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Hallo,

Ich habe in meiner Fräse Trapezgewindespindeln. Ich bin gerade dabei Glasmaßstäbe anzubauen.
Kann ich mit diesen Spindeln über den Glasmaßstab und den PID in LinuxCNC die gleiche Präzision erreichen
wie mit KUS und Glasmaßstab?
Therotisch sollte das doch möglich sein, Ich gebe ja in LinixCNC beispielsweise eine Sollpostion vor, der Schrittmotor bekommt entsprechend Signale und die Achse fährt. Nun vergleicht ja LinuxCNC immer die Sollwertvorgabe mit dem Istwert des Glasmaßstabes. Gibt es eine Differenz regelt LinuxCNC über den PID nach.
Ich verwende eine Mesa 7i76e+7i85. Scale vom Glasmaßstab:1000
Mechanisch bedingt fahre ich alle Achsen mit max. 1000mm/min.

Gruß
Sven

Oh, no worries. Thank you for the reply!

Hmm, so the thing I'm using shouldn't actually work or is it just going to be damaging in some way if I run it like that or cause other issues then? It does seem to be working the way I hooked it up but if it's going to wreck something maybe it's not good to run it like that.

Also, where should I place the resistor? I'll see if I can figure out how to go about doing that if it's something I should be doing to prevent damage somehow.

PNP sensors are suggested for 7I76E inputs as the inputs work by sensing a positive
input voltage. PNP sensors supply a positive voltage when the output is active.
NPN sensors connect their output pin to common/ground when activated.

Some NPN sensors will work with the 7I76E because they have built in pullup resistors,
but for reliable operation it best to add an external 2.2K 1/2W pullup resistor on each
NPN output to guarantee a valid high state. The pullup resistor goes from +24V to the NPN
sensor output.

You can check switch operation by measuring the voltage in both on and off
states at the 7I76E input. With a 24V supply I would make sure its >20V
when high and < 4V when low.

There is not any real possibility of damaging the 7I76E inputs unless
you continuously apply voltages > 48V to the inputs.

 

Sorry, looks like I lost a post or was distracted. The 7i76e which I saw you were using should use PNP prox sensors and your link was NPN.
You can use NPN sensors with a 2.2 k 1 W pullup resistor.

You  may  be able to set up a brake with your servo drive on the Z axis. 

Hello everyone,

My name is Philipp and i started a new project a couple of weeks ago:Retrofitting a Weiler 160 Cnc to be servoconventional (like a E35).I want to keep the original DC spindle motor and replace the X and Y servos with 750W Ac ones.(got all the parts already).

I use probe basic lathe with a touchscreen and a Mesa 7i76e and a 7i85, which works already. Now to the problem:The "pendant" for the conventional part makes some trouble:

Schematic: 
first page is the "pendant" that goes on the machine saddle, second one is the control cabinet with touchscreen.

I have printed this mockup:  

The problem is the "Vorschubsrichtung/ SVH NA 4022", its a latching joystick.
I want it to feed in the selected direction, but with a defined feed per revolution. So the feed scales with the RPM of the spindle.
I have looked through all possible articles, but could not find anythig matching.
Maybe someone here has an idea on how to do that?

Regards,
Philipp

Hello!

I hope your day is going ok. I've taken over my dad's self-made LinuxCNC machine. He's still here but he doesn't use it anymore and told me it's mine so I'm trying to figure out how to use it for making some fancy wood projects. I've spent more than a month trying to figure things out and he doesn't seem to remember a lot of it. Now I hopefully only have a few more things to figure out and I might have it somewhat ready to use properly. Although a lot of time I spent screwing with FreeCAD before deciding to just get Vectric VCarve which I don't regret at all, totally worth the price for the time it saves messing with FreeCAD. FreeCAD is great but I just couldn't get it to do what I wanted properly and was always running into bugs and it was always crashing on me.

Anyway, as far as LinuxCNC and the router itself, here are the issues I'm having with that. Any help or tips are more than welcome. I appreciate anything you can help with. Thank you for taking a look!

1. Z-axis homing. I'm having trouble figuring out how to make the z-axis with the spindle on it home first before the others. He said he has always just powered off the machine and moved it up by hand and put a little piece of wood in it to hold it up. This is obviously not ideal. From what I've seen it's supposed to home before the others will home. I believe it's in immediate homing mode and has no limit switches on it. He has some limit switches I can try to add to it but he couldn't get them to work properly so he switched to a different kind of switch. The X and the two Y joints are homing fine, X has one limit switch on one side, both Y have limit switches on each end, although I've never tested the max-limit switches on the other ends of the ball screws so I'm not sure if they are hooked up right or not yet. There are 4 lines into inputs on the Mesa board that I believe come from the limit switches. I've looked over the docs and no matter what I change in the ini file I can't figure out how to make it home the Z-axis properly. I'm not sure the proper steps to take to figure this out. I've messed with it for days. I must be missing something.

