Re: [Emc-users] Large servo selection

[andy pugh]

On 12 April 2018 at 13:27, Todd Zuercher  wrote:

> If you want to try multiple drive motors, a rack and pinion becomes a very 
> good option.

You can make quite a nice actuator reasonably easily by using a gear
on the motor spindle and a round rack running in suitable bushings.
http://www.hpcgears.com/pdf_c33/22.10.pdf
(It is titled "1.5mod" but the table has sizes between 1.0 and 5.0 mod)

I used that arrangement back when I was much less well equipped with
machine tools by welding two short pipes together in a cross with a
pinion running in one pipe and the rack sliding in the other, both
with oilite bushings.


-- 
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, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Todd Zuercher]

Hi-lead ball screws are capable of 1m/sec (lead equal to or greater than the 
diameter).  

If you want to try multiple drive motors, a rack and pinion becomes a very good 
option.  You can use the multiple motors to take up any backlash free of 
charge, simply by placing a small amount of opposed bias in the pid loops.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: David Berndt [mailto:ber...@uberwin.com] 
Sent: Wednesday, April 11, 2018 11:27 PM
To: emc-users@lists.sourceforge.net; Dave Cole 
Subject: Re: [Emc-users] Large servo selection

Hmm. Belting is a pretty interesting idea. Though for my application, the 
reverse motion of a crank/slider isn't a big negative.

I've also been toying with combining a few servos smaller servos to get the 
work done. I've got no great idea on that yet mechanically or electrically. But 
taking advantage of the maximum torque vs rated torque on a 750w drive times 2 
or 3 would seem to get me into the appropriate numbers and the smaller drives 
are much easier to find in single phase.

Dave


On Wed, 11 Apr 2018 22:19:24 -0400, Dave Cole 
wrote:

> Consider using a timing belt drive. Not exactly a timing belt, but a 
> cogged tooth belt.  They make cogged tooth belting specifically for 
> linear actuators.
> You can buy it several inches wide so 6 hp would not be a problem.   I  
> did a servo drive setup to propel a machine carriage with such a belt.   
> I think the belt was about 2 inches wide.  I think we used a 2 kw servo  
> motor with a  gearbox.   It could produce about a thousand of pounds of  
> pull.You can buy the belting by the meter or foot.  I think it is  
> "AT" belting that is generally used for linear drives.   Belts tend to  
> be a bit elastic when pulled hard so you may need a 3+ inch wide belt.
> But it can certainly move quickly.   The cost for the belting is quite  
> reasonable.
>
>
> On 4/11/2018 3:21 PM, John Kasunich wrote:
>>
>> On Wed, Apr 11, 2018, at 3:08 PM, John Kasunich wrote:
>>>
>>> On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:
>>>> I'm looking to output about 1000lbf in a linear direction via a
>>>> crank/slider or ballscrew
>>> You don't mention the stroke length.  Are you moving a few inches in a
>>> fraction of a second, or several meters over several seconds?
>> On further thought...
>>
>> Ballscrew requires unreasonably high RPM.
>>
>> Crank is very non-linear, and has major problems as stroke exceeds a  
>> couple inches - longer stroke means longer crank which means more and  
>> more torque is required.  You never use more than a half-revolution of  
>> the crank, so some serious reduction will be needed between motor and  
>> crank.
>>
>> Have you considered roller chain?  Keep the sprocket size small so the  
>> torque doesn't get crazy high, but you can use multiple revolutions of  
>> the sprocket to cover an unlimited stroke.  Still going to require a  
>> gearbox; for a 1000 lbf load you will need a few thousand in-lbs  (few  
>> hundred ft-lbs) of torque, which is a LOT for any motor.
>>
>> Interesting engineering problem to be sure.
>>
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Dave Cole]

On 4/12/2018 6:09 AM, andy pugh wrote:

On 11 April 2018 at 15:30, David Berndt  wrote:


I'm looking to output about 1000lbf in a linear direction via a crank/slider
or ballscrew with peak speed of about 1m/s.

Have you considered hydraulics? (Or possibly even pneumatics).

Hydraulics can be pretty quick with a servo-valve cylinder.
https://youtu.be/EQiAVOGONtg
For example.
Admittedly the hydraulic ring main at work that runs our 4 of these
rigs has 20  x  50hp pumps in parallel!
If he had a hydraulic accumulator he could get by with a small pump, 
assuming the duty cycle of this machine will allow the pump to pump up 
the accumulator between moves.    But nothing hydraulic is cheap unless 
it is bought surplus, then sometimes it is almost given away.


What is the total distance of the move?   It can't be very far if you 
are considering a crank and slide.  (unless the crank is huge).


Dave

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[andy pugh]

On 11 April 2018 at 15:30, David Berndt  wrote:

> I'm looking to output about 1000lbf in a linear direction via a crank/slider
> or ballscrew with peak speed of about 1m/s.

Have you considered hydraulics? (Or possibly even pneumatics).

Hydraulics can be pretty quick with a servo-valve cylinder.
https://youtu.be/EQiAVOGONtg
For example.
Admittedly the hydraulic ring main at work that runs our 4 of these
rigs has 20  x  50hp pumps in parallel!

