[battwell]

my oh my!

do you know what the on position function is mr simpson?
i dont believe you do!

remember there is a big difference between hobby drives and commercial drives in the functions etc they can provide

i use the on position function (but i know how to use it too.)
now im going to bite my tongue.

[simpson36]

my oh my!

do you know what the on position function is mr simpson?
i dont believe you do!

remember there is a big difference between hobby drives and commercial drives in the functions etc they can provide

i use the on position function (but i know how to use it too.)
now im going to bite my tongue.

I am using the 'on position' function of the J2S to auto lock a spindle. You know about Mistubishi, but perhaps you ONLY know about Mistsubishi and think that every drive uses the same terminology and function identically, but that is becuase you have a habit of NOT reading before you comment.

You may note that the MR-C and the J2S have completely differnt names for that same function and the DMM drive documentation . . which I QUOTED . . . clearly states that the function sets the FAULT. But in order to NOTICE something, you must first READ it.

[Khalid]

Hi all,
Thanks for the feed back about the Electrical gearing.. I have recently purchased OMRON drive with compatible motor.. You people here are more more experienced than me.. This is my first time using Servomotor and currently studying the manual..

I will need your help in this regards..Soon i will post some questions that perplex me about the servo motor settings in the Servo Driver..

Thanks for the answers

[mactec54]

simpson36

On position Range
So this is always put into a servo system, it does not STATE that they have this small following error, this is just part of a servo system

It's just what happens if there was a out of postion error, & what will take place after it reached 126 steps, But this is not likely to happen

When you have a 14 bit encoder (16384 counts per rev x 4= 65536 counts per rev
you would never be able to measure the amount on the cut part even if it was out
by 126 steps

Which it would never be

I have tested them at 600ipm & have not been able to measure any out of position

As I have said before they do not have this small fixed following error you keep talking about.

[battwell]

every step/direction servo is out of position as soon as its commanded to move.
if you ask the servo to move say 1000000 encoder counts by sending a pulse stream, unless the load and acceleration is set absolutely perfectly (which will never be the case) due to friction/mass etc the servo calculates its torque to comply as quickly as possible and recalcualte it as its out of position error decreases to near where its commanded.
at the start of the move it will be out of position by the full amount of commanded position already sent . This error will be reduced at either maximum speed set in the drive or maximum torque output available. this error amount will decrease as it nears its last commanded position. When it gets to its "in position range" a signal is output to notify its plc that its almost done : issue next command or wait until . On most servos this amount of encoder counts can be programmed to any value. (usually set to a few hundred encoder counts on a 32 bit encoder so the movements dont become jerky) if set to a very low value (10 or less ) the output isnt sent until the encoder pulse has settled which wastes a lot of time. would rarely be used in hobby systems however motion controllers like the galil use this to give the exact stop (yes i have read the manual!!! yes i have used them in my machines and i have the videos on utube to demonstrate this feature working superbly)
im am conversant with older yaskawa, omron, omron -yaskawa, mitsubishi h, j , j2s, j3, parvex, soprel, control techniques and allen bradley.
i will read through a mitsi c series manual and see how different everything must be programmed but at my first glance it was very similar to h series. i havnt bothered buying them as most are not on my countrys supply voltage and the encoder count is as low as the older yaskawas of which i have loads in stock.

why dont you use the mitsi software and see how far the encoder error shows as out of position when you call a fast acceleration with the drive set to normal (on load settings) you will see what im trying to explain

[battwell]

khalid. which modelnumber/ size of omron did you buy?
my first real industrial servo was a 200watt omron. The manuals are very thorough however can be fun to understand . ask anything you need to know. il help where i can

[Khalid]

khalid. which modelnumber/ size of omron did you buy?
my first real industrial servo was a 200watt omron. The manuals are very thorough however can be fun to understand . ask anything you need to know. il help where i can

Hi battwell, so nice of you for helping me... As i earlier told you i am a newbie to servo motors so i will ask silly questions, i hope you will keep up with me..

Following is the servo driver and Motor i have purchased:

Servo Driver: OMRON R88D M120
Servo Motor: OMRON R88M M1K120

I have two Gecko G302V stepper driver and I am planning to install it on X/Y carriage. The servo Motor will be installed it on Z-axis... The Z-axis total weight is 120Kg (Counter weight installed) and is supported by 2 1inch linear rails with 4-blocks.. I am using 10mm lead/ Revolution Ball screw on Z-axis.
I will need your help in servo drive only:

The servomotor will be connected with the lead screw with 10:1 reduction gearbox. The lead screw has 10mmlead/revolution and 32mm diameter ball screw. I want to get Rapid at 150IPM running Mach3 with 25KHz kernel speed.Is that 150IPM is possible?

I have the user manual for the Omron Drive having lot of parameters.. What parameters are necessary to program in the drive?

I can make a new thread to understand the SERVO as keeping writing in this thread will OFF-Topic.

PS:
You can see the retrofitted radial Drill Machine in the following thread. Currently I have fabricated the new column and the SPINDLE for this machine, to carry out Milling jobs.
http://www.cnczone.com/forums/showthread.php?t=105247

[battwell]

hi khalid.
i saw this when you first started it. cool project! and going well by the look of it.
(i converted my much smaller drill press with the same issue of z axis unknown gearing, eventually got it good enough to make parts for other machines)

have you run servo yet?
it would be worth starting a new omron thread so others find it easier too.

