Re: [Emc-users] driver for a DC motor for a BS-1.

[Thaddeus Waldner]

Hazarding a guess here so...

It appears as if you are switching the direction signals at pwm frequency. This 
would switch the high side fets and those are slow and do have high switching 
losses. The intended design is for the low side fets (controlled by the PWM 
input) to be off until the switching is complete, and only then to resume 
current. Why did they choose those transistors for that application? Who 
knows.. maybe to eliminate the need for external bootstrap circuitry...



>>> But the switching losses in the olimex board, even at only
>>> a 1 kilohertz pwm are killers, getting it hot enough to
>>> burn a finger in just 2 or 3 seconds.


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Re: [Emc-users] driver for a DC motor for a BS-1.

[Gene Heskett]

On Monday 26 October 2020 22:33:36 Chris Albertson wrote:

> Gene, I've got a ton of these chips driving motors.  They work fine. 
> Just write the software to the datasheet spec.  If the chip is getting
> hot and the motor is not mechanically stalled then you are doing
> something wrong. For debug/development replace the motor with a 100R
> power resister and then you know 100% no more then 1/4 amp is flowing
> through it.

I don't think my junk box has such a critter. And the motor runs just 
fine when connected to the 24 volt supply.

>  Place a volt meter on the resister and watch the voltage 
> change with PWM duty cycle  Put an amp meter on the power supply.  A 
> motor not under load running at 50% PWM shouldn't use even one amp.  
> The chip will not be even warm
>
> One of the best investment you can make is a $10 logic analyzer.  The
> they can collect data on 8 pins at once.  Put on on every pin
>
> When I do a direction change I ALWAYS go through a "brake" mode on the
> way.

That is not possible withing hacking up something in hal which would soon 
run out of gpio. I am using the complimentary capability's of the 7i76 
to extract the dir- and dir+ signals, which change state simultaneously.
> I've never once seen a car with a 150 audio amp driving the 
> wind shield wipers.

But it could be done.

> The problem is you are trying to futz with both a new-to-you chip and
> LCC at the same time.

This is true.

> I keep an Arduino around for leaning how 
> controller chips work.  Arduino is a very simple and clean environment
> for experiments.   In fact there is an example program in the IDE for
> testing PWM controlled motor where you control the speed with a three
> terminal pot.
>
> On Mon, Oct 26, 2020 at 6:56 PM Gene Heskett  
wrote:
> > On Monday 26 October 2020 20:33:40 Jon Elson wrote:
> > > On 10/26/2020 06:48 PM, Gene Heskett wrote:
> > > > But the switching losses in the olimex board, even at only
> > > > a 1 kilohertz pwm are killers, getting it hot enough to
> > > > burn a finger in just 2 or 3 seconds. So, I need a d2a to
> > > > drive one of the 150 watt class D audio boards after
> > > > shorting the inputs hi-pass filters caps. And I have the
> > > > feeling that even as sweet as the SpinX1 is for knocking
> > > > around a vfd, that it won't be fast enough for this, so
> > > > I'll need a real d2a that I can shove fresh data thru at
> > > > servo-thread speeds. Looking for likely suspects I might
> > > > be able to drive from the 7i76D sserial extension bus.
> > > > Suggestions?
> > >
> > > I'm guessing the thing was designed for 50 Hz PWM or
> > > thereabouts. That might actually be OK for a spindle motor.
> > > Clearly NOT OK for a positioning servo.
> >
> > Jon, Its a car seat positioner driver, claims very low milliohm on
> > r's. $13 on fleabay. Looks promising, but writes checks it can't
> > cover even with a 1 kilohertz pwm. Rated up to 10 kilohertz.  Either
> > that or the first one is fubared. I bought two, and its not hard to
> > change. I'll measure the rise and fall times being delivered to it
> > tomorrow too on the chance the Sainsmart bob is slow. Manual claims
> > up to 10 Mbits/S at any output.  For driving switches, thats
> > bordering on cook it slow. 10ns rise and fall would be a heck of a
> > lot better.  Designed for car seats, in cmos circuits, rated on time
> > delay is 100 to 300us, off time is 85 to 255us.
> >
> > And change of direction is 600 to 1800us. In polite language, that
> > explains it all. For starters, there is no measureable lag coming
> > out of the 7i76 for a direction reversal.  So with our drive, this
> > thing probably has 150us of shoot thru time for any dir signal
> > change.  I could probably design an interfacing circuit that would
> > fix that, but IMNSHO that is the semi designers job.  And STM
> > failed, miserably. Thats not a problem in this particular circuit,
> > but that geological rise and fall times for the pwm are a killer,
> > even at 1 kilohertz. At 50 hz, maybe.  At 10KHz, nearly instant
> > overtemp shut down at 170C.  Sigh...

These last two paragraphs are also true. If you are driving one of these 
with linuxcnc, show me some .hal code and schematics. I am always open 
to learning something that "gets around" the limitations the semi stuff 
imposes on us.

> > Thanks Jon.
> >
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law
> > respectable. - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> 

Re: [Emc-users] driver for a DC motor for a BS-1.

[Chris Albertson]

Gene, I've got a ton of these chips driving motors.  They work fine.  Just
write the software to the datasheet spec.  If the chip is getting hot and
the motor is not mechanically stalled then you are doing something wrong.
 For debug/development replace the motor with a 100R power resister and
then you know 100% no more then 1/4 amp is flowing through it.   Place a
volt meter on the resister and watch the voltage change with PWM duty
cycle  Put an amp meter on the power supply.  A  motor not under load
running at 50% PWM shouldn't use even one amp.   The chip will not be even
warm

One of the best investment you can make is a $10 logic analyzer.  The they
can collect data on 8 pins at once.  Put on on every pin

When I do a direction change I ALWAYS go through a "brake" mode on the
way.   I've never once seen a car with a 150 audio amp driving the wind
shield wipers.