-- 
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, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Gene Heskett]

On Thursday 12 April 2018 00:38:11 Jon Elson wrote:

> On 04/11/2018 01:01 AM, David Berndt wrote:
> > Wondering if anyone had any preference/experience/advise
> > to share with single phase capable larger servos. I'm
> > looking at an application for a 3 to 5hp motor with a vfd,
> > but if I could just get a servo to fill in that'd be nice.
> > Gear reduction will be required, but something with more
> > torque, needing less reduction will make things easier.Say
> > ~500rpm as a goal maximum output.
> >
> > I see things like Fanuc red cap servos (ai series?
> > pulsecoder encoder) 2.5kw kicking around ebay. Driving
> > something like that would seem to be the challenge?
>
> Well, I have used the Fanuc "Red Cap" motors.  The motors
> are awesome.  The encoders are proprietary, but I (Pico
> Systems)  have converters that handle most types, and give
> standard quadrature plus Hall signals.
> My brushless PWM servo amps will handle motors up to about 2
> Hp, but a number of other servo amp makers can handle larger
> motors once the encoder signals are converted to
> industry-compatible signals.
>
> Jon

I get a better figure than that out of your servo amp Jon. At its max 
volts and peak current, I get nominally 4.25 hp, so with the right power 
supply, the 3.5 hp treadmill motor could do it, and if a way to lock the 
fan to the shaft can be found, it should be able to do it going both 
ways. With nearly double the motors rated voltage, and plenty of filter 
caps in the psu, peaks of 7 hp or more should be available. But it will 
need a soft start when turning on the psu else it will clear a 30 amp 
breaker. BTDT. Sorta sick bird according to my elderly copy of the 
NEC.. :( But I haven't cleared the 20 in that branch since I put in the 
softstart.

> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> 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)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Gene Heskett]

On Wednesday 11 April 2018 21:56:17 Chris Albertson wrote:

> If you are willing to design and build your own controller and add an
> encoder, a motor from a treadmill could work
>
But only in one direction. The flywheel/pulley/cooling fan on those I 
have used is screwed onto the motor shaft, and you'll have to invent a 
method to prevent its unscrewing itself. I have such a motor cobbled 
onto the rear of my 7x mini-lathe, and being controlled by a Pico 
pwm-servo amplifier. I ruined the end of the shaft trying to keep it 
screwed on. And now, to be able to rigid tap on it, I have some extra 
hal trickery to slow the reversal accels down, and so far (ignore that 
faint knocking sound) its working yet. The disadvantage of that is that 
it doubles the overshoot at the turn around point, much worse in 
backgear, so If I turn faster that 100 revs, the overshoot can be really 
excessive, 300 rpms is nearly 5 full turns you must subtract if the hole 
is blind else you'll hit the bottom of the hole and hold services for 
the shattered tap.

Thats with around 107 volts of DC, and a peak current limit at around 16 
amps. Even though its accels are slowed, I can still hear it squeak at 
the limit when doing the turnaround.

Ditto the same pwm-servo amp for the 1hp rated PMDC motor on my G0704, 
but its not driving a 5" chuck, just an R8 spindle. There I can reverse 
it from 1500 revs in 400 milliseconds, 3000 is about 1 second but thats 
again several turns of overshoot. There I have 125 volts at 20 amps 
available, again with about a 16 amp current limit programmed.

That servo amp is one tough cookie. And its full, 4 quadrant control, so 
if you want a quick stop, code a 20 rpm command into your gcode, 
followed by a g4p.25 then the m5.

I also have switches to tally the high/low status of the backgear, and if 
neither is closed, that same 20 rpm makes the motor creep. So it can be 
turning 3000 when I grab the knob to change gears. The instant it moves, 
the motor is made to just barely turn, the gear shift is as smooth as 
silk, and when one of the switches closes, the motor control spins it 
back up long before I can remove my hand from the knob. 

