Bits of String from initial calibration at start of any model
Hi all
Am new to this, having just built our first printer. The prusa is fab at what it prints (only 3 models as of yet) but when the printer does the calibration (not the XYZ) before it starts to print, it leaves PLA on the print bed. Its not much, just a dot or a squiggle, but one is always int he centre of the print bed. I kinda of sit there with a tissue and remove them currently but am thinking I may need to adjust something.. just not sure what.
One thing on the build, I found the X carriage piece to have an issue, I set it up three times as per the manual, but as soon as I put any tension on the belt, the belt would slip through and loosen. It did it on one side (the right) so gently held this as I tried again and this time did it on the left. I never had this issue on the Bed belt holder, so suspect that the tolerances of the gap in this piece are out somehow? I used a small pvc of Plastic packaging (the hard stuff that is use around batteries and such like) folder over and then pushed in under the belt at the point where it exits on both sides of the Carriage piece. This allowed me to tension without an issue, and has held up so far but suspect that I should replace this piece, or maybe contact support for a replacement and to inform them in case they have an issue in production somewhere????
Thanks in advance for any help
Nick
Re: Bits of String from initial calibration at start of any model
Hi all
Am new to this, having just built our first printer. The prusa is fab at what it prints (only 3 models as of yet) but when the printer does the calibration (not the XYZ) before it starts to print, it leaves PLA on the print bed. Its not much, just a dot or a squiggle, but one is always int he centre of the print bed. I kinda of sit there with a tissue and remove them currently but am thinking I may need to adjust something.. just not sure what.
This is normal. You can reduce it a bit by lowering temperature a few degrees, but you don't want the probing to be done with a cold nozzle. Maybe if you are at 215C, lower to 210C and see if the leakage is reduced.
Me -- I just live with it. I'm at the printer to make sure the first few levels of all my prints look good anyway.
Re: Bits of String from initial calibration at start of any model
Thanks for this, I expected as much. Not sure if it could be done, (only printed 4 things so far) but if the initial calibration came between the heating of the bed and the Hot end, then it wouldn't happen at all. Am sure there is a good reason it cannot happen in that order though.
Re: Bits of String from initial calibration at start of any model
Not sure if it could be done, (only printed 4 things so far) but if the initial calibration came between the heating of the bed and the Hot end, then it wouldn't happen at all. Am sure there is a good reason it cannot happen in that order though.
My understanding is that the hot-end needs to be hot before calibration to ensure no hard filament is stuck to the nozzle (from the slow leakage after the previous print) which would negatively impact the Mesh Bed calibration.
Re: Bits of String from initial calibration at start of any model
FWIW, here's an extract from my start GCode:
G21 ; [mm] mode
M140 S<BED+5> ; Heat the bed + 5 degrees for Mk2
M104 S170 ; Warm it up to calib temp
G28 W ; Home all (no calibration)
M109 S170 ; Warm it up to calib temp, and wait till it's warm
G80 ; mesh bed levelling
M109 S<TEMP> ; Warm it up to print temp, and wait till it's warm
M83 ; Relative extruder
G1 Y-3.0 X50.0 F1000.0 ; go outside print area
G1 X100.0 E5 F1000.0 ; intro line
G1 E-0.5 Z2 F1000 ; Retract a bit and lift nozzle
G92 E0.0 ; Zero extruder
As you can see, I preheat the nozzle to 170 degrees for the 9-point calibration and then heat to printing temp to print the startup line and then the print.
I mainly use PLA so I do not wait for the bed to warm (usually run the bed at 60 degrees); the bed will heat from cold to the required temp while everything else is happening.
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…
Re: Bits of String from initial calibration at start of any model
Peter,
Interesting script, i like this idea. One question if I may:
M140 S<BED+5> ; Heat the bed + 5 degrees for Mk2
Why the +5 at this point?
Thanks!
Re: Bits of String from initial calibration at start of any model
Why the +5 at this point?
Because the bed temp is a material setting (in KISS) and for PLA I use 55 degrees for the Mk1 and 60 degrees for the Mk2. Being the Mk2 profile start GCode, I add the extra 5 degrees there.
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…