Watercooled Tri-Hotend

Hi guys,

my first post in this forum and it's already a big one!

Summary:
I designed an all in one printer-head for Delta printers, including watercooling, 3 hotends and a mount to the 6 steering-rods.

My goal was to make this thing as cheap and durable as possible, while being lightweight.
As you can see in the pictures, I used aluminum for all parts, except the lower coverplate, which is made of stainless steel. The brass hose connectors in the pictures are just an experimental setup, so those won't be on the finished release.
Without electronics and connectors, but filled with water and with connected nozzles, as well as screws the thing's weight is 80g.

The distance between the two arms of the head ist 37mm, so the rods on the printer should be at least this far away from each other. The head fits into most printers, according to my research (correct me if I'm wrong, please ). I used 3.5mm spacers (pic) to achieve the whole possible gimbaling motion of the IGUS KBRM-03MH bearing.

I would like to point out, that I've already made a kickstarter campaign, to buy material in big amounts-> cheaper parts. This should not be an advertisement at all, but if you'd like to contribute/share, that would be nice of course. Thinking about it now, I really should have posted this beforehand here, but I only thought about it after handing in the project, naturally.

I hope some of you take the time to answer to this post and let me know if there are any enhancements which I can make and/or just discuss with me. Ask me anything which is not clear! (I'm an engineer, not a good writer )
Happy discussing!

Cheers,
Dragobert

Dragobert,
I looked at the kickstarter details.
The parts look beautiful.
The only thing missing is some samples of how it prints, even with one nozzle.
That after all is the bottom line.

---

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!

Looks nice, but i just cant get with water and electrionic.
Also how much does it cut down on your build space. The spacing of the nozzles look like a lot.

I about the printing: I know. but since i redesigned the Rostock to make it cheaper for me, I have some trouble printing good parts. After all, I'm not a man whose in love with electronics =/
About the build space: I think that's not that much. From the centerplane (mid of screws to the rods) to the bottom of the heater block without nozzle it's 21mm. Is that much? Unfortunately I don't have much for comparison except a standard hotend (which i never used).
Thanks for the answers so far, folks! =D

Cheers

Quote
Dragobert
I about the printing: I know. but since i redesigned the Rostock to make it cheaper for me, I have some trouble printing good parts. After all, I'm not a man whose in love with electronics =/
About the build space: I think that's not that much. From the centerplane (mid of screws to the rods) to the bottom of the heater block without nozzle it's 21mm. Is that much? Unfortunately I don't have much for comparison except a standard hotend (which i never used).
Thanks for the answers so far, folks! =D

Cheers

Was more speaking in XY vs Z.
All 3 nozzle look to make a tri with about 20-25mm legs.
So if your printing single nozzle prints your losse some XY movement.
I.e you ant print on the very edge of the build plate.

Now if your printer has a larger build pkate then its no problems.
Mines is 180 round which is alot smaller then my prusia which is 200 sq. But the kossel mini can go up to 210ish height vs prusa 170.

its' very pretty, but LOTS of unnecessary weight. I'll bet you can get the down to 60 grams easily, probably more. The effector is much thicker than really necessary. How much water flow is necessary to keep the cool parts under the melting point?


i would like a smaller version.

You're right, i think it's too heavy either. I'm experimenting to get the weight down, right now the following makes sense:

• replace the lower 2mm stainless steel plate with a 1mm aluminum one
• getting lost of the brass hose connectors

I'll make an update on that!
The effector's thickness is 6mm in total, but it's wallthickness is constantly 0.8mm, which I need to not kill the parts on the mill and drive acceptable feeds (also: stiffness, but not majorly).
The waterflow must be above 6l/min. That value is the minimum to keep the whole part below 45°C, which was my goal. Of course I could cut the volume inside by approx 25%, but I want it to be failsafe. Please also note that the silicone sealant rings must be below 180°C at all times, so that's a factor for the lower 3 ones too. Also the maximum working temperature for EN-AW7075-T6 is 90°C without loosing material strength after cooling.

Edited 1 time(s). Last edit at 12/26/2015 06:33AM by Dragobert.

Quote
xile6
All 3 nozzle look to make a tri with about 20-25mm legs.
/quote]

All 3 nozzles are on a circle with a 15mm radius, which cannot be (significantly) smaller, because of the heat distribution between the nozzles trough the plate (which will be aluminum from now on).

Sorry for the late answer, I somehow overlooked your post.

Also the system with silicone hoses and without the brass hose adapters works just fine and the Wim3rl is now down to exactly 60g!

Edited 1 time(s). Last edit at 12/28/2015 10:14AM by Dragobert.

Upate:
We just got lighter, as voi9viper said. We are down to 63g with water now!
Also, we tested the new hose connectors and I'm relieved to announce that everything is tight and sealed properly.