3D Printer hot end project

[StevenQ-NE-UK]

Greetings Makers,

I just thought I'd post some "story so far" pics of my prototype 3D printer hot end.

It has an M10 mounting thread and is based on the E3D style of hot end, but in my design the heat break and the heatsink are all one part.  The nozzle is a 0.4mm Makerbot Replicator style "ebay spare part".

The pics show my heatsink (made using the space lathe) fitted to an E3D heater block and fan mount.  The next step is to make my own heater block and 3D print my own fan mount.  I plan to pick up one of those super cheap Prusa i3 kits to try it with once its done.

Anyway, here are the pics

If anyone has any ideas for improvement or would like one to try on their printer, just let me know

thanks

Steve

[Jon Davies]

Good work! Keep us posted. :)

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[Ed Bisdee]

SHINY!

[Glen Beestone]

Nice job

 

G

 

Sent: Friday, November 13, 2015 at 1:17 PM
From: "'Ed Bisdee' via North East Makers" <north-ea...@googlegroups.com>
To: "north-ea...@googlegroups.com" <north-ea...@googlegroups.com>
Subject: Re: [Makers] 3D Printer hot end project

[Greg Fenton]

Great work :)
What is the material cost and how long does each one take to make?

Greg

[Carlos Rosales]

Good Job!!!

It's look very good and compact. Did you think about do a dual hotend?

I have a 3D Printer at home, if you want I can test it some day :)

Carlos

[StevenQ-NE-UK]

So, it's update time once again.

On Thursday I powered the hot end up and the heat sink got stinking hot while the thermistor didn't ever read the target temp.  This has lead me to believe that increasing the thermal conductivity to the heat sink is a bad thing.  I proceeded to turn the heat sinks heat break thinner on the lathe.  This had positive results in the heat sink was cooler and the thermistor was reading closer to the target temp.  So, I turned the heat break a little thinner, but alas it was too thin and it snapped off under assembly.  Looks like there's a reason no one else has made a combined heat sink / heat break from aluminium.

Looks like it's back to the drawing board on this for now

Steve

[Jon Davies]

I know nothing on this subject, but it won't stop me asking (stupid) questions to get people inspired...

Is there a metal with really really low thermal conductive properties?

Is there some other strong material with really low thermal conductive properties?

Could a collar and plate be machined from such a material?

--

[Paul Hurley]

Is there a metal with really really low thermal conductive properties?

 - Yes, but they typically have poor mechanical properties (bismuth) or other issues (plutonium).  Bronze or cast iron look best...

Is there some other strong material 

with really low thermal conductive properties?
 - Wood or plastic (ptfe ?)

Could a collar and plate be machined from such a material?

 - Probably.

I'd imagine the issues here will be a trade off for mechanical strength, a smooth join between hotend, heatbreak and heatsink and minimising heat rising.  Possibly cutting grooves in the heatbreak and filling with plastic such as ptfe for strength ?

(answers from http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html )

Paul.

[glenb]

If you want to stick to metals then stainless steel is a surprisingly poor heat conductor , compared to aluminium or brass which is what the melt chamber changes is usually made of.


http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

J head bodies are machined from PEEK which is a good tough plastic and a good insulator.
But PEEK softens above 250 degrees so is no good no good for printing high temp materials like some nylons

G

[glenb]

I just realised I posted the same link as Paul.
:-)

[Jon Davies]

>or other issues (plutonium)
Oh my god %) let's pass on that material please :D

>Wood
Isn't that gonna get a bit burny???

Thanks for that though, all very I formative.  Wood is particularly cool and didn't know that about plutonium.  Absolutely no idea what Bismuth is, never heard of or interacted with it before.  (I suspect I've experimented with it as a radioactive source in school maybe???)