> On Wed, Apr 11, 2018 at 12:08 PM, John Kasunich
> 
>
> wrote:
> > On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:
> > > I'd like this to be reasonably low effort. My biggest concern is
> > > single phase input. Control/response requirements are about as low
> > > as it gets.
> > >
> > > I'm looking to output about 1000lbf in a linear direction via a
> > > crank/slider or ballscrew with peak speed of about 1m/s. So that's
> > > a real 5hp of energy.
> >
> > Mixed units are making my head hurt
> >
> > 1000lbf = 4448 newtons I think?
> > At 1m/s, that is 4448 watts.  1 HP = 746 watts, so 4454 watts =
> > 5.96HP.
> >
> > A ballscrew would have to spin pretty fast to hit 1m/s.  Obviously
> > it depends on the pitch, but a plain vanilla 5mm pitch screw would
> > have to go 12000 RPM (well above critical speed unless very short). 
> > Even a 20mm pitch screw would need 3000 RPM.
> >
> > You don't mention the stroke length.  Are you moving a few inches in
> > a fraction of a second, or several meters over several seconds?
> >
> > 4.5kW or 6HP isn't going to be small or cheap no matter what you
> > do...
> >
> > > Duty cycle will be low, and external active cooling can be
> > > provided if required. So things like steppers are out, I've never
> > > seen a stepper that outputs nearly that much, and I don't
> > > particular want to create a 4kw 80v dc power supply...
> > >
> > > re: Control requirements, I really only need to start running at a
> > > particular speed and be able to return the system to a somewhat
> > > close
> >
> > stop
> >
> > > position, which can be as simple/bad as a vfd with a switch and
> > > timed
> >
> > jog.
> >
> > > Any extra control over the system that I can get would add
> > > capabilities though.
> > >
> > > The goal here is to see if there are any industrial drives out
> > > there that might periodically pop up on ebay which are higher KW
> > > and single phase capable.I see units like the Parker Gemini
> > > GV/GV6-U12/H20 which claim single phase at 3.5kw and 5.9kw.
> > >
> > > Dave
> > >
> > >
> > > On Wed, 11 Apr 2018 09:24:32 -0400, Dave Cole
> > > 
> > >
> > > wrote:
> > > > How much time/work do you want to put into this motor/drive
> > > > setup? There are no really cheap large servo motor solutions
> > > > unless you
> >
> > stumble
> >
> > > > into a deal on Ebay or a surplus marketplace.
> > > > Larger servos generally mean 3 phase inputs.   So that becomes
> > > > an immediate issue.
> > > >
> > > > If you can live with a VFD, your life will be much simpler to
> > > > simply
> >
> > get
> >
> > > > a single phase input VFD and a suitable motor.
> > > > You can find 3 phase gearbox equipped motors on Ebay that can
> > > > get you 500 rpm max.
> > > >
> > > > Dave
> > > >
> > > > On 4/11/2018 2:01 AM, David Berndt wrote

Re: [Emc-users] Large servo selection

[Jon Elson]

On 04/11/2018 01:01 AM, David Berndt wrote:
Wondering if anyone had any preference/experience/advise 
to share with single phase capable larger servos. I'm 
looking at an application for a 3 to 5hp motor with a vfd, 
but if I could just get a servo to fill in that'd be nice. 
Gear reduction will be required, but something with more 
torque, needing less reduction will make things easier.Say 
~500rpm as a goal maximum output.


I see things like Fanuc red cap servos (ai series? 
pulsecoder encoder) 2.5kw kicking around ebay. Driving 
something like that would seem to be the challenge?


Well, I have used the Fanuc "Red Cap" motors.  The motors 
are awesome.  The encoders are proprietary, but I (Pico 
Systems)  have converters that handle most types, and give 
standard quadrature plus Hall signals.
My brushless PWM servo amps will handle motors up to about 2 
Hp, but a number of other servo amp makers can handle larger 
motors once the encoder signals are converted to 
industry-compatible signals.


Jon

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[David Berndt]

Hmm. Belting is a pretty interesting idea. Though for my application, the  
reverse motion of a crank/slider isn't a big negative.


I've also been toying with combining a few servos smaller servos to get  
the work done. I've got no great idea on that yet mechanically or  
electrically. But taking advantage of the maximum torque vs rated torque  
on a 750w drive times 2 or 3 would seem to get me into the appropriate  
numbers and the smaller drives are much easier to find in single phase.


Dave


On Wed, 11 Apr 2018 22:19:24 -0400, Dave Cole   
wrote:


Consider using a timing belt drive. Not exactly a timing belt, but a  
cogged tooth belt.  They make cogged tooth belting specifically for  
linear actuators.
You can buy it several inches wide so 6 hp would not be a problem.   I  
did a servo drive setup to propel a machine carriage with such a belt.   
I think the belt was about 2 inches wide.  I think we used a 2 kw servo  
motor with a  gearbox.   It could produce about a thousand of pounds of  
pull.You can buy the belting by the meter or foot.  I think it is  
"AT" belting that is generally used for linear drives.   Belts tend to  
be a bit elastic when pulled hard so you may need a 3+ inch wide belt.
But it can certainly move quickly.   The cost for the belting is quite  
reasonable.



On 4/11/2018 3:21 PM, John Kasunich wrote:


On Wed, Apr 11, 2018, at 3:08 PM, John Kasunich wrote:


On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:

I'm looking to output about 1000lbf in a linear direction via a
crank/slider or ballscrew

You don't mention the stroke length.  Are you moving a few inches in a
fraction of a second, or several meters over several seconds?

On further thought...

Ballscrew requires unreasonably high RPM.

Crank is very non-linear, and has major problems as stroke exceeds a  
couple inches - longer stroke means longer crank which means more and  
more torque is required.  You never use more than a half-revolution of  
the crank, so some serious reduction will be needed between motor and  
crank.


Have you considered roller chain?  Keep the sprocket size small so the  
torque doesn't get crazy high, but you can use multiple revolutions of  
the sprocket to cover an unlimited stroke.  Still going to require a  
gearbox; for a 1000 lbf load you will need a few thousand in-lbs  (few  
hundred ft-lbs) of torque, which is a LOT for any motor.


Interesting engineering problem to be sure.



--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Dave Cole]

Consider using a timing belt drive. Not exactly a timing belt, but a 
cogged tooth belt.  They make cogged tooth belting specifically for 
linear actuators.
You can buy it several inches wide so 6 hp would not be a problem.   I 
did a servo drive setup to propel a machine carriage with such a belt.  
I think the belt was about 2 inches wide.  I think we used a 2 kw servo 
motor with a  gearbox.   It could produce about a thousand of pounds of 
pull.    You can buy the belting by the meter or foot.  I think it is 
"AT" belting that is generally used for linear drives.   Belts tend to 
be a bit elastic when pulled hard so you may need a 3+ inch wide belt.   
But it can certainly move quickly.   The cost for the belting is quite 
reasonable.