The problem is you are trying to futz with both a new-to-you chip and LCC
at the same time.   I keep an Arduino around for leaning how controller
chips work.  Arduino is a very simple and clean environment for
experiments.   In fact there is an example program in the IDE for testing
PWM controlled motor where you control the speed with a three terminal
pot.

On Mon, Oct 26, 2020 at 6:56 PM Gene Heskett  wrote:

> On Monday 26 October 2020 20:33:40 Jon Elson wrote:
>
> > On 10/26/2020 06:48 PM, Gene Heskett wrote:
> > > But the switching losses in the olimex board, even at only
> > > a 1 kilohertz pwm are killers, getting it hot enough to
> > > burn a finger in just 2 or 3 seconds. So, I need a d2a to
> > > drive one of the 150 watt class D audio boards after
> > > shorting the inputs hi-pass filters caps. And I have the
> > > feeling that even as sweet as the SpinX1 is for knocking
> > > around a vfd, that it won't be fast enough for this, so
> > > I'll need a real d2a that I can shove fresh data thru at
> > > servo-thread speeds. Looking for likely suspects I might
> > > be able to drive from the 7i76D sserial extension bus.
> > > Suggestions?
> >
> > I'm guessing the thing was designed for 50 Hz PWM or
> > thereabouts. That might actually be OK for a spindle motor.
> > Clearly NOT OK for a positioning servo.
> >
> Jon, Its a car seat positioner driver, claims very low milliohm on r's.
> $13 on fleabay. Looks promising, but write checks it can't cover even
> with a 1 kilohertz pwm. Rated up to 10 kilohertz.  Either that or the
> first one is fubared. I bought two, and its not hard to change. I'll
> measure the rise and fall times being delivered to it tomorrow too on
> the chance the Sainsmart bob is slow. Manual claims up to 10 Mbits/S at
> any output.  For driving switches, thats bordering on cook it slow. 10ns
> rise and fall would be a heck of a lot better.  Designed for car seats,
> in cmos circuits, rated on time delay is 100 to 300us, off time is 85 to
> 255us.
>
> And change of direction is 600 to 1800us. In polite language, that
> explains it all. For starters, there is no measureable lag coming out of
> the 7i76 for a direction reversal.  So with our drive, this thing
> probably has 150us of shoot thru time for any dir signal change.  I
> could probably design an interfacing circuit that would fix that, but
> IMNSHO that is the semi designers job.  And STM failed, miserably.
> Thats not a problem in this particular circuit, but that geological rise
> and fall times for the pwm are a killer, even at 1 kilohertz. At 50 hz,
> maybe.  At 10KHz, nearly instant overtemp shut down at 170C.  Sigh...
>
> Thanks Jon.
>
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] driver for a DC motor for a BS-1.

[Gene Heskett]

On Monday 26 October 2020 20:33:40 Jon Elson wrote:

> On 10/26/2020 06:48 PM, Gene Heskett wrote:
> > But the switching losses in the olimex board, even at only
> > a 1 kilohertz pwm are killers, getting it hot enough to
> > burn a finger in just 2 or 3 seconds. So, I need a d2a to
> > drive one of the 150 watt class D audio boards after
> > shorting the inputs hi-pass filters caps. And I have the
> > feeling that even as sweet as the SpinX1 is for knocking
> > around a vfd, that it won't be fast enough for this, so
> > I'll need a real d2a that I can shove fresh data thru at
> > servo-thread speeds. Looking for likely suspects I might
> > be able to drive from the 7i76D sserial extension bus.
> > Suggestions?
>
> I'm guessing the thing was designed for 50 Hz PWM or
> thereabouts. That might actually be OK for a spindle motor.
> Clearly NOT OK for a positioning servo.
>
Jon, Its a car seat positioner driver, claims very low milliohm on r's. 
$13 on fleabay. Looks promising, but write checks it can't cover even 
with a 1 kilohertz pwm. Rated up to 10 kilohertz.  Either that or the 
first one is fubared. I bought two, and its not hard to change. I'll 
measure the rise and fall times being delivered to it tomorrow too on 
the chance the Sainsmart bob is slow. Manual claims up to 10 Mbits/S at 
any output.  For driving switches, thats bordering on cook it slow. 10ns 
rise and fall would be a heck of a lot better.  Designed for car seats, 
in cmos circuits, rated on time delay is 100 to 300us, off time is 85 to 
255us.

And change of direction is 600 to 1800us. In polite language, that 
explains it all. For starters, there is no measureable lag coming out of 
the 7i76 for a direction reversal.  So with our drive, this thing 
probably has 150us of shoot thru time for any dir signal change.  I 
could probably design an interfacing circuit that would fix that, but 
IMNSHO that is the semi designers job.  And STM failed, miserably.
Thats not a problem in this particular circuit, but that geological rise 
and fall times for the pwm are a killer, even at 1 kilohertz. At 50 hz, 
maybe.  At 10KHz, nearly instant overtemp shut down at 170C.  Sigh...

Thanks Jon.

>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] PC Wont Boot Debian 10

[R C]

Hi John,


I ran into issues like that. different cards might give you different 
issues, some linux-es can be picky like that (especially when you'd have 
to mess with nouveau)


The firmware it is talking about is the linux firmware I think, not the 
firmware on the board.



Did you do the install with the  cli/text interface?  or the graphical 
interface?  It might simply not have seen the integrated graphics card 
when you were installing it.


