Automated Delta Calibration Request
I'd like to request the following Delta printer setup revision, or similar, be considered. I realize some of these sequences are in place. I am requesting a refinement of process for a more fully automated delta printer setup and configuration, which will create a faster printer setup, more precise prints sooner and a better printing experience. (Maybe?)
Background
* Delta printer kinematics are now well modeled within the firmware and software.
* Properly configured Delta printers print successfully.
* The Delta printer form/configuration are generally similar, known and stable.
* The print beds are commonly either round or square and we are comfortable with the printer hardware operations.
* Many Delta printers have bed sensors/probes for Z height and bed leveling.
* There are several tedious ways to setup, calibrate and commission a Delta printer.
* To get a close tolerance print of fine quality the refinement settings are an iterative, tedious and time consuming process.
Suggestion/Request
Please consider the following calibration sequencing for Repetier firmware and Host software.
I suggest a more automated Delta Printer setup and bed level process as follows:
Wizard - Sequence suggestion for delta printer calibration and setup by Operator.
1. Turn machine on and connect PC Host to printer.
2. Initiate a First_Time/Recalibration setup wizard.
Follow wizard instructions:
1. Determine and Mark or Note print surface bed Center.
2. Place piece of paper on print surface center and manually lower and position the print nozzle onto the paper and print surface center. Allow the customary light drag of paper between nozzle and print surface.
3. Press the calibration wizard 'Next' sequence and the machine homes X, Y, Z axes/towers. The distance measurement from bed center to top/home recorded.
[Now, it will be known the tower heights from firmware measurement and print bed dimensions from the configuration.h file. The X, Y, Z heights do not have to be equal or even. The firmware/software will calculate their use. The X, Y, Z distances measured to bed center are used for calculation of preliminary printer dimensions and positions of the print bed location and condition. The firmware/software records and calculates: the print bed center, an approximate diagonal rod, smooth rod, Z height, and some other dimensions from known geometry of a delta printer. These first step software calculations are determined from a Delta printer's geometry and are good enough since more refined and detailed dimensions for the printer to print close tolerances will be calculated through and from the bed leveling process - Not from hard physical printer dimensions.]
4. Offer selection to run - Bed level sequence - or not.
[Use the Z probe to measure the bed level and to refine the delta diagonal rod dimensions as well as the other dimensions to print level while also removing the concave tendency of the delta printers.]
The above rough sequence will automate the present process quickly allowing an Operator to accurately setup and/or recalibrate a Delta printer.
Firmware & Software changes (?)
Actions/Calculations performed by Firmware and PC Host to be part of automated configuration, setup and EEPROM store:
* Print height - calculate from measurement of distance of print head travel to bed center - manual print head/nozzle placement by the Operator and noted by the printer through calibration home command.
* The print bed shape & dimensions will be input by Operator within the configuration.h file.
* Delta printer hardware configuration selected for calculations.
* From print bed center and the height of X, Y, Z towers all other information can be rough calculated.
* Run a bed level which now can be automated since the print bed dimensions and the X, Y, Z tower distances to bed center are known. The head can go to within 5mm of bed height and begin to probe the bed for level. The bed rotation for a square print bed can be determined with an edge test within the probe test. If the Z probe goes -X below bed center then an error is sent to determine a past edge condition. The process continues mapping out a surface and the edge errors. From this a rough orientation of the bed can be determined. And since the bed center is known, the geometry and dimensions then the corrected bed position and orientation can be set within the EEPROM.
Required Software Values from new process sequence -
Known and automatic measured values -
* Bed size and shape - Configuration.h file and Host, as present, input by operator - round (diameter), square (L X W).
* Print area center - Manual process via print head/nozzle placement to print bed center and a piece of paper by Operator.
* X, Y, Z heights - Calculated by printer firmware and Host interactions when special home command is executed.
Calculated -
* The diagonal rod, horizontal distance and some other printer measurements can be calculated by software to fit known Delta geometry and from values above to provide accurate printing.
* Will still require existing Z probe offsets input from measurements by Operator from physical machine geometry.