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How to win at 3D printing

Adventures with an Ender 3

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Despite being 1 of the 1st affordable printers, the Ender 3 actually a kind of anachronism. Most of the internet uses much more expensive prusa printers. The lion kingdom got an Ender 3 anyway because it was cheap. Here are the travails of surviving with it. Lions also use Cura for slicing while most of the internet uses prusaslicer.

11 years after the expiration of the FDM patent, 3D printing is still kind of like Linux in 1996, purely considered a hobby with no economic value. Like Linux, it could end up being a requirement to have any kind of job. The lion kingdom's day job buys a lot of FDM printed enclosures from China. Lions have previously taken posession of commercial FDM printed prototypes.







THE BASIC .4MM NOZZLE PLA SETTINGS:

This makes very high quality parts, but takes forever.

nozzle: .4mm 

 layer height: .2mm 

 line width: .4mm 

 wall thickness: 1.2mm 

 top/bottom thickness: .8mm 

 ironing: off 

 infill: 25% 

 nozzle temperature: 230C  Best layer adhesion is 230C

 bed temperature: 60C on a buildtak FR4 bed.  50C  on a buildtak magnetic bed.

 speed: 50mm/s 

 wall speed: 25mm/s 

 top/bottom speed: 25mm/s 

 travel speed: 75mm/s   Prevent crashing into lumps

 initial layer speed: 20mm/s 

 retraction: 5mm 

 print cooling: OFF Better layer adhesion

 support: touching buildplate

support overhang angle: 80deg 

 adhesion: skirt

Layer height must be a multiple of .04mm.  Thicker layers print faster but make rougher diagonals.  Layers over .32mm can't make diagonal overhangs at all .

Design parts with multiples of the layer height.

Design 45 degree angles instead of using support whenever possible.

Avoid brims & rafts at all costs.  The bottom layer needs to press onto the bed to be flat.

Place parts in the center of the bed because this area tends to have more stable height.

Lions have never had any use for print cooling.  It might be useful for artwork but it weakens layer adhesion & the fan has to be cleaned.


BED ADHESION:

The stock Ender 3 bed is a buildtak bed.  It works at 60C.  Increase temperature to increase adhesion.  Decrease temperature to decrease adhesion. 

For most models, the lion kingdom only heats the bed for the 1st layer.  It retains most of its adhesion after cooling.  Only difficult models with little contact with the bed need full time bed heating.

Lower the nozzle to press the filament down & increase adhesion.  Raise the nozzle to decrease adhesion.

Any print bed, whether glass or plastic, must be kept free of skin oil.  Washing it off with dishwashing soap greatly enhances adhesion.  If the bed is clean, the nozzle can achieve adhesion with very little downward pressure.

Remove the bed, let it cool down, & bend it to remove the part.  Use an xacto knife to remove the skirt & extra bits.

Ordinary glass provided no significant adhesion or improvement in leveling, but required a lot more heat.  The trick with glass is it makes a smooth surface.  There are specially treated glasses which might give better adhesion, for a price.


BED LEVELING:


Lions started out by using this file to coarsely level the bed:

https://cdn.hackaday.io/files/1764067547354304/CHEP_M0_bed_level.gcode

It's a modified version of https://www.thingiverse.com/thing:3235018

Clean excess filament from the nozzle before leveling.  Heat the bed to the printing temperature before leveling by going to control->temperature->bed.

After much experience, lions switched to just going to prepare->auto home, then prepare->disable steppers, then manually sliding the nozzle around.  Instead of sliding paper under the nozzle, lions just eyeballed the nozzle height. The nozzle height after auto home should be right on the bed.  It doesn't raise it a layer height.

Bed leveling is manely affected by changing nozzles, slippage of the springs & X arm.  The center of the bed is higher than the sides because it rocks around the center.  Turn the eccentric nuts under the bed to reduce the rocking, but it can never be completely eliminated.

Once coarsely leveled, it only needs to be fine tuned while printing the skirt.  Lions print 4 skirt lines.  There's no need to print a test pattern.

AUTOMATED BED LEVELING  

https://hackaday.io/project/176406/log/197418-auto-bed-leveling-with-the-3dtouch

Automated bed leveling is cheap enough to be considered essential...

Read more »

CHEP_M0_bed_level.gcode

Modified https://www.thingiverse.com/thing:3235018

gcode - 4.86 kB - 12/18/2020 at 21:16

Download

  • Cleaning the display

    lion mclionhead10/01/2022 at 23:45 0 comments

    The answer is no, you can't clean the display with any kind of water.  It goes into the zebra strips & kills rows of pixels.  The zebra strips are held in by expendable metal tabs.  The lion kingdom managed to trade some bad rows for other bad rows.  The display would have to be covered in packing tape to try to keep water out.  The best long term solution is to get a better display.  It's so slow, it's not worth trying to save some bad rows.