On 4/11/2018 3:21 PM, John Kasunich wrote:


On Wed, Apr 11, 2018, at 3:08 PM, John Kasunich wrote:


On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:

I'm looking to output about 1000lbf in a linear direction via a
crank/slider or ballscrew

You don't mention the stroke length.  Are you moving a few inches in a
fraction of a second, or several meters over several seconds?

On further thought...

Ballscrew requires unreasonably high RPM.

Crank is very non-linear, and has major problems as stroke exceeds a couple 
inches - longer stroke means longer crank which means more and more torque is 
required.  You never use more than a half-revolution of the crank, so some 
serious reduction will be needed between motor and crank.

Have you considered roller chain?  Keep the sprocket size small so the torque 
doesn't get crazy high, but you can use multiple revolutions of the sprocket to 
cover an unlimited stroke.  Still going to require a gearbox; for a 1000 lbf 
load you will need a few thousand in-lbs  (few hundred ft-lbs) of torque, which 
is a LOT for any motor.

Interesting engineering problem to be sure.



--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Chris Albertson]

If you are willing to design and build your own controller and add an
encoder, a motor from a treadmill could work

On Wed, Apr 11, 2018 at 12:08 PM, John Kasunich 
wrote:

>
>
> On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:
> > I'd like this to be reasonably low effort. My biggest concern is single
> > phase input. Control/response requirements are about as low as it gets.
> >
> > I'm looking to output about 1000lbf in a linear direction via a
> > crank/slider or ballscrew with peak speed of about 1m/s. So that's a real
> > 5hp of energy.
>
> Mixed units are making my head hurt
>
> 1000lbf = 4448 newtons I think?
> At 1m/s, that is 4448 watts.  1 HP = 746 watts, so 4454 watts = 5.96HP.
>
> A ballscrew would have to spin pretty fast to hit 1m/s.  Obviously it
> depends on the pitch, but a plain vanilla 5mm pitch screw would have to go
> 12000 RPM (well above critical speed unless very short).  Even a 20mm pitch
> screw would need 3000 RPM.
>
> You don't mention the stroke length.  Are you moving a few inches in a
> fraction of a second, or several meters over several seconds?
>
> 4.5kW or 6HP isn't going to be small or cheap no matter what you do...
>
>
>
> > Duty cycle will be low, and external active cooling can be
> > provided if required. So things like steppers are out, I've never seen a
> > stepper that outputs nearly that much, and I don't particular want to
> > create a 4kw 80v dc power supply...
> >
> > re: Control requirements, I really only need to start running at a
> > particular speed and be able to return the system to a somewhat close
> stop
> > position, which can be as simple/bad as a vfd with a switch and timed
> jog.
> > Any extra control over the system that I can get would add capabilities
> > though.
> >
> > The goal here is to see if there are any industrial drives out there that
> > might periodically pop up on ebay which are higher KW and single phase
> > capable.I see units like the Parker Gemini GV/GV6-U12/H20 which claim
> > single phase at 3.5kw and 5.9kw.
> >
> > Dave
> >
> >
> > On Wed, 11 Apr 2018 09:24:32 -0400, Dave Cole 
> > wrote:
> >
> > > How much time/work do you want to put into this motor/drive setup?
> > > There are no really cheap large servo motor solutions unless you
> stumble
> > > into a deal on Ebay or a surplus marketplace.
> > > Larger servos generally mean 3 phase inputs.   So that becomes an
> > > immediate issue.
> > >
> > > If you can live with a VFD, your life will be much simpler to simply
> get
> > > a single phase input VFD and a suitable motor.
> > > You can find 3 phase gearbox equipped motors on Ebay that can get you
> > > 500 rpm max.
> > >
> > > Dave
> > >
> > >
> > >
> > > On 4/11/2018 2:01 AM, David Berndt wrote:
> > >> Wondering if anyone had any preference/experience/advise to share with
> > >> single phase capable larger servos. I'm looking at an application for
> a
> > >> 3 to 5hp motor with a vfd, but if I could just get a servo to fill in
> > >> that'd be nice. Gear reduction will be required, but something with
> > >> more torque, needing less reduction will make things easier.Say
> ~500rpm
> > >> as a goal maximum output.
> > >>
> > >> I see things like Fanuc red cap servos (ai series? pulsecoder encoder)
> > >> 2.5kw kicking around ebay. Driving something like that would seem to
> be
> > >> the challenge?
> > >>
> > >> Thoughts? Suggestions? Previous experience?
> > >>
> > >> Dave
> > >>
> > >> 
> --
> > >> Check out the vibrant tech community on one of the world's most
> > >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > >> ___
> > >> Emc-users mailing list
> > >> Emc-users@lists.sourceforge.net
> > >> https://lists.sourceforge.net/lists/listinfo/emc-users
> > >
> > > 
> --
> > > Check out the vibrant tech community on one of the world's most
> > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > 
> --
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> --
>   John Kasunich
>   jmkasun...@fastmail.fm
>
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing lis

Re: [Emc-users] Large servo selection

[Gene Heskett]

On Wednesday 11 April 2018 04:32:05 jeremy youngs wrote:

> Does it have to be a servo ?? 1800 in lb nema 34 steppers are
> inexpensive and your speed needs are not great , it's possible a
> stepper and a kelling drive would get you there . But again more input
> needed.
> Gene , I know of a bunch of 700 ozin SLO-Syn but they are syncronous
> at 72 rpm, how would one drive them ? My only experience with slosyn
> is a couple small ones I purchased ten years ago , aren't they
> essentially a bldc without hall sensors?

