Nozzle Limbo - How Low Can You Go?

Does anyone use fine nozzles for printing out there? I would like to hear about your experiences and results.







I offered to print a very small, detailed part for someone here on the forums, but the results with my existing 0.36mm tip was a little too coarse for all but the largest features, so I decided to reduce the size of the nozzle hole (easy to do on Wildseyed). I was shooting for a 0.25mm nozzle, but ended up with 0.18mm, and this had me a little worried that I would strip the filament by needing too much pressure to drive it through.

I'm happy to report that 0.18 works great! I can print with a faster feed rate, AND lower flow rate, and the walls and surfaces look really smooth.

Now I'm wondering how much I can do beyond 0.18mm.

Right off the bat, I can see benefits to using a finer nozzle:

1. Raft and interface layers produced with finer nozzles should be easier to separate.
2. Sharper details in parts, of course.
3. Faster print speeds, with less heat loss on the hot end, because it's flowing slower.

And there are downsides:

1. You need a level print bed. Nothing less than glass will do.
2. It takes longer to slice the g-code.
3. Infill takes a greater number of passes to create same % infill as a larger nozzle.

Edited 7 time(s). Last edit at 07/23/2011 03:08PM by jcabrer.

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How does the smaller nozzle result in a higher feedrate? You need less energy to heat the same length, of course, but shouldn't that be no issue if you simply increase the temperature of the nozzle a little to compensate for the heat loss?

ElectricMucus Wrote:
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> How does the smaller nozzle result in a higher
> feedrate? You need less energy to heat the same
> length, of course, but shouldn't that be no issue
> if you simply increase the temperature of the
> nozzle a little to compensate for the heat loss?

Consider two extruders running at the same speed, one with a 0.36mm nozzle opening, the other 0.18mm. Since the input volume is the same...

0.36mm

XXXXXXXX
XXXXXXXX

0.18mm

XXXXXXXXXXXXXXXX

... the extrudate comes out twice as fast. By necessity, you would need to either increase the feed rate, or reduce the flow rate to prevent dispensing.

If you look at it this way... of course. But isn't the movement of the axis more of an issue?

Nice photos, that looks fine enough to be indistinguishable by the plain eye!
So did you finish both objects in the same amount of time if you get a higher feedrate?


Funny thing is: The smallest widely available drill is ø 0.2mm so any smaller than that would be difficult to make. There should be a 0.1mm around somewhere though...

Edited 2 time(s). Last edit at 07/23/2011 04:23PM by ElectricMucus.

The tips on a wildseyed simple hot end are not drilled. You start with a 0.8 mig tip, and tap it with a hammer until the desired opening is achieved. Then you stick it in a drill press and sharpen it to a point with sand paper and a file.

How do you know it's .18mm?

Andrew Diehl Wrote:
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> How do you know it's .18mm?


That's a bit of chicken and the egg. I extrude material, and use a caliper to measure O.D. And yes, I realize that the actual hole is probably smaller than the extradite, but what comes out is what counts, am I right?

I can also use a machine vision setup at work, but it's hardly worth the trouble.

Edited 1 time(s). Last edit at 07/23/2011 05:53PM by jcabrer.

Those samples look good. What layer height are you using?

I have not used anything smaller than a 0.4mm nozzle so I don't have anything useful to contribute at this time.

Layer height is 0.15mm

madscifi Wrote:
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> Those samples look good. What layer height are you
> using?
>
> I have not used anything smaller than a 0.4mm
> nozzle so I don't have anything useful to
> contribute at this time.