My 7i76e Connection Sheet

i'm working on a mill (cincinnati cim-x) there is no encoder on the mill-axis and mechanical nearly inposible to place it there
can it also work when i place the encoder on the motor and add some lines in the hal (an idea of what lines)
i like to use rigide tapping
how many puls do in need maybe 2 or 3 magnetic sensor placed on a gear in the gearbox can also work ?

fons wrote: i'm working on a mill (cincinnati cim-x) there is no encoder on the mill-axis and mechanical nearly inposible to place it there
can it also work when i place the encoder on the motor

I think that there are probably more CNC machines with the encoder on the motor than on tha axis.

Encoders on the motor works fine, and needs no special config.

when you use rigid taping the system need to know the puls/ revolution
there is a gearbox with 16 speeds
when the encoder is placed on the spindel its always the same value of pulses
not with a gearbox place in different gears
or does it mathers ? what i don't believe

fons wrote: when you use rigid taping the system need to know the puls/ revolution
there is a gearbox with 16 speeds
when the encoder is placed on the spindel its always the same value of pulses
not with a gearbox place in different gears
or does it mathers ? what i don't believe

The spindle encoder needs to be on the spindle, yes.

But there was nothing in your previous post to suggest that you were talking about a spindle.

what is the min of puls to work propper i have to make one by meselve at the outside of the gearboc
can 180puls/rev be enough ?

fons wrote: what is the min of puls to work propper i have to make one by meselve at the outside of the gearboc
can 180puls/rev be enough ?

50 is enough for lathe threading or for gar hobbing, as at a constant speed LinuxCNC can interpolate the output from a low-count encoder.
For rigid-tapping you need to know exactly when the spindle reverses.
With 180 counts you can have (about) 2 degrees of uncertainly in the reversal position.
Does this matter? Quite possibly not. The effect is to give a slightly sloppy thread (assuming perfect Z-axis tracking) but 2 degrees with a 1mm pitch tap is only 5 microns error.

thx for the quick reaction i can go work on mine project in thise way prepairing a 180puls enconder is ABZ enough or do i need also the inverve pulse-A-B-Z
an other problem why an unloaded steppermotor stall at higher speed ?
i make several test and always the same result the stepper motor will not run
i use a mesa 7i76e
i try a nema 17 motor with a lowcost stepper driver 6600 from alliexpressalso
i try it with a leadshine dm556 driver
from xinlichuan the mc425e and mc442e driver with all the same result
i use a small, the adjusted and a high a curent
what more can i try ?

fons wrote: thx for the quick reaction i can go work on mine project in thise way prepairing a 180puls enconder is ABZ enough or do i need also the inverve pulse-A-B-Z

The inverse pulses would be generated by a line-driver, not by the encoder itself.
Single-ended works fine.

why an unloaded steppermotor stall at higher speed ?

Steppers have a lot of poles, so the back-emf becomes a problem at lower speed than with a lower pole-count motor.

To run faster, use a higher voltage. What voltage are you using? what is the max that your drives can handle?

Hello Norbert,

I´m working to retrofit an EMCO VMC100 Mill, your connection sheet helped a lot for wiring.
Thank you for the great job you´ve done. MESA´s documentation to their 7i76e delivered more questions than answers to me ...

Robert

This sheet helps me a lot.
Just a question. I connected my 7i76e b board with a 5v isolated Power supply at P3 First just left it like that to test Stepper Motors etc. Then I added field power to Tb1 as on your sheet however I did not connect it to Tb3 since I assume that is powered by the 5 volt power supply. When starting linuxcnc I get an error. It warns me about undervoltage.

Also if I measure on pin 5 I get 24 volt.
But there is no power on pin 1-4

I see the manual says both power supplies should have common ground. In my case both are isolated power supplies. Does that mean I should connect the negative poles of the two power supplies together?