New Delta printer calibration method with ray of light

Hi all, I would like to share my idea about delta printer auto calibration method. I was thinking if there are some other methods for auto calibration of delta printer then the inductive sensor. Would be there a way to also automatically count the difference in the towers angel or some other possible mistakes made during the build phase of delta printers? My idea is to use a ray of light which would be sticked to the bed in angel of 90 degrees (between the bed surface and the ray of light). Then there would be a point with light sensor on the printer effector which would measure if the ray is going to this point when the effector is moved to the top and then to bottom of delta printer. If not then the effector would move in a way to get the ray of light to the effector light sensor. Then based on the steps and direction of effector move, the difference would be counted and used for correct auto calibration and correct printing. It is more about printer calibration to reduce errors done during the build then auto leveling bed calibration. Maybe use of both methods together could give the best results (inductive sensor + this method described here).

I am not sure if I correctly describe this method so if something is not clear, let me know. I also do not know if something similar is already used or not. I am sorry if this idea is completely wrong. I am not well in electronics and engineering of such devices. Please take it only as an idea for discussion.

I will appreciate your comments.

Thanks.

Edited 1 time(s). Last edit at 06/22/2017 05:59PM by boylucky.

Please explain in more detail what you mean. Are you talking about using the beam from a laser attached to the effector to pick out a visible feature built into the bed, or something else?

There are already many alternatives to using an inductive sensor for delta calibration, including my own mini differential IR sensor [miscsolutions.wordpress.com] and various types of nozzle contact sensors including this one [www.precisionpiezo.co.uk] and this one [duet3d.com]. Also there are many people using FSRs under the bed supports to detect nozzle contact, and the accelerometer on the effector in the most recent SeeMeCNC delta printer.

Edited 1 time(s). Last edit at 06/23/2017 03:24AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for your alternatives you mentioned. The IR sensor looks perfect. Is that design open source? I do not thing so, right? The piezo sensor also looks interesting. I can see that it should be open source which would be great. Anyway I like more the IR sensor. I also have to get more info about FSR wich looks also good. So thanks for all this info.

Regarding the method I described above. I ment that there would be lets say a laser device attached to the bed and then on the effector there would be a sensor which would react on the ray. The idea is to measure if the effector is still on the same X,Y when moving the effector up. If not then there would be counted the difference to adjust errors done during the build of the printer.

Yes the IR sensor is open source. The files are on github, [github.com].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].