If you do FDM 3D printing, you know one of the biggest problems is sensing the bed. Nearly all printers have some kind of bed probing now, and it makes printing much easier, but there are many different schemes for figuring out where the bed is relative to the head. [ModBot] had a Voron with a clicky probe but wanted to reclaim the space it used for other purposes. In the video, also linked below, he reviews the E3D PZ probe which is a piezoelectric washer, and the associated electronics to sense your nozzle crashing into your print bed.
There are many options, and it seems like each has its pros and cons. We do like solutions that actually figure out where the tip is so you don’t have to mess with offsets as you do with probes that measure from a probe tip instead of the print head.
Of course, there are other piezo probes we’ve seen. There are also many other kinds of sensors available. The version from E3D is available as a kit you can add to anything, assuming you can figure out how. Or you can do like [ModBot] did and opt for an E3D heatsink with the washer already in place which, presumably, will best fit E3D products.
From the printer’s point of view, the device looks like a normal end stop, so it is simple to configure the printer. There are other ways to sense a head crash, of course. We keep meaning to install one of the “real time” sensors you can get now, but our CR Touch works well enough that we never find the time.
Is this really an issue? My bed needs leveling every 50-100 prints and it takes 5 minutes max.
Are all these solutions really only for print farms? What’s the utility to the average user?
More importantly, the new drivers can detect crashes from the stepper motor current (no need for endstops), why doesn’t that work for the z axis yet? Has anyone implemented z axis stepper motor crash detection in marlin yet or is the accuracy too low?
It’s more important if you have a big bed for dealing with flatness issues, or if your printer has a flying gantry, like the voron 2.4 series, where the gantry does not remain trimmed after a power cycle.
Both are far better dealt with using Eddy current probes now in my opinion but the piezo is cool when it works. I used an early diy thing like this for a while but had a lot of failures.
I have a new machine where the bed is not metal and unheated. I wish there was something like a rolling ball which could scan the whole bed quicker than a clicky approach. I’d rather not drag the nozzle over the bed.
I’ve been printing since 2016 and until recently it would not have even occured to me that there could exist a printer without bed leveling. Hell I thought back in 2016 that automatic skew correction was absolutely standard since even cheap DIYskque MK2 had it!!
It seems to completely absurd even now to not have automatic bed leveling.
All my printers are manual levelling only (though they are very old now, and somewhat showing it I have no reason to replace ’em just yet). The only thing manual levelling can cause issue with on a well built machine with a flat enough surface is the heated bed temperature variations can mean the position shifts a little between materials. But if you only print in one or two plastics that want similar bed temperature you just level the bed warm (carefully) should levelling it while cold not give good enough results.
What you are referring to us called “sensorless homing” and it is quiet imprecise – for x/y it is good enough but is not good enough for Z. The stall detection is really just that – it detects stalls – it was never designed to be precise, just to prevent destruction.
Adding to the stall detection thing – it detects missed steps, and it is really hard to miss steps on a leadscrew setup. Maybe if you use 8mm TR8’s belted to one motor you will stall it, but it will push like crazy before actually stalling. Your nozzle and associated gantry would be lifted at least a millimeter unless it was made with steel beams and linear rails, so it would not give any practical reading.
In my case, I change the nozzles every few prints, because the fine details i use 0.2mm, normal prints 0.4mm, small prototypes for test assembly and tolerance is 0.6mm and fast large prints in 0.8mm. For me bed leveling is a regular routine.
What value do you place on your time? At some point, separate print heads for each nozzle size or even separate printers become more economical than constantly changing nozzles and re-leveling.
The utility to the average user is huge. As they are just that – they are average folks with little engineering background, the average somewhat clueless user, and often with the cheapest ready to run printer that they expect to work reliably.
Of course it’s not really an issue. We all know everyone has the exact same 3D printer. /S ::facepalm::
Been using piezo on my print head for years after too many issues with other bed sensing solutions.
Now using it as Z endstop and “rough” leveling (3 points define a plane) followed by eddy currrent probing.
I like to tinker and experiment ( too much) but for z control and bed leveling I’m set!
But it’s the third of the price of an Ender3..
Where are the cheap chinese copies?
It’s odd bed levelling is still such an issue.
I switched mine to rigid connections and leveled it once and for all. All I do is adjust the height when I switch nozzle.
After that I got a few more missed steps occurrences. I fixed that with closed loop motor control.
I built a piezo based under bed sensor for my delta. Works extremely well. I run a bed mesh probing routine on every print, since the magnetic build plate i use gets put back slightly different every time.