(there might also be a bios setting, on how the onboard graphics is 
used, it can be disabled too. Also, it might be it isn't a true radeon 
chipset, and didn't get recognized.)




what I did is get a cheap/simple/used graphics card that will work, and 
got rid of the one that didn't play well. In your case that'd mean 
disabling the onboard graphics.



hope that helps


Ron


On 10/26/20 7:15 PM, John Figie wrote:

I forgot to add a subject
John Figie


On Mon, Oct 26, 2020 at 8:18 PM John Figie  wrote:


Dear LinuxCNC users

I started a project about 6 years ago that was delayed because of several
personal issues. I am now ready to begin putting together a computer that I
want to use to control a lathe. I want to install Debian 10 (buster) on my
PC.

I have 2 identical older MBs Asus M5A 78L-M LX. Each has an AMC Sempron 145
processor. I have been running one of these for the last 5 years with
Debian 8 and it seems to work fine. I selected these MBs because they
seemed to have reasonable performance with latency test. I recently
assembled the second MB and decided to install Debian 10 using a USB drive.
The installation completes, installs GRUB and then prompts to reboot.

The GRUB graphical menu screen looks fine.

When the new system boots the last message on the screen is:
[ OK ] Started GNOME Display Manager.
Nothing further happens on the screen.

If i boot with Linux 4.19.0-12 amd64 (recovery mode) then I am able to boot
successfully
At the prompt I can enter the command # journalctl -xb
Looking at the output there is one error displayed:

drm: radeon_pci_probe ERROR radeon kernel modesetting for R600 or later
requires firmware installed.

1) Is this error significant?
2) Do I really need this firmware? I am not using any graphics card -just
the built in graphics.  Gallium 0.4 on AMD RS780 I really don't want to
mess around with trying to flash new firmware on the MB. - but if that is
what it takes I might try to figure out how to do that.

If i swap hard drives with my working Debian 8 system then the new computer
boots normally to the debian 8 GNOME desktop.

If anyone can give me some hints or ideas to try I will appreciate your
help and kindness.

John Figie

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Re: [Emc-users] PC Wont Boot Debian 10

[Leonardo Marsaglia]

Hello John,

I had the same issue and I solved the problem using the "nomodeset" option
at the grub.

This should help:

https://askubuntu.com/questions/38780/how-do-i-set-nomodeset-after-ive-already-installed-ubuntu



El lun., 26 oct. 2020 a las 22:30, John Figie ()
escribió:

> I forgot to add a subject
> John Figie
>
>
> On Mon, Oct 26, 2020 at 8:18 PM John Figie  wrote:
>
> > Dear LinuxCNC users
> >
> > I started a project about 6 years ago that was delayed because of several
> > personal issues. I am now ready to begin putting together a computer
> that I
> > want to use to control a lathe. I want to install Debian 10 (buster) on
> my
> > PC.
> >
> > I have 2 identical older MBs Asus M5A 78L-M LX. Each has an AMC Sempron
> 145
> > processor. I have been running one of these for the last 5 years with
> > Debian 8 and it seems to work fine. I selected these MBs because they
> > seemed to have reasonable performance with latency test. I recently
> > assembled the second MB and decided to install Debian 10 using a USB
> drive.
> > The installation completes, installs GRUB and then prompts to reboot.
> >
> > The GRUB graphical menu screen looks fine.
> >
> > When the new system boots the last message on the screen is:
> > [ OK ] Started GNOME Display Manager.
> > Nothing further happens on the screen.
> >
> > If i boot with Linux 4.19.0-12 amd64 (recovery mode) then I am able to
> boot
> > successfully
> > At the prompt I can enter the command # journalctl -xb
> > Looking at the output there is one error displayed:
> >
> > drm: radeon_pci_probe ERROR radeon kernel modesetting for R600 or later
> > requires firmware installed.
> >
> > 1) Is this error significant?
> > 2) Do I really need this firmware? I am not using any graphics card -just
> > the built in graphics.  Gallium 0.4 on AMD RS780 I really don't want to
> > mess around with trying to flash new firmware on the MB. - but if that is
> > what it takes I might try to figure out how to do that.
> >
> > If i swap hard drives with my working Debian 8 system then the new
> computer
> > boots normally to the debian 8 GNOME desktop.
> >
> > If anyone can give me some hints or ideas to try I will appreciate your
> > help and kindness.
> >
> > John Figie
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
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Re: [Emc-users] PC Wont Boot Debian 10

[John Figie]

I forgot to add a subject
John Figie


On Mon, Oct 26, 2020 at 8:18 PM John Figie  wrote:

> Dear LinuxCNC users
>
> I started a project about 6 years ago that was delayed because of several
> personal issues. I am now ready to begin putting together a computer that I
> want to use to control a lathe. I want to install Debian 10 (buster) on my
> PC.
>
> I have 2 identical older MBs Asus M5A 78L-M LX. Each has an AMC Sempron 145
> processor. I have been running one of these for the last 5 years with
> Debian 8 and it seems to work fine. I selected these MBs because they
> seemed to have reasonable performance with latency test. I recently
> assembled the second MB and decided to install Debian 10 using a USB drive.
> The installation completes, installs GRUB and then prompts to reboot.
>
> The GRUB graphical menu screen looks fine.
>
> When the new system boots the last message on the screen is:
> [ OK ] Started GNOME Display Manager.
> Nothing further happens on the screen.
>
> If i boot with Linux 4.19.0-12 amd64 (recovery mode) then I am able to boot
> successfully
> At the prompt I can enter the command # journalctl -xb
> Looking at the output there is one error displayed:
>
> drm: radeon_pci_probe ERROR radeon kernel modesetting for R600 or later
> requires firmware installed.
>
> 1) Is this error significant?
> 2) Do I really need this firmware? I am not using any graphics card -just
> the built in graphics.  Gallium 0.4 on AMD RS780 I really don't want to
> mess around with trying to flash new firmware on the MB. - but if that is
> what it takes I might try to figure out how to do that.
>
> If i swap hard drives with my working Debian 8 system then the new computer
> boots normally to the debian 8 GNOME desktop.
>
> If anyone can give me some hints or ideas to try I will appreciate your
> help and kindness.
>
> John Figie
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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[Emc-users] (no subject)

[John Figie]

Dear LinuxCNC users

I started a project about 6 years ago that was delayed because of several
personal issues. I am now ready to begin putting together a computer that I
want to use to control a lathe. I want to install Debian 10 (buster) on my
PC.

