Hello.
I'm about to take on a project regarding winding up a thin thread on a drum in a single layer. So far it sounds simple...
But...
HW:
From this set-up I have some questions that I hope you gurus can guide me with.
Best regards from Knut.
I'm about to take on a project regarding winding up a thin thread on a drum in a single layer. So far it sounds simple...
But...
- The thread does not like beeing touched, so the drum will have a square shape so the thread are thouched only 4 times per revolution-lenght.
- The thread can be thight but does not tolerate beeing stretched. So the drum must vary the winding-speed so the perimeter of the square wheel has a constant speed.
- The extruder that delivers the thread, will give me the "line-speed".
HW:
- S7-315T-2DP and Sinamics S120 (had a course in this some years ago)
- Use servomotors with gears for the drum and traversing axis (the winding will be very slow, aprox. 1 rev./min)
- Only use the encoders on the servomotors for the winding application. (keeping cost and complexity down)
- Recomend the mechanics of the traversing-axis to consist of a ball-screw.
- Use the "line-speed" from the extruder to control a virual axis as a master.
- Set up a cam-connection from the virtual axis to the Drum-axis. The cam having a sine-function that repeats 4 times every revulotion, hopefully giving a constant perimeter-speed.
- Set up a gear-connection from the Drum-axis to the traversing axis that lays the thread on the drum.
From this set-up I have some questions that I hope you gurus can guide me with.
- Should the virtual axis be set up as a linear or rotary axis, with/Without modulo?
- The drum, same apply here, should that be set up as a linear or rotary axis, with/Without modulo?
- As I understand, the cam must be synchronized so the sine-function corresponds with the cornes of the square. I believe this must be done with a ind. sensor looking at a flag on the drum. Will it be neccesary to sync at every revelution?
Best regards from Knut.