Jump to content
Ultimaker Community of 3D Printing Experts

Need help with TPU


gone_bush
 Share

Recommended Posts

Posted · Need help with TPU

HELP!!!

 

I just cannot seem to be able to hit on the right settings for TPU. What I am getting is extruder clicking.


 

Environment
    Ender 3 with MicroSwiss Direct Drive

Filement
    ESun Black TPU, temperatures: 210 - 240

Cura settings
    Flow 50%
    Layer height 0.12
    Retraction 1.5mm 10mm/s
    Speed 10mm/s
    Temperatures 230/220 and 50/50

Start GCode
    M140 S40                        ; set bed temperature
    M104 S230.0                        ; set hot end temperature

    M190 S40                        ; wait for bed to reach temperature
    M109 S230.0                        ; wait for hot end to reach temperature

    M220 S100                        ; Reset Feedrate
    M221 S100                        ; Reset Flowrate

    G92 E0                            ; Reset Extruder
    G28                                ; Home all axes
    M420 S1 Z5                        ; Enable bed levelling and set Z fade height to 5mm

    G1 Z2.0 F3000                    ; Move Z Axis up little to prevent scratching of Heat Bed
    G1 X5 Y20 Z0.3 F5000.0            ; Move to start position
    G1 X5 Y200.0 Z0.3 F1500.0 E15    ; Draw the first line
    G1 X5.3 Y200.0 Z0.3 F5000.0        ; Move to side a little
    G1 X5.3 Y20 Z0.3 F1500.0        ; Draw the second line

    G92 E0                            ; Reset Extruder
    G1 Z2.0 F3000                    ; Move Z Axis up little to prevent scratching of Heat Bed
    G1 X5 Y20 Z0.3 F5000.0            ; Move over to prevent blob squish

 

  • Link to post
    Share on other sites

    Posted · Need help with TPU

    Because TPU is quite a bit different than printing PLA I think you should consider adding another Ender 3 in Cura with the StartUp Gcode I'm including below (name it "Ender 3 TPU" or something).  When you want to print TPU just pick the other printer in Cura as well as your TPU material profile.

    The main changes that I've made in this StartUp Gcode is that the hot end goes to 170 for bed leveling, then after leveling, it moves to the left front corner of the bed, and then heats to printing temperature before starting the purge lines (your second purge line didn't have any extrusion in it).  That keeps it from drooling all over the place during leveling.

    The second main change is to slow down the purge lines from 25mm/sec to 10mm/sec and also to lower the flow.  The purge lines were designed for PLA and are way too fast and heavy for TPU.

    ;Start GCode
    M140 S{material_bed_temperature_layer_0}                        ; set bed temperature to initial layer bed temperature
    M104 S170                        ; pre-heat the hot end to leveling temperature

    M190 S{material_bed_temperature_layer_0}                        ; wait for bed to reach temperature
        
    M109 S170                        ; wait for hot end to reach temperature
    M220 S100                        ; Reset Feedrate
    M221 S100                        ; Reset Flowrate

    G92 E0                           ; Reset Extruder
    G28                              ; Home all axes
    M420 S1 Z5                       ; Enable bed levelling and set Z fade height to 5mm
    G1 X0 Y0 Z10.0 F3000            ;Move to 0,0,10
    M109 S{material_print_temperature_layer_0}                        ;set hot end to initial layer printing temperature and wait
    G1 Z2.0 F3000                    ; Move Z Axis down
    G1 X5 Y20 Z0.3 F5000.0           ; Move to start position
    G1 X5 Y200.0 Z0.3 F600 E12    ; Draw the first line
    G1 X5.3 Y200.0 Z0.3 F5000.0      ; Move to side a little
    G1 X5.3 Y20 Z0.3 F600 E24     ; Draw the second line

    G92 E0                           ; Reset Extruder
    G1 Z12.0 F3000                   ; Move Z Axis up to prevent scratching of Heat Bed
    G1 X5 Y20 Z0.3 F5000.0           ; Move over to prevent blob squish
    ;End Start Gcode

     

    TPU is fussy.  Speed is a big thing and 10mm/sec is about right but with a layer height of .12 and a Flow setting at 50% you are hardly moving any material.  0.25mm³/sec is only 0.1mm/sec of filament.

