I'm deciding whether to work on a LinuxCNC feature and would like to know first whether anyone would actually use it.

Today, when a rotary axis moves together with X, Y or Z, F applies to the linear axes only, and a rotary move on its own runs at F in degrees per minute. On a 4th-axis wrap, where the surface of a cylinder is cut with X and A, the surface speed therefore doesn't match F. The usual workaround is inverse time (G93) from the CAM.

The idea is a reference radius for each rotary axis, set in the INI. For example, `[AXIS_A] FEED_RADIUS = 25` puts A in the feed calculation as if it were a length at 25 mm from its centre. A move of A alone at F100 would then run at 100 mm/min on the surface at that radius, and X with A would run at F along the combined path. Siemens (FGREF) and Fanuc (a parameter) do the same.

Questions:
1. Would you use this, or does G93 from your CAM already cover it for you?
2. What machine: 4th-axis wrap, rotary table, something else?
3. The useful radius is usually the stock radius, which changes per job. Is a fixed INI value good enough, or would you need to set it from G-code?

A short "yes, I'd use it", "no" or "G93 is fine" helps. If nobody needs it, I'll leave it.

 

@plasmanfm

1.0.7 will release today and the help file fix is in.

I received the braking resistor yesterday and mounted it on the left side of the cabinet. The cables that came with it were just long enough to reach all the way to the spindle drive.

 

 

With the braking resistor installed and the parameters set in the spindle drive the faults when stopping the spindle from high RPM disappeared.

As the machine seemed to be ready for the first test cuts I cleaned the vices in the parts cleaner and installed them.

 

Getting all three of them trammed in took it's time as usual...

 

For the first nervous test cuts with the new spindle I used a piece of 7075 aluminum.

I started with an 80 mm face mill and immediately noticed a clear improvement in surface finish which I hadn't expected.

 

Next I milled the sides with a 16mm DLC coated solid end mill. The resulting finish was something I've never seen on this machine before.



This was just a quick cut with a width of 0,5 mm so this feels very promising. I'll report back when I've milled a few real parts.

Got myself one. I will add it to my collection of backup ISO's

I managed to get it working. Here are the files.

Dear everyone, i have posted about my cnc issues and am kindly asking for help here   but i think this may become harder to find then i thought. Any tips if there is consulting help or physical help and an option, please do not hesitate. I am happy to spend a dime. 

BUT i am preparing myself for a week of CNC evenings and nights as this is ultra urgent to fix for me and my small shop. 

I am using a mesa MESA 7I76EU STEP/IO STEP DIR plus I/O controller card on my CNC. its about 1.5m X 1.2m with 35cm Z axis travel distance. 
Sadly i was not able to perform the full retrofit fully myself due to time constraints. I did though the complete electronics overhaul. 
I have added a new tool length sensor and a 3d probe. 

From my cnc workflow so far i have this process in mind and I would love your take on it. I have used multiple CAD / CAM solutions in the past, the longest i have used fusion360 and right now im trying out onshape cam. 
But in general the workflow was the same:

1. CAD design the part
2. In Cam I am creating a setup
3. I create and define stock (if necessary)
4. or I set up the part reference point 
5. that defines the WCS XYZ 
6. This allows the postprocessor to generate toolpaths.
7. Using the postprocessor to output G-code
8. I load whatever CNC program (right now linux CNC QT Dragon)
9. I home the machine (if necessary) 
10. This sets G53
11. Then I either do this: 
12.  A) I insert Tool 1, measure tool 1 at the tool lenght sensor. G43 H1 mit Z20 z.b. . Then I take my tool length sensor, place it on top of the material. I am zeroing Z-height (G54 Z = new coordinate - tool length sensor dimension)) and i place the machine head roughly where i want to cut
13. I take a 3D probe, probe the stock or piece or reference that i need. I align the WCS to it. (if the probe needs calibration, i probe the table or a defined height of a pin right next to the tool length measure.) This sets G54 XYZ. Then I insert Tool 1 and measure tool length on my tool length sensor. G43 H1....
14. Run
15. Tool change
16. Measure T2 G43 H2 is stored
17. continue and repeat

BUT it seems that in our setup of linux this process does not work at all. I am getting homing error and out of probe errors the moment i am doing the basic qt dragon features for probing and sensing. 

 































 

Sorry my edit was left in draft mode and did not got posted.

No no actually its good. I think I am looking into two avenues. Either i fix it myself but completely redo the setup or i find help and am happy, very happy, to provide some financing for next cnc project to someone. I need the machine basically and the bodged retrofit or rather not completed retrofit is killing hours.

If you or anyone would be open to jump on a video call or something. I think most of you here would probably spot the issue instantly.

darm, the mods have moved the topic to the dark corner of the forum ...  
Just kidding. @tommylight, would you be open for a call? 

I am diving int the cnc setup again and need to fix the processes. I am getting errors constantly wheras it should be a normal operation. 
I will post a detailled process question later today
 

Hello folks

Very good news: The MAHO mill retrofit has entered the finishing state. 
LinuxCNC can now read all inputs, sensors, thermal-switches, ... and also control everything, from the gearbox-motors, the VFD with the spindle motor, the Indramat DC motor driver and all the other components.

Features working at the moment:
- Working DC axis motors (PID not tuned)
- Reading the Heidenhain LS403 glass scales directly with modified EL5021 terminals
- Working gearbox and VFD (EL7332 controlling gearbox motors, Danfoss FC302 controlling original spindle motor)
- Working toolclamp-mechanism (with added button)
- Safety related inputs handled with TwinSafe Safety Hardware (EK1914 and EL1918)
- BusCheck monitors EtherCAT bus config (SafetyPLC CRC now too)
- Faulthandler gives operator detailed info, warning and alarm messages (message conditions need to be cleaned up)

The best feature probably is the continuously adjustable spindle speed. When a speed between 8 and 4400 RPM is requested, the best suited gear of the gearbox is selected (and will be used for all further requested speeds until a M5 command is sent) and the last speed adjustments are done by setting the spindle motor speed accordingly. That way it should be possible to cut threads with rigid tapping in theory up to 260 Nm in the lowest gear. A video of the three LinuxCNC spindle related components (fc302VFD, gearbox and spindle_master) working together  is over on YouTube .

Beckhoff has their own way of implementing a zero logic for their encoder terminals - for the Z(ero)/reference impulse. There is now also a component, which ties this index zero logic into the LinuxCNC homing logic. The component should work with all Beckhoff encoder input terminals and boxes - it was only tested with an EL5021 terminal. All components and the whole machine config can also be found over on github .

There are still quite some things that need to be done, like tuning the PID controllers, designing and building the new monitor-arm and so on... But we are getting there

Hey Tommy.. thanks for the offer. I am really looking for someone who is willing to take the deep dive . The language is not the issue, the physical locale rather. I was thinking maybe its good if the one could come over.

can we control servo motors and drives in linux cnc