Different first layer results every new print  

Re: Different first layer results every new print

I have the exact same issue. I have no idea what could possibly keep changing where the first layers are not consistent. By the time I get to the 3rd or 4th print the line appears to be separated and I have to recalibrate.

Re: Different first layer results every new print

I have the exact same issue. I have no idea what could possibly keep changing where the first layers are not consistent. By the time I get to the 3rd or 4th print the line appears to be separated and I have to recalibrate.

Exactly like me...
Second layer comes out much better but first is inconsistent...
I have tried many calibrations, the result is always the same

Re: Different first layer results every new print

I experienced the same thing when I changed from PLA to PETG.
The first prints I had to cancel because they became so bad.

But I discovered that if the bed had been heated for a while, the prints were perfect.
Every day, when I boot up the printer, I activate "Preheat PET" for 10 minutes and let it warm up the printer while I prepare my prints.
So my advice is to calibrate the first layer when the machine is properly heated, and also start printing with a heated machine.

Re: Different first layer results every new print

I experienced the same thing when I changed from PLA to PETG.
The first prints I had to cancel because they became so bad.

But I discovered that if the bed had been heated for a while, the prints were perfect.
Every day, when I boot up the printer, I activate "Preheat PET" for 10 minutes and let it warm up the printer while I prepare my prints.
So my advice is to calibrate the first layer when the machine is properly heated, and also start printing with a heated machine.

This is very plausible, since the PINDA is temperature-sensitive. That's why the PINDA has an embedded thermometer, so the printer can correct for temperature effects. But if the printer is warming up, the PINDA temperature readout might be a little different from the actual temperature.

In my experience, PETG is more sensitive to the first layer height than PLA (actually PETG is more sensitive in general to getting the settings exactly right), so it would make sense that this would be more of a problem with PETG than PLA.

Re: Different first layer results every new print

Hi,
I had the same issues for five days of continual printing and tweaking to get my first layer correct. I have been all over the spectrum with Live-Z, readjusted the PINDA, recalibrated what seems like 1,000 times and still had issues in the same locations in every print. Same locations during single layer test prints from Thingiverse. So no matter what I did with LIVE-Z it was always the same problems.

I moved the LIVE-Z to where I thought it should be and then started tweaking my setting in Simpllify 3D (S3D). What has worked for me in S3D is the following:

I am using these settings with MakerGeeks Raptor PLA. Other PLA types are going to print differently so they will need their own tweaking.

I dropped the default First Layer Height (on the layer tab) from the 150% default to 90% for a .20 mm primary layer height.
I drop this to 75% when I print at .15
I run a 235 degree temp for my first layer, no fan.
I drop the temp to 230 with a 70% starting on layer 2.

My LIVE-Z is now at -.600 for this PLA type at .20 mm.
My LIVE-Z is near -.650 when I print at .15.

I don't know if any of this can help you but I can definitely feel your frustration. I was ready to throw this thing across the room.
Good luck to you.

Re: Different first layer results every new print

Thank you for all the information.
My ambient temperature this days are 9ºc to 14ºc. What i found best is to heat up the printer with the head near the bed, if too high from bed the result will vary a lot, i will keep testing but for now i'm heating up at auto home height, so pinda have time to stable and not be chocked when it get into pre-print calibration.
I also found easier to ajust the Live-Z based on the second or next layers than in the first, because first comes out a bit random, and at the second i can cath what going on.
I will keep inform of my tries.
Regards

Re: Different first layer results every new print

Z-live is only intended for the first layer.
If the first layer is not properly calibrated, it affects the quality of the next layer.

I use a 75x75 mm one layer rectangle for calibration. Then you have plenty of time to make adjustments.
The square I divide into 4 calibration zones that I can compare, for example. -625, -630, -635 and -640.
I run the calibration several times until I have found the optimal Z setting (here -560).

Re: Different first layer results every new print

I also have this problem. And it drives me insane.

I thought it was a hardware problem, so Prusa Support send me a replacement PINDA probe. This did not solve the problem at all. With Prusa Support I then arranged a replacement of my MK3. The new kit arrived and - believe it or not - has the same problem.

So my conclusion so far for this problem is: Obviously not all MK3s behave this way, so the chance of getting one with this problem is low. Yet - I got a replacement which behaves exactly the same way - so was this VERY bad luck or is there another problem?

My guess is that there is a bug in the software which uses the new PINDA probe with thermistor. I really hope the developers will look into this more to catch that bug!

For me, when printer is cold, the layer is to high, when it gets hot, the layer is to low.

Guys, do you use an E3D sock on your machine? I do and have yet to try if this thing is the root cause (I must confess I do not understand why it should be the problem, but there HAS to be reason)

Re: Different first layer results every new print

Thank you for all the information.
My ambient temperature this days are 9ºc to 14ºc. What i found best is to heat up the printer with the head near the bed, if too high from bed the result will vary a lot, i will keep testing but for now i'm heating up at auto home height, so pinda have time to stable and not be chocked when it get into pre-print calibration.
I also found easier to ajust the Live-Z based on the second or next layers than in the first, because first comes out a bit random, and at the second i can cath what going on.
I will keep inform of my tries.
Regards

I think in MK2 there is an option to preheat PINDA before every print. The MK3 PINDA with thermistor should make exactly this unnecessary. But since the MK3 seems so very much temperature sensitive for us suggests that there must be a bug in the firmware which handles the new PINDA. What I do not understand is why the bug does not trigger for everybody. Is it a mechanical issue that only some kit builders run into? Or is it the position of the stepper motors on Z relative to each other? Maybe it is the trinamic drivers? But then why is temperature such an huge influence?

