Hi,
should explain..Machs 'kernel' refers to the parallel port pulse engine. As you are using an ESS you are not using
Machs parallel port and therefore its pulse speed limitation is irrelevant.

therefore I should have a 4:1 electronic gear ration in order to force the motor
to run at higher speed of 4*685=2740 ?

If you run the motor at four times the speed the axis will move four times as fast UNLESS you use a different reduction
gearbox. "Electronic gearing' has no bearing on that.

Craig

Hi Craig

I would like to thank you for your detailed replies, and explanations

I should mention that servo motors are new to me, and there are a lot that I need to learn.

All along i was imagining that one can control the speed (rpm) by modifying Electronic Gearing, apparently that is not the case, I tried to find some

Reading on this issue, but it is very hard to find good reading on it. if you have some good reading or clips, please let me know.

Apparently with my Servo motor, it's driver and pinion setup, I should make it easy for my self, and i do not need to Change or modify much.

I have movements, and Electronic gear is Ok as it is, off course I should mention that as you said the default value for

P1-44   16  Numerator
   
P1-45   10  denominator

Do I need to change this value to both (10, or 16) or should I leave it as it is?

Also is there any thing else that I need to change in order to get better performance out of my motor/

regards
jhonansaro

Hi,
by my calculation you don't need any electronic gearing at all.

Denominator=Numerator =1

Would suggest you enter max speed of 800 rpm say.  Keep the max acceleration somewhat less than the absolute theoretical best. The real challenge with
a servo comes when you are decelerating. The motor turns into a generator and energy comes from the servo back into the servo drive and they don't
like it. There may be optional braking resistors for your servo to improve the situation. If you try to decelerate too quickly the drive will fault 'bus overvoltage'
and the servo will coast to a stop. If it coasts right off the end of the axis....to bad....should've been more careful planning the deccel phase.

Modern AC servos are extremely capable, if you can only get 10% of best out of one it will still be amazing. Don't worry about it, get it set it up and
use/experiment with it, you'll be really impressed. The trick is to be a little conservative about accel/deccel, they are so capable that you are inclined to keep
upping the ante only to find that you break your machine.

Craig

Hi Craig

On the issue of electronic gearing, today i was experimenting with my Servo, and with low value of P1-44 (Numerator Gear Ratio) set like 10 or 16, with value of P1-45(Denominator) set
at value of 10. I will get barely any movement, But as I increase the P1-44 to some thing like 160, I will get a good RPM out of the servo.
In conclusion it appears that by increasing the Numerator I can increase the RPM, but you said that they are not related. How could you explain this?

I should mention that I was using mach3 Motor tuning in order to increase the speed. but with low values of P1-44 no matter how much i increase the speed in mach3 I would not gain
Much RPM, I get some but very little. Basically with speed set to some value like 1000 rpm/min in mach3 has different meaning with Low P1-44 vs High values for p1-44

regards
jhonansaro

Hi,
electronic gearing is a means of controlling or setting the number of input pulses necessary to produce a
movement  of a number of encoder counts.

If you had a signal generator producing a steady 1000 pules per second then with no gearing (default
10,000 count encoder) it would move 1/10 rev per second.
As you increase the electronic gearing it will get faster, that is that the same 1000 pulses will cause an
encoder count movement of 20,000 say or 2 revs per second.

You can set both nominator and denominator equal and that means that one input pulse causes movement
of one encoder count. Whether you set them both at 16 (or 10 or 1 or 57....) doesn't matter.

If you are going to do some testing use Mach3 to produce the pulses but don't alter it otherwise you can't be
sure what it is thats changing.

Craig

Hi,
try this from the manual:

P1-45▲ GR2 Electronic Gear Ratio (Denominator) (M) Address: 015AH
015BH
 Operation
Interface: Keypad/Software Communication Related Section:
Section 6.2.3
 Default: 10
 Control
Mode: PT
 Unit: pulse
 Range: 1 ~ (231-1)
 Data Size: 32-bit
 Display
Format: Decimal
Settings:
This parameter is used to set the denominator of the electronic gear ratio. The
numerator of the electronic gear ratio is set by P1-44. P2-60 ~ P2-62 are used to set
the additional numerators.
As the wrong setting may cause motor to run chaotically (out of control) and it may
lead to personnel injury, therefore, ensure to observe the following rule when setting
P1-44, P1-45.
The electronic gear ratio setting (Please also see P1-44, P2-60 ~ P2-62):
f1 f2 = f1 x N
M
N
M
Pulse input
Position
command
The electronic gear ratio setting range must be within: 1/50<N/M<25600.
Please note:
1. In PT mode, the setting value of P1-45 can not be changed when the servo drive
is enabled (Servo On).
The electronic gear function provides easy travel distance ratio change. However, the over
high electronic gear ratio will command the motor to move not smoothly. At this time, the users
can use low-pass filter parameter to improve this kind of situation. For example, assume that
the electronic gear ratio is equal to 1 and the encoder pulse per revolution is 10000ppr, if the
electronic gear ratio is changed to 0.5, then the motor will rotate one pulse when the command
from external controller is two pulses.
For example, after the proper electronic gear ratio is set, the reference travel distance is 1

Note that the formula expressed is not displayed correctly in the quote. Read the manual.

Craig

Hi Craig

Well your last reply was just over my head, and with my current state of concentration I do not think I can digest it any time soon.

But my setting currently for my servo are as follow, and I should say that I am getting a smooth run so far, but off course i have not install them completely yet;

P1-44       480
P1-45        16
P1-36          5     ms
P1-52         100
P2-08         36

Could you please verify all these for me
Finally pulse per unit in mach3 is set at  571 , "as you calculated before "

regards
jhonansaro

Hi,
did you read the page 6-8 in the manual?

It doesn't appear so.

Currently you have the numerator =480 and denominator at 16.
One input pulse will result in 480/16=30 encoder counts, not what you want, you want one input pulse to effect one encoder count, ie no electronic gearing
at all.

Make P1-44 equal to P1-45, I don't really care what, if you set one as 16 then set the other as the same.

The formula on page 6-8:

F2= F1 X (M/N)

You want F1=F2, therefore M/N must equal one, therefore M must equal N.

Craig

Hi Craig

thanks for the reply.
are you telling me that the Electronic gear Ratio(EGR) must be equal 1 in order to satisfy the formula? then what is the use of having such ratio?

Also I did what you asked me, and I set the value of
P1-44 =16
P1-45 =16

But even Thu in mach3 motor tuning i set the speed at 10000 mm/min, my speed has been reduced considerably to some thing like 1 rev/sec, which seems
not bad 1*60= 60 rev/min and 60*175=10500 mm   But please be reminded that I have a 10:1 GearBox so I think I need to Increase my speed 10 times more?

When I had :
P1-44 =480
P1-45 =16

My speed was much higher, I do not have the means to calculate (Or may be I have through the use of driver and/or the software, But I just do not know how to)
But i could say that my speed was to some thing like over 10 rev/sec, which is what i need.
Could you verify all these to me?

on the issue of checking my actual speed, do you know how can find out about from the software of the driver, (you can get the software form the net, or I could send it to you)

regards
jhonansaro



 

Hi,
the point of having an electronic gear ratio is that if you have a controller that has a slow output pulse rate that it can still be used to provide the
fast encoder count required by the servo. Just because the manufacturer put electronic gearing there doesn't mean you have to use it.

With the electronic ratio set to 1 (numerator and denominator equal) if Mach/ESS produces 114,000 pulses per second your servo should spin 11.4 revs per
second or 684 rpm.
Note this assumes a 10000 count encoder. Make sure that this is the case.

Craig