Enough of a resemblance that if the coils are brought out right, you can 
drive them with most any old 2 phase stepper driver.

But probably even slower than a 60hz frequency drive, most are for 120 
volt line power.  A 40 volt supplied m542 does not have the cajones to 
drive a slow-syn with "usable torque"

And I believe that same comment would apply to the 3 phase stepper 
drivers too. I've begun to see some of those for sale, even considered 
one for the lathes Z but couldn't find a driver for the bigger ones.  
That AC powered stepper 8 amp that sells for about $160, seems to have 
some pretty advanced current mapping, at no speed is it resonant. I'm 
using that driver on the G0704's Z, and it can run, direct drive, 
from .001" minute on up to about 140 ipm, lifting the head, and making 
less noise than the N23 sized 470's on the xy table. The dm860h that 
came with that kit, was all done at 27 ipm driving a N34-1600 oz/in. 
Noisy as all get out. Its on the Sheldon Lathes Z now, running faster, 
but you can still hear it across the street with the garage door closed.

-- 
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)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[John Kasunich]

On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:
> I'd like this to be reasonably low effort. My biggest concern is single  
> phase input. Control/response requirements are about as low as it gets.
> 
> I'm looking to output about 1000lbf in a linear direction via a  
> crank/slider or ballscrew with peak speed of about 1m/s. So that's a real  
> 5hp of energy. 

Mixed units are making my head hurt

1000lbf = 4448 newtons I think?
At 1m/s, that is 4448 watts.  1 HP = 746 watts, so 4454 watts = 5.96HP.

A ballscrew would have to spin pretty fast to hit 1m/s.  Obviously it depends 
on the pitch, but a plain vanilla 5mm pitch screw would have to go 12000 RPM 
(well above critical speed unless very short).  Even a 20mm pitch screw would 
need 3000 RPM.

You don't mention the stroke length.  Are you moving a few inches in a fraction 
of a second, or several meters over several seconds?  

4.5kW or 6HP isn't going to be small or cheap no matter what you do...



> Duty cycle will be low, and external active cooling can be  
> provided if required. So things like steppers are out, I've never seen a  
> stepper that outputs nearly that much, and I don't particular want to  
> create a 4kw 80v dc power supply...
> 
> re: Control requirements, I really only need to start running at a  
> particular speed and be able to return the system to a somewhat close stop  
> position, which can be as simple/bad as a vfd with a switch and timed jog.  
> Any extra control over the system that I can get would add capabilities  
> though.
> 
> The goal here is to see if there are any industrial drives out there that  
> might periodically pop up on ebay which are higher KW and single phase  
> capable.I see units like the Parker Gemini GV/GV6-U12/H20 which claim  
> single phase at 3.5kw and 5.9kw.
> 
> Dave
> 
> 
> On Wed, 11 Apr 2018 09:24:32 -0400, Dave Cole   
> wrote:
> 
> > How much time/work do you want to put into this motor/drive setup?
> > There are no really cheap large servo motor solutions unless you stumble  
> > into a deal on Ebay or a surplus marketplace.
> > Larger servos generally mean 3 phase inputs.   So that becomes an  
> > immediate issue.
> >
> > If you can live with a VFD, your life will be much simpler to simply get  
> > a single phase input VFD and a suitable motor.
> > You can find 3 phase gearbox equipped motors on Ebay that can get you  
> > 500 rpm max.
> >
> > Dave
> >
> >
> >
> > On 4/11/2018 2:01 AM, David Berndt wrote:
> >> Wondering if anyone had any preference/experience/advise to share with  
> >> single phase capable larger servos. I'm looking at an application for a  
> >> 3 to 5hp motor with a vfd, but if I could just get a servo to fill in  
> >> that'd be nice. Gear reduction will be required, but something with  
> >> more torque, needing less reduction will make things easier.Say ~500rpm  
> >> as a goal maximum output.
> >>
> >> I see things like Fanuc red cap servos (ai series? pulsecoder encoder)  
> >> 2.5kw kicking around ebay. Driving something like that would seem to be  
> >> the challenge?
> >>
> >> Thoughts? Suggestions? Previous experience?
> >>
> >> Dave
> >>
> >> --
> >>   
> >> Check out the vibrant tech community on one of the world's most
> >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> >> ___
> >> Emc-users mailing list
> >> Emc-users@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > --
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


-- 
  John Kasunich
  jmkasun...@fastmail.fm

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[John Kasunich]

On Wed, Apr 11, 2018, at 3:08 PM, John Kasunich wrote:
> 
> 
> On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote:

> > I'm looking to output about 1000lbf in a linear direction via a  
> > crank/slider or ballscrew 

> You don't mention the stroke length.  Are you moving a few inches in a 
> fraction of a second, or several meters over several seconds?  

