Is this tech. model printable in stainless steel?

Hi Shapies,

I´ve made a model water cooler with a spiral channel inside the cylindrical body.
Material: Stainless Steel
The channel cross-section is 2mm x 2mm.
The wall thickness made on recommended minimum = 1mm.

Is there a chance to get this model printed & cleaned by Shapeways?

3D preview 1:
https://www.shapeways.com/model/3dtools/4602394/0/23?key=38a 0e1950053e8e3d7da89aa4aef0f32
3D preview 2 (cross section view):
https://www.shapeways.com/model/3dtools/4603028/1/23?check=4 &key=bec6bc28f8f1a67386cd8d3784c31054

Cross section view:

Doubtful. I mean, you can always send it up the flagpole, but I bet they reject under the "3mm clearance" rule.

When they're depowdering these, if there are holes below a certain size they have to poke the powder out of them with a pin or something, and it's not very easy to do that for channels that aren't straight. They want these to be big enough that the powder can flow out. Also sharp inside corners are a pain point because powder wants to stick in them: even at the 3mm diameter you might have better luck with round, or round-cornered, channels than square.

Steel printing is not done in-house at Shapeways, so you're not talking to the guys who will be doing the poking.

...Ok,- changed the channel from 2mm x 2mm to 3mm x 3mm.
"3mm clearance" rule should be accepted.

I don´t know, how the company cleans the model and I don´t know how much the powder is compacted inside the channel.
Could it be cleaned in an ultrasound bath? I do this possibly even at home

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I remember RamaRakosi tried something vaguely similar - a slightly bent pipe design, not even curled up like yours, and it would have required both a larger diameter and multiple "escape holes" along the side for cleaning. See this thread, where it is also explained that the problem is two- or even threefold - first they need to remove the loose steel powder that acted as support during printing, then they have to fill the void again with some refractory material so that it does not collapse or flood with bronze, finally they have to get that out again after the sintering.
(There was a happy ending to the pipe project after a redesign and a switch to cast brass, as seen in the It arrived thread - not sure if this would work for your model as well )

This is why they can't just leave the powder in and let you poke it out at home, it's part of an intermediate production stage.

Thank you for your advice.
To tell the truth, I forgot this one process step.

Thus, this model would be feasible bronze?

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You'll have to try - I do not think we ever saw a description of the support material used with the "wax", but it is probably something that can be dissolved or otherwise liquified for removal (same printer as for FxD as far as I know). The hurdles would then be whether they feel confident that the plaster slurry can fill the channel (probably without using a syringe or a vacuum pump) and later whether they think they can get the hardened plaster out (or are willing to ship it with plaster still stuck in the channel).

A two part solution and assembly with a gasket might be an option. Unless it must be one part. Or if you can stand a bit less cooling efficiency maybe get rid of the spiral and go with a larger internal cavity?

BTW, are you making a steam engine or an moonshine still?

I doubt it. A wax print might conceivably work (I wouldn't bet the farm on that), however in any cast material it would be extremely difficult to remove investment from a thin curved channel without escape holes. I doubt you can get that.

My reading of the other thread, about the pipe, was that it ended with the designer rethinking the curved tube, not having received it from Shapeways in any material.

Is the model for practical purposes? I guess so, since from the outside there is not much to see.

What kind of temperatures will you be operating with?
What kind of temperature drop are you looking for in the target flow?
What kind of flow rates?

Have you created this after calculations, or simply imagined a good solution?

Is a helical arrangement necessary, or would a simple cooling jacket work (with volume for turbulence it might be more effective).

Are there constraints on the external diameter? Could you replace this with a finned surface (think of a motorcycle engine) for example. Or a combination jacket / fins



Sorry I don't have an answer for you, but maybe these are useful questions...

Good luck.

The design was made for a FDM printing head cooler.

Function:
The filament starts from above and moves through the "cold end"
The yellow part is the "heat break"
The heat block & nozzle is mounted on the lower thread. (not shown )
So the main function of the heat break is, to separate the ~ 220° lower area from the cooled upper area.
This is the reason, why there´s an area without thread, to reduce heat transfer as much as possible.
( 1mm wall thickness only)
https://skfb.ly/N6Tp

I´ve tried to design a efficient light weight water cooler,- instead of the conventional air cooling with cooling fins.
I don´t want to simplify the design, because it would decrease efficiency.
Edit: & idealy it should work "out of the box" ... to cut only one thread.
Not acceptable to make this from 2-3 separate parts & extra sealings etc. ... too much work.
Maybe, I have just to wait a little bit for new 3D technologies... ( and acceptable prices )

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