Herewith report on follow-up actions to the anomalous behaviour experienced.
The rather disorganised structure of the .ini file comes straight out of
PNCconf utility, and it in fact inserts the MIN_VELOCITY globals. The actual
'bug' is that it defaults the fourth joint to ANGULAR (which is acce
Gene Heskett wrote:
> With a big enough flywheel to assure a pretty constant angular velocity in
> the presence of the motors natural cogging tendency, I still don't think
> the diffs would be all that visible on the scope.
These brushless SERVO motors have VERY little cogging. I have some
slot
On Thursday 12 July 2012 22:28:46 Jon Elson did opine:
> Todd Zuercher wrote:
> > Is there a Way to tell if a motor is trapezoidal wound?
>
> In theory, if you spun it at a constant rate and observed the waveform
> on an oscilloscope, it would be non-sinusoidal. But, I've never been
> able to te
Todd Zuercher wrote:
> Is there a Way to tell if a motor is trapezoidal wound?
>
In theory, if you spun it at a constant rate and observed the waveform on
an oscilloscope, it would be non-sinusoidal. But, I've never been able
to tell the difference.
> Besides trying it both ways and seeing whi
andy pugh wrote:
> In that case the motors will work nicely with almost any conventional
> drive including the Pico one. http://www.pico-systems.com/acservo.html
> It will also work with the 8i20, but that needs a Mesa interface card
> (whereas I think the Pico drive will work with any PWM source,
Todd Zuercher wrote:
> There are 15 wires in the encoder cable plug:
> Shielding
> +Vcc Data (5volt)
> GND Data
> S1 (Hall Signals on the encoder)
> S2
> S3
> +Vcc COMM (5volt)
> GND COMM
> CH A (Differential encoders)
> CH A-
> CH B
> CH B-
> Index
> Index-
> TC1 (these two go to the a temp sen
I will do a lot of repetitive motion testing this afternoon, with an LVDT
and 6.5 digit multimeter to measure the position. I'm going to implement
some slightly more sophisticated logic first, along with a multiplexer instead
of the tri-state buffers.
I'll report back tomorrow :-).
I don't want
2012/7/12 Chris Radek :
> On Thu, Jul 12, 2012 at 02:25:48PM -0400, Kenneth Lerman wrote:
>>
>> I understand that you are "...not very worried about a couple of counts
>> every 75mm." It would be nice to have a cleaner solution.
>
> I didn't want to harp on it... but I would want to determine
> wh
On 7/12/2012 3:15 PM, Chris Radek wrote:
> On Thu, Jul 12, 2012 at 02:25:48PM -0400, Kenneth Lerman wrote:
>> I understand that you are "...not very worried about a couple of counts
>> every 75mm." It would be nice to have a cleaner solution.
> I didn't want to harp on it... but I would want to de
On Thu, Jul 12, 2012 at 02:25:48PM -0400, Kenneth Lerman wrote:
>
> I understand that you are "...not very worried about a couple of counts
> every 75mm." It would be nice to have a cleaner solution.
I didn't want to harp on it... but I would want to determine
whether the error was cumulative o
Yes, Ken, it is not a perfect solution. One simple improvement will be to use
a mux instead of tri-state buffers. A somewhat more complicated
improvement will make use of the fact that there is actually a large
range of overlap between the sensors. This can be used as "hysteresis"
to prevent the
Hi Ralph,
I forget who said it, but... "It is not sufficient that there be no
obvious bugs. It should be obvious that there are no bugs." (Probably
Hoare or Dikstra or some other pioneer.) I believe your solution fails
that test.
I could easily imagine a small amount of servo hunting in normal
I solved my multiple-encoder problem for my linear motor. It turned
out to be almost trivial. The encoder counter doesn't care where it
is getting A and B signals from, just so each pulse represents a fixed
amount of movement of the carriage. So I connect all my A&B outputs
together with tri-sta
On Thu, Jul 12, 2012 at 1:19 PM, Todd Zuercher wrote:
> Is there a Way to tell if a motor is trapezoidal wound?
>
If it has halls on one connector and an encoder added, it probably is
trapezoidal. If it just has halls, it definitely is trapezoidal. Most of
the higher-end servo motors are wound f
Is there a Way to tell if a motor is trapezoidal wound?
Besides trying it both ways and seeing which works best.
I did try spinning the motor and looking at what the back EMF was with a
scope, and what I saw on the screen looked like a smooth sine wave to
me. But maybe that isn't a valid test.