If I set HOME to anything other than 0 it just waits and does nothing and seems to eventually time out and not home anything. I've tried every combination of things I can think of in the ini file and I'm not sure if I have to change anything in hal or not.

Does the Z-axis require a limit switch before LinuxCNC will let it home? Or should I be able to somehow configure it to just use a soft limit or tell it to go somewhere?

Can I use the ClearPath MSP software to set the motors to home or will they just get reset since they'll lose power? There is an option to configure them to home when they are powered on. I'm a bit confused by all of this. I suppose maybe that's the next thing I should figure out since it seems like a good possibility to potentially solve the issue.

I was just concerned that the only way to stop them would be to turn off the power to them if something didn't work right. Furthermore, when the Z-axis is powered off it seems it doesn't lock into position and can fall down, which I suppose makes sense if it doesn't have any physical locking mechanism and the weight of the spindle can just pull it down or it can be moved by hand. I'm not sure how the motor would know it's moved when it has no power and how it would be able to reset itself to home when powered on. It seems like maybe they can somehow detect the home automatically even when there aren't limit switches but I'm not sure and don't want to wreck it. I suppose more research is necessary before I risk blowing something up.

2. Vibrating Y-axis. I noticed that the Y-axis was extra jittery. Really, really badly, and sometimes would continually vibrate the ball screws when stopping. It was like the whole house was vibrating. Eventually we figured out we could auto-tune the motors. They only had windows software so now I have a new windows laptop I can hook up to them that I got yesterday.

However since it's a tandem y-axis we found an idea somewhere to put a similar weight of the gantry onto the X-axis and tune that motor and copy it to both Y-axis motors. This has surprisingly seemed to somewhat work, it's way better now, although there still seems to be a bit of vibration and finishing paths aren't perfect, they are kind of dotted or have lines or imperfections still. I think due to the gantry sometimes vibrating and I'm not sure exactly why that happens but I was thinking maybe it had to be tuned better than how we did it. Everything seems tight and nothing seems to wiggle at all when I try to move it by hand, although the gantry does seem to sometimes wobble or jiggle a bit when in operation due to the forces. I suspect it would be good to tune both y-axis motors at the same time since it has unique behaviours and the ball screws are about twice as long and the gantry might slightly jiggle when the motor stops or changes abruptly, or maybe even in certain areas, I'm not completely sure. But it doesn't seem that tuning both at once is really possible that I can tell, unless there is some trick to it.

The ClearPath MSP software also has fine tuning option where it's possible to set the stiffness which I wonder if it will help or if I have to do something else somewhere else in LinuxCNC. I don't want to mess with things if it's going to make things worse or blow something up. I'm going to try this as well and see what happens.

3. Servo firmware updates. When I originally auto-tuned the X-axis and Z-axis motors I also updated their firmware. Since I did this, or at least I think, it seems that the Y-axis motors no longer will go into standby with the orange lights, so I cannot upgrade their firmware because of this. Maybe it's not necessary to upgrade their firmware but I'm wondering if it might help the issues I'm having.

I don't know why this would happen and it makes no sense to me, however, I did also notice that they may be on a separate circuit than the X and Z. There are two power switches on the outside of the box he setup that has the Mesa board and whatnot inside of it. One turns the power on for the computer and one for the Mesa board, or at least I hear the fan come on when I turn the other one and it seems like the other motors come on and LinuxCNC only recognizes it on after that switch is on and LinuxCNC won't start unless I have that switch on because it doesn't find the board. I noticed when I turn the power on for the computer it lights up the other two motors, I think the Y-axis motors, if my memory serves me right. I might be wrong about which switch turns on which motors, but the point is that the Y-axis motors no longer go into their orange state where they should be able to be flashed. Previously they would go into that state the same as the X and Z motors when only one of the switches was on. So I'm not sure why it does this or what he has done from here and I'm not sure what would cause this to change. I was thinking maybe it was the firmware update of the other two motors since I noticed it around that time. I'm not sure what else has changed besides that but I'm not sure how that would do that. I am completely clueless about this part. I understand this might be beyond LinuxCNC, however maybe someone will know something or have some tips of what to do about this.

I can provide any images or files or additional info if necessary. I don't currently have the most up to date files on the computer I'm posting from but I can certainly get them if they are required. The hal files are split into several separate files for various things including the pendant.

Here is a list of hardware if it's relevant:
Mesa 7I76E | manual
Teknic ClearPath-SDSK Servos
Spindle
HY01D523B-VFD | manual
vistaCNC iMachIII P2-S pendant

Mesa 7i76E ist die controller.
Umdrehzahl fur die spindel?
Normal ein 100-1000PPR encoder ist OK.

Ich habe die Mesa 7i76e. Muß ich die Spindel denn referenzieren können (wegen Index)?
Was meinst du mit Controller?
Wieviel Impulse sollte der Drehgeber haben?

After running some prolonged milling sessions with my mill I've decided to go a different route here.

