Delta Calibration Docs

Put this guide together last night while waiting for some parts to print. Thought I'd conglomerate what I'd seen out there and lump it all into one document. Feedback welcome!

[delta-calibration.s3-website-us-west-2.amazonaws.com]

Very nice doc !

Thanks for your time and effort !!

I've take a look at your delta calibration document and it seems to me to be fairly comprehensive. I have just a few comments:

- The variable names you list appear to be from one particular firmware (Marlin I think). Not all firmware uses the same variables.

- Some firmwares (e.g. the Duet firmware I have just finished, and I think at least one variety of Marlin) allow the endstops to be adjusted in software. This is generally easier than adjusting them in hardware, especially when the adjustments are small. You just send the adjustment command, then re-home the printer and take the measurements again.

- Some firmwares (e.g. Duet) don't separately define DELTA_CARRIAGE_OFFSET, DELTA_EFFECTOR_OFFSET and DELTA_SMOOTH_ROD_OFFSET, they just provide DeltaRadius, and allow it to be adjusted in software using the M665 command.

- You don't say how much to adjust the delta radius (or DELTA_SMOOTH_ROD_OFFSET) by to get the printing plane flat. A good starting point for standard delta printer geometries (i.e delta radius about half the diagonal rod length) is to adjust it by twice the value of the height difference between the centre and the edges of the bed.

- In your scale correction section, if you just change the value of the diagonal rod length, the printing plane will no longer be flat. You need to adjust the delta radius by the same factor as the diagonal rod length on order to keep the printing plane flat.

I have described a partial calibration procedure for use with the Duet firmware at [miscsolutions.wordpress.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].

Thanks for the feedback At this stage I'm not going to cover calibration in other firmware, only because I use Marlin and I'm not familiar with others (yet). But good points regarding the scale correction section and adjusting delta radius - I'll add that in. Interestingly I haven't noticed the printing plane going out of flatness when adjusting diagonal rod, but in saying that, my adjustments to it were very minor (measured the rods with callipers) and I was adjusting radius simultaneously.

I'll cover setting up a printer with software endstops and delta correction (i.e. using a fork of Marlin like Rich Cattell's) once I get around to finishing my Kossel variant build as well.

Quote
iira
Thanks for the feedback At this stage I'm not going to cover calibration in other firmware, only because I use Marlin and I'm not familiar with others (yet).

Fair enough; but then you ought to replace the line "This document outlines calibration procedures for 3D Delta Printers." by "This document outlines calibration procedures for 3D Delta Printers using Marlin firmware".

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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].

Very nice calibration guide! Thanks a bunch!

I tired to download the calibration doc and it is giving an access denied.... Any other place I can find it?

This is result on your link :

403 Forbidden

Code: AccessDenied
Message: Access Denied
RequestId: 72D65CC43AD20193
HostId: Ju6YVEJRbpoFORBFiWZDHs26pVFSpi9Hn90RyoPwxSjrfvevmiVwoFA/oqI2bqWv1ER4t3N+rF4=

I was all exited that someone had put together a comprehensive delta calibration guide..... would be very helpful!!! too bad about the 403.....

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patrickrio
I was all exited that someone had put together a comprehensive delta calibration guide..... would be very helpful!!! too bad about the 403.....

You could try my delta printer calibration calculator at [escher3d.com]. The instructions are at the top, but let me know if something isn't clear.

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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 once again David/dc42