October 2017 at 20:58, Nicklas Karlsson
wrote:
>> You could look at STMBL.It's an STM32-based servo drive. Communication
>> with the LinuxCNC system is by CAT5 cables carrying the Mesa
>> Smart-Serial protocol.
>
> What kind of signals there in this protocol?
Smart-serial is RS485 at 2.5Mb
> The video is very good and he walks through the design in detail.
> Actually, it was enough to make me think canbus might be simpler.
Canbus is simpler but I calculated speed will be at the limit so I will not
build something new with CANbus.
---
> A real time host is still needed for CNC coordinated motion with Ethercat
> slaves. Ethercat does no change this at all. Laptops will work in some
> circumstances but can cause troubles with multiple ms real time delays
> when doing power management tasks.
A smart device could figure out the
> You could look at STMBL.It's an STM32-based servo drive. Communication
> with the LinuxCNC system is by CAT5 cables carrying the Mesa
> Smart-Serial protocol.
What kind of signals there in this protocol? Is it possible to get like ten of
these?
> (quadrature and step/dir also supported)
> With
>From what I know of control theory you are right. You will not find a set
of gains that work for both gear ratios. The gears are doing their job and
changing the apparent momentum of the spindle and available motor torque by
quite a lot.
I think you will need an input to the controller to tell
On 30 October 2017 at 17:49, Gene Heskett wrote:
> Which is computationally less cpu usage 1, a 6 pack of mux2's, or another
> pid with separate settings and just one mux2 to select which pid gets
> sent to the spindle servo?
PID is not very CPU intensive, neither is mux2. I wouldn't really
worr
Greetings all;
I've been playing with pid settings for the spindle on the G0704 until
I'm discouraged at ever coming up with a setting that is useable in both
high and low gears of the head. What works great at 300 revs in low gear
sound like its ripping the teeth off the gears from oscillation
> What I'm looking into is a distributed system with computing pushed closer
> to where it is used. Grapical stuff should happen on a GPU connected to
> the monitor. Servo lop can be close on the motor
Control loop for servo make sense to run twice each switching period, slower
might be enou
Timing is everything!
Ray
--J. Ray Mitchell Jr.
jrmitche...@gmail.com
(818)324-7573
The dogmas of the quiet past, are inadequate to the stormy present. The
occasion is piled high with difficulty, and we must rise with the occasion.
As our case is new, so we must think anew and act anew. We mus
On Monday 30 October 2017 04:22:06 Chris Albertson wrote:
> The whole _point_ of EMC was to do the realtime on off-the shelf
>
> > general purpose computers rather than on specialised hardware.
>
> Yes, that was the point. But look today people are building systems
> using a $35 ARM based "PC co
On 10/29/2017 08:05 PM, Gene Heskett wrote:
Which I guess is why I've never noticed a problem other than
whatever creates it always creates it only with root perms. I'm the
only user, no others.
But it was always my understanding that tmp's were cleaned out in
the boot process. And thats not tru
On 30 October 2017 at 08:22, Chris Albertson wrote:
> I think the current trend in the industry is to move the control loops
> closer to the motors
...
> In fact I can by a STM32F on a PCB for less than the price of a good power
> cable.
...
> What I'm looking into is a distributed system with
>
> The cheapest system I could find is by Leadshine in China and the
> smallest size controller is $350 per axis but they are unable to
> support you if you are in North America buying low retail quantities.
>
> I looked into what it would take to build a DIY Ethercat based client
> controller.
The whole _point_ of EMC was to do the realtime on off-the shelf
> general purpose computers rather than on specialised hardware.
>
Yes, that was the point. But look today people are building systems using
a $35 ARM based "PC connected to a $100 FPGA board and then to a couple
hundred dollars wo
On Sunday 29 October 2017 23:47:27 jrmitchellj . wrote:
> I do have something resembling that, it will not likely find action in
> my shop.
>
> Ray
now you tell me. :)
The sheckles have been spent already. Maybe I should have asked the list
first?
> --J. Ray Mitchell Jr.
> jrmitche...@gmail.c
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