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3 Stepper Z Leveling (NOT just calibration!)

Posted: Thu Jan 18, 2018 3:45 pm
by kraegar
Z bed leveling using 3 independent Z-steppers / leadscrews has now been implemented and tested, to actually level the bed in Z. Thanks to David for implementing this in firmware - it's one of the coolest features to use.

There's some minor refinement to do with the system, but so far it's working very very well.

Once the final few tweaks have been made, we'll publish the BOM for this - is will be an option to the build, not a requirement. It will require a duex2 or duex5, a third Z tower (using Tr8*4 leadscrews for all 3 z towers) and an alteration to the Z-Yokes, bed carrier, and bottom panel.

Here are the results from one of my runs of leveling today.

Leadscrew adjustments made: -0.106 -0.088 0.102, points used 3, deviation before 0.062 after 0.000
Leadscrew adjustments made: -0.076 -0.003 0.014, points used 3, deviation before 0.034 after 0.000
Leadscrew adjustments made: -0.036 -0.003 0.015, points used 3, deviation before 0.016 after 0.000
Leadscrew adjustments made: -0.010 -0.002 0.016, points used 3, deviation before 0.007 after 0.000


Image

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Thu Jan 18, 2018 7:26 pm
by kraegar
Details on what's being done are here: https://www.duet3d.com/wiki/Bed_levelli ... t_Z_motors

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Fri Jan 19, 2018 7:42 am
by DeltaCon
That is really interesting!

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Fri Jan 19, 2018 8:26 am
by kraegar
It's one of the cooler things I've implemented on a 3d printer. To actually physically dial in your bed using software, to a level you can't by hand, is really cool. It's levelling the bed faster than I could by hand, and to greater precision. In the end, I don't think it'll make an overwhelming impact on print quality, but I should get great first layers and nice square prints every time now!

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Wed Feb 07, 2018 11:24 am
by RanchRifle
I am stupidly excited about the possibility of building one of these with the 300mm build plate! Should be a bit of a step up from my poor little Monoprice Maker Select (Wanhao Duplicator I3).

Have you found any difficulty keeping all of the motor synchronized?

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Thu Feb 08, 2018 7:47 am
by kraegar
None at all - you power on, level once. If it was close (almost always is if you haven't messed with it by spinning a leadscrew.... because you like to watch it re-level) print. I don't even always bother to level before a print.

The design for the 300 will be done in the next day or two. The ZL version of it will take a couple days longer. There's a slight bit of work needed on the BOM for it, and some minor updates to the assembly guide for the 250 to make it work for the 300.

We're calling the 300 a "beta" until a couple have been built and verified, but it should go together just as well as the 250 did.

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Fri Feb 09, 2018 10:59 am
by RanchRifle
Incredible. I just may have to be one of your beta testers. :)

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Tue Feb 13, 2018 10:40 am
by kraegar
RanchRifle wrote:Incredible. I just may have to be one of your beta testers. :)


You're welcome to - the 300 standard build is complete in f360, touching up the BOM now. Next up is the documentation, then the ZL in F360.

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Thu Feb 15, 2018 6:09 pm
by BikingViking
Thanks for all this, found you on the duet forum, I'm not actually building a Railcore per se, but picking and choosing and modifying your models to convert my TronXY X5S into something that isn't garbage.
I'd already bought linear rails, but I now have to wait for a few more because my basic human needs now include three point mechanical levelling.
Currently designing the top enclosure and filament spool enclosure to go on top, I've got carbon filters and 200mm fans to go on the sides. Even if I'm printing something that doesn't like airflow, I can have an ending gcode script that rams all the air inside through the filters before opening the doors.
For the sides I'll be using aluminium dibond sheets because I think the air cavities insides will provide some insulation for the chamber.

My thought is to enclose the pulleys and belt above the xy steppers in clear acrylic boxes open to the inner enclosure so I can see them moving while still having the body of the stepper outside to keep it cool. If necessary I have suitable heatsinks to attach to the motors for further cooling. I bought 10 40x40mm plus same size thermal adhesive for a stupidly low price.

I'm still not sure about how to copy your bed, ideally I'd have some tooling plate cnced, but cashflow is now limited. I have a load of 4mm aluminium sheet and a router table, so may go that way for now with a 460watt silicone heater and vermiculite insulation. Will post all my mods with attribution when done. Keep up the good work!

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Tue Feb 20, 2018 12:52 am
by cluelessmaker
Do you think that with the 3-Z-stepper leveling, the manual bed-leveling screws are even a necessary design feature any more?

(BTW, I've been poking through your Fusion files, they've been a huge help for a novice trying to figure out how the pieces fit together, so thanks a ton for making them available.)

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Tue Feb 20, 2018 7:37 am
by RanchRifle
cluelessmaker wrote:Do you think that with the 3-Z-stepper leveling, the manual bed-leveling screws are even a necessary design feature any more?

(BTW, I've been poking through your Fusion files, they've been a huge help for a novice trying to figure out how the pieces fit together, so thanks a ton for making them available.)


While you are looking at the fusion 360 model for the version with z leveling, you may notice that there is no bed carrier nor are there any adjustment screws there.

Looks pretty neat to me. ;)

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Tue Feb 20, 2018 2:05 pm
by kraegar
My printer has no method to manually level anything. It levels itself, and very well.

https://imgur.com/xUhAayR

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Tue Feb 20, 2018 2:40 pm
by RanchRifle
kraegar wrote:My printer has no method to manually level anything. It levels itself, and very well.

https://imgur.com/xUhAayR


That is really quite impressive. Once the files are posted for the 300mm zl version, I will be one of the first to start working on it. Sadly, the rate at which I work on things, you will be playing with the RailCore XIV by the time I finish.... :oops:

Re: 3 Stepper Z Leveling (NOT just calibration!)

Posted: Thu Feb 22, 2018 11:09 am
by kraegar
The BOM is out, but parts of it may change slightly. A 250 ZL bed is on its way to me now, and I need to verify things before we fully "release" either ZL version.

That said, I don't see it changing much - just need to verify the bed attachment to the yokes, and do some stress testing.