Retrofit an Emco Compact 6P-CNC
06 May 2013 05:19 #33669
by andypugh
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...oolchanger_component
Replied by andypugh on topic Retrofit an Emco Compact 6P-CNC
There is a special HAL component:The biggest problem I can see coming is the question of controlling the tool turret. Has anyone done that on one of these?
Can the stock hardware be utilized or will something else be needed to be purchased and put in place?
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...oolchanger_component
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06 May 2013 13:28 #33670
by smprobban
Replied by smprobban on topic Retrofit an Emco Compact 6P-CNC
I just wanted to ask if i later want to retrofit a bigger machine whats the biggest diffrence in cost? Cause this one will cost approx 20000 skr for just fixing the machine so i can think that an big machine will cost very much more.
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- Zahnrad Kopf
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07 May 2013 05:34 #33687
by Zahnrad Kopf
Well, that _IS_ good news... Thanks gentlemen. Hmmm... I may have to start putting a list together of necessary items and see if this is doable right away.
I've searched, but the forum and site are slow from here. Are you guys aware of any specific examples of Emco Compact6/120/220P conversions with details?
Let's see... I'd need a 3Ø motor for the spindle, two servos or steppers and drives, a PC and ... I wonder what MESA cards would be applicable...?
I imagine that just about everything else can be used... No?
Thanks.
Replied by Zahnrad Kopf on topic Retrofit an Emco Compact 6P-CNC
Is the tool turret the kind that runs fwd then rev against the stop? That has been done many times in LinuxCNC. John
There is a special HAL component:
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...oolchanger_component
Well, that _IS_ good news... Thanks gentlemen. Hmmm... I may have to start putting a list together of necessary items and see if this is doable right away.
I've searched, but the forum and site are slow from here. Are you guys aware of any specific examples of Emco Compact6/120/220P conversions with details?
Let's see... I'd need a 3Ø motor for the spindle, two servos or steppers and drives, a PC and ... I wonder what MESA cards would be applicable...?
I imagine that just about everything else can be used... No?
Thanks.
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07 May 2013 06:39 #33688
by andypugh
If you want to use servos, then it might be a bit tricky if you intend to keep the toolchanger as a stepper. I _think_ that the changer relies on the stepper stalling against the end-stop.
You could swap that for a servo, too. Monitoring the PID output ought to let you spot the point that it stalls against the stop. With a wide-enough f-error band that is probably OK.
Replied by andypugh on topic Retrofit an Emco Compact 6P-CNC
They are horribly slow from everywhere.I've searched, but the forum and site are slow from here.
A Google search shows that a few have been done, but bear in mind that things move on, and the optimum choices they made may not be optimum now.Are you guys aware of any specific examples of Emco Compact6/120/220P conversions with details?
It would probably be a 5i25/7i76 candidate (very cost-effective combo). That gives you lots of IO, plenty of steppers and an analogue voltage to control the VFD.Let's see... I'd need a 3Ø motor for the spindle, two servos or steppers and drives, a PC and ... I wonder what MESA cards would be applicable...?
I imagine that just about everything else can be used... No?
If you want to use servos, then it might be a bit tricky if you intend to keep the toolchanger as a stepper. I _think_ that the changer relies on the stepper stalling against the end-stop.
You could swap that for a servo, too. Monitoring the PID output ought to let you spot the point that it stalls against the stop. With a wide-enough f-error band that is probably OK.
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07 May 2013 09:21 #33697
by Zahnrad Kopf
From here - emcocncretrofits.wikia.com/wiki/120_Toolchanger
"The toolchanger on the 120 comes in two versions: early (4-slot, 4-hole) and late (8-slot). It uses a 24VDC motor and has 4 photosensors for feedback (also 24VDC). It works by ratcheting: it moves the turret past a station, then reverses into the station and holds the motor in reverse, keeping the turret securely backed up against a pawl. The repeatability and rigidity comes from this pawl mechanism, allowing crude position feedback sensing and a motor without position control.
The original control used the photosensors as well as motor current sensing as inputs and generated a PWM output to control the motor. This is probably the only control scheme that will work"
I will ask him, but I believe that it is a simple 24DC motor. Not a stepper.
( thinking out loud, here )Otherwise, I guess I could be fine with it continuing as a stepper based system... could add encoders easily enough for feedback...
So... $200 for MESA cards... have a PC already... would need steppers, drivers, and encoders... and much time wiring... would really like some commo with someone that's running one for clarity on the turret hardware...
Thanks Andy.
Replied by Zahnrad Kopf on topic Retrofit an Emco Compact 6P-CNC
It would probably be a 5i25/7i76 candidate (very cost-effective combo). That gives you lots of IO, plenty of steppers and an analogue voltage to control the VFD.
If you want to use servos, then it might be a bit tricky if you intend to keep the toolchanger as a stepper. I _think_ that the changer relies on the stepper stalling against the end-stop.
