Precision Piezo v1.2



  • @hevilp glad you figured it out. The piezo reliability really depends on the carriage design. I never found one that fit my needs and so my piezo kit sits unused.



  • @3dmntbighker I'm not sure what your bed surface is or how it's mounted but that looks like it's bowed a bit. If it were more uniform I would say maybe it's a mechanical issue on the y axis. If you lay a straight edge ruler across the bed can you tell there is a bow to the bed? At any rate the bed compensation should be able to take care of it.



  • The "bow" in your bed may be caused by deflection of the bed when the contact point is far from the Z axis screws. This is something I've seen on my TronXY X5s, it was greatly improved when I changed the plastic Z bearing mounts to metal ones but I haven't been able to eliminate it completely yet.

    Idris (Precision Piezo)



  • @phaedrux I have a quarter inch 300 x 300 MIC6 aluminum plate with a 1mm PEI sheet attached with 3M adhesive. And it's 3 point spring supported over 2020. Checking with a business card the center definitely has less clearance than the edges. It seems like the plate is less flat since using 100C bed print temps. Which is odd with this kind of plate material.



  • How did you mount the 3 point support? If there is no clearance to allow expansion, something will give up. How thick is your plate?



  • @sigxcpu Plate is 0.25 inch thick MIC6 machined fixture plate. It sits on 5mm screws with springs and ABS mounts. Pretty sure there is enough give for expansion. The support frame is 2020/2040 with PETG lead screw mounts. It's very solid.



  • I found that the easiest way to check whether the bed was bowed or flexing about the leadscrews was to remove the plate and rotate it 90 degrees. If your readings now show a bow in the other direction then the bed itself is bowed, if the bow still appears to be in the same direction then the bed itself is moving.

    Idris



  • @Moriquendi

    how does the "new" solution look like?



  • @moriquendi The next thing I plan to do is remove my PEI sheet. This will be a massive pain getting all the 3M adhesive off. Then run a probe on the bare aluminum. I'm going to try using my new PEI sheet with clips but I'm afraid I won't get the heat transfer I want. Ultimately I want a removable spring steel "Prusa-esk" sheet with PEI coating. Or at least some for of removable springy build sheet.


  • administrators

    @3dmntbighker if you want to try probing bate alu without removing the sheet can you turn the bed over as a test?



  • I can't rotate or flip over. I have a heater stuck to the bottom with the wires on one end. I got the PEI off last night and used about half a bottle of 91% Isopropyl so far trying to get the glue off. When I went to re-probe I found that the cheap Chinese wire I used for the Piezo probe has a break somewhere. So the nozzle crashed into the bed. Until I can get some decent wire and rebuild my gantry cable I'm dead in the water.



  • @hevilp It's like the Orion but instead of having the filament pass through the PCB it's designed to mount between two parts ( eg the extruder and the carriage), similar in concept to your carriage but more integrated.

    Idris



  • Here is the bare aluminum plate probe run. And BTW, I never put the M375 in config.g until yesterday. Doe!!!!!

    0_1534620887439_Screen Shot 2018-08-15 at 10.23.45 PM.png



  • Here is my latest probe run after thoroughly cleaning the glue off of the plate and doing 2 probes per point with bed at 70c and hot end at 180. I also increased the trigger threshold to 600 so it hits slightly harder. And it now has a stiffer Piezo upper mount I printed in Taulman 910. My BuildTak magnet system will be here tomorrow. I ordered an extra steel plate so I can have a Buildtak and a PEI option. At this point I won't be attempting to make the plate any flatter than it is.

    edit:

    I did a calibration print for square, and it appears I'm good other than a fraction of a degree off 90 degrees Z to Y. So my Z uprights are not quite vertical.

    0_1535686955327_Screen Shot 2018-08-30 at 8.30.21 PM.png


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