What is your experience with springs for adjusting the bed leveling and for head crashes and all that. Are they really necessary? What is the best approach for bed leveling and connecting the bed to the support plate? nuts below the printbed for adjusting height or springs pushing the printbed?
Springs pushing the bed upwards, nuts on bottom. Easy to adjust height with an Allen key. Works well for me, and I find the adjustability very useful.
Definitely prefer springs pushing up on plate.
What about the cushioning effect of springs does it do any service? As far as I see it the springs are always pretty tensioned to reduce vibrations/wobble so the cushioning effect is kind of negated by that tension.
Well yeah, the spring should be strong enough that the bed isn’t really movable up and down. That would defeat the purpose; you want some adjustment in the screws to get it level, but beyond that it should be solid.
As for helping with head crashes, I’d say the more appropriate course of action is to just make sure they don’t happen. Unless your Z endstop is broken or grossly maladjusted, the nozzle should never be able to get low enough to hit the bed.
Z Motor just shouldn be strong enough to kill it. Havent got springs…
@VolksTrieb Leveling can be done without springs, with just bolts and nuts, but no bolts at all means your bed is really level from the start … that’s a nice thing to achieve. Any link to your setup?
Ups ive ment springs ^^
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Well the interesting thing about springs under the bed is how you square the X/Z axis to each other if you have dual z motors…
I use silicone vacuum tubing and pull the bed down onto the tubing. They can’t chafe the epoxy and cause shorts like springs and can.
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Springs can introduce extra overshoot artifacts if you have a moving bed (along the Y-axis). My suggestion would be to make it rigid and to simply take some care not to crash the nozzle into it
@Thomas_Sanladerer My Z is designed on Z but I agree with no springs and simply nuts adjustments for 3-point leveling.
@VolksTrieb thanks for the pic that looks like quite a heavy bed stack, can’t the bed support be lighter -thinner alu plate or milled to some shape that takes much of the mass away?
@Jim_Christiansen those silicone footings are nice, I’ve seen it before but they act just like springs and are meant to replace them not sure though of any advantages…
Hi @Florian_Ford . I was worried about the silicon compressing under load, too. I cut them to about 7 mm in length then compress them to 4 mm. This is thick walled automotive tubing. Under load, the Y shaft stock deflects easily before the silicon in its compressed state. I actually chose to use the tubing so my student’s many printers each had 4 fewer places to short out. Our aluminium heated bed have traces that run right up to the mounting holes and I was very concerned about student printers shorting out at their homes!