I have 2 identical older MBs Asus M5A 78L-M LX. Each has an AMC Sempron 145
processor. I have been running one of these for the last 5 years with
Debian 8 and it seems to work fine. I selected these MBs because they
seemed to have reasonable performance with latency test. I recently
assembled the second MB and decided to install Debian 10 using a USB drive.
The installation completes, installs GRUB and then prompts to reboot.

The GRUB graphical menu screen looks fine.

When the new system boots the last message on the screen is:
[ OK ] Started GNOME Display Manager.
Nothing further happens on the screen.

If i boot with Linux 4.19.0-12 amd64 (recovery mode) then I am able to boot
successfully
At the prompt I can enter the command # journalctl -xb
Looking at the output there is one error displayed:

drm: radeon_pci_probe ERROR radeon kernel modesetting for R600 or later
requires firmware installed.

1) Is this error significant?
2) Do I really need this firmware? I am not using any graphics card -just
the built in graphics.  Gallium 0.4 on AMD RS780 I really don't want to
mess around with trying to flash new firmware on the MB. - but if that is
what it takes I might try to figure out how to do that.

If i swap hard drives with my working Debian 8 system then the new computer
boots normally to the debian 8 GNOME desktop.

If anyone can give me some hints or ideas to try I will appreciate your
help and kindness.

John Figie

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Re: [Emc-users] driver for a DC motor for a BS-1.

[Jon Elson]

On 10/26/2020 06:48 PM, Gene Heskett wrote:
But the switching losses in the olimex board, even at only 
a 1 kilohertz pwm are killers, getting it hot enough to 
burn a finger in just 2 or 3 seconds. So, I need a d2a to 
drive one of the 150 watt class D audio boards after 
shorting the inputs hi-pass filters caps. And I have the 
feeling that even as sweet as the SpinX1 is for knocking 
around a vfd, that it won't be fast enough for this, so 
I'll need a real d2a that I can shove fresh data thru at 
servo-thread speeds. Looking for likely suspects I might 
be able to drive from the 7i76D sserial extension bus. 
Suggestions?
I'm guessing the thing was designed for 50 Hz PWM or 
thereabouts. That might actually be OK for a spindle motor.  
Clearly NOT OK for a positioning servo.


Jon


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Re: [Emc-users] driver for a DC motor for a BS-1.

[Gene Heskett]

On Monday 26 October 2020 18:32:00 Jon Elson wrote:

> >> On Monday 26 October 2020 14:16:55 Chris Albertson wrote:
> >>> 20% PWM duty cycle and a 24V power supply is about  4.8 volts to
> >>> the motor.   Many DC motors will not move at 20% of rated volts.
> >>> I'd not be surprised if it took 10 or 12 volts to overcome
> >>> internal friction.
>
> A standard test for servo motors is to apply a single "D"
> cell.  The motor should turn VERY slowly, maybe 5-10 RPM,
> but move smoothly. If the movement is "lumpy" or it doesn't
> move at all, then it is a poor motor, or having a problem.
>
> Jon
>
In which case Jon, is having a huge problem, but I am now a wee bit 
schmardter after wiring that controller properly. My diagnosis is that 
its about 2 decades slower internally than one of your pwm-servo's. The 
switching losses when the pwm is about 2% on time are such that it over 
heats and shuts down in a couple seconds, AND it leaks enough voltage 
from the 5 volt supply used to run its internal logic that the motor 
supply never gets below 4.11 volts, which is not low enough to allow a 
reset.  I slowed it down to a kilohertz in the pwmgen, and that slowed 
the spindle loop response time badly enough that the wild swings from 
the pid_s.output were actually sending a reversal to your driver that 
was then slowing the spindle motor and I could hear the iron 
complaining. Dropping its Pgain from 20 to 3.5 stabilized that and got 
rid of the noisy iron singing..

But the switching losses in the olimex board, even at only a 1 kilohertz 
pwm are killers, getting it hot enough to burn a finger in just 2 or 3 
seconds.  So, I need a d2a to drive one of the 150 watt class D audio 
boards after shorting the inputs hi-pass filters caps.  And I have the 
feeling that even as sweet as the SpinX1 is for knocking around a vfd, 
that it won't be fast enough for this, so I'll need a real d2a that I 
can shove fresh data thru at servo-thread speeds. Looking for likely 
suspects I might be able to drive from the 7i76D sserial extension bus.

Suggestions?

Thanks Jon.
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] driver for a DC motor for a BS-1.

[Jon Elson]

On Monday 26 October 2020 14:16:55 Chris Albertson wrote:

20% PWM duty cycle and a 24V power supply is about  4.8 volts to the
motor.   Many DC motors will not move at 20% of rated volts. I'd not
be surprised if it took 10 or 12 volts to overcome internal
friction.
A standard test for servo motors is to apply a single "D" 
cell.  The motor should turn VERY slowly, maybe 5-10 RPM, 
but move smoothly. If the movement is "lumpy" or it doesn't 
move at all, then it is a poor motor, or having a problem.


