Another little 3D printer milestone
Posted by
Graham Stabler
on 2007-05-25 15:30:56 UTC
I can now detect paper feed and syncronize a stepper motor with the
encoder signal with a programmable divide, at the moment I have 12
encoder pulses (after quadrature) to one half-step. That puts the
shafts in sync, in the finished item the belt drive pulley will be
smaller than the paper feed roller so the ratio will be 6.
It certainly manages to keep up without a load, I'm not ramping up to
catch the pulse frequency at the moment but that may be required with
a load. Unfortunately I don't have the required pulleys yet to test
(ordered on Monday).
The nice thing on the propeller is that I can create a printer sync
object running in its own processor and just set a flag in the main
memory when I want it to syncronize, that lets the main program do
other things if it wants like monitor limit switches or provide
pointless statistics to the user.
Graham
encoder signal with a programmable divide, at the moment I have 12
encoder pulses (after quadrature) to one half-step. That puts the
shafts in sync, in the finished item the belt drive pulley will be
smaller than the paper feed roller so the ratio will be 6.
It certainly manages to keep up without a load, I'm not ramping up to
catch the pulse frequency at the moment but that may be required with
a load. Unfortunately I don't have the required pulleys yet to test
(ordered on Monday).
The nice thing on the propeller is that I can create a printer sync
object running in its own processor and just set a flag in the main
memory when I want it to syncronize, that lets the main program do
other things if it wants like monitor limit switches or provide
pointless statistics to the user.
Graham