Temporary alternative for first layer issue?
 
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Tiago
(@tiago)
Reputable Member
Temporary alternative for first layer issue?

Hello,

Currently i'm too lazy to print anything because i have to ajust live z multiple times, cancel and reprint util it got perfect, as i print often in ABS i have to give aprox. -0.200 um at every new print (pinda at +/-80ºc at this stage), which cause a huge offset in the end, so i have to reset value and reset printer from prints to prints to get value back to the original. This is a big pain and i belive it will be fixed soon, but in meanwhile i want to temporary overcome this situation, so i have an ideia that i would like to ask if it will work without problems, which is:

1) Preheat bed to a value where pinda preheat to it's best value (i think is 40ºc?)
2) wait util pinda have 40ºc stable all the time
3) Print and set the best live Z for first layer
4) From this point forward slice all files without the (G80 ; mesh bed leveling) so it will not read values again and create that huge offsets, so its like a manual calibration that will be trusted and used every new print

Since i never move printer this can be a solution or can cause some problems? Are the values from "G80 ; mesh bed leveling" saved and used again if we do not run the command each print?

Posted : 26/03/2018 11:57 pm
Ewout
(@ewout)
Eminent Member
Re: Temporary alternative for first layer issue?

Interesting approach. I haven't printed with ABS yet, closest I'm getting is PETG. At 85 degrees C bed temperature I move the Z-axis up fully to minimize the heat the PINDA soaks up from the bed. I leave the bed to warm up for 10 minutes to let everything get to steady state temperature and bed offsets. When that is done I let the nozzle heat up by selecting the print. This minimizes the heat soaking of the probe.

I believe the temperature calibration offset of the pinda only starts at 30 degrees C and with PETG it stays below that during the bed probing. You can monitor the pinda temperature via the Support tab in the menu I think. Way down the list there is a temperatures option. I've been seeing fairly consistent results that way but keeping the probe cool is clearly more challenging with ABS. Most annoying thing is waiting for the printer to cool down fully before starting the next print.

Hopefully we'll see a solution soon. In the meanwhile I'll keep happily printing, then some waiting, and then more happy printing :mrgreen:

Posted : 27/03/2018 12:20 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Temporary alternative for first layer issue?

You could change your print start script, to calibrate PINDA at 60c (or whatever) then increase bed temp.

(Basically preheat print bed all the way after calibration)

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Posted : 27/03/2018 12:28 am
Tiago
(@tiago)
Reputable Member
Topic starter answered:
Re: Temporary alternative for first layer issue?


Interesting approach. I haven't printed with ABS yet, closest I'm getting is PETG. At 85 degrees C bed temperature I move the Z-axis up fully to minimize the heat the PINDA soaks up from the bed. I leave the bed to warm up for 10 minutes to let everything get to steady state temperature and bed offsets. When that is done I let the nozzle heat up by selecting the print. This minimizes the heat soaking of the probe.

I believe the temperature calibration offset of the pinda only starts at 30 degrees C and with PETG it stays below that during the bed probing. You can monitor the pinda temperature via the Support tab in the menu I think. Way down the list there is a temperatures option. I've been seeing fairly consistent results that way but keeping the probe cool is clearly more challenging with ABS. Most annoying thing is waiting for the printer to cool down fully before starting the next print.

Hopefully we'll see a solution soon. In the meanwhile I'll keep happily printing, then some waiting, and then more happy printing :mrgreen:

I see your point, still with 120ºc bed when pinda get near it will impact hard and the offset across bed will be large, so i'm doing the oposite, preheat with pinda near bed, that way when calibration start and end the pinda temperature is almost the same during the procedure. I print large objects and they come good as soon i get a good first layer

Posted : 27/03/2018 12:36 am
Tiago
(@tiago)
Reputable Member
Topic starter answered:
Re: Temporary alternative for first layer issue?


You could change your print start script, to calibrate PINDA at 60c (or whatever) then increase bed temp.

(Basically preheat print bed all the way after calibration)

Not in a automatic way, theres no gcode for wait for pinda temp...
Cold calibration will not work either, and sometimes the ambient temperature here is 10ºc

Posted : 27/03/2018 12:41 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Temporary alternative for first layer issue?



You could change your print start script, to calibrate PINDA at 60c (or whatever) then increase bed temp.