Jon


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Re: [Emc-users] driver for a DC motor for a BS-1.

[Gene Heskett]

On Monday 26 October 2020 14:56:37 Gene Heskett wrote:

> On Monday 26 October 2020 14:16:55 Chris Albertson wrote:
> > This is hard to follow because you are referring to pin number on a
> > PCB with no schematic.   How do these relate to the pins on the
> > driver chip?
>
> Ahh, but the schematic is downloadable from the olimex site. Printed
> in color on glossy photo paper its an excellent drawing. Get it from
> 
>
> > Also, 10 KHz is at the limit.  For initial testing better, I think
> > to work near the midpoint of the acceptable range, perhaps 1KHz. 
> > Then after it works sneak up on the max.
> >
> > 20% PWM duty cycle and a 24V power supply is about  4.8 volts to the
> > motor.   Many DC motors will not move at 20% of rated volts. I'd not
> > be surprised if it took 10 or 12 volts to overcome internal
> > friction. Motion control is always the hardest to make work at the
> > slow speed end. The motors all take a high voltage to "break free"
> > and then run too fast so you have to slow them below the break free
> > voltage so make them run slow.   This is why we have PID and
> > encoders and why PID tuning is hard.
>
> Agreed.  Unforch I can't run the mesa pwmgens at different speeds, and
> the other one is running the spindle. But I'll try a kilohertz just
> for S
>
> > A trick is to use a power supply that is a bunch higher than the
> > motor's rated voltage and let the control logic do whatever it takes
> > to drive the motor to its set-point.
>
> But this driver only has a 40 volt 30 amp limit.  I do have higher
> voltage sapplies that would foldback at the currants involved.
>
> > All brushed motors have brushes and hence friction.   You can use
> > BLDC but they cost more.(note that a stepper is a type of BLDC.
> >
> > What will make this work is that I doubt an index table needs to
> > spin fast in both directions and start and stop with high
> > accelerations. Set the speed and acceleration limits in LCNC
> > way-slow.
>
> Thats assumed since this motor is a worm drive, 220 rpms at 24 volts.
> And it will be driving the worm in a BS-1.  But first it needs to move
> laying on the mills table. I'll sneak up on the pid's Pgain.  And it
> didn't trip from following error as I've set that way up until I get
> the encoder hooked up. Which has not been done just yet.
>
> > On Mon, Oct 26, 2020 at 10:48 AM Gene Heskett 
>
> wrote:
> > > On Sunday 18 October 2020 22:21:11 Chris Albertson wrote:
> > >
> > > Advice on the OLIMEX board for a motor driver.
> > >
> > > I have it wired up, I think.  Grounded to system ground on pin 3,
> > > system logic 5 volts on pin 2.
> > >
> > > With complementary 5 volt dirs feeding ENA/ENB on pins 4-5 and a 5
> > > volt pwm on pin 6, the motor on its terminals and a 24 volt psu on
> > > its set of terminals, pins 1-7-8 aren't connected. It will bring
> > > up the leds according to the dir sigs, modulated by the % of pwm.
> > > The motor is not moving at up to about a 20% pwm at 10 kilohertz,
> > > and above 20%, it disables the outputs until a powerdown is done.
> > > I'm switching all the motor power off with the f2 key, so 15-20
> > > seconds off to let all the switchers bleed off seems to reset it
> > > ok. Pins 7-8 are sitting just a few millivolts above ground which
> > > looks duff to me since they have 3.3k on-board pullups to the 5
> > > volt line.  But thats how it powers up.
>
> No comment?

Not needed, I just uncovered a printout of the pdf, which clearly states 
the two diag pins must be pulled high. See the top of page 7. So that is 
mistake #1.  There are likely more. The .hal file is 17 landscape pages 
long, 100% out of my ancient wet ram, and I have famously fat fingers. 

> > > It does warm up when the output direction leds are lit, but
> > > nowhere near too hot. So I'd assume some current is flowing, just
> > > not enough to move the motor.
> > >
> > > Obviously I'm doing something wrong, but what?. Do I need +5 volts
> > > fed to pins 7-8?
> > >
> > > I am NOT impressed with the pushbutton terminals OLIMEX uses, they
> > > do not grab a wire heavy enough to carry the expected 10+ amps of
> > > currant to keep a good connection if the wire moves.  And its
> > > damned sure NOT a long term gas tight joint. I may yet pull them
> > > out and replace them with the green screw terminal plugs. 
> > > Something I can put some serious torque on.
> > >
> > > The 150 watt audio class D can make quite an effective hand
> > > massager out of this motor at 20 hz, its dc powered and doesn't
> > > get warm doing it. The 430 watters need an AC supply, and don't
> > > work at all with DC from this supply fed to its FW bridge power
> > > input, so apparently it needs a balanced + and - supply. Either
> > > would need a d/a to feed a bypass the input hf pass filter that
> > > wants to protect the speakers. But other than a spinx1 that would
> > > be too slow, I don't have a D/A to drive them with. But its a
> > > thought and the 150 

Re: [Emc-users] driver for a DC motor for a BS-1.

[Gene Heskett]

On Monday 26 October 2020 14:16:55 Chris Albertson wrote:

> This is hard to follow because you are referring to pin number on a
> PCB with no schematic.   How do these relate to the pins on the driver
> chip?