On further thought...

Ballscrew requires unreasonably high RPM.

Crank is very non-linear, and has major problems as stroke exceeds a couple 
inches - longer stroke means longer crank which means more and more torque is 
required.  You never use more than a half-revolution of the crank, so some 
serious reduction will be needed between motor and crank.

Have you considered roller chain?  Keep the sprocket size small so the torque 
doesn't get crazy high, but you can use multiple revolutions of the sprocket to 
cover an unlimited stroke.  Still going to require a gearbox; for a 1000 lbf 
load you will need a few thousand in-lbs  (few hundred ft-lbs) of torque, which 
is a LOT for any motor.

Interesting engineering problem to be sure.

-- 
  John Kasunich
  jmkasun...@fastmail.fm

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[theman whosoldtheworld]

In my zone there are a lot of big servo motor manufactorer ( 30-50 hp and
more) it work for siemens, snider, and many other big company  as I
can see that power single phase is for special pourpuse only, and it can be
found normally in last page of big general product catalog of big company,
but if you call the producer no one know that it exist .. the better
response to your first post is: buy an inverter for convert single phase to
3phase  and than use cheap cina servo. ;)

obviuslly other motor type can solve your situation at minor cost.
About STMBL  there are a certain number of commercial model ... but I
see not it is so used in industry machine/autoamation manufactoring 
sincerely not know the reasons ... there are stmbl the electrical wheel of
tesla?

bkt

2018-04-11 16:59 GMT+02:00 andy pugh :

> On 11 April 2018 at 15:40, Ed  wrote:
>
> > I have to check on a regular VFD to drive it, Toshiba claims to be able
> to
> > drive (most) PM motors.
>
> The Parker Unidrive is another option, can run induction or PM motors
> equally well (the clue is in the name).
> Available to huge power outputs, but you probably don't want to pay
> new prices for them.
>
> > Tell me more about STMBL!
>
> You can read the (incomplete) documentation on the project's Github site
> https://github.com/rene-dev/stmbl/blob/master/docs/src/
> Getting%20Started.adoc
> Also look at the Wiki for a bit more information.
>
> One advantage of this drive for LinuxCNC use is that it can be
> controlled digitally through Mesa smart-serial. Plug it in to a Mesa
> system and HAL pins appear automatically.
>
> --
> 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, 1916
>
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[andy pugh]

On 11 April 2018 at 15:40, Ed  wrote:

> I have to check on a regular VFD to drive it, Toshiba claims to be able to
> drive (most) PM motors.

The Parker Unidrive is another option, can run induction or PM motors
equally well (the clue is in the name).
Available to huge power outputs, but you probably don't want to pay
new prices for them.

> Tell me more about STMBL!

You can read the (incomplete) documentation on the project's Github site
https://github.com/rene-dev/stmbl/blob/master/docs/src/Getting%20Started.adoc
Also look at the Wiki for a bit more information.

One advantage of this drive for LinuxCNC use is that it can be
controlled digitally through Mesa smart-serial. Plug it in to a Mesa
system and HAL pins appear automatically.

-- 
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, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Ed]

On 04/11/2018 08:38 AM, andy pugh wrote:

On 11 April 2018 at 14:24, Dave Cole  wrote:


You can find 3 phase gearbox equipped motors on Ebay that can get you 500
rpm max.

Another alternative would be to simply get a slow-speed motor.
I have an 8-pole motor on my Rivett lathe. This one here is suggested
for use from 72 rpm to 1000rpm:
https://inverterdrive.com/group/Motors-AC/ac-Motor-3kw-3HP-8Pole-MAA132MA8/
Add a 2:1 belt reduction and you have 30 to 500 rpm.
(I am unclear if there is any advantage between a many-pole motor and
a 2-pole motor with a large belt reduction).

As for drives to suit bargain motors from eBay: The STMBL (as
mentioned by John above) is useful up to about 2.2kW / 3hp and can be
configured to run rust about any 3-phase motor. (Induction or
permanent magnet).
They are pretty cheap (about £100 all-in) but the downside is that
availability is a bit spotty as they are an open-source hardware
design and you need to find someone ordering a batch if you don't want
several.
(I recently bought an batch of 50, but they are all spoken-for)




The red cap Fanucs that I have are 8 pole motors that make 6K RPM with 
400Hz from the spindle amp.



I have to check on a regular VFD to drive it, Toshiba claims to be able 
to drive (most) PM motors.


Tell me more about STMBL!

Ed



--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[David Berndt]

I'd like this to be reasonably low effort. My biggest concern is single  
phase input. Control/response requirements are about as low as it gets.


I'm looking to output about 1000lbf in a linear direction via a  
crank/slider or ballscrew with peak speed of about 1m/s. So that's a real  
5hp of energy. Duty cycle will be low, and external active cooling can be  
provided if required. So things like steppers are out, I've never seen a  
stepper that outputs nearly that much, and I don't particular want to  
create a 4kw 80v dc power supply...


re: Control requirements, I really only need to start running at a  
particular speed and be able to return the system to a somewhat close stop  
position, which can be as simple/bad as a vfd with a switch and timed jog.  
Any extra control over the system that I can get would add capabilities  
though.


