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I want to connect my spindle to a 5 Axis Breakout Board Interface Adapter via a raspberry pi5. I can control the stepper motors (XYZ). I just can't control the spindle. Is there an example for the HAL file?

If I bypass the relay contact. Then the spindle will rotate to the maximum. If I press the + button it slows down. When I press the - button it speeds up. When I press the stop button, it starts running at maximum speed. 
Anyone have a solution?

Greetings Philip

Hi All, 

Not a major issue, but my spindle speed is varying significantly under contant load. Sometimes during a cut and sometimes when it's just sitting and spinning up under no load and should be at constant speed. I'm not sure how much it varies because if I try to probe the pin the variance disappears, but audibly it slows down as if I ploughed it into a slightly too heavy cut that wasn't enough to stall the motor but enough to bog it down noticably. 
My VFD (AT4 Aliexpress job) is driving a 3 Phase induction motor, 2.2kW, 2 pole. 

The VFD has a 24v output but takes a 10v analog input, so I've just wired the 24v out to a simple voltage divider resistor pair (<5k total resistance) and I'm using that to feed the high side of the digipot on my 7i76e with 7v or therabouts. I tried using my 24v rail that supplies the limit switch, e-stop etc  originally but the spindle speed was varying a lot (under constant load) so I assumed the VFD reference voltage and 24v rail might be too de-coupled and switched to using the VFD output thinking that would be a more consistent Vref for the VFD, but the spindle speed is still varying a lot.

My .ini file has got the SPINDLE_SCALE set to 8000 (It's an 8k RPM spindle), so I used M3 S8000 and then adjusted the vfd paramaters (P73) to get 60Hz, then checked at M3 S4000 and got roughtly 30Hz showing on the VFD screen so it seems to be working OK at max rpm and  linear to within a few hundred RPM at 50%. 

If I try to probe the voltage on the pin the impedance of the multimeter is enough to pull the VFD back to max RPM as soon as I probe it so I can't tell what the VFD vout or analog signal from the 7i76 is when a dip occurrs. My instinct is that the multimeter has some huge resistance in voltage mode and that a weak pullup / pulldown (1Meg?) would help, but I'm not sure so want to check to see if this is typical behaviour, I'm surprised that it doesn't 'just work'

On a separate (but potentially related?) note, I've got a significant AC voltage leakage to the machine frame ground, I'm not sure if this is the VFD itself or the SMPS which feed 72v to the stepper drivers, I need to do some un-plugging and checking. It's enough that you get a tingle if you touch the frame and you're grounded. I'm getting no DC voltage from machine frame to protective earth in the garage, but 20-60v AC showing on the multimeter. If I use current mode and check leakage current from machine frame to ground it immediately trips the RCD, so >>30mA. Not sure if this is an independant thing or if this leakage could be messing with the analog voltage signals. 

Thoughs? Next steps? Independant things or related? What would you do next....

Hello,

I tried to figure that out, but not really successful, so I spam the forum with the questions. (I have the feeling I should have found the information somewhere; maybe someone can point me in the right direction) 
I have a 6i25 card with a 7i76 card connected to my PC. Some stepper motors are running and can be moved with keyboard, a basic configuration is running.

Now I got stuck, trying to hook up the old BLDC driver (labeled TONMAN Brushless DC driver) or the machine (which I have no documentation for) seems not to run with an analog input. 
I tried to connect the Spindle interface somehow, but it does not want to run.

There is a pair of pins labeled +- (PWM / ANNA), but I think it is not really for analog input signal.
Hooking up a potentiometer (allowing to create a voltage between 0 and 5V) does nothing to a certain voltage. At approx. 2.6V it switches from "off" to "full speed".
I tried one of those PWM generators   which works fine. It allows to control the speed of the motor, no issue. I can adjust the motor speed by setting the duty cycle to anything between 10% and 100% and it seems to be what I need. 

Now the questions: Is it correct that in my situation the spindle interface of the 7i76 is just the wrong choice for my BLDC amplifier?
                                How do I make a PWM control for my spindle with the 7i76 (6i25)?
                               
Greetings Timo



 

Hi folks,

First, apologies as I know this has been discussed before several times, but I can't seem to find enough recent information about what I'm hoping to do. I have a 2024 model Tormach PCNC 440, currently running Pathpilot 2.12, and has a Mesa 7i92tf as controller and Leadshine MX3660 as 3-axis driver. I added a Xoomspeed USB I/O box to enable spindle reversing (mostly for tension/compression tapping) and it works nicely (thanks David Loomes)! I have configured a 4th axis with a 4-wire Nema32 stepper (plus 100:1 harmonic reduction), using a Leadshine DMA860H as a driver. It works nicely too! 

