how thin can I go with AA0.4?

[aag 6]

I am trying to print this M4-M3 adapter: https://a360.co/2DiFZOO

With my current parameters, Cura does not even bother to slice the upper part, presumably because the 0.6mm wall is too thin. Might somebody advise me if (1) such a part is printable at all with an AA0.4 print core, and (2) if so which wall thickness parameters would I need to input into Cura, or (2) whether it would be printable with a AA0.25 core? Thanks in advance!

 

Edited May 18, 2019 by aag

[rcfocus 0]

The wall is 0.3mm, not 0.6mm: (4.0 - 3.4)/2 = 0.3mm

That's too thin even for injection mold.

You might have to change your design.

[aag 6]

Thanks rcfocus, you are right. I however tried to print it with a Formlabs 3 resin printer, and it came out flawlessly even at its lowest resolution (100 micron)!

When it comes to small mechanical parts, I feat that SLA beats FDM hands-down (and it's competitive even on price, both equipment and consumables...).

[kmanstudios 1,120]

1 hour ago, aag said:

When it comes to small mechanical parts, I feat that SLA beats FDM hands-down.....

Yeah, I would agree, but I think most would agree.

 

Although my prints are not usually mechanical in nature, I do sometimes make small things.

 

A while back I printed up a series of parts for a much larger scene. This is a picture of a bunch of 'lab equipment' pieces. They may look really so-so in the picture, but that is because it is so close on such small objects. The comparison object is a U.S. nickel. Even at 0.1 layer heights, some of the objects are only 50 layers in height.

 

[geert_2 557]

Even if you could get it to print, you are likely to run into cooling issues, like this below. Unless you would print multiple parts next to each other, or with a dummy cooling tower next to it (=the square blocks in this picture).

 

An option might be to make the walls 0.5mm thick, so they print well on a 0.4mm nozzle, even after converting to STL. And then manually drill out the hole with a separate drill chuck. But it won't have much strenght.

 

I don't have a 0.25mm nozzle, so I can't comment on that.

 

Maybe you might want to search for a totally different solution too, if the purpose allows that. Or go for SLA if it doesn't need any strength (these light-curing resins might become very brittle and might deform under loads).

 

 

 

[aag 6]

Thanks but I do not fully understand. Did the bevels collapse because the thin parts melted? Also, what is the principle by which the neighboring tower would prevent this from happening?

[kmanstudios 1,120]

If the nozzle remains in an area too long, it will retain heat on the printed parts, thus issues with the melting shown above.

 

Those little tiny things I printed were several in the print environment while printing. That is how I got the really, super tiny coiled ' tube on on of the lab beakers.

 

They may look rough, but I am so zoomed into the part that it shows all the flaws. But it looks much better in real life.

 

edit:

Oh yeah, and when I am printing things like that, I am telling the line width to be 0.28 or 0.26 with the 0.4 nozzle.

Edited May 20, 2019 by kmanstudios

[geert_2 557]

15 minutes ago, aag said:

Thanks but I do not fully understand. Did the bevels collapse because the thin parts melted? Also, what is the principle by which the neighboring tower would prevent this from happening?

 

The cones can not solidify because the hot nozzle (200°C) is continuously on top of it, and it keeps radiating heat, so the model can't get below 50°C. The "dummy cooling tower" allows the nozzle to be busy for some time, far away from the object, so then it has time to cool down. This greatly reduces this overheating deformation, but it does not totally eliminate it. In very small objects you might still run into it.

 

This is another picture showing the effect: they are 20mm high. The ones printed standing (left, printed in different temperatures and speeds) are deformed due to insufficient cooling. The ones printed laying on their back (right) with several together, are okay.

 

Try various approaches, and various temps and speeds, with and without "dummy cooling tower", so you see the difference.