    When I print TPU on my Ender 3 Pro (stock bowden setup) I turn retraction off but your direct drive should be able to handle some retraction.  I don't have real experience with DD but 1.5mm retraction seems like a lot.

     

    I do change my Flow for TPU.  For PLA and PETG my E-steps are at 97 but calibrating the extruder for TPU they went to 110.  Rather than fooling with the E-steps every time - my TPU profile in Cura has all the flows at 113%.  I end up pushing more material and so I question your 50% flow number.  I'm guessing a single wall calibration cube?  I suggest that you go back to 100% in Cura and watch the print and adjust the flow with the Tune menu on the LCD until it looks good on the print.  Then you will have a good solid Flow number to enter into Cura.

     

    Then we come to layer height.  Mostly, I print custom gaskets with TPU.  It's pretty resistant to gasoline and if the area where it's mounted sees less than about 140°C it holds up quite well.  Consequently I don't care how they look as long as they seal so 0.2 layer height works well for me.  My numbers give me a flow of 0.8mm³/sec which is 3.2 times the flow that you are using.  I haven't had any trouble pushing the filament at that rate, but with my bowden setup retraction was a definite problem as the TPU just doesn't want to react to the extruder movement.

     

    • Like 1
    Link to post
    Share on other sites

    Posted · Need help with TPU

    Thank you for your VERY detailed reply and the amount of time you've obviously spent on it. It is very much appreciated.

     

    1) The second second purge line didn't have an extrusion specified because I had assumed it would be inherited from the previous line. Fixed.

     

    2) Re "the hot end goes to 170 for bed leveling": Why? What does that do that my "M104 S{material_print_temperature_layer_0}" doesn't?

     

    3) Intriguing idea re second printer, I'd never thought of that. Done.

     

    I've implemented your suggestions but I'm still getting clicking. The fight goes on.

     

    The settings in my post were after a _lot_ of trial and, mostly, error to see what would work so I'm not surprised at the lack of quality.

     

    Sorry about the delay in responding but by the time I'd posted my query I'd had enough of the printer for one day.

     

  • Link to post
    Share on other sites

    Posted · Need help with TPU

    "I'd had enough of the printer for one day."

    I know that one.

    "2) Re "the hot end goes to 170 for bed leveling": Why? What does that do that my "M104 S{material_print_temperature_layer_0}" doesn't?"

    I don't have ABL but even manually leveling, if the hot end is at printing temperature it oozes.  Leaving it at 170 for leveling allows the printer to move the head around without oozing onto the build area (but it's heated enough for most of the thermal expansion to have occurred).  Then it heats up to printing temperature when it's sitting over in the corner.

    Each line of Gcode stands alone so an extrusion does not carry on to the next line.  The printer-processor knows where the head is, a line of Gcode tells it where it's going, and it calculates getting all 4 motors there at the same time.  When an axis isn't mentioned in a line then that motor just doesn't move.

    You've got that fancy DD on there so TPU should be no problem.  Could it be a spring-tension thing on your extruder arm?  Maybe it just isn't putting enough pressure on the filament (although that's hard to believe).  Have you had any problems with the extruder skipping steps with harder material like PLA?

    If you have a 0.6 nozzle handy maybe you should give that a try.  

     

  • Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
     Share

    • Our picks

      • The Ultimaker Showcase — October 14. What's new?
        Your dear friends at Ultimaker have some exciting news and insights for you!
         
        • 0 replies
      • New here? Get ahead with a free onboarding course
        Hi,
         
        Often getting started is the most difficult part of any process. A good start sets you up for success and saves you time and energy that could be spent elsewhere. That is why we have a onboarding course ready for
        Ultimaker S5 Pro Bundle, Ultimaker S5, Ultimaker S3 Ultimaker 2+ Connect.   
        They're ready for you on the Ultimaker Academy platform. All you need to do to gain access is to register your product to gain free access. 
        Ready? Register your product here in just 60 seconds.
          • Like
        • 10 replies
    ×
    ×
    • Create New...