What I'm hoping to do next is add a 5th axis, and I already have another DMA860H and 5th axis (one nema23 mounted on another, both with 50:1 harmonic reductions. I talked with someone at Mesa and I believe I understand the wiring and controller firmware updates I need to make (I have a Sainsmart 5-axis breakout board to connect as daughter card to the 7i92tf, Mesa is writing me firmware for this). I also believe I have what I need to program CAM, using Fusion 360 with the manufacturing extension. What I will need help with is configuring Pathpilot to work with a 5th (C) axis, as well as modifying the post processor (ideally David Loomes' Xoomspeed Pathpilot with Probing post since I use in-program probing and prefer that one, especially angle probing for coordinate rotation!).

Now, I know that Tormach apparently removed the 5th axis functionality from Pathpilot. My first question to the forum is: would you recommend adding it back into Pathpilot? Or should I switch to a regular LinuxCNC install? I do like the Pathpilot interface and post processors for Fusion 360 I'm using, plus I'm not very familiar with Linux in general (even though my "Pathpilot computer" is of course running Linux and I have worked with it to add a VistaCNC pendant and the Xoomspeed I/O box, 4th axis, and Samba LAN filesharing. And I'm comfortable modifying ini/hal files and running terminal commands as long as I know what they should be), so I would prefer to stay with Pathpilot. Having a DRO for the C axis in the GUI is a nice-to-have but I think I could live without it, at least for now, so I won't necessarily need to modify the Pathpilot GUI. But if LinuxCNC is the way to go, my second question is: would it be possible to dual-boot on my linux box ("Pathpilot Computer") so that I can use Pathpilot for 3 or 4-axis jobs and switch to LinuxCNC for 5-axis jobs? I like the idea of having a separate partition for LinuxCNC, especially because I'm worried about messing something up and not getting it to work at all, and having to do a full Pathpilot re-install (plus redo all the modifications I've made) just to get back to a usable 3/4axis setup.

For the modify Pathpilot route, my next question is: how exactly do I go about adding the 5th axis (simultaneous 5th, not just indexing of course.. with or without TCP, I still need to figure out exactly what TCP is and if I want/need it.. or if it's even relevant here)? I can't seem to find a tutorial or much documentation about this, can anyone here point me towards a resource, or possibly give me a list of what files I'll need to modify (I might be able to figure out what the modifications are from the LinuxCNC documentation, but it's hard to be sure that I know the full list of what needs to be modified)? I learned that Pathpilot will overwrite any firmware changes to the controller on each startup, but I think I found how to disable that too so that I can use the firmware modified to work with the breakout board. I'll also need to know what to modify (if anything) in either Tormach's post or, preferably David's post, though for testing I'm happy to write the NC code by hand or use MDI. I'm a little familiar with modifying posts from analyzing sections of David's post that were giving me weird g-code (rapid move during expanded tapping?! turned out it was intentional and a clever hack for tension/compression heads) and to add back the code to apply coordinate rotation after angle probing, which David had removed apparently due to some random errors with axes limits he ran into during testing. Anyway, bonus points if you can tell me exactly what the mods would be or give me modified files.. actually, I'd happily pay someone a few hundred dollars for this service if it results in a working 5-axis system (seriously, let me know if you're interested)!

For the LinuxCNC path, other than dual-booting/partitioning I think I can find the documentation I need to configure the 5th axis, and hopefully make the SW connections to my hardware. Actually I can probably figure out the dual booting too, just want to know if it's possible and advisable. But if anyone wants to give any advice on this path here (a list of steps or files to modify, gotchas, workarounds, links to tutorials/helpful documentation/etc.) I would also be very grateful. And a question, maybe for a later time - how easy (or possible) is it to put the Pathpilot GUI onto a generic LinuxCNC install? I don't necessarily need the conversational functionality, but I do really like how probing and ETS works in Pathpilot.

Anyway, thanks for reading and in advance for any replies! Apologies again if people are tired of talking about 5th axes in Pathpilot. I'm a resourceful guy and usually pretty good with research (and retired so I have a lot of time on my hands) so I don't necessarily need step-by-step instructions but I can sense that there are some gaps in what I can find and understand here. Any hints to fill those gaps would be super helpful and very much appreciated!
-Ryan in Mexico 

I am using a stepper motor with a brake on the Z-axis to prevent the spindle from dropping due to gravity during a power outage or when the machine is powered off. The brake is designed to activate when power to the stepper motor is cut, but there is a delay of one or two seconds before it engages. This delay allows the spindle to drop significantly before the brake takes effect.Is it possible to control the brake directly using LinuxCNC to eliminate this delay?

@spumco
Thanks for the information and the files!
But now i have just 1 sensor - the index (sense-0).
There are no pocket sensor for sense-1.
Need i put one more sensor for pocket?
I thought 1 sensor enough for a stepper type control mode to home the "axis" and the position of each tool is known.
Before there was a KFLOP system with tool change in the config file[/code]
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Salame wrote:

I have found this combo and read somewhere that they are somehow rebranded Leadshine, they comes with a good documentation (For what I can understand). 

