Auto Hight Probing Status

[altarke]

To All,

Can anyone inform all of us, 3D Printer owners, who are anxiously awaiting the release of some reliable 3d height probing solution we can all easily implement into our printer.

I saw something about an effector that the head itself is actually attached to a switch that senses the height of the bed (I really liked it).

[Eaglezsoar]

To All,

Can anyone inform all of us, 3D Printer owners, who are anxiously awaiting the release of some reliable 3d height probing solution we can all easily implement into our printer.

I saw something about an effector that the head itself is actually attached to a switch that senses the height of the bed (I really liked it).

I will tell you the same that was told to me, it's going to be be quite awhile before the height probing will be avalbale.
The answer was: You're after auto-radius and frankly, it could be a while. It doesn't appear to be a priority with the folks that are doing work on the various firmware branches.

There are many of us who would like to see this implemented but it appears that we are a minority, read page three of this: http://forum.seemecnc.com/viewtopic.php ... 2&start=20

[geneb]

The best way to get it done is to contact the firmware author directly via github and ask him for it.

Roland has put an "auto-level" feature into the .90 development branch, but it won't work very well if your PRINTER_RADIUS is off at all.

g.

[Eaglezsoar]

The best way to get it done is to contact the firmware author directly via github and ask him for it.

Roland has put an "auto-level" feature into the .90 development branch, but it won't work very well if your PRINTER_RADIUS is off at all.

g.

I think you mentioned this before but to clear it up once and for all, do you know if the one incorporated in Marlin is Auto-Radius or Auto-Level?
If it is auto-level then it also will be worthless to delta owners because it would require the printer_radius to be perfect as well. If this is the
case then what we see appearing on the other deltas is basically hype just to sell the printer. It also would mean that as Rostock Max owner
switching to Marlin hoping to get auto-level would be a waste of time, is this correct?

[Polygonhell]

I don't know definitively, but from the videos of the marlin auto level I'd guess it's some sort of parametric compensation. Probably treating the bed as a set of flat pieces, or some curve fitted through the samples. This MIGHT remove the radius effect, but it may also introduce others.

Actually fixing values like DELTA_RADIUS isn't mathematically difficult, but you have to be able to identify the actual center of the machine, and that's affected by the end stops.

You can probably get away with setting the outside points to form a plane, then back figure delta radius from the ouside to inside point differential, but that wouldn't accommodate other geometry errors.

[626Pilot]

SeeMe has a prototype depth probe based on an endstop switch. It has to be cut from wood or acrylic and they aren't selling it yet, but they will give you the CAD files if you own your own laser cutter or CNC mill. I made a printable Z probe that requires a Hall-O board from mauk.cc, neodymium magnets from Amazon, and a metal rod from McMaster-Carr. Full instructions on putting it together and wiring it up are there.

As far as firmware is concerned, I have opened an issue about Repetier's "tower leveling" not working. Roland posted a couple of theories about what it might be, but has done nothing since as far as I'm aware. If you REALLY care about this, the best way to get it to happen would be to post in that GitHub issue asking for a status update and letting him know that you appreciate his work and would really like Repetier to fully support this feature.

There is also a fork of Marlin that has working bed probing for Rostock printers. I believe this is what the commercial (Kickstarter) printers are using. Marlin is not my first choice for firmware, but if you want something that Works Right Now, that would be it. I would like to give that a shot, but haven't had time yet.

[Eaglezsoar]

SeeMe has a prototype depth probe based on an endstop switch. It has to be cut from wood or acrylic and they aren't selling it yet, but they will give you the CAD files if you own your own laser cutter or CNC mill. I made a printable Z probe that requires a Hall-O board from mauk.cc, neodymium magnets from Amazon, and a metal rod from McMaster-Carr. Full instructions on putting it together and wiring it up are there.

As far as firmware is concerned, I have opened an issue about Repetier's "tower leveling" not working. Roland posted a couple of theories about what it might be, but has done nothing since as far as I'm aware. If you REALLY care about this, the best way to get it to happen would be to post in that GitHub issue asking for a status update and letting him know that you appreciate his work and would really like Repetier to fully support this feature.

There is also a fork of Marlin that has working bed probing for Rostock printers. I believe this is what the commercial (Kickstarter) printers are using. Marlin is not my first choice for firmware, but if you want something that Works Right Now, that would be it. I would like to give that a shot, but haven't had time yet.

I left Roland a comment but no one else seems to leaving any. Please members of this forum, leave Roland a comment as suggested by 626pilot, this is too important to ignore.
626pilot, I definitely would consider going to Marlin and I appreciate your work. The one from SeeMECNC seems so much simpler and less moving parts, it's also the one I see the
most of on the You Tube videos. Would you consider that one along with the one you designed when you get this operational. SeeMeCNC would produce a kit if they had the
firmware to make it work.

[geneb]

I feel like I'm on a tape loop here...

If your printer radius value is not perfect, no amount of "auto-level" is going work, even the fancy multi-point version in the Marlin firmware...

If your printer radius IS perfect, then there's no need for auto-level.

g.

[Nylocke]

You keep saying this Gene, but this is from Johan's blog,


Add the autolevel Z probe to your end effector. It will automatically calibrate before each print if you add G29 to your slicer prefix. This will detect the bowl shape and automatically correct it so that your print is completely parallel to the print surface, and the first layer thickness is always exactly right


Which seems to completely contradict what you are saying. I was under the impression you have spoken with him about it, and you seem to insist that he said something to contradict the statement on his blog. Maybe you know more about what he means when he said this, but that's just my impression.

[geneb]

I say it because it doesn't work. I've tried it on my own machine and the end result of the calibration renders the machine unusable until the calibration info is dumped. If memory serves, the issue was that it starts with a perfectly calibrated machine and introduces a huge convexity to the bed shape. This was from Johann's branch of the code as of about 2 months ago. I emailed him directly about it at the time and he couldn't be bothered to reply.

g.

[Nylocke]

That's interesting, though considering your experience with the rep version that works on the one guys machine but not yours , I'm not actually that surprised...

[lordbinky]

In the google groups they discuss this is more detail with occasional pretty pictures of the height data mapped and other various aspects as to the theoritical improvements, and so far it appears to be far from certain that auto-level is a good solution. What seems to be a better automatic calibration function is closer to an Auto-tower calibration, because any variations in tower distance from center and their 120° positioning make auto-level not fully work independent of delta_radius.

So from what I understand unless you're build is spot on or you changed your firmware to match your build (such as tower positioning) auto-level won't correct bed level errors and instead moves those errors to other mechanics which may or may not improve printing but either ways makes outcomes less predictable.

[Eaglezsoar]

In the google groups they discuss this is more detail with occasional pretty pictures of the height data mapped and other various aspects as to the theoritical improvements, and so far it appears to be far from certain that auto-level is a good solution. What seems to be a better automatic calibration function is closer to an Auto-tower calibration, because any variations in tower distance from center and their 120° positioning make auto-level not fully work independent of delta_radius.

So from what I understand unless you're build is spot on or you changed your firmware to match your build (such as tower positioning) auto-level won't correct bed level errors and instead moves those errors to other mechanics which may or may not improve printing but either ways makes outcomes less predictable.

This is exactly what GeneB has been saying. I guess my excitement over the prospects of getting auto-level is slowly disappearing. Thanks Lordbinky for shattering my dreams.