The goal here is to see if there are any industrial drives out there that  
might periodically pop up on ebay which are higher KW and single phase  
capable.I see units like the Parker Gemini GV/GV6-U12/H20 which claim  
single phase at 3.5kw and 5.9kw.


Dave


On Wed, 11 Apr 2018 09:24:32 -0400, Dave Cole   
wrote:



How much time/work do you want to put into this motor/drive setup?
There are no really cheap large servo motor solutions unless you stumble  
into a deal on Ebay or a surplus marketplace.
Larger servos generally mean 3 phase inputs.   So that becomes an  
immediate issue.


If you can live with a VFD, your life will be much simpler to simply get  
a single phase input VFD and a suitable motor.
You can find 3 phase gearbox equipped motors on Ebay that can get you  
500 rpm max.


Dave



On 4/11/2018 2:01 AM, David Berndt wrote:
Wondering if anyone had any preference/experience/advise to share with  
single phase capable larger servos. I'm looking at an application for a  
3 to 5hp motor with a vfd, but if I could just get a servo to fill in  
that'd be nice. Gear reduction will be required, but something with  
more torque, needing less reduction will make things easier.Say ~500rpm  
as a goal maximum output.


I see things like Fanuc red cap servos (ai series? pulsecoder encoder)  
2.5kw kicking around ebay. Driving something like that would seem to be  
the challenge?


Thoughts? Suggestions? Previous experience?

Dave

--  
Check out the vibrant tech community on one of the world's most

engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[andy pugh]

On 11 April 2018 at 14:24, Dave Cole  wrote:

> You can find 3 phase gearbox equipped motors on Ebay that can get you 500
> rpm max.

Another alternative would be to simply get a slow-speed motor.
I have an 8-pole motor on my Rivett lathe. This one here is suggested
for use from 72 rpm to 1000rpm:
https://inverterdrive.com/group/Motors-AC/ac-Motor-3kw-3HP-8Pole-MAA132MA8/
Add a 2:1 belt reduction and you have 30 to 500 rpm.
(I am unclear if there is any advantage between a many-pole motor and
a 2-pole motor with a large belt reduction).

As for drives to suit bargain motors from eBay: The STMBL (as
mentioned by John above) is useful up to about 2.2kW / 3hp and can be
configured to run rust about any 3-phase motor. (Induction or
permanent magnet).
They are pretty cheap (about £100 all-in) but the downside is that
availability is a bit spotty as they are an open-source hardware
design and you need to find someone ordering a batch if you don't want
several.
(I recently bought an batch of 50, but they are all spoken-for)

-- 
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, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[jeremy youngs]

Snip

On Wed, Apr 11, 2018, 03:59 andy pugh  wrote:

>
>
> That doesn't sound right.
>
> A brushless servo should be able to give rated torque indefinitely at
> absolutely zero rpm.
>
Mine is a brushed baldor motor , I agree a brushless will go all the way to
zero .

It sounds to me like your drive might be set up funny?
>

It may be , I just installed this last night and tuned, I suspect the 20:1
control ratio of the carotron has some to do with this. Although the selema
drive and the brown boveri I replaced had a similar low end response.
I presumed the red cap servo he is discussing to be a06 which should be
brushed unless I am wrong.

>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Dave Cole]

How much time/work do you want to put into this motor/drive setup?
There are no really cheap large servo motor solutions unless you stumble 
into a deal on Ebay or a surplus marketplace.
Larger servos generally mean 3 phase inputs.   So that becomes an 
immediate issue.


If you can live with a VFD, your life will be much simpler to simply get 
a single phase input VFD and a suitable motor.
You can find 3 phase gearbox equipped motors on Ebay that can get you 
500 rpm max.


Dave



On 4/11/2018 2:01 AM, David Berndt wrote:
Wondering if anyone had any preference/experience/advise to share with 
single phase capable larger servos. I'm looking at an application for 
a 3 to 5hp motor with a vfd, but if I could just get a servo to fill 
in that'd be nice. Gear reduction will be required, but something with 
more torque, needing less reduction will make things easier.Say 
~500rpm as a goal maximum output.


I see things like Fanuc red cap servos (ai series? pulsecoder encoder) 
2.5kw kicking around ebay. Driving something like that would seem to 
be the challenge?


Thoughts? Suggestions? Previous experience?

Dave

-- 


Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[andy pugh]

On 11 April 2018 at 09:11, jeremy youngs  wrote:

> The red caps are generally 2-3 k rpm , what response do you need at your
> lowest rpm? And what is the lowest rpm. The red caps will give you great
> low end torque but will have a threshold below which it will be weak
> usually under 50 rpm on a 3000 rpm motor most drives give a 50:1 rpm ratio,
> my carotron ( 5hp drive , driving a 3kw baldor servo motor) only gives a
> 20:1 and my low rpm below 50 can be hand stalled easily at 52 it will burn
> your skin off.

That doesn't sound right.

A brushless servo should be able to give rated torque indefinitely at
absolutely zero rpm.

It sounds to me like your drive might be set up funny?

