live z adjustment requiring -1.550 is that normal? and what can be done to fix?  

Re: live z adjustment requiring -1.550 is that normal?

Everything I read it should be when set properly be close to -.500.

Re: live z adjustment requiring -1.550 is that normal?

No, -1,550 is not normal. You need to lower the PINDA sensor.
Screw it down 0.75 to 1 turn and then calibrate XYZ again.
If you try to calibrate the printer without lowering the PINDA sensor, there is a risk of the nozzle being scratched in the heating bed.
The bottom of the PINDA sensor should be 0.6 to 1 mm higher than the tip of the nozzle.

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

-1.550 is not normal. It means that your PINDAprobe is to close to the heatbed.

I disaagree with RHDreambox. Your pinda needs to go up by one thread.

If you try to screw the pinda up that far. You will strain the cable. Instead remove the clamp screw almost all of the way. And then push the probe up one click. Then tighten the clamp screw again
NOTE... ADJUST LIVE Z TO ZERO. BEFORE RE RUNNING YOUR LIVE Z ADJUSTMENT G CODE.

LIFTING THE PINDA WILL RESULT IN THE EXTURDER BEING CLOSER TO THE HEAT BED.

if your current filament layer is 0.2mm. And you only adjust your pinda. The printer will try to dig the Nozzle 0.8mm into the heatbed...

Which will be upsetting.

Regards Joan

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

Joan’s words +1 and do xyz calibration again

Ne sure the nozzle does NOT CATCH THE PAPER. happens when pinda is to heigh.

Read chapter preflight of the build manual again

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

Of course you're right Joan.
It's a little confusing with negative numbers, one has to think inverted 😳 😀

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

I've been running at -1.65 for several weeks now and it seems to work well. When I tried to calibrate with the PINDA up one notch it repeatedly failed to calibrate.

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

On my original (black cable) pinda, I could get 0.7-0.8 to work great.

When my replacement grey pinda turned up, I can only get around 1.2, trying any improvement (using feeler gauges) means I can't pass calibration.

So: I don't really know if the pindas are different now, but it works fine so I'm leaving it alone 😀

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

hi art.p, look at this http://manual.prusa3d.com/Guide/9.+Preflight+check/514?lang=en on step 3

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

I've been concerned about the acceptable range for live z. The guide for new users video shows an example with -1.100 as "good", but the 3D Printing Handbook (V3.01, V3.02) says "set value should not exceed -1mm. If you have to adjust it more, move the probe slightly higher." (Bold in the original)

If larger than -1.000 values are OK, it would be nice if the documentation gets updated.

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

Hi Luther,

We need to define 'Ok'

if Ok, is, it works fine when everything else it working properly, then I expect -1.1mm is OK...

I have personally had my mk3 at -1.300 and nothing untoward happenned... however I was concerned that the Pinda was not much higher than the nozzle. If my print lifted, I may get a collision with the pinda
so I adjusted the Pinda up, and the current print is running at live Z -.440mm, this gives me greater distance between model and pinda...
so if I get a bit of lifting, I will not get a pinda colision...

to a great degree, it's Your decision.

are you feeling Lucky?

on the early mk2, the pinda mount was less sturdy, a pinda collision, could break the mount off... and acetone or cyano acrylate adhesive could put it back again...

on the later Mk2 and Mk3, the mount is more robust. and there have been reports of the end of the pinda being knocked off... this requires a new Pinda

Regards Joan

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

I run mine at around -1.1, i did this on purpose to raise the nozzle during z calibration. I was having issues with my nozzle oozing, and sticking to the heat bed during calibration. I lowered the nozzle a touch. (Still around .5mm clearance from printed parts) so i feel safe with that.

I also to help prevent my oozing issue, i turn the cooling fan on, when nozzle hits 170c(before calibration happens) and turn it off before the extrusion line.

Using good filament, its nearly perfect. (Zero oozing) and with cheap filament, slight oozing, but it won't stick during calibration due to height and fan.

3 pieces of paper is roughly 0.3mm that is a bit close. I'm not sure how high I am exactly, but I would worry about crashes from warping that close!

Re: live z adjustment requiring -1.550 is that normal? and what can be done to fix?

I discovered I had a slight partial clog that wasn't obvious. Because of that, it took a much more negative value to get an appropriate squish when setting live z. 😀