You could swap that for a servo, too. Monitoring the PID output ought to let you spot the point that it stalls against the stop. With a wide-enough f-error band that is probably OK.
From here - emcocncretrofits.wikia.com/wiki/120_Toolchanger
"The toolchanger on the 120 comes in two versions: early (4-slot, 4-hole) and late (8-slot). It uses a 24VDC motor and has 4 photosensors for feedback (also 24VDC). It works by ratcheting: it moves the turret past a station, then reverses into the station and holds the motor in reverse, keeping the turret securely backed up against a pawl. The repeatability and rigidity comes from this pawl mechanism, allowing crude position feedback sensing and a motor without position control.
The original control used the photosensors as well as motor current sensing as inputs and generated a PWM output to control the motor. This is probably the only control scheme that will work"
I will ask him, but I believe that it is a simple 24DC motor. Not a stepper.
( thinking out loud, here )Otherwise, I guess I could be fine with it continuing as a stepper based system... could add encoders easily enough for feedback...
So... $200 for MESA cards... have a PC already... would need steppers, drivers, and encoders... and much time wiring... would really like some commo with someone that's running one for clarity on the turret hardware...
Thanks Andy.
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07 May 2013 16:36 #33706
by ArcEye
Replied by ArcEye on topic Retrofit an Emco Compact 6P-CNC
Hi
The turret is a 24v motor, the whole set up is very similar to the Denford Orac except there are 4 sensors, so the truth table is different
Have a look at this thread
www.linuxcnc.org/index.php/english/forum...parport?limitstart=0
Bad_German was able to modify the component I wrote for the Orac quite simply and his notes with the contributed component posting show how he connected up and dropped down the 24v to TTL
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...oolchanger_component
regards
I will ask him, but I believe that it is a simple 24DC motor. Not a stepper.
The turret is a 24v motor, the whole set up is very similar to the Denford Orac except there are 4 sensors, so the truth table is different
Have a look at this thread
www.linuxcnc.org/index.php/english/forum...parport?limitstart=0
Bad_German was able to modify the component I wrote for the Orac quite simply and his notes with the contributed component posting show how he connected up and dropped down the 24v to TTL
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...oolchanger_component
regards
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07 May 2013 17:38 #33707
by andypugh
The appropriate driver card will rather depend on the motors and drives that you end up with. It may make sense to see what you can find looking tempting on eBay and then choose drivers to suit.
You would probably want a simple H-bridge controller for the toolchanger motor, but you may be able to use 2 channels of a three-phase controller.
So, you might end up with a Mesa 5i20 + 7i39 + 7i40 setup.
Just be clear that there are two mutually incompatible Mesa systems, the 5i25 / 6i25 with DB25 connections and the 5i20 / 5i22 / 5i23 with 50-pin header connections. (Both types can also add-on Smart-serial devices). I don't think any of the Mesa motor drives (other than the smart-serial 8i20) work with the DB25 connection, those boards expect to be controlling third-party servo or stepper drives.
Rather complicating the issue is the increasing prevalance of step-dir input servo drive systems, such as:
www.ebay.co.uk/itm/CNC-KIT-3-Axis-Servo-...Plasma-/151038743524
These do repeat the encoder signals back to the PC, so can be used in a closed-loop system (you can view the pulse/dir interface as just anothr speed command signal protocol) but the required interface board would be stepper-style pulse outputs, not servo-style analog outputs.
This would either be a 50-pin Mesa card (5i23 for example) and the 7i47, or possibly a 5i25 + 7i76 but with an additional 7i85 on the second header for encoders.
There are other options too. I am not as familiar with the Pico-systems interfaces, but they have many happy users.
pico-systems.com/motion.html
Replied by andypugh on topic Retrofit an Emco Compact 6P-CNC
"The toolchanger on the 120 comes in two versions: early (4-slot, 4-hole) and late (8-slot). It uses a 24VDC motor and has 4 photosensors for feedback (also 24VDC). It works by ratcheting: it moves the turret past a station, then reverses into the station and holds the motor in reverse, keeping the turret securely backed up against a pawl. The repeatability and rigidity comes from this pawl mechanism, allowing crude position feedback sensing and a motor without position control.
The appropriate driver card will rather depend on the motors and drives that you end up with. It may make sense to see what you can find looking tempting on eBay and then choose drivers to suit.
You would probably want a simple H-bridge controller for the toolchanger motor, but you may be able to use 2 channels of a three-phase controller.
So, you might end up with a Mesa 5i20 + 7i39 + 7i40 setup.
Just be clear that there are two mutually incompatible Mesa systems, the 5i25 / 6i25 with DB25 connections and the 5i20 / 5i22 / 5i23 with 50-pin header connections. (Both types can also add-on Smart-serial devices). I don't think any of the Mesa motor drives (other than the smart-serial 8i20) work with the DB25 connection, those boards expect to be controlling third-party servo or stepper drives.