Late response, but the A6 series are rebranded Inovance SV660's.  The Ethercat version is SV660N.

Inovance offers both 17-bit and 23-bit encoder motors, but Stepperonline appears to only offer the 17-bit version.

Stepperonline's "T6" servos are rebranded Leadshine EL6's.  Looks like they've dropped the "T7" series of ethercat drives which were available last year.

Side note: From a couple YT vids I watched, Tormach appears to be using Inovance SV660N's in the MX1500.  They also appear to have made their own breakout board to use the SV660N's onboard IO, rather than buying (or building) a separate dedicated ethercat IO board.

No idea what the spindle drive is; maybe an Inovance ethercat VFD.

With four drives (X/Y/Z/ATC), this would give them 20 inputs and 12 outputs... not including assignable IO from the spindle drive.

timo wrote:

Yes, You can do that. I have my old LPT machine were two steppers are still on the old "as is" Chinese beakout board. (z-Axis stepper driver died recently, so I moved that to Mesa as well)
One stepper (now two) , the Spindle, the Spindle Encoder and the MPG (handwheel are handled with the Mesa Card)

Greetings Timo

p.s. the simple reason for the "Frankenstein" was that I was too lazy to re-wire all the steppers and had no documentation for the stepper driver interface, so I kept the running 3 axis config and only added the "new functions, (damaged functions) to to the Mesa card.
 

Was it PCI or ethernet mesa, and what version of linux cnc?

Yes, You can do that. I have my old LPT machine were two steppers are still on the old "as is" Chinese beakout board. (z-Axis stepper driver died recently, so I moved that to Mesa as well)
One stepper (now two) , the Spindle, the Spindle Encoder and the MPG (handwheel are handled with the Mesa Card)

Greetings Timo

p.s. the simple reason for the "Frankenstein" was that I was too lazy to re-wire all the steppers and had no documentation for the stepper driver interface, so I kept the running 3 axis config and only added the "new functions, (damaged functions) to to the Mesa card.

Hey, everyone.I'm doing a linuxcnc conversion on a ShopSabre 23 machine. Just got a 7i96 board in the mail and have been setting it up on my desk. It's been good so far, got the relays and endstops working. Unfortunately the spindle is giving me some trouble. We have an 18k rpm spindle driven by Mitsubishi A800 VFD which accepts 5-10 analog speed control.

I was under the impression that I would be able to convert PWM into analog voltage with this card and that's how I set it up in the Pncconf 18000 rpm at 5v, but the rpm readout in qtdragon only goes up to 500 for some reason. The spindle setup looks like another stepper config and I'm confused about the scale. I've read pretty much every spindle related post here which lead me to more confusion since everybody has different hardware.I haven't flashed any firmware on the card, just working with the stock one that it came with.I have a PWM to analog converter board

Here is the VFD manual   you can find the speed control on page 115

Can somebody please steer me into the right direction?I will include my ini an hal files just in case.

You say LinuxCNC is way way better than Mach 3.

How so?

As far as I could research, Mach3 is not able to do fully closed loop operation with feedback between motor axis and rotary or linear encoders.

• feed rate based on spindle power (cutter breakage detection)
• EDM with reverse movements or slow down based on electrical values
• a hobbing machine that slows down workpiece spindle and tool spindle in case something reaches the limits.
• Turning excenters or augers on a lathe
• cam shaft grinding
  
  These are examples I can think of. Things that Mach3 could not provide, according to my understanding of the available information.
  Of course those items go bejond the average DIY user and will not be easy to do. Not easy to do in any system, unless available as turnkey in exchange for $$$
  
  Linux CNC seems to be in the gap between, "very basic good enough" and "just pay money to one of the usual suspects"
  
  I see a lot of misconception that Linux CNC ist "Parallelport technology" for 3-axis open loop stepper machines. Which is actually only the lower end of the spectrum.

Mach3 can obviously do a lot that I do not even immagine, same as Linux CNC.
Mach3 seems to be a dead end (obsolete hardware, obsolete software)

The Mesa Card is definitely better documented and I bought fairly cheap DM860 stepper drivers that seem to work (good enough for who its for).

This week I threw some of the equipment on the workbench and started messing with pncconfig.
Four motors are running The spindle drive is still an issue. (that ist next up)

Thank you for the answers.

This keeps things easier, "problems solved" so far. Next up is to hook up the spindle drive.

Greetings Timo

On the ec300 I measure 24V on OT1 to GND when set low, 0V when set high. (Strange. I expected it to be reverse, because of safety reasons...)
 I've tested it with and without spindle setting in HAL, because you don't have spindle configured in yours (it's not the problem).

Do you have any other usable and functioning output pins (other than the working steppers)?

What voltages do you read, if the outputs pulled low?