(Basically preheat print bed all the way after calibration)

Not in a automatic way, theres no gcode for wait for pinda temp...
Cold calibration will not work either, and sometimes the ambient temperature here is 10ºc

I mean do the mesh bed leveling at a SINGLE temp, REGARDLESS of what you are printing. That will provide consistency. You could also do the mesh bed leveling when it's cold... though I would be worried things might move between the two "times"

Heat nozzle
Level Bed
Heat print Bed.
That would provide extremely consistent results as long as you have climate control where your printer is. It would add a few minutes to your "pre-print" times though.

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Posted : 27/03/2018 5:24 am
stahlfabrik
(@stahlfabrik)
Honorable Member
Re: Temporary alternative for first layer issue?

Steps to take:

1. Try if the build in temperature calibration helps
2. Never start a print with a PINDA that is colder than 35C (That is lowest temperature the software CURRENTLY (March 2018) accounts for)
3. If 1. does not help, I would advise to do my proposed manual print based temperature calibration using my custom firmware. I completely resolved the issue for me...

You should set your Live adjust Z value when the PINDA has 35C.

Posted : 27/03/2018 10:49 am
Tiago
(@tiago)
Reputable Member
Topic starter answered:
Re: Temporary alternative for first layer issue?


Steps to take:

1. Try if the build in temperature calibration helps
2. Never start a print with a PINDA that is colder than 35C (That is lowest temperature the software CURRENTLY (March 2018) accounts for)
3. If 1. does not help, I would advise to do my proposed manual print based temperature calibration using my custom firmware. I completely resolved the issue for me...

You should set your Live adjust Z value when the PINDA has 35C.

I do not have any source of ambient regulator in my house, so ambient temperature is different all the time

1) does not help and they recommend to do it in a specific temperature range, which i can't right now
2) 35C is a limitation of the hardware or best sweet spot for a pinda reading in hardware terms? if no, are they to lazy to start at 0c?
3) i saw your firmware but i perfer to wait at least for the next official release and see if they fix

I have test my approach suggestion, but it don't work well, maybe because Auto Home will trigger different depending on temp too. But the result was the same at my 4 attemps, nozzle start print a bit high, even if i set live Z down and reprint without calibration same behavior happen. Was testing with ABS.

I will try to do as suggested, calibrate when pinda reach it best temperature and wait a bit more than the normal.

Thank you

Posted : 27/03/2018 5:27 pm
stahlfabrik
(@stahlfabrik)
Honorable Member
Re: Temporary alternative for first layer issue?



Steps to take:

1. Try if the build in temperature calibration helps
2. Never start a print with a PINDA that is colder than 35C (That is lowest temperature the software CURRENTLY (March 2018) accounts for)
3. If 1. does not help, I would advise to do my proposed manual print based temperature calibration using my custom firmware. I completely resolved the issue for me...

You should set your Live adjust Z value when the PINDA has 35C.

I do not have any source of ambient regulator in my house, so ambient temperature is different all the time

1) does not help and they recommend to do it in a specific temperature range, which i can't right now
2) 35C is a limitation of the hardware or best sweet spot for a pinda reading in hardware terms? if no, are they to lazy to start at 0c?
3) i saw your firmware but i perfer to wait at least for the next official release and see if they fix

I have test my approach suggestion, but it don't work well, maybe because Auto Home will trigger different depending on temp too. But the result was the same at my 4 attemps, nozzle start print a bit high, even if i set live Z down and reprint without calibration same behavior happen. Was testing with ABS.

I will try to do as suggested, calibrate when pinda reach it best temperature and wait a bit more than the normal.

Thank you

2) is a software limitation - implementation detail. The temperature compensation is defined in the range of 35 to 60C (Pinda temperature). Below 35C is not compensated (compensation is 0).

If you can start the print with always the same PINDA temperature you should be mostly fine as well:-) So yes, heating up the system, moving PINDA to always the same location and then wait until temperatures have evened out should work fine for a certain temperature. With different bed temperatures (and nozzle temperatures) your PINDA temperature that you achieve will be different though, so your live Z then might be different. But you could write down the values that work for you for each bed temperature. But that is really just a workaround that might not work too well after all:-) But it is better than nothing.

Posted : 27/03/2018 5:34 pm
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