I'm going completely replace the VFD, the gigantic 2kw AC spindle motor and the noisy 6 speed transmission.

I'll be replacing the whole setup with a Delta B3 2kw 400v AC servo rated for max 6000 RPM and use a belt drive with 1:1 ratio pulleys to drive the spindle directly.

This should give me plenty of low end torque, a built in encoder and double the max RPM of what I had before at much lower noise level.

But I just realized that the question of how to read the spindle load from the servo drive still remains. The load is available from the Delta servo drive either as an analog signal or via Modbus.

As I'm using a Mesa 7i96S + 7i84 combo I have no analog inputs available and the Modbus capable RS422/485 port is already used for the 7i84.

What's the best way around this?

Do I try to source a Mesa 7i76EU which has a few analog inputs and replace the Mesa 7i96S board?

Can I use the FPGA expansion port in some clever way without adding too many expansion cards?

 

Actually I believe that another user referenced perhaps the same issue here .

Are you using the auto tool length probing on your machine?

Not sure what you are referencing here?

If you look at the picture of my machine in this post you can see what I call a "Tool Length Sensor", I believe that's correct CNC terminology.
I also have a touch-off plate but I have not got that to function properly with my 7i76e. I know that my spindle is properly grounded at both ends so I believe that all I need is one wire connected to the plate and I should be able to touch off with the plate.

What I am trying to achieve is the ability to machine a part, remove it from the table and then later machine it again without losing my initial coords.

Regards
Andy

Good morning.

EuSurplus now have good availability - and with a better availability a better price on most of the Mesa boards. Still missing 7i76EU and 7i76U, but with good stock on 7i95T, 7i97T, 7i96S ...

Check us on EuSurplus.com

NT4Boy wrote:

"Connect the 7I83 analog out hal pins to the PID outputs"
Is that a physical wire, or something to be written in the hal file?

In hal file.

NT4Boy wrote:

In hal, make a new config for 7i76E with 7i77, that should get you all the pins for everything, then make a copy and edit the copy to match the Mesa naming and pins:
Stepgens change from 7i76E to 7i95
Encoders change from 7i77 to 7i95
analog out/pid change from 7i77 to 7i83

Edit a hal file, there you have lines that contain stepgen and the Mesa card pins, the Mesa board name must be changed only, but sometimes also the serial addresses must be changed to correspond to your hardware

NT4Boy wrote:

You say to Change the Stepgens
With  analogue servos and an analogue output card, what stepgen output  entries are required?

None, no need if using analog outputs.
Try the MesaCT it should also work for 7i95:
github.com/jethornton/mesact/releases
Download the version for your PC (probably amd64), double click, install with gdebi then run from main menu.

tommylight wrote:

NT4Boy wrote:

Another stupid question from me. When you say:-
"Connect the 7I83 analog out hal pins to the PID outputs"
Is that a physical wire, or something to be written in the hal file?
In hal, make a new config for 7i76E with 7i77, that should get you all the pins for everything, then make a copy and edit the copy to match the Mesa naming and pins:
Stepgens change from 7i76E to 7i95
Encoders change from 7i77 to 7i95
analog out/pid change from 7i77 to 7i83


You say to Change the Stepgens
With  analogue servos and an analogue output card, what stepgen output  entries are required?

@PCW

Now I am trying the shared index . But I have a problem. With the old firmware, the multiplexer inputs work. With new firmware that can use the index with stepgen all Input not works.

"hm2_7i98.0.inmux.00.input-23" does not exist 3566

I am attaching a link just for clarification

forum.linuxcnc.org/24-hal-components/329...-with-7i76e?start=20

PS:  The pins inmuxAddr0Pin ...  InMuxDataPin  are read as  inputs and outputs

PCW wrote:

Since the xy2-100 interface is very new its not available in standard distributed bitfiles
This means in general you would have to compile your own firmware to include the xy2-100 module.
The module is compatible with any Mesa FPGA card, typically you need 4 differential (RS422) outputs
at the minimum to interface to the galvanometer hardware (clock,sync,xdata,ydata).
These can be step/dir outputs from cards with differential drivers:
(7I76, 7I76E, 7I96, 7I47, 7I52S, 7I78, 7I85S, 7I88 etc etc)

I used a 7I96 for most of my testing, here is a bare bones hal/ini file set that replaces the
X, Y stepgen axis with the galvanometer interface:

File Attachment:

File Name: 7i96_xy.zip
File Size:4 KB

Note that the galvanometer hal interface mimics a stepgen run in velocity mode
This is to allow the XY2-100 interface module to interpolate positions at the
standard data rate (so 100K positions per second)

Peter where can I find this module and maybe some example of the PIN file please. Someone asked me to assist with getting this done with a 7i96S.
 

In the ethernet connection I made I changed the last three numbers from 192.168.1.121 to 192.168.1.100 just how you said and it worked like a charm! I can now open linuxcnc and jog the motors with GMOCCAPY thank you very much!