[vroemm]

Basically, the outputs from the parallel port are swtiching a darlington pair inside the ULN2803 chip. I have +5 via a 10K resistor connected to the output of the ULN2803. When switched it is suppose to go to ground.

Then you have a 10K resistor in series with the 220 ohm resistor.
Your using 10220 ohm, not 220 ohm.
The optocoupler input is not getting enough current.

Try the idea mentioned by someone ealier.
Disconnect the UHU from breakout board and computer.
Put 5 volt on the STEP input.
If you keep switching this 5 volt on and off the servo should step.

If this works why not connect the UHU direct to the parallel port ?
Without the breakout board.

[Chris D]

Latest update - problem is definitely the break out board. If I trigger the opto with 5 volts (at the Dir or Step connection), the far side of the opto operates properly.

I have to tinker some more with the resistor value of the breakout board and the ULN2803 chip. If that fails I am going to "Hot wire" the damn thing straight to the parallel port!

Wish me luck!

Chris

[vroemm]

I have to tinker some more with the resistor value of the breakout board and the ULN2803 chip.

Thats not the best idea.
The basic principle of using a dalington here is not good.

Wish me luck!

Allways :-)

[slp_prlzys]

hello,
this is a very interesting thread,
I just want to add this overlay
of UHU controller
for future builders and myself
pardon the name just having fun.
I hope it's right.

Happy Holidays!!

[Chris D]

Well,

I now know my breakout board design is fundamentally wrong - that's okay, I can fix that!

However! I think the servo may have been running longer than I thought!

In my last round of tests, I was just tapping the jog button in frustration (pouting that it was working) when I noticed that the servo shaft was spinning VERY slow each time I tapped the jog key! I then stepped up the speeds in the CNC control software and then I got to see it working in "real time" !

At this point I am so darned happy, I will be thrilled to re-design my breakout board.

So far, what I can observe (with the motor on the bench), it is running as smooth as silk - outstanding!

Back out to the bench to play some more!

THANKS EVERYONE!

Chris

[vroemm]

So far, what I can observe (with the motor on the bench), it is running as smooth as silk - outstanding!

Yeaah :-)
Have FUN ! :-)

[Chris D]

Had my moment of joy for the holidays, now I will leave well enough along so as to make sure I don't let the smoke out of anything (yeah right, I will be out there playing before the rest of the family wakes up).

I must say, I believe 100% that there would have been no problems getting this up an running had it not been for my breakout board. That just impresses the hell out of me. MANY MANY THANKS to everyone that has helped and especially to those that created the software (Uli) and the circuit board design.

HOT DOG! This is exciting!

Thanks again so very much!

Chris

[ejkoeze]

@Chris

Congratulations.

Have fun with it and have a nice Christmas.

@All
Merry Christmas to all of you. And have fun building new things.

Erik Jan

[ulihuber]

Chris,

congratulations and Merry Christmas !

Uli

[khootk]

Hi all,
My exiting Mini Mill with spindle motor DC230v, 2.2A ,350W ,speed 6000 rpm, after deduction gear the maximum spindle speed reduce
to 2500 rpm.Here is my questions , Does UHU servo drive can handle with this motor rating ? When using 6000 rpm 1:1 spindle with UHU
servo does it maintain the cutting torque ? (If do some modification to the output driver (Hfet to IGBT)). It would be interesting to some guy
that using DC spindle motor. If someone know please try to help up.

Thank you,
Khootk

[Chris D]

Thanks Uli and Erik -hope you guys had a great Christmas too! Getting that servo driver running was one heck of a present for me!

Chris

[NC Cams]

To ESjaavik: Tried to connect to the PDF link you posted.

Result: got the dreaded "File not found" error message.

[ulihuber]

@ NC Cams:
Sorry this one got lost while restructuring my pages.
It's put in place again.
But better look directly into the pages www.uhu-servo.de and visit the english section. You'll find this version of the manual and the new manual of the US-version which has been adapted to the 3.00e controller. This one does not use german commands any more.

Uli

[jrz126]

I'm working on creating my own layout in Eagle and I noticed that the supplys for the opamp (IC3, lower right corner of the schematic) has a +5V and -12V, shouldnt it be +12 and -12?

[ulihuber]

jr126,

in one word: no.

It drives the 4013 which has to be TTL compatible.

Uli

[jrz126]

ahhh ok, that makes sense, and the diode prevents the -12V from going to the 4013.
Thanks

[Chris D]

Regarding the step signal, how long of a duration does the step signal need to be to cause the servo driver to make a step? Also, what is the maximum frequency the driver can operate at?

Thanks guys!

Chris

[truman]

I tried emailing uli a couple of times about how much to send for processors but no reply just wondering if he is really busy or is not getting the emails

[ulihuber]

truman,

it's always difficult to know who is who with all these forum names. But I answered all emails I got. I hope I did not forget one and that nothing got lost in the spam filter of my provider....

Uli

[turmite]

Uli I noticed on your site that you like hot sauces. How hot? Do you like pickeled peppers? I have a good reason for asking!

Mike