Ahh, but the schematic is downloadable from the olimex site. Printed in 
color on glossy photo paper its an excellent drawing. Get it from 


> Also, 10 KHz is at the limit.  For initial testing better, I think to
> work near the midpoint of the acceptable range, perhaps 1KHz.  Then
> after it works sneak up on the max.
>
> 20% PWM duty cycle and a 24V power supply is about  4.8 volts to the
> motor.   Many DC motors will not move at 20% of rated volts. I'd not
> be surprised if it took 10 or 12 volts to overcome internal friction.
> Motion control is always the hardest to make work at the slow speed
> end. The motors all take a high voltage to "break free" and then run
> too fast so you have to slow them below the break free voltage so make
> them run slow.   This is why we have PID and encoders and why PID
> tuning is hard.

Agreed.  Unforch I can't run the mesa pwmgens at different speeds, and 
the other one is running the spindle. But I'll try a kilohertz just for 
S

> A trick is to use a power supply that is a bunch higher than the
> motor's rated voltage and let the control logic do whatever it takes
> to drive the motor to its set-point.

But this driver only has a 40 volt 30 amp limit.  I do have higher 
voltage sapplies that would foldback at the currants involved.

> All brushed motors have brushes and hence friction.   You can use BLDC
> but they cost more.(note that a stepper is a type of BLDC.
>
> What will make this work is that I doubt an index table needs to spin
> fast in both directions and start and stop with high accelerations. 
> Set the speed and acceleration limits in LCNC way-slow.

Thats assumed since this motor is a worm drive, 220 rpms at 24 volts. And 
it will be driving the worm in a BS-1.  But first it needs to move 
laying on the mills table. I'll sneak up on the pid's Pgain.  And it 
didn't trip from following error as I've set that way up until I get the 
encoder hooked up. Which has not been done just yet.
>
> On Mon, Oct 26, 2020 at 10:48 AM Gene Heskett  
wrote:
> > On Sunday 18 October 2020 22:21:11 Chris Albertson wrote:
> >
> > Advice on the OLIMEX board for a motor driver.
> >
> > I have it wired up, I think.  Grounded to system ground on pin 3,
> > system logic 5 volts on pin 2.
> >
> > With complementary 5 volt dirs feeding ENA/ENB on pins 4-5 and a 5
> > volt pwm on pin 6, the motor on its terminals and a 24 volt psu on
> > its set of terminals, pins 1-7-8 aren't connected. It will bring up
> > the leds according to the dir sigs, modulated by the % of pwm. The
> > motor is not moving at up to about a 20% pwm at 10 kilohertz, and
> > above 20%, it disables the outputs until a powerdown is done. I'm
> > switching all the motor power off with the f2 key, so 15-20 seconds
> > off to let all the switchers bleed off seems to reset it ok. Pins
> > 7-8 are sitting just a few millivolts above ground which looks duff
> > to me since they have 3.3k on-board pullups to the 5 volt line.  But
> > thats how it powers up.
> >
No comment?

> > It does warm up when the output direction leds are lit, but nowhere
> > near too hot. So I'd assume some current is flowing, just not enough
> > to move the motor.
> >
> > Obviously I'm doing something wrong, but what?. Do I need +5 volts
> > fed to pins 7-8?
> >
> > I am NOT impressed with the pushbutton terminals OLIMEX uses, they
> > do not grab a wire heavy enough to carry the expected 10+ amps of
> > currant to keep a good connection if the wire moves.  And its damned
> > sure NOT a long term gas tight joint. I may yet pull them out and
> > replace them with the green screw terminal plugs.  Something I can
> > put some serious torque on.
> >
> > The 150 watt audio class D can make quite an effective hand massager
> > out of this motor at 20 hz, its dc powered and doesn't get warm
> > doing it. The 430 watters need an AC supply, and don't work at all
> > with DC from this supply fed to its FW bridge power input, so
> > apparently it needs a balanced + and - supply. Either would need a
> > d/a to feed a bypass the input hf pass filter that wants to protect
> > the speakers. But other than a spinx1 that would be too slow, I
> > don't have a D/A to drive them with. But its a thought and the 150
> > watter can seriously hammer that motor. So thats a potential what
> > if.  :)

Thanks Chris.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] driver for a DC motor for a BS-1.

[Chris Albertson]

This is hard to follow because you are referring to pin number on a PCB
with no schematic.   How do these relate to the pins on the driver chip?

Also, 10 KHz is at the limit.  For initial testing better, I think to work
near the midpoint of the acceptable range, perhaps 1KHz.  Then after it
works sneak up on the max.

20% PWM duty cycle and a 24V power supply is about  4.8 volts to the
motor.   Many DC motors will not move at 20% of rated volts. I'd not be
surprised if it took 10 or 12 volts to overcome internal friction.
 Motion control is always the hardest to make work at the slow speed end.
 The motors all take a high voltage to "break free" and then run too fast
so you have to slow them below the break free voltage so make them run
slow.   This is why we have PID and encoders and why PID tuning is hard.

A trick is to use a power supply that is a bunch higher than the motor's
rated voltage and let the control logic do whatever it takes to drive the
motor to its set-point.

All brushed motors have brushes and hence friction.   You can use BLDC but
they cost more.(note that a stepper is a type of BLDC.

What will make this work is that I doubt an index table needs to spin fast
in both directions and start and stop with high accelerations.  Set the
speed and acceleration limits in LCNC way-slow.

