Zero offset Z sensor

I've been working on getting automatic bed levelling working on my two deltas for a while, and wasn't happy with all the current solutions out there.

Here is my solution.



The biggest plus about this design is that It has zero offset from the nozzle, so that any effector tilt doesn't affect the readings.

Other pluses include:
* Works with any bed surface with no preparation required
* Automatic deployment and retraction
* Repeatability of around 0.01mm
* Cheap and easy to obtain parts

More details here:
[www.thingiverse.com]

Let me know what you think. It's certainly working well for me on both my printers.

Edited 1 time(s). Last edit at 04/25/2016 01:26AM by nebbian.

Thanks for sharing. It looks promising.
I think the servo motor is optional feature to lazy user like me.
I used to run level probe during calibration stage.

Three optical endstops and one optical level probe I'll order soon.

Nicely done, sir! I especially like the fact that the retraction servo mechanism *should* not influence the accuracy. That was a drawback in other servo-based designs up to now.

Can you show how it's mount to the effector? Is it a standard Kossel effector? Thanks!

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docpayce
Nicely done, sir! I especially like the fact that the retraction servo mechanism *should* not influence the accuracy. That was a drawback in other servo-based designs up to now.

Can you show how it's mount to the effector? Is it a standard Kossel effector? Thanks!

Thank you very much

The retraction servo doesn't affect accuracy, it only retracts the sensor when you're done. Even the position of the screw doesn't affect the accuracy, it's all down to the length of the spoke.

I've updated the Thingiverse entry with a picture of how it's mounted, and here are pics from both my deltas showing how it works.

It's been working perfectly since I've installed it on both machines. I wouldn't print without it now.



This one is an aluminium effector from RobotDigg, with a pre-drilled and tapped 3mm thread in it. I just used the existing hole.



This one is a self-printed PLA effector. I drilled a small hole in the effector, and used a self-tapping screw.

Edited 1 time(s). Last edit at 04/28/2016 10:09AM by nebbian.

Very nice. It looks like it is hanging which is great. The way you orient it is very clever too.