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towlerg
(@towlerg)
Noble Member
Can anybody explain the rational

I note that many default settings for filament temperatures have different values for first layer for bed and nozzle. What is the rational behind this?

Posted : 23/06/2020 10:38 pm
bobstro
(@bobstro)
Illustrious Member
RE: Can anybody explain the rational

For PLA, a hotter first layer will improve adhesion for the important first layer while not introducing as much heat further up that can cause problems with warping or distortion like elephant's foot.

For PETG, a cooler nozzle will help the filament to adhere to the bed and underlying layers instead of the nozzle.

Interestingly, my bed adhesion on both my Prusa with the removable PEI smooth spring steel sheet and Sidewinder with Ultrabase-style glass bed both went to crap with the recent warm days and increase in humidity. Had to give both a good cleaning to restore adhesion.

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 24/06/2020 1:17 am
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towlerg
(@towlerg)
Noble Member
Topic starter answered:
RE: Can anybody explain the rational

@bobstro

Thanks for the info. There are just so many variables. One massive advantage of using a Prusa printer (sadly I do not) is all the pretested settings in PrusaSlicer.

How about 2 step bed temp for PETG?

What do you clean the Ultrabase with? 

Posted : 25/06/2020 2:18 pm
bobstro
(@bobstro)
Illustrious Member
RE: Can anybody explain the rational
Posted by: @towlerg

[...] Thanks for the info. There are just so many variables. One massive advantage of using a Prusa printer (sadly I do not) is all the pretested settings in PrusaSlicer.

I'm using PrusaSlicer with my Prusa and Sidewinder printers. I definitely have to work on separate profiles for each device. Lots of similarities, but the hardware capabilities are very different. Both of my printers are direct drive, but if I were using a Bowden setup, life would be even more of an adventure.

How about 2 step bed temp for PETG?

I find that using a "no-ooze" temperature of 160C works for PLA, PETG and most filaments. Not hot enough to ooze, but just soft enough that any accumulated crud on the nozzle will bend away easily when homing to avoid bed damage.

What do you clean the Ultrabase with? 

I'm glad I had my Prusa experience starting out. I spend a lot of time working on bed leveling and keep the bed simple. I clean it with isopropyl alcohol, only occasionally a warm cloth if there's build up. I have had very good luck with the Vision Miner adhesive as it doesn't build up much and is very effective.

The big 300x300 Artillery glass beds are notorious for a dip in the center. I've compiled and installed Marlin to allow manual mesh bed leveling (7x7 takes a LONG time manually) and I find the bed doesn't drift too much over time. This makes a huge difference for adhesion. Just like on the Prusa, the combination of bed leveling and cleanliness is important.

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 25/06/2020 8:15 pm
towlerg
(@towlerg)
Noble Member
Topic starter answered:
RE: Can anybody explain the rational

Thanks again.

Posted : 26/06/2020 1:59 pm
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