On Mon, Oct 26, 2020 at 10:48 AM Gene Heskett  wrote:

> On Sunday 18 October 2020 22:21:11 Chris Albertson wrote:
>
> Advice on the OLIMEX board for a motor driver.
>
> I have it wired up, I think.  Grounded to system ground on pin 3, system
> logic 5 volts on pin 2.
>
> With complementary 5 volt dirs feeding ENA/ENB on pins 4-5 and a 5 volt
> pwm on pin 6, the motor on its terminals and a 24 volt psu on its set of
> terminals, pins 1-7-8 aren't connected. It will bring up the leds
> according to the dir sigs, modulated by the % of pwm. The motor is not
> moving at up to about a 20% pwm at 10 kilohertz, and above 20%, it
> disables the outputs until a powerdown is done. I'm switching all the
> motor power off with the f2 key, so 15-20 seconds off to let all the
> switchers bleed off seems to reset it ok. Pins 7-8 are sitting just a
> few millivolts above ground which looks duff to me since they have 3.3k
> on-board pullups to the 5 volt line.  But thats how it powers up.
>
> It does warm up when the output direction leds are lit, but nowhere near
> too hot. So I'd assume some current is flowing, just not enough to move
> the motor.
>
> Obviously I'm doing something wrong, but what?. Do I need +5 volts fed to
> pins 7-8?
>
> I am NOT impressed with the pushbutton terminals OLIMEX uses, they do not
> grab a wire heavy enough to carry the expected 10+ amps of currant to
> keep a good connection if the wire moves.  And its damned sure NOT a
> long term gas tight joint. I may yet pull them out and replace them with
> the green screw terminal plugs.  Something I can put some serious torque
> on.
>
> The 150 watt audio class D can make quite an effective hand massager out
> of this motor at 20 hz, its dc powered and doesn't get warm doing it.
> The 430 watters need an AC supply, and don't work at all with DC from
> this supply fed to its FW bridge power input, so apparently it needs a
> balanced + and - supply. Either would need a d/a to feed a bypass the
> input hf pass filter that wants to protect the speakers. But other than
> a spinx1 that would be too slow, I don't have a D/A to drive them with.
> But its a thought and the 150 watter can seriously hammer that motor.
> So thats a potential what if.  :)
>
> Thanks Chris.
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
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>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] Limit switches for my lathe

[Gene Heskett]

On Monday 26 October 2020 11:27:20 Alan Condit wrote:

> Hi all,
>
> I am trying to wrap my head around limit switches for my Grizzly G4000
> lathe that I have converted to CNC.
>
> The X limit switches are not a major problem. They always goes to the
> same spot. I have the X+ switch mounted. Figuring out where to mount
> the X- switch so it doesn’t interfere with anything else is a little
> tricky.
>
>  I am having trouble figuring out the placement of the Z limit switch
> or switches. I can mount the Z+ limit switch on an adjustable mount on
> the ways down by the tailstock or even on the tailstock itself. But
> having a limit switch that is moveable seems problematic for
> configuration. The Z- limit switch could be attached to a moveable
> mount on the ways down by the head but it seems that it might be
> desirable to have the limit set to keep the cross-feed from running
> into whatever chuck is mounted. I have a 3” 4-jaw, a 4” 3-jaw, a 5”
> 3-jaw and a 5” 4-jaw. So I might need a different config for every
> chuck. What do you guys think.

I have the x switch on the front of the apron. with its roller reaching 
up so the crossfeed backs into it at the front, a long ways from center.

I found a bolt hole in the bed about a foot away from the chuck, and have 
another identical switch mounted there which gets dinged by the gib 
strip which is full length of the carriage H pattern so the switch also 
tells the homeing function which way to the switch. 

Just to make sure there is work clearance, I remove the tool from the 
QCTP before homing.  But if it hits, the steppers are now 3 phase 
stepper/servos, and Z will trip off before wrecking the tool.

The rest is just .ini file vars.

HTH, Alan
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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[Emc-users] Need help please. Shipping to South africa

[Henk du preez]

Hi.

I ordered a Farand controls rotary inductosyn encoder off eBay some time
ago.

Normally I ship my eBay purchases to a forwarding company in Florida who
then consolidates a package and forwards that to me.

This time around they say that they say that they could not verify the
export compliance because the seller did not send them the required info.

Is there anyone in the US that is willing to forward this package to me in
South Africa? I will pay the costs obviously.

Thanks for your help

He k du Preez

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Re: [Emc-users] Limit switches for my lathe

[andy pugh]

On Mon, 26 Oct 2020 at 15:29, Alan Condit  wrote:

>  I am having trouble figuring out the placement of the Z limit switch or 
> switches

I was troubled by the same issue, and did some bodgery to make the
resolvers return an absolute position, so that now I can home without
moving.

This might be an argument in favour of fitting linear scales.

Otherwise, it's probably best to home towards the tailstock and accept
that it's your job to move it to the end of the bed before pressing
the button.

You can (I think) move the soft limits using the ini.* HAL pins to
allow for different chucks.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] driver for a DC motor for a BS-1.

[Gene Heskett]

On Sunday 18 October 2020 22:21:11 Chris Albertson wrote:

Advice on the OLIMEX board for a motor driver.

I have it wired up, I think.  Grounded to system ground on pin 3, system 
logic 5 volts on pin 2.

With complementary 5 volt dirs feeding ENA/ENB on pins 4-5 and a 5 volt 
pwm on pin 6, the motor on its terminals and a 24 volt psu on its set of 
terminals, pins 1-7-8 aren't connected. It will bring up the leds 
according to the dir sigs, modulated by the % of pwm. The motor is not 
moving at up to about a 20% pwm at 10 kilohertz, and above 20%, it 
disables the outputs until a powerdown is done. I'm switching all the 
motor power off with the f2 key, so 15-20 seconds off to let all the 
switchers bleed off seems to reset it ok. Pins 7-8 are sitting just a 
few millivolts above ground which looks duff to me since they have 3.3k 
on-board pullups to the 5 volt line.  But thats how it powers up.

