English
Forums
English forum
Original Prusa i3 MK3 & MK3S & MK3S+
Assembly and first prints troubleshooting
Can't get first layer right
 
Notifications
Clear all

Can't get first layer right  

    Last Post
  RSS
Veritas
 Veritas
(@veritas)
Active Member
Can't get first layer right

Hey! I've tried calibrating my first layer a bunch of times but no matter what setting I pick it comes out bad. What am I doing wrong here? Why are there bumps in my print?

Best Answer by --:

@veritas

You also have a drive gear problem. One or both of your gears driving the X and Y belts is loose on the shaft. 

They should be fixed asap.  Use the flat-first method.

  1. Loosen both set screws so the gear spins on the shaft.
  2. Align and tighten a set screw on the shaft flat, wiggling it as you tighten to ensure the flat on the set screw is flat on the shaft. Torque the screw down to spec (don't over tighten it and strip the aluminum threads or head).
  3. Only after the flat is set, now begin tightening the set screw on the round.
    -- do not go back and retighten the screw on the flat - it gets tighter when you tighten the screw on the round and you'll end up stripping it.
  4. Reverse the procedure when you need to maintain the belt.

 

Posted : 07/05/2021 3:55 am
Veritas
 Veritas
(@veritas)
Active Member
Topic starter answered:
RE: Can't get first layer right

Few more pictures of first benchy layer.

Posted : 07/05/2021 4:01 am
bobstro
 bobstro
(@bobstro)
Illustrious Member
RE: Can't get first layer right

Your Live-Z adjustment appears to be very high. Those lines should stick firmly to the PEI smooth sheet.

If you have not already done so, try using Jeff Jordan's "Life Adjust" procedure for calibrating your Live-Z setting. It is much easier to use and understand than the onboard routine and much easier to make mid-print adjustments accurately with. In general, start high (less negative) and work lower (more negative) in large increments (e.g. 0.1mm) until the filament starts to stick on its own. When you've got your Live-Z setting adjusted properly, you should be able to gently rub the extruded lines on the PEI surface without dislodging them.  Then start lowering (more negative) the level until there are no gaps between layers. You should not be able to peel the lines apart after printing, but the top should be regular. 
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 : 07/05/2021 6:45 am
--
 --
(@)
Illustrious Member
RE: Can't get first layer right

@veritas

You also have a drive gear problem. One or both of your gears driving the X and Y belts is loose on the shaft. 

They should be fixed asap.  Use the flat-first method.

  1. Loosen both set screws so the gear spins on the shaft.
  2. Align and tighten a set screw on the shaft flat, wiggling it as you tighten to ensure the flat on the set screw is flat on the shaft. Torque the screw down to spec (don't over tighten it and strip the aluminum threads or head).
  3. Only after the flat is set, now begin tightening the set screw on the round.
    -- do not go back and retighten the screw on the flat - it gets tighter when you tighten the screw on the round and you'll end up stripping it.
  4. Reverse the procedure when you need to maintain the belt.

 

This post was modified 4 years ago 2 times by --
Posted : 07/05/2021 6:57 am
Veritas
 Veritas
(@veritas)
Active Member
Topic starter answered:
RE: Can't get first layer right

Thank you both! I think the main problem was the X belt drive gear was loose like you said. Once I fixed that the prints started coming out reasonably and I was properly able to set the Z-level/offset. 

Posted : 07/05/2021 3:26 pm
  All forum topics
  Previous Topic
Next Topic  
Share: