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Check Z-height before loading filament  

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alexis.r
(@alexis-r)
Active Member
Check Z-height before loading filament

Hi,
Sometimes I forget to raise the head before loading filament and it can be bad (especially if your head was left way too close to the bed).
If I remember correctly even Josef Prusa made the mistake in his explanatory youtube video (then he explained how to manually move the head).

So I suggest the following improvement for the next firmware : move the head up automatically or refuse to start loading filament if Z if less than 1cm to the bed.

My 2 cents.
Cheers,
Alexis

Posted : 29/03/2017 7:11 pm
Knickohr
(@knickohr)
Member Moderator
Re: Check Z-height before loading filament

1cm ?

Make 5, better 10 and we are friends 😉

By the way, is it possible to move extruder at least to 10cm absolute after a print ?

Thomas

Posted : 29/03/2017 9:04 pm
maxx78
(@maxx78)
Estimable Member
Re: Check Z-height before loading filament

...

By the way, is it possible to move extruder al least to 10cm absolute after a print ?

Thomas

why absolute ? wouldn't 100mm relative better ? it will always be abvoe the finished print.

Posted : 30/03/2017 10:21 am
Knickohr
(@knickohr)
Member Moderator
Re: Check Z-height before loading filament

Hmm, you printing an object like 150mm tall and move extruder additional 100mm ? 😉 😮

So, my idea is to move extruder at least 100mm absolute, but don't move extruder if object is taller than 100mm.

This has enough distance from bed to extruder for cleaning the oozing and stringing.

Yes correct, an small move of, say 10mm, from the object is good. But the same problem. You printing an object with 200mm and move extruder additional 10mm ? 😯

Thomas

Posted : 30/03/2017 10:54 am
maxx78
(@maxx78)
Estimable Member
Re: Check Z-height before loading filament

Hmm, you printing an object like 150mm tall and move extruder additional 100mm ?
Thomas

Why not ? the firmware stops the printer at 200mm (or 210 ?), at least i think it does but i have to check.
If you move the z axis via the menu it stops at 210mm

Posted : 30/03/2017 2:48 pm
Knickohr
(@knickohr)
Member Moderator
Re: Check Z-height before loading filament

Did it really stop ?

I test it. It's going up to the top and rattling. So it doesn't stop 🙁

Yes, in the menu it stops at 210, but only the value in on the LCD.

Thomas

Posted : 30/03/2017 3:57 pm
richard.l
(@richard-l)
Member Moderator
Re: Check Z-height before loading filament

If I turn my printer off and then back on it has no idea where z is. It assumes it is at 0 so if I have parked my extruder at the top (210) then go to load filament and it is forced to move 10mm up it will grind at the top for some time before stopping. Not ideal. You are already in the menu to load filament, why not just move the z-axis while you are there. Simple.

Posted : 30/03/2017 4:02 pm
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Check Z-height before loading filament

The latest firmware (MM Beta) will only move the Z axis up if it is lower than 20mm.

The MAX_Z within firmware, is 210, so the movement will stop at that point, but it will rattle the physical end stops for about 5mm.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 31/03/2017 9:31 am
maxx78
(@maxx78)
Estimable Member
Re: Check Z-height before loading filament

Did it really stop ?

I test it. It's going up to the top and rattling. So it doesn't stop 🙁

Yes, in the menu it stops at 210, but only the value in on the LCD.

Thomas

Ah, ok than i am wrong. 🙁 I expected the firmware to be smart...

Posted : 31/03/2017 9:54 am
JLTX
 JLTX
(@jltx)
Reputable Member
Re: Check Z-height before loading filament

It is simple to add post-gcode in slic3r to do simple uplift after print is done.

If you want fancier (absulte placement) you can hook in a post-process script from slic3r to find last Z and adjust accordingly. Simple Perl script. Done things like this many times.

-- Jon

Posted : 08/04/2017 5:44 pm
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