Rather complicating the issue is the increasing prevalance of step-dir input servo drive systems, such as:
www.ebay.co.uk/itm/CNC-KIT-3-Axis-Servo-...Plasma-/151038743524
These do repeat the encoder signals back to the PC, so can be used in a closed-loop system (you can view the pulse/dir interface as just anothr speed command signal protocol) but the required interface board would be stepper-style pulse outputs, not servo-style analog outputs.
This would either be a 50-pin Mesa card (5i23 for example) and the 7i47, or possibly a 5i25 + 7i76 but with an additional 7i85 on the second header for encoders.
There are other options too. I am not as familiar with the Pico-systems interfaces, but they have many happy users.
pico-systems.com/motion.html
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07 May 2013 20:45 #33727
by PCW
Replied by PCW on topic Retrofit an Emco Compact 6P-CNC
How much current does the turret motor draw?
It might be pretty easy to rig up a driver if the existing driver is
too hard to interface (an AC OPTO and a shunt resistor may be all thats
needed for current sense)
It might be pretty easy to rig up a driver if the existing driver is
too hard to interface (an AC OPTO and a shunt resistor may be all thats
needed for current sense)
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07 May 2013 23:15 #33734
by Zahnrad Kopf
I can find Vexta 5 phase drivers for these motors on eBay for about $130 each ( give or take ). I'm not tied into these motors though, and would switch without much fuss unless there's some erason that 5 phase motors are superior...
What's an H-bridge controller? I don't recall that from my previous escapades.
That's what I was musing about, in my head - some of the step/dir servos... cuold easily stay with steppers, too.
If I do this, I want it to be quick and dirty. I'm too busy already and have actual work to get done. Still... I do like the machine part of the machine and it already doesn't work...
Nothing wrong with Jon's stuff, at all. I've just been wanting to try some of the Mesa cards for a few years now.
Knowing myself, I'll likely rip the control off just to have a reason to do this...
Replied by Zahnrad Kopf on topic Retrofit an Emco Compact 6P-CNC
The appropriate driver card will rather depend on the motors and drives that you end up with. It may make sense to see what you can find looking tempting on eBay and then choose drivers to suit.
I can find Vexta 5 phase drivers for these motors on eBay for about $130 each ( give or take ). I'm not tied into these motors though, and would switch without much fuss unless there's some erason that 5 phase motors are superior...
You would probably want a simple H-bridge controller for the toolchanger motor, but you may be able to use 2 channels of a three-phase controller.
So, you might end up with a Mesa 5i20 + 7i39 + 7i40 setup.
Just be clear that there are two mutually incompatible Mesa systems, the 5i25 / 6i25 with DB25 connections and the 5i20 / 5i22 / 5i23 with 50-pin header connections. (Both types can also add-on Smart-serial devices). I don't think any of the Mesa motor drives (other than the smart-serial 8i20) work with the DB25 connection, those boards expect to be controlling third-party servo or stepper drives.
What's an H-bridge controller? I don't recall that from my previous escapades.
[/quote]Rather complicating the issue is the increasing prevalance of step-dir input servo drive systems, such as:
www.ebay.co.uk/itm/CNC-KIT-3-Axis-Servo-...Plasma-/151038743524
These do repeat the encoder signals back to the PC, so can be used in a closed-loop system (you can view the pulse/dir interface as just anothr speed command signal protocol) but the required interface board would be stepper-style pulse outputs, not servo-style analog outputs.
This would either be a 50-pin Mesa card (5i23 for example) and the 7i47, or possibly a 5i25 + 7i76 but with an additional 7i85 on the second header for encoders.
There are other options too. I am not as familiar with the Pico-systems interfaces, but they have many happy users.
pico-systems.com/motion.html
That's what I was musing about, in my head - some of the step/dir servos... cuold easily stay with steppers, too.
If I do this, I want it to be quick and dirty. I'm too busy already and have actual work to get done. Still... I do like the machine part of the machine and it already doesn't work...
Nothing wrong with Jon's stuff, at all. I've just been wanting to try some of the Mesa cards for a few years now.
Knowing myself, I'll likely rip the control off just to have a reason to do this...
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07 May 2013 23:19 #33735
by Zahnrad Kopf
No idea. Not familiar enough with the 'tronic side of this thing to tell you off the top of my head. I can try and find out, though.
Maybe one of the people that have already converted a 120/Compact6/220P can chime in and say.
While I have you, though, can you give me any input on your opinion of the best card choices for this based on what's been discussed?
Thanks!
Replied by Zahnrad Kopf on topic Retrofit an Emco Compact 6P-CNC
How much current does the turret motor draw?
It might be pretty easy to rig up a driver if the existing driver is
too hard to interface (an AC OPTO and a shunt resistor may be all thats
needed for current sense)
No idea. Not familiar enough with the 'tronic side of this thing to tell you off the top of my head. I can try and find out, though.
Maybe one of the people that have already converted a 120/Compact6/220P can chime in and say.
While I have you, though, can you give me any input on your opinion of the best card choices for this based on what's been discussed?
Thanks!
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