• Tags
  • Documentation
  • Order
  • Register
  • Login
Duet3D Logo Duet3D
  • Tags
  • Documentation
  • Order
  • Register
  • Login

Automatic XY skew calibration

Scheduled Pinned Locked Moved
Firmware wishlist
11
25
6.3k
Loading More Posts
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • undefined
    Dougal1957
    last edited by 26 Mar 2017, 08:46

    What we seem to be missing here is that the Prusa system does Need a specific Bed with the sensor points in it. It will not work and just any old Bed? That to me severely limits it's appeal.

    As Deckingman points out we already have the tools to be able to compensate for the error using the M556 command and if done that way manually unless you have to strip down the Axis then it is never going to change.

    I to prefer to make sure my Printer is as Accurate as possible have not as yet used Bed Compensation I will however run it on the New Delta to check the bed but hopefully won't need to implement it at all.

    The fewer things the FW Has to contend with whilst printing is IMHO better

    just my two penworth

    Doug

    1 Reply Last reply Reply Quote 0
    • undefined
      boelle
      last edited by 26 Mar 2017, 09:18

      "Prusa system does Need a specific Bed with the sensor points in it"

      Yep or almost yes… it needs a bed with 9 points that triggers the probe, probe must not be triggered outside these points. other than that there is not so much special about it other than it has zoned heating so that the heat is more unitform

      "I to prefer to make sure my Printer is as Accurate as possible" same here, but i might have bad tools or screwing up something so its less precise. having an option to be told you did a bad job on the frame and by this much would help. If i get it right hurra, but if i just cant get it spot on then i might have to bite the dust.

      but as said above it could be a selling point, but as I said it should sit on the bottom of the list

      And if at all possible it should of course be expanded so its dealing with more than just XY skew, and it should of course be possible to totally disable it for those that do not need or want it

      1 Reply Last reply Reply Quote 0
      • undefined
        DjDemonD
        last edited by 26 Mar 2017, 10:37

        I also fall into the build it properly camp now, but I didn't used to. This is a useful feature at the lower end of the market, but that's not where duet users typically are.

        I'd say do it if it's easy to include (which I suspect it's not) or don't use time that could be better spent on more useful features.

        Simon. Precision Piezo Z-Probe Technology
        www.precisionpiezo.co.uk
        PT1000 cartridge sensors NOW IN, just attach to your Duet board directly!

        1 Reply Last reply Reply Quote 0
        • undefined
          Dougal1957
          last edited by 26 Mar 2017, 12:58

          @DjDemonD:

          I also fall into the build it properly camp now, but I didn't used to. This is a useful feature at the lower end of the market, but that's not where duet users typically are.

          I'd say do it if it's easy to include (which I suspect it's not) or don't use time that could be better spent on more useful features.

          Agree 100% with this sentiment!

          1 Reply Last reply Reply Quote 0
          • undefined
            pjr3D
            last edited by 27 Mar 2017, 14:39

            I agree that this is a feature that is most useful to new users with specific hardware ( Prussia i3 mk2).

            But then again, should we not include support for those who most need it rather than just support the experienced and competent users? It seems that this kind of sense/compensate feature has uses in multi-axis/cnc applications and it would be good to support it - but not perhaps at the top of the list!

            1 Reply Last reply Reply Quote 0
            • undefined
              boelle
              last edited by 27 Mar 2017, 15:15

              "with specific hardware ( Prussia i3 mk2)."

              what about others users with the same bed but not the same printer?

              agree that it could be placed somewhat down the list and maybe be expanded to compensate for other than XY skew if possible

              1 Reply Last reply Reply Quote 0
              • undefined
                dc42 administrators
                last edited by 27 Mar 2017, 17:11

                I didn't express my own opinion earlier because I didn't want to bias the discussion. But this thread has been live for a couple of days so I'll express my opinion now.

