Load cell probe on Ender 3? Bed leveling like a Cr6-Se

[@DrawModelPrint]

literally was planning on doing this to my ender 3 s1 glad to know Im not the only one that wants to do ridiculous things to their ender

[@FatNonsense]

This is great, I am looking at the Anycubic Vyper with envy and now I will try to upgrade my printers with this too. This is even better than the traditional touch probes as this really covers the whole bed, and there is no probe to nozzle offset. Thank you!

[@ArvinG]

Thats pretty cool.

[@agentl3r]

Lovely work

[@holz_ps]

Very cool build. Did you measure how large the threshold force is? I don't know how large this force usually is but if its too high the bed will still move a bit before the HX-711 triggers, even if you rigit mount your bed. Have you tried measuring how much the bed moves while probing on the edge?

[@yonggor]

Threshold force is very much depends on the machine setup. It's possible to set it to just a few grams (I use gram because I measure with kitchen scale), but vibration, z & x motion can trigger the endstop if the threshold is too small. On my Ender 3 it was about 20g, Anything I add or remove from the hotend will require me to recalibrate the threshold value. If the system works properly the bed doesn't move noticeably. But after 1 month of operation I noticed the ABL probing of far front-right point tends to fail. After a painful journey of diagnosting I found out it's due to both springiness of bed and unsupported x-gantry. It dampened the "impact" when nozzle touches the bed. When this happened the bed moves or the x-gantry gives in, all I have left is massive spike on ABL mesh and a sweet tune of printer halt. I eventually move away from load cell probe due to frustration of frequent recalibration.

[@ericbommer2280]

Just curious, are you still working on this. It seems to be the best solution for bed leveling. How difficult is it dealing with temperature drift. Great job.

[@yonggor]

I had ditched the strain gauge and went for the optical endstop for bed leveling, because of the better stability and very good accuracy. The temperature drift is basically unavoidable, so I designed my code to detect spikes instead of setting a static threshold.

[@Rozbujnik_Rumcajs]

@@yonggor are you talking about normal optical endstops mounted on frame (no abl), allan key type probe or something different? I was considering using load cell probe similar to yours in combination with stiff mounted bed.

[@yonggor]

@@Rozbujnik_Rumcajs the slot sensor optical endstop. Mount on the hotend. I forgot the exact design I used but might be this one: www.thingiverse.com/thing:3303618.