Quick All Metal Rebuild Hot End March 10, 2014 01:06AM |
Registered: 13 years ago Posts: 27 |
Re: Quick All Metal Rebuild Hot End March 10, 2014 01:48AM |
Registered: 11 years ago Posts: 246 |
Re: Quick All Metal Rebuild Hot End March 10, 2014 02:42AM |
Registered: 10 years ago Posts: 1,381 |
Re: Quick All Metal Rebuild Hot End March 10, 2014 03:28PM |
Registered: 13 years ago Posts: 27 |
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I would like to see you conduct a simple test, if it's not too much of a bother. smoking smiley
Re: Quick All Metal Rebuild Hot End March 10, 2014 10:02PM |
Registered: 10 years ago Posts: 1,381 |
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bstott
You say to duct air using aluminum foil? Foil on fan and not on SS? Purpose of this?
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bstott
Questions?
* Is the heatsink drawing the heat up the SS tubing? Quessed Answer: Probably.
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bstott
* Would this design be better as with regpye's to have the heatsink smaller and further from the hot end? Quessed Answer: Probably
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bstott
* Without the heatsink will the heat not travel up the tubing as readily and the hot end be able to print? Quessed Answer: Probably.
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bstott
Possible Conclusion: You are probably right that I crippled my hot end with the large heatsink and should mimic what regpye and the original T-O-M of three years ago had done
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bstott
So - how long could I print with an aluminum heater block, stainless steel riser and a small aluminum heatsink without a fan?
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bstott
Quessed Suggestion to others - keep a distance between the heater block and heatsink. The heatsink will then be smaller, further from heat source not drawing heat up the riser and would not require the active cooling from a fan
Heat sinkQuote
If there is no air flow around the heat sink, energy cannot be transferred.
Natural convection requires free flow of air over the heat sink.
If fins are not aligned vertically, or if fins are too close together to allow sufficient air flow between them,
the efficiency of the heat sink will decline.
Re: Quick All Metal Rebuild Hot End March 10, 2014 11:53PM |
Registered: 13 years ago Posts: 27 |
Re: Quick All Metal Rebuild Hot End March 11, 2014 12:51AM |
Registered: 10 years ago Posts: 22 |
Re: Quick All Metal Rebuild Hot End March 11, 2014 01:18AM |
Registered: 10 years ago Posts: 1,381 |
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bstott
The heatsink was drilled and reamed to be interference fit (press fit) with the SS riser. The two parts were hydraulic pressed together.
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bstott
Air flow? - The air flow idea for this build was to be forced air.
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bstott
In this application the rough cast SS piping surface also contributes a larger amount of external cooling surface area to the riser than a smooth rod. Good for my active cooling?
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bstott
was remembering that their effectiveness dimishes over length
[sound.westhost.com]Quote
If the heatsink is made double the width, the thermal resistance is halved as you would expect
However, should you decide to make the heatsink twice as long, the thermal resistance is
reduced by the inverse of the square root of the increase - in this case 1 / √2 (0.707).
To get half the thermal resistance, the heatsink would need to be 4 times longer.
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bstott
If for a passive application it would be better to design vertical fins rather than horizontal?
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bstott
the backstop of the heatsink will trap air to heat rather than cool. Negligible?
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bstott
- Heat Flow? ---- As you state - The heat flows to least resistance. Since the heatsink is full length of the SS riser it will contribute to the draw of heat from the heater block up the riser surface? and out the fins.
Re: Quick All Metal Rebuild Hot End March 11, 2014 08:47PM |
Registered: 13 years ago Posts: 27 |
Re: Quick All Metal Rebuild Hot End March 11, 2014 11:18PM |
Registered: 13 years ago Posts: 27 |
Re: Quick All Metal Rebuild Hot End March 12, 2014 06:26PM |
Registered: 13 years ago Posts: 27 |
Re: Quick All Metal Rebuild Hot End March 12, 2014 10:21PM |
Registered: 13 years ago Posts: 27 |
Re: Quick All Metal Rebuild Hot End March 24, 2014 12:51PM |
Registered: 13 years ago Posts: 27 |