  • Power usage study

    lion mclionhead09/20/2022 at 04:37 0 comments

    The Ender 3 came in at 322W when starting up & 60W when printing PLA with a 50C bed & 230C nozzle.  The power supply was only rated for 300W.  When heating the bed & nozzle simultaneously, it dumps the full output & probably browns out.  

    This brings up the question of how practical a 300x300mm bed is.  Even if the print is 10x10mm, the entire bed has to be heated.  So if you're paying for electricity instead of using solar panels, you'd need a smaller printer for smaller prints & a bigger printer for bigger prints.  If electricity is unlimited, you could use a bigger printer full time.

    Printing TPU with a 260C nozzle & no bed heating burns 65W.  10 hours of printing burned 0.650kW hours.

    The idle printer burns 7W.  With the motors on, it burns 22W.  Motors + 260C nozzle heating burns 65W.  Motors + 260C nozzle + 65C bed heating burns 330W as the worst case PETG setting.  Once at steady state, it oscillates between 65W & 300W with the worst case PETG temperature settings.  300W seems to happen when the bed is heating.  The nozzle heating seems to be proportional while the bed heating is binary & sucks most of the power.

  • The creality direct drive

    lion mclionhead06/27/2022 at 19:04 0 comments

    The bowden extruder stopped extruding partway through a print.  The reason was 

    scotch tape being used to keep the filament untangled.  It deposited adhesive on the filament which got in the bowden tube.  It pressed through the nozzle easily.  It pressed through the extruder easily.  It didn't press through the bowden tube anymore.  Retiring the bowden tube was believed to be the best strategy.  The lion kingdom has now spent as much in upgrades as a new printer.

    Direct drive extruder: $40

    EZR struder: $40

    3D Touch bed leveling: $20

    Copper heating block: $15

    Metal hot end: $15

    Glass bed: $15

    Magnetic bed: $15

    Nozzle assortment: $15

    The latest replacement was the Creality direct drive

    https://www.amazon.com/dp/B08J7N2LNL

    It contained a completely new hot end, fans, cables.  It was a lot of work to install.  They say it can be easily swapped with the bowden extruder, but lions say fuggedaboutit.  The stock creality gear section was back.  The X axis then sagged to the right.  New parts had a slight tilt to the left but at least it printed again.  If right angles are really required, the easiest solution is to hack the G code rather than try to keep the X axis level.

    The filament has to go in front & unroll sideways.  This is distinctly missing from the sales pitches for prusa MK III's & ball bearing filament rolls.

    It successfully overcame the problem that killed the bowden tube, whether or not it really was friction in the tube.  The lion kingdom has now lived through the dual gear craze, the EZR struder craze, & the direct drive craze.  Will it print the unprintable Matterhackers PRO TPU from 2 years ago?

    It did print the matterhackers Pro TPU even without a dual gear or a constrained path.  It still ran only at 20mm/s.  An important lesson is not throwing away filament that won't print. It might print in the future.  This filament was much softer than the tried & true filament, but it was twice the price & would require redesigning the tires.

  • Magnetic bed

    lion mclionhead04/04/2022 at 21:51 0 comments

    The stock buildtak on FR4 bed had problems with air pockets between the buildtak & FR4 & not sticking flat on the aluminum.  The solution was seen as the mighty 

    "Build Plate Ultra Flexible Removable Magnetic Build Surface Hot Bed Cover for Ender 3"

    https://www.amazon.com/dp/B084YSZFXL

    It's overall an improvement.  There are no more discernible air pockets.  There's much less warping.  The mane problem is sticking the adhesive magnet on the aluminum without creating air pockets.  The lion tried to stick down the back edge, then roll it forward but was off by 3mm.  

    Taking it off & trying again would probably damage it or trap air bubbles.  It still managed to conduct enough heat.  The polarity of the magnets in bottom pad has to match the polarity of the magnets in the top pad.  

     There haven't been any air pockets when sticking down the buildtak magnet.  The 2 magnets create a uniform bond to the aluminum with minimal warping.

    Having 2 magnet pads between the buildtak & aluminum means less heat gets through.  Fortunately, the magnetic buildtak is much stickier than the stock bed.  50C bed temperature was enough for PLA while the stock bed needed 65C.  0C with a 1st layer temperature of 220C is essential for TPU.  Higher layers for TPU can be 250C.

    Combined with automatic bed leveling, the magnetic bed yielded gootuber quality 1st layers, all the way from edge to edge.  The mane problem was the magnetic bed caused the front row of probe points to always be .1mm lower, almost like a firmware bug more than a bed deformation.  It could be because the front row is 1st to be probed & there's a change in bed height in that motion.  

