Just got the (almost) last parts for my MK8 hotend together.

3D Printing
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Just got the (almost) last parts for my MK8 hotend together. I think it looks quite nice. The hotend is custom made to bear a thermocouple and a heater.

To do:

  • update openbuilds
  • get spacers done
  • wait for nozzle

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b94e501a518bd3a8a344ebcc0705e404.jpeg4640×3480 5.03 MB

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f2f2d96e4dc6404e959ea76d46aac13e.jpeg4640×3480 5.16 MB

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41854bb119410596720e1cd513cebb1b.jpeg4640×3480 6.38 MB

56a2a63a6f8f71db32c4d88f3033e063.jpeg
56a2a63a6f8f71db32c4d88f3033e063.jpeg4640×3480 6.01 MB

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ALLAH ACKBAR

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Not concerned about heating the extruder drive motor? It’s looking like you’ll have more thermal transfer between the the extruder parts themselves (gold part) and the motor than the heat sink.

I don’t have a lot of experience with direct drive extruders (my printers are both bowden setups) but yeah… can you get some small washers in between the gold extruder plate and the motor, so you don’t have the large, soon to be hot metal plate in contact with it?

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I know what you mean ans it reminds me of the big fan that sits on the side of the setup. I totally forgot it. It will act as an active cooling for the filament and also take care of the heat climbing up to the motor.

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You mean another fan, not pictured? Because the fan on the heat sink is not going to cool the motor at all; airflow will enter the heat sink then blow out the sides of the sink, which has only moderate contact with the extruder itself.

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Best to use a gasket
Look at this on eBay http://www.ebay.com/itm/281285157404

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@Nathan_Walkner ​ not heat from the motor, heat TO the motor. Needs a gasket/washer/spacer

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@Nathan_Walkner ​ my concern isn’t the motor generating heat, as correct voltage settings keep that controlled. My concern is, without a gasket, that hot end is heating the extruder feed itself while the heat sink has minimal contact. Thus, the extruder is going to keep getting hotter, and transfer that heat into the motor.

There’s better thermal transfer between the extruder and motor than between the extruder and heat sink.

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Everything will be fine with that setup. @Derrick_Whittet_Wint ​ yes, there must be one more fan mounted to the side. This setup also works very good in the replicator2 1st gen for instance. And the front mounted fan is just enough to keep the filament cooled.

The only thing I am concerned about is how cool the extruder if the is not enough to cool down temperatures of 400 degrees (if even possible) for peek printing. But that would have to be tested.

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@ThantiK ​ was this related to the custom heater block you were talking about in another thread?