Emco Toolchanger Wiring & 7i77

Using this for reference - LINK HERE can someone explain to me _where_ ( as in what pins ) to wire this into a 7i77? ( as opposed to the referenced parallel port ) I'm not exactly sure what kind of input this would be considered...

Thank you.

Like the proximity switch question it depends on whether the outputs source or sink current

Maybe arceye or cncbasher can chime in here to shine some light on how the EMCO outputs work

You could also apply the +24V and GND power and measure the voltage
(with a DVM) on the output pins relative to GND and +24V to see

PCW wrote:

Like the proximity switch question it depends on whether the outputs source or sink current

Maybe arceye or cncbasher can chime in here to shine some light on how the EMCO outputs work

You could also apply the +24V and GND power and measure the voltage
(with a DVM) on the output pins relative to GND and +24V to see

Peter,

Yes, the forum is VERY buggy for me. ( incredibly slow and errors out ) Actually for a while, now. Hence why I don't usually post.
So, after it errored out for the umpteenth time, I wrote him directly. I do like your idea about the DVM and will do so if I get there before hearing back.

...................So, after it errored out for the umpteenth time, I wrote him directly

There is something wrong with the forum presently, very slow and errors out a lot.

However I did not reply earlier because I was fast asleep, you posted at 0112 hrs in the UK

Using this for reference - LINK HERE can someone explain to me _where_ ( as in what pins ) to wire this into a 7i77? ( as opposed to the referenced parallel port ) I'm not exactly sure what kind of input this would be considered...

This component was adapted from my Orac one by Bad_German to suit his Emco lathe, so I have never actually tested it.

All he did to change it, was to add a fourth opto to the truth table and use PWM on the motor to reverse and hold it (whereas the Orac had a designated lower voltage feed which did this)

So far as the connection of the pins, the Orac optos were just a 5v TTL signal from the optical switches reading the greyscale disc in the ATC.
It looks like the outputs for the Emco are 24v, but Bad_German used a voltage divider to bring them down to 5v.

I don't have a 7i77, but assume the GPIO pins can take up to 24v, so you could connect direct.
PCW would be best placed to advise on that

If you see this post, Bad_German is using a 5i25 and 7i76 but the toolchanger does not appear in his configs, so perhaps in a seperate file and / or still using the parport, you could always ask him.
www.linuxcnc.org/index.php/english/forum...-encoder-setup#39344

regards

ArcEye wrote:

This component was adapted from my Orac one by Bad_German to suit his Emco lathe, so I have never actually tested it.

All he did to change it, was to add a fourth opto to the truth table and use PWM on the motor to reverse and hold it (whereas the Orac had a designated lower voltage feed which did this)

So far as the connection of the pins, the Orac optos were just a 5v TTL signal from the optical switches reading the greyscale disc in the ATC.
It looks like the outputs for the Emco are 24v, but Bad_German used a voltage divider to bring them down to 5v.

I don't have a 7i77, but assume the GPIO pins can take up to 24v, so you could connect direct.
PCW would be best placed to advise on that

If you see this post, Bad_German is using a 5i25 and 7i76 but the toolchanger does not appear in his configs, so perhaps in a seperate file and / or still using the parport, you could always ask him.
www.linuxcnc.org/index.php/english/forum...-encoder-setup#39344

regards

ArcEye ( and anyone else interested ) -

I did finally hear back from Bad_German and he was very kind with his response -
"The tool changer was run off a H-bridge, for power and direction. The feedback from the tool change encoder was run directly into the mesa card, I had no opto etc, just straight 24V for the signals. "

He also included his configs for me. It's all Greek to me at this point, but I am hoping that I'll be able to understand them at such time as I need to. I can post them if someone thinks they might be of use or help.

I do have another, heavy duty 2A 24V power supply and it appears that it now has found its way into the cabinet as well... ( to keep it separate from the two for the 7i77 and the other controls )

Oh yeah... I almost forgot...

Where would one purchase an appropriate H-Bridge for this purpose, being 'tronicly impeded? ( K.I.S.S. rules and all... )

He also included his configs for me. It's all Greek to me at this point, but I am hoping that I'll be able to understand them at such time as I need to. I can post them if someone thinks they might be of use or help.

If you attach them, I will include them with the tool changer code on the wiki page.

Regards H Bridges, there seem to be a lot on ebay for the arduino / rpi / modelling market, one of them might do it.

Something like this one but working?
www.ebay.co.uk/itm/High-Current-DC-Motor...ol-NEW-/321045121657

regards

yes i'd be interested to see BadGerman's mods to the toolchanger

Dave

ArcEye and Dave ( good to see ya Dave! ) - I've placed them here for you. ( was having issues attaching )
thegearmaker.com/images/emco/linuxcnc/tool_changer/linuxcnc.rar

ArcEye - would that H-bridge be any better than any of the thousands of "L298" based ones out there, for me?

Like this ? www.ebay.com/itm/Simple-H-General-Purpos...&hash=item4184f79080

Or like this ? www.ebay.com/itm/L298-Based-Stepper-DC-M...main_0&hash=item231a

would that H-bridge be any better than any of the thousands of "L298" based ones out there, for me?

I don't know, I only picked that one because most of the L298 based ones are very low power, designed for use with arduinos and small steppers, not larger DC motors.

You will have to work out what ratings you need and see what is available.

regards