Advice on my watercooling setup

Hey guys, I'm looking for advice or suggestions about watercooling my Delta printer. I'm using it to experiment with very, very high speed printing. It's going to have a heated chamber with a max most likely around 90C.

At these temps, my fan on E3DV6 is insufficient, so I need to either to resort to watercooling or having cool air funneled in. I've decided to go with watercooling.

I'm not sure how much watercooling I'll need. I'm going to drive my stepper drivers at higher currents (2A, can I push it further? Or diminishing returns?) to get the most out of my NEMA17s to get as high as accelerations as I can so I will be watercooling an E3DV6 hotend, 3 NEMA17s, the smoothieboard stepper drivers, and at least 2 Extruders inside of the chamber (Floating Extruder setup).


I haven't convinced myself on what kind of water pump i'll use. I have thought about the Kraken hotend pump

Filastruder Waterpump

,but it's only 240L/hr and was not designed with a heated chamber in mind with multiple components.

The rest of components will draw from PC watercooling components, a waterpump/reservoir combo, and generic waterblocks (aluminum) and an RC waterjacket for the E3DV6.

I'm trying to keep all the parts in the loop aluminum due to galvanic corrosion if I introduce other metals. I'll be using a biocide to prevent algae growth which I haven't seen anyone who has done watercooling for 3d printing mention, distilled water, and most likely an anti-corrosive mix just in case since I may not be able to find an aluminum radiator block for cheap.

Now about the radiator block, this is the most important of the loop because it controls how much heat transfer is possible. In the PC world, it is recommended to have 120mm for each component (CPU, GPU, etc). Now, our 3D printer motors don't usually get to that temperature, but with such a high temperature chamber on the extruders, it may be necessary to use a 240mm radiator (I don't mind, the delta printer will be quite large, relatively). I just want to avoid so much cooling that the hotend can't do its job properly (which is my largest worry).


Any tips or critiques are very welcomed. Thanks and Happy Holidays.

Edited 1 time(s). Last edit at 12/15/2014 09:54PM by 3DRapidClone.

"very, very high speed printing" ?
Well, good luck!

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Waitaki 3D Printer

3DRapidClone,

I'd like to see you succeed, I have a few worries tho...

I think that a 90C chamber temp will be too high. You will run into problems as with PLA where the filament does not freeze by the time the next layer goes over it.

Quote

I will be watercooling an E3DV6 hotend, 3 NEMA17s, the smoothieboard stepper drivers, and at least 2 Extruders inside of the chamber (Floating Extruder setup).

- Unless you buy separate high amperage drivers you will not be able to achieve even 2A reliably. Perhaps if you directly water cooled the driver chips you might approach that.

There are at least 8 issues that all combine together to affect quality at high speed:
1) Achievable stepper speed depends on voltage
2) Holding torque depends on current,
3) Acceleration - too much and it will miss steps.
4) Resonance can build up and caused missed steps, especially when doing infill (Slic3r can set different accelerations depending on the type being printed)
5) Moving mass of the effector, bearing blocks etc VS (a combination of acceleration + holding torque + resonance), a larger mass must have lower acceleration. Make it as light as possible.
6) The extrusion must cool enough between layers
7) Printing fast means higher hot end pressures, and the hot end has to be pressurized and depressurized rapidly or you will get blobbing. This is more difficult with a long bowden tube, and requires special firmware settings.
8) The hot end has to be able to extrude quickly enough.

I really do not understand why you want to put _any_ silicon electronics in the heated chamber. That's asking for big trouble. Since it's a Delta, your steppers could also be outside.

For the radiator block, you can use an auto heater core as your radiator. I had a water cooled PC I built that used one years ago with two slow and nearly silent 120mm fans on it, with a bit of antifreeze to keep things happy inside. You could smell that a bit tho... Used a large aquarium pump.

Good luck with your build

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My printer: Raptosaur - Large Format Delta - [www.paulwanamaker.wordpress.com]
Can you answer questions about Calibration, Printing issues, Mechanics? Write it up and improve the Wiki!

Quote
Paul Wanamaker
3DRapidClone,

I'd like to see you succeed, I have a few worries tho...

Thanks. and I hope to answer them all.

I think that a 90C chamber temp will be too high. You will run into problems as with PLA where the filament does not freeze by the time the next layer goes over it.

Stratasys recommends between 70C-90C. Realistically, I am going to be running the chamber at 70C. But 90C is the upper limit of what it can do and I wanted to account for that.

Quote

I will be watercooling an E3DV6 hotend, 3 NEMA17s, the smoothieboard stepper drivers, and at least 2 Extruders inside of the chamber (Floating Extruder setup).

- Unless you buy separate high amperage drivers you will not be able to achieve even 2A reliably. Perhaps if you directly water cooled the driver chips you might approach that.

The Smoothieboard Drivers are rated for max current of 2A and with either good heatsinks or watercooling I should be able to have it work fine. My Steppers are also rated for 2A

There are at least 8 issues that all combine together to affect quality at high speed:
1) Achievable stepper speed depends on voltage
2) Holding torque depends on current,
3) Acceleration - too much and it will miss steps.
4) Resonance can build up and caused missed steps, especially when doing infill (Slic3r can set different accelerations depending on the type being printed)
5) Moving mass of the effector, bearing blocks etc VS (a combination of acceleration + holding torque + resonance), a larger mass must have lower acceleration. Make it as light as possible.
6) The extrusion must cool enough between layers
7) Printing fast means higher hot end pressures, and the hot end has to be pressurized and depressurized rapidly or you will get blobbing. This is more difficult with a long bowden tube, and requires special firmware settings.
8) The hot end has to be able to extrude quickly enough.

I really do not understand why you want to put _any_ silicon electronics in the heated chamber. That's asking for big trouble. Since it's a Delta, your steppers could also be outside.

My steppers for moving the machine are in fact outside of the chamber, I just wasn't sure that using high current with high acceleration at high speed would make the stepper motors far too hot. I have found out that, that only current really makes the stepper motor hot and not how fast it accelerates. So it was just a safeguard to prevent overtemp protection. They won't be cooled by watercooling anymore, just heatsinks.

As for the the moving mass of the effector, it should still be extremely light. An RC water jacket is designed for RC boats so weight is of great concern. The water jacket only weighs in at about 14g. The tubing I will use is pretty small in diameter so the flow rate makes up for that. This also means the amount of water flowing through and onto the hotend will be lighter.

For the rapid pressure and depressurizing, It is the reason I am using a floating extruder setup and explains why I am having the extruder inside the chamber which then also explains why I am using watercooling. This means I can reduce the the bowden tube length down to about 100mm greatly increasing my ability to print flexible materials and decreasing blobbing and stringing which is important with high speed.

If the E3DV6 proves to be insufficient, I will be using the Prometheus hotend which allows me to customize the melting zone for higher speed printing.

I am still working on improving the extruder design however. I'll publish everything I get from my experimentation though on my blog once its up and running



For the radiator block, you can use an auto heater core as your radiator. I had a water cooled PC I built that used one years ago with two slow and nearly silent 120mm fans on it, with a bit of antifreeze to keep things happy inside. You could smell that a bit tho... Used a large aquarium pump.

I will be using either no radiator or a single 120mm (no fan) radiator to cool the system. Other than the extruder inside, there isn't much heat to be dissipated. 2 extruders, hotend essentially.

Good luck with your build
Thank you.

Excellent.
Looking forward to seeing it.

Edit:
Note that Stratasys does use a jet of cooling air.
See here about a third of the way down.

Edited 1 time(s). Last edit at 12/16/2014 08:17PM by Paul Wanamaker.