                • The only thing that Prusa is offering that we don't do already is automatic (as opposed to manual) compensation for XY skew.
                • From what I can see, Prusa isn't offering any sort of compensation for XZ or YZ skew, whereas RRF does
                • If a printer build doesn't have X and Y accurately at right angles to each other, then I suspect it won't have Z accurately at right angles to both X and Y, unless the nature of the design makes it likely that the XY angle will be much less accurate than the XZ and YZ angles. So I don't see much value in automatic XY skew compensation without also having automatic XZ and YZ skew compensation.
                • Measuring XZ skew and YZ skew automatically would not be easy, because the mechanism of using a bed with markers placed in it restricts you to probing at a height very close to the bed.
                • That type of bed also restricts you to using only as many mesh bed compensation points as there are markers on the bed, which is 9 in the case of the Prusa i3 Mk2 bed. Whereas the Duet WiFi supports up to 441 bed probe points. 9 points is likely to be sufficient for small Cartesian printers, but not for larger printers.
                • As far as I know, no firmware other than RRF has supported any form of skew compensation before Prusa added it, and I've never seen anyone raising skew on Cartesian printers as an issue on any of the forums I monitor. So I see no evidence that XY skew is a common issue (or even a rare one).

                So my gut feeling is that automatic XY skew compensation is a solution to a non-problem. Most people don't have difficulty getting their X and Y axes perpendicular. For those who do, manual skew compensation is available, and if used as instructed it also provides XZ and YZ skew compensation.

                So I'm inclined to put it waaay down on the priority list. But we're customer-driven at RRF, so your votes are what counts.

                Duet WiFi hardware designer and firmware engineer
                Please do not ask me for Duet support via PM or email, use the forum
                http://www.escher3d.com, https://miscsolutions.wordpress.com

                1 Reply Last reply Reply Quote 0
                • undefined
                  kraegar
                  last edited by 27 Mar 2017, 17:56

                  I saw a couple printers that would have benefited from this compensation at MRRF due to errors induced in transport - some traveled better than others. Or at least on brief inspection, a few looked a bit off. But that's typical for MRRF, people slap their printers down and hit print, any auto-cal is beneficial because no one's wanting to sit around calibrating when they could be talking to others and enjoying the fest. Now whether the issue should have not occured if they'd been build more solidly is a different question, but I was very glad to have full autocalibration on my delta while there.

                  That might be a rather unique use case, though, not sure how often people travel with their printers.

                  Co-Creator of the RailcoreII CoreXY printer
                  https://www.thingiverse.com/thing:2407174

                  1 Reply Last reply Reply Quote 0
                  • undefined
                    boelle
                    last edited by 27 Mar 2017, 18:02

                    "no firmware other than RRF has supported any form of skew compensation"

                    Repetier does, but also has to be done manual

                    Q…. Would the mini IR board be a batter choice here? and how well would it work on that black matt surface with PEI sheet on?

                    1 Reply Last reply Reply Quote 0
                    • undefined
                      T3P3Tony administrators
                      last edited by 28 Mar 2017, 18:00

                      boelle

                      There could be a way of using an IR sensor, combined with an accurately manufactured "datum" sheet to do the same form of compensation. A pattern (similar to a bar code) can be printed at various points on the datum sheet which the IR sensor, if scanned at the right height, can detect. The sheet would need to be manufactured with cutouts or very varied reflectivity

                      This would be a lot of work to implement and (unlike other forms of auto calibration like delta auto calibration) is not as common an issue.

                      Further more neither of these methods works with a touch probing system like the peizo sensor.

                      My view is it is a low priority in comparison to most other things.

                      www.duet3d.com

                      1 Reply Last reply Reply Quote 0
                      • undefined
                        kingfisher
                        last edited by 31 Mar 2017, 22:45

                        I'm thinking of signing up to the indiegogo campaign, but have a quick question as I use a Mini height sensor board…

                        Will the Mini height sensor board be be compatible, based on the height sensor instructions:

                        "PEI: this is highly transparent to IR. Paint the underside matt black (see below) before using adhesive sheet to attach it to the bed plate."