    No-one really knows why the pogo probes have constant errors like this. They do provide manual tweeking in some firmware. The memory constrained Ender 3 could use some gcode commands, but only if the errors changed.  The easiest solution for a constant errors was hard coding the firmware & flashing.

    The mane problem with the bed is it's very fragile.  Any nozzle crash leaves a hole.  Fold it sharply & it leaves a crease.  It tries to fold sharply & form creases when removing prints.  Waiting for the print to cool, using the spatula & xacto knife is essential for tough prints.

  • High temperature nozzle

    lion mclionhead12/11/2021 at 08:43 0 comments

    After stripping a heater, the lion kingdom got a copper heater for higher temperatures.

     https://www.amazon.com/dp/B09DS1P9VJ

    Instead of what was pictured

    The actual product had no holes for the studs which resist the torque during a nozzle change.

    There was an experiment in resisting nozzle changes by grinding a flat & using a bigger set screw.

    But tightening enough to resist nozzle changes stripped the heat sink.

    The lion kingdom resigned itself to a future of grabbing the heater with pliers to resist torque while changing nozzles.

    The most expensive consumable for lions has proven to be electricity rather than the filament.  

  • Fixing the button

    lion mclionhead11/24/2021 at 23:05 0 comments

    Many animals have exited a menu only to find their nozzle temperature was suddenly too cold or their probe Z offset was .1mm too high.  For animals who destroyed a print by trying to exit from a menu, the solution is to whack on a separate button instead of using the dial as a button.

    The hardest part is drilling through the 2mm thick depleted uranium steel armor that is the front panel.

  • Mane filament colors

    lion mclionhead11/05/2021 at 22:29 0 comments

    Lions never print in any clear filament because

    it's what prison gadgets are made of.  The mane colors are 

    silver for the default material

    orange for high visibility gadgets & simulating wood with a brown sharpie

    black for anything flexible.

    A dedicated spool of brown would be good for simulated wood, but might not be as realistic as orange with brown sharpie.

  • 1st nozzle burn

    lion mclionhead11/05/2021 at 05:40 0 comments

    Felt the pointy end & ejected before feeling any heat.  Fortunately, lions don't need to feel heat to know what's coming.

  • Overclock the Ender 3 display

    lion mclionhead09/28/2021 at 19:59 0 comments

    You can make the display slightly faster.  It uses software SPI.  For Marlin 1.1.x, the timing values are defined in Conditionals_LCD.h

    #elif ENABLED(CR10_STOCKDISPLAY)
    
      #define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
      #ifndef ST7920_DELAY_1
    //    #define ST7920_DELAY_1 DELAY_NS(125)
        #define ST7920_DELAY_1 DELAY_NS(64)
      #endif
      #ifndef ST7920_DELAY_2
    //    #define ST7920_DELAY_2 DELAY_NS(125)
        #define ST7920_DELAY_2 DELAY_NS(64)
      #endif
      #ifndef ST7920_DELAY_3
    //    #define ST7920_DELAY_3 DELAY_NS(125)
        #define ST7920_DELAY_3 DELAY_NS(64)
      #endif
    
    #elif ENABLED(MKS_12864OLED)
    

    The lion kingdom managed to get them down to 64, but no lower.  

    More SPI delays are defined in ultralcd_st7920_u8glib_rrd.h

    ST7920_WRITE_BYTE, ST7920_WRITE_BYTES, ST7920_SET_CMD, ST7920_SET_DAT, ST7920_CS

    all have delays but the lion kingdom didn't have any luck reducing those.

  • Ender 3 heat block stripping

    lion mclionhead09/12/2021 at 06:37 0 comments

    A common problem for animals who frequently change nozzles is the heat block getting stripped.

    They're all made of aluminum.  The stock nozzle had red thread locker.  The maximum torque before stripping probably isn't enough to get a reliable attachment.  Replacing just the heat block is a huge pain, manely because all the bits which have to be removed can only be removed when they're hot, so the lion kingdom replaced the heat block, heat sink, heater, & thermocouple.  

    https://www.amazon.com/dp/B07H8TSM95

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tediouszzzz wrote 12/14/2021 at 13:43 point

Someday maybe you'll win. For now, this is a somewhat convoluted mess of printing...   Get a cricut and step away from the 3D printing.

  Are you sure? yes | no

benkster wrote 08/26/2021 at 20:29 point

Pretty extensive explanation - Nice!
Can you buys yourself a artillery sidewinder and do the same for it ;-)
Just kidding of course - well done

  Are you sure? yes | no

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