John Prentice wrote:
> On a related topic I have wondered if it would be possible to have a second
> set of following error settings for rapids. I feel in my tuning that I
> sacrifice rapid performance to avoid "errors" that really only need to be
> tight during cutting.
>
EMC2 already has it
On Wed, 2011-09-21 at 07:29 +1000, Frank Tkalcevic wrote:
> I have a Hitachi SJ200 VFD that I will be hooking up to EMC. I'm just
> wondering what the best combination of signals I should use to control, and
> monitor it.
I'm using two digital pins and a DAC to run my SJ200. So far, so good.
Addi
On 20 September 2011 22:29, Frank Tkalcevic wrote:
> What it seems to lack, compared to my servo amplifiers, is an Enable line,
> something that stops it from doing anything unless the Enable is asserted.
Generally if neither "Forward" nor "Reverse" are set, nothing happens.
--
atp
"Torque wre
On Tuesday, September 20, 2011 06:10:14 PM Peter Blodow did opine:
> Gene, just for the records: kinetic energy E = 1/2 times M times V
> square. We are not on relativistic terms here. But as far as this
> current discussion is concerned, this is not so important.
>
> Peter
>
And I have never s
On Mon, 19 Sep 2011 23:02:08 +0300, you wrote:
>Thinking about decreasing stepper (and servo, to some extent) torque at
>higher speeds, I just thought that having variable axis acceleration would
>be perfect. I.e., the highest at lower speeds and lower at higher speeds. Is
>that ever possible with
I have a Hitachi SJ200 VFD that I will be hooking up to EMC. I'm just
wondering what the best combination of signals I should use to control, and
monitor it.
What it seems to lack, compared to my servo amplifiers, is an Enable line,
something that stops it from doing anything unless the Enable is
Gene, just for the records: kinetic energy E = 1/2 times M times V
square. We are not on relativistic terms here. But as far as this
current discussion is concerned, this is not so important.
Peter
gene heskett schrieb:
> On Tuesday, September 20, 2011 03:45:13 PM craig did opine:
>
>
>> Al
On Tuesday, September 20, 2011 03:45:13 PM craig did opine:
> Although my education, long ago, was in physics, I do not really
> understand the physics of electric motors.
>
> Are there reasons to limit the rate of change of acceleration?
Every hear of E=MV2? The machine has a mass that must
On Tue, 2011-09-20 at 18:09 +0100, John Prentice wrote:
... snip
> On a related topic I have wondered if it would be possible to have a second
> set of following error settings for rapids.
... snip
I think there is, in the .ini file:
FERROR = 0.001 <-- Normal error
MIN_FERROR = 0.005 <-- Low
craig wrote:
> Although my education, long ago, was in physics, I do not really
> understand the physics of electric motors.
>
> Are there reasons to limit the rate of change of acceleration?
>
> for example: Are there reasons that one would not want to go from max
> acceleration in one directio
On Sep 20, 2011, at 11:09 , John Prentice wrote:
> On a related topic I have wondered if it would be possible to have a second
> set of following error settings for rapids. I feel in my tuning that I
> sacrifice rapid performance to avoid "errors" that really only need to be
> tight during cutti
On Tue, 2011-09-20 at 19:38 +0300, Andrew wrote:
... snip
> It just stops and shows something like "Overvoltage" when connected to PC.
... snip
I've seen this message from my VFD's while setting up dynamic braking
where the motor back EMF from motor deceleration (motor becomes more
like a generato
- Original Message -
From: "Steve Stallings"
>
> Accomodating a variable acceleration limit would
> seem to be fairly complex.
>
> Perhaps there is a solution that would offer some
> of the benefit without as much pain.
>
> Since rapid moves are done without cutting loads,
> perhaps we c
On Tue, 20 Sep 2011, Andrew wrote:
> Date: Tue, 20 Sep 2011 19:38:08 +0300
> From: Andrew
> Reply-To: "Enhanced Machine Controller (EMC)"
>
> To: "Enhanced Machine Controller (EMC)"
> Subject: Re: [Emc-users] Variable axes acceleration
>
> 2011/9/20 Dave
>
>> On 9/20/2011 11:34 AM, Andrew
2011/9/20 Dave
> On 9/20/2011 11:34 AM, Andrew wrote:
> > It looks like lack of capacity at
> > higher speed.
> You may be simply running out of servo power
>
I've thought about it already, thanks. That's what I intend to try -
increase supply power.
> Servos oftentimes have some reserve power
On 9/20/2011 11:34 AM, Andrew wrote:
> It looks like lack of capacity at
> higher speed.
>
You may be simply running out of servo power.
Servos oftentimes have some reserve power that you can use for a short
period of time, but that is limited.
If your drive power supply is undersized, that
The rate of change of acceleration is "Jerk".Limiting Jerk literally
make the machine less "Jerky" which is much more noticeable when running
at high speeds.
Andy hinted at it with car braking..Have you ever been in a car with
a new driver? Oftentimes everyone suffers from a bit of
Accomodating a variable acceleration limit would
seem to be fairly complex.
Perhaps there is a solution that would offer some
of the benefit without as much pain.
Since rapid moves are done without cutting loads,
perhaps we could have a separate set of acceleration
and velocity limits that are us
On 20 September 2011 16:01, craig wrote:
> Although my education, long ago, was in physics, I do not really
> understand the physics of electric motors.
>
> Are there reasons to limit the rate of change of acceleration?
Two different idea have been conflated here.
Andrew was suggesting altering
2011/9/20 Dave
> I would think that this would be very hard to implement successfully.
> You are talking about optimizing the acceleration settings to a
> particular motor/drive/load setup.
>
> I can only see this being of a benefit if you were running a fixed part
> with the same cutter over and
Although my education, long ago, was in physics, I do not really
understand the physics of electric motors.
Are there reasons to limit the rate of change of acceleration?
for example: Are there reasons that one would not want to go from max
acceleration in one direction to max acceleration is
I would think that this would be very hard to implement successfully.
You are talking about optimizing the acceleration settings to a
particular motor/drive/load setup.
I can only see this being of a benefit if you were running a fixed part
with the same cutter over and over again with a under
On 19 September 2011 21:02, Andrew wrote:
> Thinking about decreasing stepper (and servo, to some extent) torque at
> higher speeds, I just thought that having variable axis acceleration would
> be perfect. I.e., the highest at lower speeds and lower at higher speeds. Is
> that ever possible with
I thought I remembered a name for that from college physics.
Velocity is meters/sec
Acceleration is meters/sec^2
Jerk is meters/sec^3
Jerk is the rate of change of acceleration.
http://en.wikipedia.org/wiki/Jerk_(physics)
On Mon, Sep 19, 2011 at 3:02 PM, Andrew wrote:
> Thinking about decreasin
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