It does warm up when the output direction leds are lit, but nowhere near 
too hot. So I'd assume some current is flowing, just not enough to move 
the motor.

Obviously I'm doing something wrong, but what?. Do I need +5 volts fed to 
pins 7-8?

I am NOT impressed with the pushbutton terminals OLIMEX uses, they do not 
grab a wire heavy enough to carry the expected 10+ amps of currant to 
keep a good connection if the wire moves.  And its damned sure NOT a 
long term gas tight joint. I may yet pull them out and replace them with 
the green screw terminal plugs.  Something I can put some serious torque 
on.

The 150 watt audio class D can make quite an effective hand massager out 
of this motor at 20 hz, its dc powered and doesn't get warm doing it.  
The 430 watters need an AC supply, and don't work at all with DC from 
this supply fed to its FW bridge power input, so apparently it needs a 
balanced + and - supply. Either would need a d/a to feed a bypass the 
input hf pass filter that wants to protect the speakers. But other than 
a spinx1 that would be too slow, I don't have a D/A to drive them with. 
But its a thought and the 150 watter can seriously hammer that motor.  
So thats a potential what if.  :)

Thanks Chris.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Limit switches for my lathe

[Sam Sokolik]

If it is a small enough lathe - I would just take the tail stock off to
home..  (that is what I do on the emco)

Have a cam style follower.   So it home somewhere halfway down the travel.
(so most of the time the tailstock is out of the way.  (if it is past the
trip point - it will home the other direction)  Then have a switch on the
tail stock that acts as an overtravel.

On Mon, Oct 26, 2020 at 10:29 AM Alan Condit  wrote:

> Hi all,
>
> I am trying to wrap my head around limit switches for my Grizzly G4000
> lathe that I have converted to CNC.
>
> The X limit switches are not a major problem. They always goes to the same
> spot. I have the X+ switch mounted. Figuring out where to mount the X-
> switch so it doesn’t interfere with anything else is a little tricky.
>
>  I am having trouble figuring out the placement of the Z limit switch or
> switches. I can mount the Z+ limit switch on an adjustable mount on the
> ways down by the tailstock or even on the tailstock itself. But having a
> limit switch that is moveable seems problematic for configuration. The Z-
> limit switch could be attached to a moveable mount on the ways down by the
> head but it seems that it might be desirable to have the limit set to keep
> the cross-feed from running into whatever chuck is mounted. I have a 3”
> 4-jaw, a 4” 3-jaw, a 5” 3-jaw and a 5” 4-jaw. So I might need a different
> config for every chuck. What do you guys think.
>
> Alan
>
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[Emc-users] Limit switches for my lathe

[Alan Condit]

Hi all,

I am trying to wrap my head around limit switches for my Grizzly G4000 lathe 
that I have converted to CNC. 

The X limit switches are not a major problem. They always goes to the same 
spot. I have the X+ switch mounted. Figuring out where to mount the X- switch 
so it doesn’t interfere with anything else is a little tricky.

 I am having trouble figuring out the placement of the Z limit switch or 
switches. I can mount the Z+ limit switch on an adjustable mount on the ways 
down by the tailstock or even on the tailstock itself. But having a limit 
switch that is moveable seems problematic for configuration. The Z- limit 
switch could be attached to a moveable mount on the ways down by the head but 
it seems that it might be desirable to have the limit set to keep the 
cross-feed from running into whatever chuck is mounted. I have a 3” 4-jaw, a 4” 
3-jaw, a 5” 3-jaw and a 5” 4-jaw. So I might need a different config for every 
chuck. What do you guys think.

Alan

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Re: [Emc-users] Cutting fluid

[Sven Wesley]

Many moons ago, but sure we did experience some bad allergy reactions from
cutting fluid. Some fluids are prone bacteria growth and if the system
isn't cleaned regularly you may end up with a biohazard de luxe.
Don't ask me how I know, but the sanitation of 25 machines sized workshop
took a while

Den tors 22 okt. 2020 kl 20:25 skrev Nicklas SB Karlsson :

> In some oils there are PAHs polyaromatic hydrocarbons and these have
> been linked to some forms of cancer
> https://en.wikipedia.org/wiki/Polycyclic_aromatic_hydrocarbon Then
> reading about Creosot https://en.wikipedia.org/wiki/Creosote I found
> there is difference in chemical properties between coal-tar and wood-tar
> Creosot and I also expect difference in chemical properties between
> mineral oil and vegetable oil.
>
> Expect food oil to be relatively harmless also then used as a cutting
> fluid, no rust and does not freeze during winter. Maybe bacterial growth
> might be a problem but in such case I could kill them by heating
> regularly. Do not freeze during winter is an important future for me as
> is now.
>
>
> Den 2020-10-21 kl. 21:44, skrev marcus.bow...@visible.eclipse.co.uk:
> > On 2020-10-21 20:10, Nicklas SB Karlsson wrote:
> >> I learned cutting fluid could be unhealthy. Anyone here have any
> >> experience?
> >>
> > I understand the problem has been that soluble cutting oil tends to
> > drench the operator at waist level (on older machines which do not
> > have total enclosures). That led to a noted connection between cancer
> > and soluble oil.
> > I don't know of any link between neat cutting oil and medical
> > conditions, but it is an oil, so the usual hazards apply.
> >
> > I have serious reservations about the current fashion for atomised
> > mist spray coolant, which I believe to be a real danger to the lungs
> > and possibly the eyes, nose and mouth. I have not seen any medical
> > studies on this, but atomised fluids of all sorts are generally a bad
> > idea.
> > Just my opinion.
> >
> > Marcus
> >
> >
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>
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