Adventures in 3D printing a watercooling reservoir

Alright folks, this is probably going to be either entirely uneventful or a complete waste of time. I don’t think there’s an in-between here.

I’ve had a need for a very specifically designed reservoir for a while now, so I can fit it in my ITX build. I’ve seen the hardcore DIY folks making their own acrylic reservoirs out of panels and cement before, so I figured “well, I’ve got a 3d printer, why not try it myself?”

I’ve got my printer tuned fairly well to the point where layer adhesion isn’t going to be a major issue.

I’m currently printing a 40x40x40mm test res with 3 ports, inlet, outlet and fill. The idea here is to just hook it up to a spare pump I’ve got laying around and do a pressure test. Will it hold water?

Printing at 205c, 70c, 55mm/s at a layer height of 0.24mm

Rocking the Ender 3 pro, glass bed and BLTouch upgrades.

I’ll update yall in ~3 hours, when the print’s done.


I can’t think of any reason why it wouldn’t work. What material are you using for the print?

Just straight PLA for now.

I know it’s biodegradable and probably won’t last with watercooling, but once I bootstrap my ABS printer, I’ll get something stronger sorted.

Cranked the feedrate up to 200%, So hopefully this will be a quick print xD

I never tinkered with 3D-Printing. So excuse this potentially dumb question: How much do 3D prints behave like clay?

From my (limited) experience when doing pottery without a wheel (by layering coils) is the seams inside the vase are never tight enough to hold water so you get wet spots. A layer of glaze will fix that.

Would a coat of paint fix that in 3D printing, if that is an issue at all?

So that really comes down to layer adhesion.

people 3d print coffee mugs regularly, and they seem to hold water fine.

I haven’t personally tried messing with water yet, so that’s why this thread is titled “adventures in”

But yes, they do have “3d print glaze” compounds that sort of “finish” prints, but it’s not specifically geared towards waterproofing them.


PETG is a common material for watercooling parts, and it’s less stinky than ABS.

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Yeah, I’m thinking I might try a petg. I have a spool but haven’t opened it yet, so I can’t speak to it’s quality.

Best to have a drybox available when you do open it. It absorbs water from the atmosphere the same way PVA and nylon does.

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Yeah, I’ve got a drybox for my tpu

At least, it’s 19% according to the shit cheap sensor I put in the box.

Print went wrong, reprinting with some support in the holes where it’s needed.

How many walls and what is your infill % ?

4 walls, no infill needed (walls touch). 0.4mm. Mostly wanna develop proof of concept, then I’ll move to better mats.

Should be able to hold.

From asking others into trying to 3d print vs CNCing stuff, there are certain types of designs that don’t work with plastic based 3D printed parts–for the most part 3D printers are great for quick protoyping and then working on a final revision. (don’t know anyone with a metal 3D printer) In my opinion there are cases of its better to over-engineer when in doubt about the limits or quality level of a 3D print(or the printing material)

Only downside I could see with a watercooling reservoir is the seal factor could be more of a problem than just micro-layer leaks–a layer of glaze would still be a good idea.

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4 should be good probably, but yeah PETG would be better for that layer adhesion, but it can be such a pita to print with.

I have plans to switch to other mats and possibly not even use 3d printing in the end for this.

I think something like XTC-3D will be used on the final product if I don’t switch over to acrylic welding.

I’ve learned how to optimize prints, so I’m confident I can get it to come out fairly good.

I’m working on designing the next stage now.

I’ve learned how to optimize prints, so I’m confident I can get it to come out fairly good.

I’m working on designing the next stage now.

Oh I am confident in your prints too, was just having problems with my own prints with PETG after flawless PLA prints.

Btw, wouldn’t it be better to do circular model for this? Circular walls would spread the pressure around model much better.

I’m not using a d5 pump, so I’m not concerned with pressure. DDC doesn’t make much head pressure at all.