[woffler]

Hi ,everyone i am having a problem on my X axis over shooting by .0015 checked with several instruments same thing all report over travel , any one have a idea as to what would keep causing this?

Dyna 2 driver with a .75 KW motor DHT
Thank You Dusty

[mactec54]

woffler

What are the settings you have in the drive, .015 is a big number, if the drive is set correct it would go into a fault with such a big number

[woffler]

Hi Mactec 54,sorry it took so long to back to you ,i have isolated the problem to noise from the VFD it is external from the metal case that the drives are in but the drives are still picking up the noise,it will either gain or loose steps when the spindle is running.

If i turn off the spindle and put a 1/thousandth indicator on it the axis will repeat to a set zero ,this axis has C3 ground screw on it with a 5:1 gear reduction on it and a C3 bearing block mount .

This has been driving me nut's for awhile and parts Turing out wrong dimensions , i just kind of stumbled across it when i would rapid with the spindle on i could hear a kind of rumbling noise come from the axis and not with the spindle off.

So i measured with spindle off and on and with it on, it was all over the place losing as much or gaining as much as .015 weird Huh !

So now to try and find a solution to the noise problems on the drives, how are you setting up your VFD as far as wiring to solve this problem or maybe to try another drive?

[mactec54]

woffler

Yes you will have to get the VFD noise fixed, Spindle to the VFD Drive, do you have a good shielded cable, you can Ground the shield at both ends for this cable

The servo motors to the Drive, do you have a Ground wire in this cable, this can help that part, any other wires that are not shielded, should be twisted together

A photo of your wiring may help, Cabinet Etc

[woffler]

I think the problem is coming from the drives they are not grounded, i isolated them when i did the install several years ago, i do not remember why ?

I hooked a ground wire in series to the cases of the drives and to the case ground and that has seem's to have stopped the problem i will do a little more testing after lunch and see for sure .

Did you ground the cases on your dyn 2 drives?

[mactec54]

woffler

The cases on the Dyna2 drive are mostly plastic, the heatsink is the only metal part, that should be mounted to a metal plate, the Plate is Grounded, ( or have a Star Ground point on it ) that is all that is needed, They should not be isolated, I have never seen the Dyna2 Drives ever have a noise problem, They can be affected by Noise from other electronics, like a VFD

Grounding like the photo will work, but correct mounting of the Drives will be better

[woffler]

Hi Mac ,i grounded every thing and ordered a special tray power cord for the drive motor to the vfd it has copper shield with a ground wire in it ,the one i have is just twisted wire.

I ran some test cut's first i set the steps and double checked movement with a indicator .

Ran two test cuts ,they where off by (- .017) less than they should have been i can still not get this thing to cut correctly ,my next try will be to swap the driver and then the motor ,and see if this has any effect.

I have no backlash to speak of , not even a thou. so it has to be a control issue of some kind the funny thing is it only happens on one axis the Y.

[mactec54]

woffler

What control are you using, have you set the step/per with an indicator

Do your Drive settings look similar to this, the 3rd row has to be the same as this, apart from the Drive ID which will be different for each axes

[woffler]

I am using mach 3 with a eithernet smooth stepper ,my gear number is different and is set to 1000,everything else is the same on the third line.

I am ruuning the gain and the others on the first line at 24 same as on my outher a axis it runs at 51 gain but it is lifting 135 lbs with a ten to 1 ratio.

[mactec54]

your gear setting should be set at 500,they can be set higher when using the Smooth Stepper, but the smoothest the motor will run is with it set at 500, your Gains are way to low to run a machine, you will need the first line set to at least what I posted above, on all the drives, a setting of 24 would be with the motor not connected to anything

Your drive ID needs to be set X axes=0 Y axes=1 Z axes=2

When you set the gearing correct, you will have to reset the step/per, once you get it close, use Mach to set the steps/per with your Indicator

[woffler]

Thanks for back to me ,i will increase the settings tomorrow , and report back i had to get away from it today before i set it on fire!

[woffler]

I am sorry it took so long to get back to this, but life happens,any way while testing i lost the driver it would trip out on start up ,so after checking every thing, it is the servo motor that is the problem it binds when rotated with out any power to it ,unhooked from the axis.
I will send back for warranty as it less than a year old.

And buy a new driver to luckily i have purchased spares,driver and motor,it feels like a bearing has gone and i am not prepared to take it apart having not done it before.

I will post back with result's as soon as i get everything back to together .

Thanks Dusty

[mactec54]

woffler

Make sure there are no wires touching each other, this also will make it feel like it is binding, if any wires are touching

[woffler]

I took it off and disconnected it from the cables ,and if you turn it it feels like it is binding like the bearing is bad ,i checked it against my spare and the spare turns smooth and no binding .

I am gong to put the spare motor and driver on and check everything again, this is the second motor problem i have had of late the last one the encoder failed and had to be replaced.

I am going to replace them with a new system later in the year with a regular closed system drive and motor and get away from Mach 3 , its time .

[mactec54]

woffler

Can you take a photo of the motor, I would like to see, which model motor you have, there have been a lot of changes, to there motors

[woffler]

Here they are

[mactec54]

woffler

That the very oldest motor they sold, sometimes with that model, if the exposed encoder, is bumped it can get out of alignment, this will also cause the binding you can feel when you turn the shaft, they have not had this motor for more than 2 years, there has been 2 modifications since that was used, mainly a metal cover that protects the encoder, & with a much better quality motor, this is ( 1 ) of the new motors, with the encoder enclosed to protect it, the new motors Drives are very good

[woffler]

I saw those on the web sight ,this is probably what i will end up with ,but if i am going to spend that kind of money i might as well get a one solution system, controller and drives and motors.

Most of the control folk's want you to use there total system or they will not sell it to you,i guess i can understand that.

I just finished putting all ground screws in C3 accuracy with bearing blocks on all three axis so it will have to wait for awhile ,what i need to do is go buy a VMC and get it over with !

But then i would have nothing to drive me crazy everyday Ha!

I wrote to the sales folks for a new drive and motor one of the new DYN 2 with the new motor ,but have not heard any thing from them, i know that they where at a show ,probably have not got home yet.

[mactec54]

woffler

One thing with the a control/motor packages, is the low count Encoders they have, most are not as good as what you have, you want the largest count Encoder you can find, the new Dmm 16 Bit 65,384 counts per rev is where you want to be, the new Dyna 2 Drives are nice, I'm using 70v power supply for them

[woffler]

I will research them very carefully , the problem is the Control and getting one that it will work with the Dmm breakout board, i guess with the (+ - ) drives you could get away from there B/O board.