slicer, extruder, layer, pause tips learned last year

Hi All, Thanks for all the help you guys and gals gave me during my early printing days. It has been about four months of printing experience and at least five Kg of filament extruded so far. I still use the Ormerod1 as I have not commissioned my Ormerod2 yet. I have Dave's aluminum bed and X-arm as well as the Spring loaded extruder and anti-vibration feet by iamburny, the other mods are my own takes on open mods for the Z-axis herringbone gears and I lowered the nozzle as compared to the sensor. Recently I made two small changes, one that really helped the quality of my prints and the other mostly solved my common issue - filament stopping extruding. I changed my layer height to increase the Z axis accuracy and last is how I started to print in multiple colors using the single nozzle.

Quality fix:
I turned "Wipe" on in Slic3r on the printer settings tab - Extruder section. This stopped all the blobs seen on the face surfaces and now I can print multiple objects at the same time with no loss of quality. I was mostly printing completed objects using sequential printing due to the blobs. Don't forget to set Retraction Length to 3mm as Ian from Reprap suggests (seen on same page and is in screenshot)

Problem solution:
Remove the spring. My most common issue has always been the filament stops extruding in mid print. This is worse for solid infills than anything else. I slowed the machine down to 60mm/s max and even slower if I really want it to work. Certain filaments worked great while a few absolutely refused. I put my finger in the gap under the extruder as it was printing and I could feel the gap open and close slightly as the filament went past. Thinking about the RepRap squeaky extruder I remembered how crushed the filament comes out of it and decided the variability of the spring was a potential issue.. Last night I removed the spring from the spring loaded extruder. It is now a Adjustable Extruder with a solid pressure setting and has worked far better without the spring. I have so far printed two of the worst filaments that I have labeled as "un-extrudable" with no issues since taking the spring out.

Layer accuracy improved:
Use 0.3333 layer height. I was never happy with the Z height accuracy as I started printing at 0.30 layers with a 0.40 initial layer. Mathematically this does not add up to even heights as measured in mm other than 1mm. So it is logical that the Z height would not be even for most objects. I tried printing @ 0.25 with a first layer of 0.25 but found I had issues with the bed contact. Noticing the printer has an accuracy of six places I decided to try a layer height of 0.3333 and a first layer of 0.3334 - this allows accurate even mm heights - even though any half mm heights will still be approximated. You still need a 0.25 layer height if you choose to print a height of 0.5mm accurately. For my purposes the 0.3333 layers make a compromise between speed and accuracy.

Getting tricky (use a pause and my filament change technique):
I started printing multiple colors using the single nozzle and a pause command inserted in the G code.

G1 X220 Y199 Z7 F2000 ; move head to allow change filament
M25 ; pause
M104 S205 ; hot end on (just to make sure, the bed and nozzle stays hot during the pause)

The train car is made with three pauses, two filament changes and once to add a set of hidden nuts. You use Slic3r to find the right Z height in your design and search the G code for the z height i.e. Z1.3 to find the right place in the code. Insert the pause line to stop the print and move the bed out of the way of the nozzle. I cut the filament at the extruder and just extrude the rest out through the bowden tube using pronterface and a 550mm @ 300mm/min extrusion command. I start with a shorter 100mm @ 300mm/min to get the new end started by pushing it into the extruder as the old is slowly moving, you will need to lightly push the end as it feeds into the extruder and past the knurled knob. You can adjust the tension screw on the extruder as it pulls the 500mm though. Mine always has some trouble pushing the new end into the hot nozzle and I usually watch and help it by pushing the filament into the extruder, it tends to pop once as it enters the nozzle and the new color will then appear in moments as extruded. Not all filaments need this push, but most do. Clean the nozzle and hit Resume. I made a pronterface Resume button M24 - I use pronterface for homing and some direct printer controls. I print and upload files via the Reprap web based interface.

I hope this helps someone have a more successful and enjoyable printing experience.
Happy Holidays to all the forum members!
Thanks again for your help and all the time you spend trying to help random strangers who we will probably never meet in person!

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Socrates ~ The Amsterdamman
slic3r-1.2.9

I also removed the curved tube leading to the extruder and just go straight from the edge of the printer now. I use a bearing supported filament roll as well.
Still like the single piece of 200mm wide Klapton tape. I found the white corner stickers are easier to apply on top and I don't print that far into the corners anyway.

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Socrates ~ The Amsterdamman
slic3r-1.2.9

Some excellent results Kimon. I should think that tightening the extruder screw would achieve the same as removing the spring - after all, with the spring completely compressed it is the same as having no spring. I have not found the need to use a spring loaded extruder, but have modified the original with herringbone gears and a wider feed tube to take a PTFE insert. I plan on making a dust remover to clean the filament when I get a round tooit (lots to choose from [www.thingiverse.com] ). I've had to replace the nozzle once when it got clogged and would not clear (I now have a spare just in case it happen again).

I print with either a .25mm layer height with first layer also .25mm, or with a .20mm layer height and first layer 0.4mm. With the aluminium bed support I can get the bed level enough for a first layer of 0.25mm, but 0.2mm is pushing it which is why I use 0.4mm first layer height when I print with 0,.2mm layers. Very few prints require a Z height accuracy of better than 0.1mm. but like yourself I prefer the layer heights to exactly fit the design dimensions.

Dave

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Amsterdamman
Don't forget to set Retraction Length to 3mm as Ian from Reprap suggests (seen on same page and is in screenshot)..

Thank you for taking the time to share you experience, those wagons look great! - I have retraction set to 5mm but that's just on my system

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Problem solution:
Remove the spring. My most common issue has always been the filament stops extruding in mid print. This is worse for solid infills than anything else

Never had any problem with the spring loaded extruder (10kg.+) - only one stoppage ever because of oversized filament (1,98mm!), got stuck in the ptfe tube insert, so can't blame the extruder, also never had any filament breaking as others have experienced

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Getting tricky (use a pause and my filament change technique):
I started printing multiple colors using the single nozzle and a pause command inserted in the G code.

Thanks, will try that

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Happy Holidays to all the forum members!
Thanks again for your help and all the time you spend trying to help random strangers who we will probably never meet in person!

Thank you Kimon, thanks for the tips and happy holidays to you and yours!

Erik

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dmould
..I plan on making a dust remover to clean the filament when I get a round tooit (lots to choose from [www.thingiverse.com] )..

Ditto - I want my shirt back!



Erik