T
My CNC Mill uses Yaskawa analog input servo drives with Pico Systems PPMC. You
need to use a PI/P (not PID) cascaded control scheme. There are articles in
Digital Machinist magazine that describe the entire build, but Part Three is
most relevant to your concern. It also has a full schematic:
On 12 July 2012 17:31, Todd Zuercher wrote:
>
> There are 15 wires in the encoder cable plug:
> Shielding
> +Vcc Data (5volt)
> GND Data
> S1 (Hall Signals on the encoder)
> S2
> S3
> +Vcc COMM (5volt)
> GND COMM
> CH A (Differential encoders)
> CH A-
> CH B
> CH B-
> Index
> Index-
> TC1 (thes
There are 15 wires in the encoder cable plug:
Shielding
+Vcc Data (5volt)
GND Data
S1 (Hall Signals on the encoder)
S2
S3
+Vcc COMM (5volt)
GND COMM
CH A (Differential encoders)
CH A-
CH B
CH B-
Index
Index-
TC1 (these two go to the a temp sensor in the motor)
TC2
--
P. Graham Dunn
Phone:
Todd Zuercher wrote:
>
> Is there enough of an advantage to sinusoidal commutation to justify the
> added expense of a sinusoidal drive, or is an inexpensive trapezoidal
> drive good enough?
>
The older the motor, the more likely they are wound SPECIFICALLY for
trapezoidal drive. Some newer mot
Todd Zuercher wrote:
> My motors are brushless, and I intend to use Linuxcnc.
>
> It sounds like (as I suspected) Yaskawa drives are not an option.
>
If you don't need 6000 RPM, then I might suggest the Pico Systems brushless
PWM servo amp and our PWM controller. They are good to 120 V, so
you
Todd Zuercher wrote:
> Can a Yaskawa servo drive be used with other servo motors?
>
>
>
> I am saw some Yaskawa SGDA-04AS drives on ebay but looking through the
> manual I downloaded gives me the impression they are only intended to
> work with their motors. Any one have any experience mixing and
On Thu, Jul 12, 2012 at 11:07 AM, andy pugh wrote:
> Looking on eBay at similar motors, there seems to be an awful lot of
> wires on the encoder connector. Have you any idea what sort of encoder
> it is?
>
I couldn't find one of those motors, and I'm not familiar with that series,
but typically t
Looking on eBay at similar motors, there seems to be an awful lot of
wires on the encoder connector. Have you any idea what sort of encoder
it is?
There are enough wires for it to be an absolute encoder, I think. Or
it could just be power and differential encoder + halls (14 wires,
maybe 16 with se
I have some brushless servos that I am trying to find some drives for.
I want to use them with Linuxcnc and I don't have any other hardware to
go with them (yet).
They are old ElectroCraft servos.
XBR-2910 (part# 1834629030) Specs:
Torque Constant (Kt) : 1.8 in-lbs/ amp
Voltage Constant (
My motors are brushless, and I intend to use Linuxcnc.
It sounds like (as I suspected) Yaskawa drives are not an option.
--
P. Graham Dunn
Phone: 330-828-2105
E-mail: to...@pgrahamdunn.com
630 Henry St.
Dalton, OH 44618
www.pgrahamdunn.com
-Original Message-
From: andy pugh [mailto:bo
On Thu, Jul 12, 2012 at 8:49 AM, Todd Zuercher wrote:
> Can a Yaskawa servo drive be used with other servo motors?
>
> According to the docs I have found, there isn't even compatibility between
a wide range of Yaskawa motors and their own drives. Once I get my power
supply issues straightened out
We use these on our machines and they must use the motor from Yaskawa designed
for them. another caution is that not all motors wrk with all drives.
Jim
Todd Zuercher wrote:
> Can a Yaskawa servo drive be used with other servo motors?
>
>
>
> I have some motors and I need to find some
On 12 July 2012 13:49, Todd Zuercher wrote:
> I have some motors and I need to find some drives to work with them.
Brushed or Brushless motors?
Are you intending to use them with LinuxCNC?
--
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto
-
Can a Yaskawa servo drive be used with other servo motors?
I have some motors and I need to find some drives to work with them.
The motors specs are:
Torque Constant (Kt) : 1.8 in-lbs/ amp
Voltage Constant (Ke) : 19.9 - 23.1 V/KRPM
Rated Voltage : 230 volts
Continuous Speed (no load)
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