-- 
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, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[jeremy youngs]

Does it have to be a servo ?? 1800 in lb nema 34 steppers are inexpensive
and your speed needs are not great , it's possible a stepper and a kelling
drive would get you there . But again more input needed.
Gene , I know of a bunch of 700 ozin SLO-Syn but they are syncronous at 72
rpm, how would one drive them ? My only experience with slosyn is a couple
small ones I purchased ten years ago , aren't they essentially a bldc
without hall sensors?
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[jeremy youngs]

Far more information is needed to give you a fitting response. You need to
know what your actual torque needs are, even roughly quantified. I've
recently purchased several servo motors , due to not having a known torque
needed.
Your rpm requirement is quite low leaving a vfd 3phase motor wit not such a
good cooling.
What is the application? Spindle or motion control? If control then
attention has to be paid to the gearing mechanism or backlash will kick you
in the bum.
How is this motor to be mounted? What are your physical size constraints? 5
hp dc servo motors are available surplus for cheap that would drag a house
but they weigh half what a car does. A bldc motor and drive will get you
the most torque in the smallest area and give speed , matching 2.5kw bldc
and drive will be a b.o.a.t. ( break out another thousand)
The red caps are generally 2-3 k rpm , what response do you need at your
lowest rpm? And what is the lowest rpm. The red caps will give you great
low end torque but will have a threshold below which it will be weak
usually under 50 rpm on a 3000 rpm motor most drives give a 50:1 rpm ratio,
my carotron ( 5hp drive , driving a 3kw baldor servo motor) only gives a
20:1 and my low rpm below 50 can be hand stalled easily at 52 it will burn
your skin off.
The drive and power supply matter a lot as well for at least this reason.
Kb drives work well and don't require a power supply but are not isolated
and therefore require more hardware and strict electrical safety . So the
real answer is a few more questions.
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[Gene Heskett]

On Wednesday 11 April 2018 02:01:07 David Berndt wrote:

> Wondering if anyone had any preference/experience/advise to share with
> single phase capable larger servos. I'm looking at an application for
> a 3 to 5hp motor with a vfd, but if I could just get a servo to fill
> in that'd be nice. Gear reduction will be required, but something with
> more torque, needing less reduction will make things easier.Say
> ~500rpm as a goal maximum output.
>
> I see things like Fanuc red cap servos (ai series? pulsecoder encoder)
> 2.5kw kicking around ebay. Driving something like that would seem to
> be the challenge?
>
> Thoughts? Suggestions? Previous experience?
>
> Dave
>
The only comment I might make is that vfd's have a minimum usable speed 
they can drive a std "induction" motor, due to the current levels 
involved when trying to develop sufficient torque, causing ohmic heating 
in the motors windings, unless the motor has a hard armature, one 
permanently magnetized which in effect makes it a stepper. They are 
made, but my impression is that transferring the ownership is costly.

I've no clue where one could find a "slow-syn" of such a horsepower 
rating. But I'd suspect you would wind up using a honking big one. 
Rather than horsepower in such a case, I think you should be looking at 
stall torque instead.

At my place, with a 1 horse 3 phase and a cheap vfd, I have a minimum hz 
shutdown at 10hz. And the motor is pretty warm in 15 minutes, but most 
lathe operations don't take that long. With the backgear engaged, thats 
less than 20 rpm at the chuck. But its not stopped, and its not a 
positioning servo. It may be the red cap is the answer, but I've zero 
experience with them.

> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> 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)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Large servo selection

[John Dammeyer]

My plan is to find a 2HP 240VAC 3 phase motor and add an encoder.  Then use
one of my STMBL AC Servo Drives to run it.  I haven't yet decided how I will
control the speed from LinuxCNC or BBB Machinekit.  So far I've only had
experience with my 3 phase Harmonic Drive and the STMBL but it's step/dir.
The STMBL is a product that has potential.

John

> -Original Message-
> From: David Berndt [mailto:ber...@uberwin.com]
> Sent: April-10-18 11:01 PM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] Large servo selection
> 
> Wondering if anyone had any preference/experience/advise to share with
> single phase capable larger servos. I'm looking at an application for a 3
> to 5hp motor with a vfd, but if I could just get a servo to fill in that'd
> be nice. Gear reduction will be required, but something with more torque,
> needing less reduction will make things easier.Say ~500rpm as a goal
> maximum output.
> 
> I see things like Fanuc red cap servos (ai series? pulsecoder encoder)
> 2.5kw kicking around ebay. Driving something like that would seem to be
> the challenge?
> 
> Thoughts? Suggestions? Previous experience?
> 
> Dave
> 
>

--
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Large servo selection

[David Berndt]

Wondering if anyone had any preference/experience/advise to share with  
single phase capable larger servos. I'm looking at an application for a 3  
to 5hp motor with a vfd, but if I could just get a servo to fill in that'd  
be nice. Gear reduction will be required, but something with more torque,  
needing less reduction will make things easier.Say ~500rpm as a goal  
maximum output.


I see things like Fanuc red cap servos (ai series? pulsecoder encoder)  
2.5kw kicking around ebay. Driving something like that would seem to be  
the challenge?


Thoughts? Suggestions? Previous experience?

Dave

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users