[battwell]

just had a 10 minute search for the manual. cant find it!
if you have a link to a download for it can you post?
im hoping it will support step/direction to make it easy.

il try to x reference it to its yaskawa part number too.

[simpson36]

every step/direction servo is out of position as soon as its commanded to move.

why dont you use the mitsi software and see how far the encoder error shows as out of position when you call a fast acceleration with the drive set to normal (on load settings) you will see what im trying to explain

I completey understand what you are saying and I agree with everything you said. It is obvious that you do have an understanding of how the servo drives work conceptually, and therefor you woudl have to agree that statements like 'there is no following error' are simply nonsense. As you correcty pointed out, there is ALWAYS following error because that is how servo drives work; by constantly attempting to reduce the following error. The entire PID scheme is simply parameters that control how . . 'enthusiastically' the drive behaves in meeting this goal.

The issue with the DMM drive is that the FAULTING of the drive is integrated into the 'positioning reached' function and the drive will FAULT when the position error (which is just another way of saying following error) reaches 126 steps. This is according to their own documentation, which I quoted erlier.

Many of the drives that I tested have no 'position reached' function, but those that do implemented it SEPARATELY from the faulting function which is generally programmable. In my review, I state how each drive handles faulting and what the error limits are.

You also mentioned resolution. As you surely know, the higher the encoder resolution, the larger the numbers will be for the same azimuth delta.With a high res encoder, 125 steps is some tiny fraction of a degree. If accelleration is set to anything aproaching a high performance setting, by the time the drive and motor can react and get the motor up to speed, it has faulted. This was the problem with the early Gecko drives. Gecko, however, recognized this and increased the faulting limit from 128 to 2048 (or thereabout). The DMM is still maxed at 126

You will discover that the 'position reached' signal has a different name in the MR-C and the J2S. But in both cases, the FAULT is separate and is programmable over a wide range.

[simpson36]

simpson36

So this is always put into a servo system, it does not STATE that they have this small following error, this is just part of a servo system

As I have said before they do not have this small fixed following error you keep talking about.

As usual, you just don't get it and you just keep repeating the same nonsense statements. I am done trying to explain it to you. Believe what you want.

'It is better to light a candle that to curse the darkness' . . instead of whining about my review, do what you said you would do and write your own.

[Khalid]

Hi battwell,
I am attaching the manual here.
Now, I will start from the terminal connections. All is clear to me except:
The Controller need 3-Phase 220V whereas I have Single Phase 220V as shown in figure attached. Will this work? We also have 3-Phase 380V but the controller not shows any three phase 380V supply>.. So can I run it with Single phase 220Volts?

Second thing is the INITIAL SETTINGS as attached in picture. All is clear to me except the Control mode options given in Page-16 of attached manual.
It has following Options:

1- Analogue Speed Control
2-Analogue current control
3- Analogue speed or current Control
4- Pulse train Position control
5- Pulse train Position control with FF

What mode should i use to control with Mach3? Mode 4 or mode5?

[Khalid]

Sorry guys i am starting new thread for my problem...

[Khalid]

Here is the Thread on OMRON drive... I will be thankful to you helping in running my machine
http://www.cnczone.com/forums/showth...414#post814414

[battwell]

the dmm manual may not explain things clearly. does it actually state that the drive will fault if it goes over 127 counts of error?
have you got a link to the dmm manual? post it.

from the video mactec put up they seem to be well sorted drives!
that machine has fantastic acceleration and great accuracy from what i could see. its obviously working very well for that machine and not faulting when fast on load acceleration is required?
ive never personally come accross those drives but would love to get my hands on one to test.

my advice to anyone is dont knock it till you tried it, and even then it may be something youve overlooked or done wrong? (done this many times in earlier days. so easy to overlook a parameter thats not well explained in a manual. try changing a parameter that states in later revisions of a manual that states do not change! all hell breaks loose.)
ive done loads of servo things that people said cant be done. i very rarely let these things beat me.
im just running out of machines to retrofit now.

[mactec54]

simpson36

Yes I told you before as well, that all drive's have some kind of following error, but those that have very good control do not need the big number of out of position steps before they fault out, like the Gecko has

If a drive can not operate without faulting out, because of out of postion setting
is not large enough, ( In Your Mind ) Then what use would that drive be to anyone

The point here is that the DMM drives do not have a problem because they are not ever going to reach anywere near the fault out number of 127 steps

So they don't have a out of position error problem,(or as you keep say a small following error problem)

[mactec54]

battwell

Here are the PDF for the DMM drive

Sorry Khalid but you are getting attention about your drive, yes you can run it on 220/230 single phase
do not use the neutral wire if you have one, Your drive will be derated when you do this

[Khalid]

Okay Thanks Mactec54 I have input connection R S T where S=Ground Phase, So I will just connect R and T of the single phase 220V????
I have studied somewhere that this will Derate as you mentioned..I want to know how much loss of torque?

[mactec54]

Khalid

I not sure I understand what you mean with the S being the ground phase, I don't think you have it wired correct

With your 10/1 ratio I don't think you will have a problem with the torque loss

[Khalid]

Hi Mactec54
I have not wired the system..The Motor is very beefy and the servo driver is as big as motor.. Frankly speaking i afraid to see both sizes...Compared to stepper motors and drivers these servo drives and Motor are like HULK...
I will first make sure all the wiring well with all of your help then i will wire and test run after parameter settings

Hmmm.. Thanks for the Torque thing... With 10:1 reduction and further reduction with ball screw i will have immense torque... This is my first time using servo so asking some very basic questions..

Thanks