50 Micron Layers and Marvin

[Snortimer]

Those are great suggestions.

What material are you using? Reducing speed a bit more can help with some issues.

Regarding the Lulzbot Mini auto-leveling, I’ve seen it cause problems and try to print below the bed surface, so some troubleshooting might be in order there. Make sure the nozzle is clean when it levels (the wiping isn’t always sufficient if the temperature is too cool).

I’ve heated the nozzle, manually retracted the filament a bit, and wiped the nozzle with folded paper or a scrubby sponge, then continued as normal with some extra skirts, and it’s helped. You can also tweak the starting gcode temperatures for better wiping based on what material you’re using or have recently used.

I’ve tried printing Marvin at 50 microns on my TAZ 4/5, and I had some success in ABS, though the edges curled so the bottom curved surfaces were a bit rough. The top was beautiful! I have yet to try PLA. I expect I can improve my results using the suggestions others have made in this thread. At the time I tried, the specs for the TAZ 4 listed 70 microns as the limit.

[tpalagyi]

Hi,

Would suggest to lower the nozzle temperature for 50 microns, as the filament spends more time in the melting chamber in the print head it don’t need high temperature 185-195 should work.

The other thing is the cooling, you need damn good and consistent cooling of your print. So make some experiments with bigger or extra fans etc. (if you have, print Marvin from with low cooling from ABS than you should see the eyes will be much nicer this means cooling is not enough or you have too high head temperature for PLA)

Also don’t bother with low first layer, print it with 0.2mm than you can change it to 0.05, also 5-6 lines of brim should be enough to make a consistent flow from the head in the beginning. If the brim is not printed correctly add some extra extrude into the start code in your silcer.

BR.,

T.

[Scholarch]

Hmm I know 50 microns is possible I’ve gone as far down as 25 with mine with success. It shouldn’t take all that long to prime the extruder. Make sure the tension on the hob gear is correct.

[Snortimer]

Thanks to all these tips, I’m now inspired to push the limits on my TAZ! I’m trying a 30-micron Marvin. I’m up to 1.4mm (-ish), and it seems to be working.

If I have success, I’ll put my settings up here (they should be very similar for the Mini).

I suspect I’ll start to have issues on the lower half of the body, but the legs are great!

[my3dconcepts]

if you want great results at 50 microns, you have to change the nozzle size - 0.35mm or even 0.25 mm. I would say with 0.5 mm nozzle you can go as low as 100microns. It’s really easy to swap the nozzle on the mini! personally I wouldn’t even try to print at 50microns with 0.5mm nozzle!

[huffworks3d]

Also consider the overhangs on Marvin. When printing the eyebrows and eyes at say, .2 layers, the overhang is minor relative to the layer height As the layer height decreases to .05mm, the overhang becomes that much greater (4 times in this case) relative to the layer height, and 4 times as difficult to maintain its form.

Lowering print temperature a bit should indeed help with this, increasing fan power if you are using PLA or Colorfabb XT that can take the extra cooling without warping.

[Jackson_Moody]

Thanks for the detailed reply!

I have already lowered my temperature, and increased the cooling to 100%. I also increased my first layer height to .2. Should this work? I haven’t tested a new Marvin with these new settings yet…

[tpalagyi]

Great! Yes these settings should work, just make a test. Also lower the print speed to 60% if its prints good then you can try also at higher speed.

Regards.

Tamas

[Jackson_Moody]

Wow! Thanks for the super detailed reply!

I am currently using nGen material (which is made by Colorfabb). As for cleaning the nozzle, is their a certain material you recommend? Should I use the isopropyl alcohol that I use to wipe down the bed? Other than that, though, I think the Auto-Leveling is working pretty good! And any minor miscalculations should have been fixed by the Z-Offset adjustments.

I as well will be trying most of the other suggestions made in this forum. Hopefully I can improve my results!

[Jackson_Moody]

Ok, thanks for the clarification Tamas!

The standard print speed for nGen is 50mm/s, so I lowered it to 25mm/s (just to be safe). I’m assuming that if it prints correctly that slowly, then I can slowly speed the printer up?

[Jackson_Moody]

Thanks for the reply!

I’m pretty sure that my tension is correct, because filament has been extruding wonderfully on my Mini (when printing at .2mm). It’s incredible that you’ve dialed in your printer so much that you can print at 25 microns! Kudos to you!

[Jackson_Moody]

Awesome!

I would love it if you posted your settings, so we could all get some standard settings that would work! 30 Microns is really low, but I wish you could luck!

[Jackson_Moody]

Hmmm. This is an interesting suggestion! I haven’t tried changing my nozzle yet! Which nozzles would you recommend for the Lulzbot Mini?

[Jackson_Moody]

Thanks for the suggestions!

I have heard from numerous people that I should increase the fan and decrease the print temperature, and that is exactly what I’ll be doing! Just for reference, I’m using Colorfabb nGen, which is pretty similar to XT, except for the lower melting temp.

[Jackson_Moody]

Thanks for the reply!

I have heard that I need to up my cooling, and it sure seems like I should take this into account!

[tpalagyi]

50 microns is really sensitive printing with FDM everything has impact on it. Temperature, speed, filament etc.

As I have just read you have a 0.5 nozzle on your machine? If yes change it to 0.3 to for 50 microns prints to get good result. also recommend to use 0.4 for normal prints its a bit better quality.

The rules:

0.5 nozzle 0.3-0.1mm layers

0.4 nozzle 0.25-0.1mm layers

0.35 nozzle 0.2-0.075mm layers

0.3 nozzle 0.2- 0.05mm layers

[Jackson_Moody]

Ok! Which .3 nozzles do you recommend for the Mini? I have never tried changing my nozzle before!

[Jackson_Moody]

Wow! Thanks for all the detailed responses everyone! I’m sure this will all help a lot!

For those of you asking, I am printing with Colorfabb’s nGen material.

So far, I have gathered the following list of suggestions. If you have anything new or different to add, (or you disagree with one of the suggestions) please let me know!

• Lower print temperature
• Lower print speed
• Up cooling a lot!
• Change nozzle size
• Check Auto-leveling procedure
• Up first layer to .2mm

Again, if you have anything else to add, please let me know! I am so grateful that 3D Hubs has such a friendly supportive community

[tpalagyi]

Nozzle:

As I have just checked you should have a Hexagon all-metal hot end with 0.5 nozzle by default witch uses 3mm filament (hmm this could be a problem but hope it will work otherwise you have to make an upgrade to 1.75mm filament, so new hotend and extruder and new rolls of filaments)

So just look for a store in the US who sells this kind of nozzles, so you will need 0.3, 0.35, 0.4 nozzles for !!!3mm!!! filament (make sure its for the 3mm not for 1.75mm version).

Just googled and found this store (they have the 0.3 out of stock but have 0.35 and 0.4)

http://www.makerfarm.com/index.php/hot-ends/hot-end-parts.html

T.

[Snortimer]

Well, my print wasn’t great, but it at least completed the print. I’ll put up a photo later this afternoon, but I did learn a lot!

Speed really, really matters. Faster areas have ripples. Overhangs are problematic, as is expected. I can probably drop the temperature a little more. I can probably increase cooling a bit. I’m printing in brown ABS, so cooling is a sensitive topic.

The parts that look good look REALLY good, and the rest looks messy. I’ll probably use 50-75 microns as my finest resolution, but this experiment will help me optimize my settings.