Calibration of Delta-Pi is no different to any other delta printer. There are several good posts already on how to do the calibration so I will just give you a quick version here.
It will take you at least an hour to do it properly. Maybe longer the first time.
There are 5 stages you need to go through in order.
You adjust the tower end stops by driving the printer to positions in front of each tower and adjusting the end stops until all 3 positions are the same height. From memory X0 Y-90, X45 Y78 and X-45 Y78 are about as close as you can get with Marlin firmware due to internal limit checking.
These positions are for Delta-Pi which has 1 tower in front and 2 towers at the back. Normal Rostock is the other way round.
You need to do a home after each adjustment and recheck the height.
Once this stage is complete your build plane is parallel with your build surface.
After adjusting the end stops you need to readjust the Z_MAX_LENGTH (with the head at X0 Y0)
The next stage is to adjust PRINTER_RADIUS so that the height in the centre (X0 Y0) matches the height in front of the 3 towers. Only adjust PRINTER_RADIUS. You should leave DELTA_DIAGONAL_ROD set to the length you made the delta arms. After all you did make them accurately and you know their length.
Increasing PRINTER_RADIUS will lower the head in front of the towers. It will not affect the height at the X0 Y0.
With the 3 tower positions and the center now all at the same height the build plane should be flat and the print head should be just touching the surface at each position at Z0.
Just the extruder feed rate to calibrate and you're done.
I have been working on adding the bed leveling to Delta-Pi and I have a working probe and firmware. I am in the process of replacing the hot end that has given me so much trouble and when that is complete I'll publish details.
The bed leveling is a MAJOR advance for the delta designs because it practically eliminates the need for the above calibration process.
It will take you at least an hour to do it properly. Maybe longer the first time.
There are 5 stages you need to go through in order.
- Adjust Z_MAX_LENGTH
- Adjusting the tower end stops
- Readjust Z_MAX_LENGTH
- Adjusting the delta_radius
- Calibrating your extruder steps per mm
You adjust the tower end stops by driving the printer to positions in front of each tower and adjusting the end stops until all 3 positions are the same height. From memory X0 Y-90, X45 Y78 and X-45 Y78 are about as close as you can get with Marlin firmware due to internal limit checking.
These positions are for Delta-Pi which has 1 tower in front and 2 towers at the back. Normal Rostock is the other way round.
You need to do a home after each adjustment and recheck the height.
Once this stage is complete your build plane is parallel with your build surface.
After adjusting the end stops you need to readjust the Z_MAX_LENGTH (with the head at X0 Y0)
The next stage is to adjust PRINTER_RADIUS so that the height in the centre (X0 Y0) matches the height in front of the 3 towers. Only adjust PRINTER_RADIUS. You should leave DELTA_DIAGONAL_ROD set to the length you made the delta arms. After all you did make them accurately and you know their length.
Increasing PRINTER_RADIUS will lower the head in front of the towers. It will not affect the height at the X0 Y0.
With the 3 tower positions and the center now all at the same height the build plane should be flat and the print head should be just touching the surface at each position at Z0.
Just the extruder feed rate to calibrate and you're done.
I have been working on adding the bed leveling to Delta-Pi and I have a working probe and firmware. I am in the process of replacing the hot end that has given me so much trouble and when that is complete I'll publish details.
The bed leveling is a MAJOR advance for the delta designs because it practically eliminates the need for the above calibration process.