Post by wjsteele on May 10, 2013 6:02:01 GMT -5
When you first build your PiMaker, it will need to be calibrated to your specific assembly.
The PiMaker can be configured to run all of it's settings from the hard coded firmware, or most of those same values can be overridden in the EEPROM settings page of the PiMaker Host software.
I've updated the basic Firmware image to include the settings that I have found to work with the PiMaker in the configuration I build them in.
DO NOT TRY TO PRINT WITHOUT CHANGING THESE SETTINGS!
To start, set your acceleration values to very low values, like 100 or so, so that it doesn't accidently overpower the build plate drive.
I used a value of 39.96 steps per mm for both the X and Z values. The Y axis is different because it has to be handled in two ways. So, the value I use on my prototype is 1139.86 steps per Angle. That is not the same as the other values due to the polar coordinate conversion. Please be aware of this... when you tell the PiMaker to move the build plate, it is not moving it per MM from the control panel, it is moving it per degree. 100 degrees, 10 degrees, 1 degree... etc. But, now hears the kicker... that's only if you are moving in Polar mode... when in Cartesian mode, the value becomes steps per MM. This have a different meaning entirely and will simply rotate the build platform. It should still be MM when drawn on a 1 inch circle on the build plate.
I use a protractor set on the build plate to measure just how far it is going when I am tuning that value.
Once those values are set, you can start to increase the X and Z accelerations. The Y must be treated differently due to it's extreme gear ratio... but X and Y should be roughly 1000 and 300 for their max speeds and 300 and 300 for acceleration values.
As we go along, I'd like you guys to fill in your values here to help tunes these even better. My numbers are very conservative, which prevents the machine from moving too quickly or causing the build plate to "pop off" the screws holding it in place... but it works nicely.
One last point... when you are manually controlling the build plate, it might seem very jerky, but once you start to print, you should see that it is a very smooth operation... if not, your acceleration might be to aggressive.
I will be updating the software stack with the latest Firmware as well and Ben has posted the config file to Git hub where it should be available to all.
Bill
The PiMaker can be configured to run all of it's settings from the hard coded firmware, or most of those same values can be overridden in the EEPROM settings page of the PiMaker Host software.
I've updated the basic Firmware image to include the settings that I have found to work with the PiMaker in the configuration I build them in.
DO NOT TRY TO PRINT WITHOUT CHANGING THESE SETTINGS!
To start, set your acceleration values to very low values, like 100 or so, so that it doesn't accidently overpower the build plate drive.
I used a value of 39.96 steps per mm for both the X and Z values. The Y axis is different because it has to be handled in two ways. So, the value I use on my prototype is 1139.86 steps per Angle. That is not the same as the other values due to the polar coordinate conversion. Please be aware of this... when you tell the PiMaker to move the build plate, it is not moving it per MM from the control panel, it is moving it per degree. 100 degrees, 10 degrees, 1 degree... etc. But, now hears the kicker... that's only if you are moving in Polar mode... when in Cartesian mode, the value becomes steps per MM. This have a different meaning entirely and will simply rotate the build platform. It should still be MM when drawn on a 1 inch circle on the build plate.
I use a protractor set on the build plate to measure just how far it is going when I am tuning that value.
Once those values are set, you can start to increase the X and Z accelerations. The Y must be treated differently due to it's extreme gear ratio... but X and Y should be roughly 1000 and 300 for their max speeds and 300 and 300 for acceleration values.
As we go along, I'd like you guys to fill in your values here to help tunes these even better. My numbers are very conservative, which prevents the machine from moving too quickly or causing the build plate to "pop off" the screws holding it in place... but it works nicely.
One last point... when you are manually controlling the build plate, it might seem very jerky, but once you start to print, you should see that it is a very smooth operation... if not, your acceleration might be to aggressive.
I will be updating the software stack with the latest Firmware as well and Ben has posted the config file to Git hub where it should be available to all.
Bill