Re: Different first layer results every new print

I also have this problem. And it drives me insane.

I thought it was a hardware problem, so Prusa Support send me a replacement PINDA probe. This did not solve the problem at all. With Prusa Support I then arranged a replacement of my MK3. The new kit arrived and - believe it or not - has the same problem.

So my conclusion so far for this problem is: Obviously not all MK3s behave this way, so the chance of getting one with this problem is low. Yet - I got a replacement which behaves exactly the same way - so was this VERY bad luck or is there another problem?

My guess is that there is a bug in the software which uses the new PINDA probe with thermistor. I really hope the developers will look into this more to catch that bug!

For me, when printer is cold, the layer is to high, when it gets hot, the layer is to low.

Guys, do you use an E3D sock on your machine? I do and have yet to try if this thing is the root cause (I must confess I do not understand why it should be the problem, but there HAS to be reason)

I use a sock, tied with a zippy for best performance and security, i can assure you, that will not solve your problem 😀 But will help prints.
I have ajusted Z during a live print and it work best for me, since then i just print and ignore and everything comes out great. What i have learn is even if first layer don't looks great the second layer will glue and solve that, with correct Live Z set just print and forget 😉 At least my prints are coming great now.
So my advice adjust live Z based on second layer if you unable to do with the first, find the perfect second layer and forget the first, it work to me

Re: Different first layer results every new print

I had very similar looking issues with my first layer at the start. In one print it would be perfect, and in the next it would have small raised patches that looked like your pictures. When it happened, it was because a very small part of the layer (the location was different every time) wasn't sticking to the bed. I cleaned my bed with acetone and the problems went away.

Re: Different first layer results every new print

I had very similar looking issues with my first layer at the start. In one print it would be perfect, and in the next it would have small raised patches that looked like your pictures. When it happened, it was because a very small part of the layer (the location was different every time) wasn't sticking to the bed. I cleaned my bed with acetone and the problems went away.

I clean with IPA 99.99%, and had the issue, don't know if acetone will help better, but i can try 💡

Re: Different first layer results every new print

I had very similar looking issues with my first layer at the start. In one print it would be perfect, and in the next it would have small raised patches that looked like your pictures. When it happened, it was because a very small part of the layer (the location was different every time) wasn't sticking to the bed. I cleaned my bed with acetone and the problems went away.

I clean with IPA 99.99%, and had the issue, don't know if acetone will help better, but i can try 💡

FWIW, I was using 91% IPA, which didn't help, then tried Acetone out of desperation.

Re: Different first layer results every new print

i'm a new mk3 user as i have had my mk2s for a year now.

one big difference i have seen with my MK3 is it appears to massively under extrude. i noticed it when i ran my first prints through the new mk3 but i let it go until i started to run some test bench marks. i grabbed a extrusion multiplier test object and had to keep increasing the multiplier to make it work.
i ended up having to increase my multiplier between 15-17% above 100% to get good infill depending on filament. once that was set then i could go back and set the Live Z better, i also had to crank up the Live Z between .650-.750 depending on material to get a good first layer.

run some extrusion tests and see if your machine is acting the same.

compared to my MK2S everything is set to 1 on the extrusion multiplier, on my MK3 i have to increase to 1.15-1.17 to get the same results.

Re: Different first layer results every new print

This is not about a clean bed and not about extrusion. It is about temperature dependency during mesh bed leveling which greatly influences the height of the first layer.

So let's say my printer was just printing and I do a first layer calibration which yields a perfect first layer. Let the printer cool down for 10 minutes: The first layer is way to high (hardly sticking to the bed). Now home the printer and preheat. let the printer sit for 5 minutes. Now start a print: the first layer is way to low (squished).

This is repeatable and it is impossible to dial in live Z perfectly. Because on the next print the temperature will be different (aka not exactly the same)

Re: Different first layer results every new print

This is not about a clean bed and not about extrusion. It is about temperature dependency during mesh bed leveling which greatly influences the height of the first layer.

So let's say my printer was just printing and I do a first layer calibration which yields a perfect first layer. Let the printer cool down for 10 minutes: The first layer is way to high (hardly sticking to the bed). Now home the printer and preheat. let the printer sit for 5 minutes. Now start a print: the first layer is way to low (squished).

This is repeatable and it is impossible to dial in live Z perfectly. Because on the next print the temperature will be different (aka not exactly the same)

Have you tried running the temperature calibration from the calibration menu? It looks like that heats the bed up to different temperatures then reads the PINDA at each of those temperatures.

Re: Different first layer results every new print

Hi! Yes, with the first MK3 I had I tried all of that:-)

Now with the second MK3, which is only three days here, I have not yet tried a temperature calibration. But to be honest, the temperature calibration should be for fine tuning as far as I understand the intend of the function. And in this case, it is not about fine tuning but about working at all:-)

Re: Different first layer results every new print

I had this issue but quickly resolved it by adjusting the first layer extrusion.

Re: Different first layer results every new print

Did you change that in the printer or the slicer?