Help on choosing the right hot end - j-head vs. magma January 22, 2014 06:36AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 08:59AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 09:06AM |
Registered: 10 years ago Posts: 10 |
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Ohmarinus
J-head 0.5mm nozzle for 1.75mm filament.
Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 09:49AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 10:03AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 10:58AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 11:00AM |
Registered: 10 years ago Posts: 869 |
As a non-engineer, it would seem to me that stainless barrel would be the more ideal solution then the worse one. If the tollerance of the inner diameter of the barrel is more consistant, then its easier to design around. If you presume that the diameter essentially remains a fixed size across a reasonable range of temperature then you know what that cavity size is. And if your extruder advances X amount of filament into the hot end, then X amount of filament is then extruded out. Where if the inner material is PTFE the thermal expansion is greater, giving a larger variance of the cavity size. Larger variance in cavity size leads to a larger variance in the amount of material extruded leading to inconsistances in print quality.Quote
ShadowRam
So no wonder PLA (that expands like a mo-fo) jams in these Hot-Ends. The stainless barrels aren't expanding enough to allow the 'warm' PLA to travel through.
Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 11:49AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 12:55PM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 12:59PM |
Admin Registered: 11 years ago Posts: 3,096 |
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Hobbit85
Ok thanks for the quick reply!
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Ohmarinus
J-head 0.5mm nozzle for 1.75mm filament.
isn't the 0.5mm nozzle for the 3mm filament? or both?
Sounds like a reasonable argumentation to start with a rock solid hotend which is commonly available and then upgrade if necessary... I just wonder why Colin recommended me the magma.
Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 01:38PM |
Registered: 10 years ago Posts: 553 |
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ShadowRam
ya know,
I've just been reading up on some of the problems people have been having with All Metal Hotends and jaming, and I was trying to figure out why the J-Head has been so awesome with no problems.
The Thermal Expansion of PTFE Liner is ~ 100 (x10-6/K) with a conductivity of 0.25 (W/m-K)
The Thermal Expansion of PEEK is ~ 47 (x10-6/K) with a conductivity of 0.25 (W/m-K)
The designers of the these new Hot Ends have picked Stainless Steel due to the fact that it's conductivity is ~ 18.
So Stainless doesn't conduct heat nor heat up well at all. 18 compared to 0.25
But I think they failed to take into account that stainless steel also only expands at ~16 (x10-6/K)
So not only does these stainless tubes not absorb heat, but they also don't expand at all. Double Whammy.
So no wonder PLA (that expands like a mo-fo) jams in these Hot-Ends. The stainless barrels aren't expanding enough to allow the 'warm' PLA to travel through.
The reason PTFE liners work so well is because they expand with the PLA at close to a similar rate.
Stainless Steel is a terrible choice.
EDIT: Researching some more there really isn't a good material choice. If it's a thermally non-conductive material, it usually means it won't expand much either. So the only way I could see a all metal Hot-End working well is if the stainless portion is short, and over-sized.
Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 01:51PM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 01:53PM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 03:33PM |
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Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 04:18PM |
Registered: 11 years ago Posts: 265 |
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tjb1
I've run quite a bit of PLA, ABS and PC through my E3D with no problems (besides the PC having too much moisture). I've even switched from ABS to PLA midprint to get a dual color print...materials are different because I wanted those colors and those were the materials I had the color in.
Re: Help on choosing the right hot end - j-head vs. magma January 22, 2014 07:32PM |
Registered: 12 years ago Posts: 39 |
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ShadowRam
So Stainless doesn't conduct heat nor heat up well at all. 18 compared to 0.25
But I think they failed to take into account that stainless steel also only expands at ~16 (x10-6/K)
So not only does these stainless tubes not absorb heat, but they also don't expand at all. Double Whammy.
Quote
ShadowRam
So no wonder PLA (that expands like a mo-fo) jams in these Hot-Ends. The stainless barrels aren't expanding enough to allow the 'warm' PLA to travel through.
The reason PTFE liners work so well is because they expand with the PLA at close to a similar rate.
Re: Help on choosing the right hot end - j-head vs. magma January 23, 2014 08:48PM |
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Re: Help on choosing the right hot end - j-head vs. magma January 25, 2014 11:43AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 25, 2014 11:47AM |
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Re: Help on choosing the right hot end - j-head vs. magma January 25, 2014 04:10PM |
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Re: Help on choosing the right hot end - j-head vs. magma January 25, 2014 07:48PM |
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Re: Help on choosing the right hot end - j-head vs. magma February 25, 2014 09:49AM |
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Re: Help on choosing the right hot end - j-head vs. magma February 25, 2014 03:11PM |
Admin Registered: 15 years ago Posts: 1,470 |
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Robdizz
Crap, So I just ordered my Makerfarm i3 8" with the .35mm J-Head hotend...and Im a noob to 3d printing...Did I just screw myself??
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