                        I assume that as the MK42 heated bed is black and the PEI is applied directly to this, this step wouldn't be required?

                        1 Reply Last reply Reply Quote 0
                        • undefined
                          boelle
                          last edited by 5 Apr 2017, 12:32

                          you are right

                          the mk42's are matt black and the PEI is put on top

                          i too will end up with the mini ir, i assume that the duet will make use of the analog output

                          1 Reply Last reply Reply Quote 0
                          • undefined
                            kingfisher
                            last edited by 30 Jul 2017, 10:00

                            My heated bed from the indiegogo campaign has arrived
                            Does anyone know if the Mini height sensor will be able to cope with the matt black PCB and thin PEI or would i be better off getting a sheet of Buildtak instead?
                            Willing to experiment, but if the PEI is a lost cause I'd rather not put it on to only have to peel it off 30mins later…

                            1 Reply Last reply Reply Quote 0
                            • undefined
                              dc42 administrators
                              last edited by 30 Jul 2017, 10:19

                              PEI placed on top of a matt black surface with no intervening adhesive should be OK, but if there is an intervening adhesive sheet then reflections from the light-coloured adhesive are likely to cause problems.

                              Duet WiFi hardware designer and firmware engineer
                              Please do not ask me for Duet support via PM or email, use the forum
                              http://www.escher3d.com, https://miscsolutions.wordpress.com

                              1 Reply Last reply Reply Quote 0
                              • undefined
                                kingfisher
                                last edited by 30 Jul 2017, 20:18

                                @dc42:

                                PEI placed on top of a matt black surface with no intervening adhesive should be OK, but if there is an intervening adhesive sheet then reflections from the light-coloured adhesive are likely to cause problems.

                                Thanks for the reply the PEI does have a thin adhesive layer. I might play safe to start with and get in a bigger buildtak sheet as I know that works well with the sensor.

                                I like the idea of the piezo sensors but I will need to think about how to mount it on a i3 with a Titan Aero…

                                1 Reply Last reply Reply Quote 0
                                • undefined
                                  DjDemonD
                                  last edited by 30 Jul 2017, 21:00

                                  We have a titan bracket system now not many in use currently but it works. Will work with titan and titan aero. See the site below or search DjDemonD on thingiverse. It's based on the official bracket from e3d.

                                  Simon. Precision Piezo Z-Probe Technology
                                  www.precisionpiezo.co.uk
                                  PT1000 cartridge sensors NOW IN, just attach to your Duet board directly!

                                  1 Reply Last reply Reply Quote 0
                                  • undefined
                                    kingfisher
                                    last edited by 31 Jul 2017, 14:45

                                    @DjDemonD:

                                    We have a titan bracket system now not many in use currently but it works. Will work with titan and titan aero. See the site below or search DjDemonD on thingiverse. It's based on the official bracket from e3d.

                                    Thanks, I had a look at that I'll need to redesign it to fit my setup, I see that your bracket has some flex built in the base I'll need to come up with a way to add this to my carriage or make a two part carriage to incorporate your bracket

                                    I've just made this for the IR sensor which is working quite well. (https://www.thingiverse.com/thing:2441400) So I'll stick with this and buildtak in the short term and keep an eye out for Cartesian Piezo carriages/brackets and switch if i need to move over to PEI

                                    1 Reply Last reply Reply Quote 0
                                    • undefined
                                      DjDemonD
                                      last edited by 31 Jul 2017, 15:30

                                      No worries, these things are quite versatile. The tuning window (the usable range if you prefer) will be narrow but they can work just bonded to the side of any part that flexes on nozzle contact.

                                      Simon. Precision Piezo Z-Probe Technology
                                      www.precisionpiezo.co.uk
                                      PT1000 cartridge sensors NOW IN, just attach to your Duet board directly!

                                      1 Reply Last reply Reply Quote 0
                                      • First post
                                        Last post
                                      Unless otherwise noted, all forum content is licensed under CC-BY-SA