Pinda probe height simple question  

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GT390
(@gt390)
Active Member

In the manual it says

"Set value should not exceed -1 mm, if you have to adjust it more, move the probe slightly higher"

Does that mean in a negative or positive direction ?  my setting seems  good at -0.620 mm so I have "exceeded" -1 mm

or does it mean in a negative direction i.e. -2 would be exceeding -1  

What is a good figure to aim for so I can adjust the probe to get it as close as possible

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Posted : 08/04/2020 8:58 pm
joan.t
(@joantabb)
Veteran Member Moderator

There have been a number of different maximum values posted over the years, 
Whilst -1mm to -2mm  is now considered  acceptable I would try to get a smaller number because it gives you greater clearance for the PINDA, in the event of  the model warping. 
With the advent of interchangeable  build plates and different build plate surface materials, it is useful to have a bit extra LiveZ to play with,. 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 08/04/2020 11:07 pm
GT390
(@gt390)
Active Member

Thank-you Joan, when you say a smaller number than -1 to -2 what exactly do you mean, as per my original post I still don`t know what  direction (negative or positive /+ or - )   we are referring to, a smaller number than -2 for example would be  -3, and a bigger number would be -1,  or are we talking about a smaller number away from Z zero, in that case a smaller number than -2 would be -1.... sorry if I am being dumb here but the wording and the minus number thing has fried my brain.. are you saying I should be aiming for around -2.5 or should I aim for  -0.5. I guess what I am trying to ask is, the manual states don`t exceed -1 so would you say -1.01 is exceeding -1 or is -0.99 exceeding -1 ?

 

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Posted : 09/04/2020 1:01 am
Marty
(@mrschultz02)
Eminent Member

In this case when they say don't exceed -1 it's relative to zero, so don't go farther away from zero than -1.

You are good at -0.62, that puts the probe high enough away from the bed so it shouldn't bump into warped prints and not too far away that the nozzle might hit the bed.

If you want to understand what's happening I'll give some examples with made up numbers:

Say the probe triggers at 2mm above the bed, and you have the probe adjusted 1mm higher than the tip of the nozzle.  When the probe triggers and sets Z to zero the probe is 1mm above the bed, so to get the plastic extruded from the nozzle to squish correctly you'll need to dial in about -0.75mm to get the nozzle 0.25mm above the bed.

If the probe is too low you'll need a more negative number to get the nozzle close to the bed, if the probe triggers at 2mm and you end up needing close to -2mm to get good squish then the probe is going to be dragging on the prints. 

You also don't want too small a number because then the probe would be too high, so if you were near zero to get a good squish the probe is triggering when the nozzle is too close to the bed and it will probably do some damage.

Hope that helps make it clearer

 

 

Posted : 09/04/2020 5:12 am
GT390 liked
GT390
(@gt390)
Active Member

Thankyou mrshultz02, that has explained it perfectly to me

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Posted : 10/04/2020 12:04 am
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