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Ceramic union for joining hot end and cold end. Something to try...
Posted by Qcks_
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Ceramic union for joining hot end and cold end. Something to try... May 21, 2015 09:28PM |
Registered: 9 years ago Posts: 52 |
So... I have an idea and I'm kinda wondering what y'all think.
High thermal transfer is a great property in a hot end, but it makes joining it to a soft plastic cold end difficult (whether it's a bowden PEEK tube or a direct drive extruder is kinda irrelevant here.).
For all metal hot ends, they work around this by using fans, but I've seen just enough about fans disrupting prints that I think glass and ceramic would be a better solution.
Specifically, I want to make a ceramic piece that holds a glass capillary tube in a sleeve that conforms to the basic shape of a J head. The ceramic piece could be molded using a silicone mold (for someone looking to DIY this).
After it dries, it could be green fired (if it's a low temp clay) and drilled out so that a single glass capillary tube could be inserted down the length of the ceramic piece. The glass tube would replace the PEEK liner and would be smooth. If it doesn't hold in place through compression and/or tension, sodium silicate could be used to glue the capillary tube in place. The ceramic piece would be done at that point, but if you had a kiln you could experiment and make a porcelain piece.
If i was more into glass blowing, I'd probably just make a glass cylinders with the proper notch work. That'd make a clear joiner between the hot and cold end that could be instantly checked for jams, have the needed smoothness to print soft filament, and provide thermal isolation of the hot end from the cold end, but I don't have glass working skills/supplies.
With regards to the thermal expansion mismatch, As long as the glass is thick enough, it should handle compression stresses without issue. The real problem would be stretching (tension), but that can be mitigated by design some what.
High thermal transfer is a great property in a hot end, but it makes joining it to a soft plastic cold end difficult (whether it's a bowden PEEK tube or a direct drive extruder is kinda irrelevant here.).
For all metal hot ends, they work around this by using fans, but I've seen just enough about fans disrupting prints that I think glass and ceramic would be a better solution.
Specifically, I want to make a ceramic piece that holds a glass capillary tube in a sleeve that conforms to the basic shape of a J head. The ceramic piece could be molded using a silicone mold (for someone looking to DIY this).
After it dries, it could be green fired (if it's a low temp clay) and drilled out so that a single glass capillary tube could be inserted down the length of the ceramic piece. The glass tube would replace the PEEK liner and would be smooth. If it doesn't hold in place through compression and/or tension, sodium silicate could be used to glue the capillary tube in place. The ceramic piece would be done at that point, but if you had a kiln you could experiment and make a porcelain piece.
If i was more into glass blowing, I'd probably just make a glass cylinders with the proper notch work. That'd make a clear joiner between the hot and cold end that could be instantly checked for jams, have the needed smoothness to print soft filament, and provide thermal isolation of the hot end from the cold end, but I don't have glass working skills/supplies.
With regards to the thermal expansion mismatch, As long as the glass is thick enough, it should handle compression stresses without issue. The real problem would be stretching (tension), but that can be mitigated by design some what.
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Re: Ceramic union for joining hot end and cold end. Something to try... May 22, 2015 02:39AM |
Admin Registered: 16 years ago Posts: 13,889 |
... search through the forums with "All Dates" set for "limestone" and "glass hotend" - some 6-7 years ago some people (especially nophead) tested with ceramics, limestone and glass as materials ...
Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
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Re: Ceramic union for joining hot end and cold end. Something to try... May 22, 2015 10:19AM |
Registered: 9 years ago Posts: 52 |
Actually, I have read through the entry in the wiki on all-glass hot ends several times. It's interesting, but the methodology is kinda weird.
I suspect that the different rates of expansion and contraction was the reason for the solid one material hot end. It makes sense, but I think the baby went out with the bath water.
The brittleness is quite as a problem with water glass, but full ceramics are not discussed in the forum topics I could find. The issue maybe that I'm on my phone ATM, but the water glass stuff was kind interesting. I'm still kinda advocating a different process here though. Water glass is a glass product, but it's not often used alone. If you carved a firebrick and then used water glass as an outside finishing treatment, that probably would have yielded better results.
I suspect that the different rates of expansion and contraction was the reason for the solid one material hot end. It makes sense, but I think the baby went out with the bath water.
The brittleness is quite as a problem with water glass, but full ceramics are not discussed in the forum topics I could find. The issue maybe that I'm on my phone ATM, but the water glass stuff was kind interesting. I'm still kinda advocating a different process here though. Water glass is a glass product, but it's not often used alone. If you carved a firebrick and then used water glass as an outside finishing treatment, that probably would have yielded better results.
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