1 Topic by foul_owl

  • foul_owl
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Topic: Attaching thermocouple

Hi folks,

I'm trying to determine how to attach the thermocouple. Obviously the location of this sensor has an impact on the filament quality, if I put it in the wrong spot my temp is going to be offset by a certain amount.

The instructions simply say "attach to plug with kapton tape" but no pictures or further instructions are included. I am assuming this means just anywhere on the flat face of the brass plug. Is that correct?

If so, there are two issues here.
1. We need to attach a spherical element to a flat surface. This requires forming the kapton tape around the spherical thermocouple tip, which doesn't allow much surface area for adhesion. I set this up last night, and everything seemed to work when cold. I used multiple pieces of tape, and pushed the tape down hard against the brass plug with my fingernail. However, once I started heating things up, the kapton tape lost adhesion, the thermocouple slipped off, and the heater went on full blast. Obviously this scenario needs to be avoided at all costs to avoid destruction of the abs, or I suppose possibly a fire.

2. The kapton tape doesn't stick at 180C.

Please just tell me the best way to do this. Thanks!

2 Reply by IanJohnson

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Re: Attaching thermocouple

There is a hole in one of the flats on the side of the plug for the thermocouple.  Stick it in there, and then wrap kapton around the plug several times.

3 Reply by foul_owl

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Re: Attaching thermocouple

Aha! Thank you, I must have missed that hole. I'll try that tonight.

4 Reply by elmoret

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Re: Attaching thermocouple

The instructions say to "insert the thermocouple in brass plug"  I guess I could revise this to "the hole in the side of the brass plug", but I thought that was apparent. Sorry for the trouble!

Also, there's only enough heater power available to get to 230C by design, so extreme temperatures should not be a possible outcome if the thermocouple were to come off, or give a bad reading.

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5 Reply by kocy

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Re: Attaching thermocouple

The electrical part in the documentation comes after the mechanical. So i insulated the hot end. Should the thermocouple wiring be inside the insulation? I suspect all cables have to be kept out of the insulation?

6 Reply by elmoret

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Re: Attaching thermocouple

Either is OK.

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E3Dv6 All Metal Hotend - the premier 3D printing hotend

7 Reply by cmcc

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Re: Attaching thermocouple

This is what I use, that sucker is never coming out:

http://www.mpja.com/Thermocouple-Type-K … o/32106+MI

8 Reply by davek

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Re: Attaching thermocouple

cmcc wrote:

This is what I use, that sucker is never coming out:

http://www.mpja.com/Thermocouple-Type-K … o/32106+MI


Ah, now I was looking at one of those threaded ones.  I'm guessing you tapped into the nozzle where the hole is - how deep?  Also, did you drill further than you tapped?  If so what depths and what sizes?

9 Reply by cmcc (edited by cmcc 2016-02-20 22:42:25)

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Re: Attaching thermocouple

I won't be home for a while so I can't check, but it shouldn't make a big difference. I used a bottoming tap so the threads go all the way down. You just need to be careful, because there is almost not enough material to drill/tap for a 6mm drill and tap. You  see the where the tap pushed the threads out from the thinnest section of the outer wall. I just eyeballed the depth, deep enough for the probe to screw in but not so deep to break through the extrusion hole.

EDIT: They are harder to find, but it would probably be easier to use something smaller than M6, which is one of the most common threaded thermocouples.

This should work: http://www.newegg.com/Product/Product.a … 27C3TY9948