Schaublin 125-CNC retrofit.

RotarySMP wrote:

Could you please send me the link to your lathe spindle speed control comp again, so I can have a look? 

Here is the fancy one that does gear shifts at non-zero speed when the shaft speeds are equal:

 

WOW cool input here.
You also could change the variator motor to a closed loop stepper (Just to prevent step loss) or servo in position mode. This way you don't chew the relays. As an alternative you could use the variator with "fixed" gears and let the VFD correct it to a smooth ramp. This way you can minimize the use of the contactors. So many options

anfänger wrote:

You also could change the variator motor to a closed loop stepper (Just to prevent step loss) or servo in position mode. 

Oh, yeah, why has it taken so long to come up with that obvious idea

Replaceing that beautifully integrated little 3Ph variator motor and it's angle gearbox is something I am rather loathe to do. It is true that it would be a good solution.

I took a course in machine tool design which the local Technical Uni offers, so I thought I'd try to apply the lessons learned to the Schaublin.
There is also a summary of my thoughts about the variator control.

RotarySMP wrote:

Replacing that beautifully integrated little 3Ph variator motor and it's angle gearbox is something I am rather loathe to do. 

I have been thinking about this off-and-on there is a fairly simple scheme that I think might work. 

1) Use a PID to control the VFD, in the normal way. 
2) Use "wcomp" to trigger the variator if the VFD frequency is <40 or >60 Hz. 

There will need to be some interlocking on the second point, ensuring that the spindle is turning at a minimum speed for variator operation, and also possibly blocking during a G1 to prevent unusual behaviour on facing cuts. 

What I see happening is that the fixed speed of the variator shift will either stay in the window (which is fine), accelerate through the window (which provides some automatic hysteresis (though measures might need to be taken to prevent the variator motor reversing at that point, perhaps a function to lock-out the variator for a second once it has operated?) or "chase" the window up or down to the required speed (which is also fine) 

And, writing this, I am now wondering whether enabling the variator based only on vfd-at-speed is an option. So the VFD does the speed control, then once up to speed the variator optimises the torque. 
 

Hei Mark, 

unfortunately no good input about the spindle drive from my side. 

I just wanted to let you know how much I like your work and content. 
I’m going to start the work on my Schaublin in a few weeks and your videos are very useful to understand how things have to go together. 
And the quality of your work is great, definitely going to steal some ideas from you 

Maybe you could write me a dm so I could send you package to show my appreciation. 

 

Hi Guys,

Andy, I like that suggestion. I'll have to look into that wcomp widget. You have an excellent knowledge of all those easter egg features of LinuxCNC.

Unfortunately I have been rather busy at work, so I haven't been able to make any progress on laying out the control logic yet.

Aussschuss-Manufaktur (Great name), cool that you are also doing an Schaublin retrofit. Great to see this quality iron getting some love. Please post some pictures of your Schaublin here.
There is no DM feature in this forum, but my email address is on the "about" page of my youtube channel, so please drop me a line.
Mark

Hey,
I posted some pictures last year when I got the machine. They are somewhere on page 18.
The next decade is probably going to be cleaning and checking the mechanics, so no interesting stuff in the near future.
Keep up the great work

I got a decent Z axis mount made,