Bed temp drop/DEF SOLVED!!

[skyjuice]

I just found the problem with my machine (V3) and why the bed was dropping in temp, then both temps reading DEF. The whole time, the bed thermistor was touching just a sliver of the metal ringed hole the glass bulb sticks out of. I put a piece of Kapton tape down over the hole, popped a hole in the tape and that prevents any contact with the surface and the thermistor...and now I am printing better than ever! If anyone is struggling with DEF temps and hasn't looked at this, I would highly recommend taking a close look at how yours is inserted into that hole. Hope this helps someone!!!

Rostockmax V3

[BacklashRC]

You put the tape between the thermistor and the glass? I would think that it would be better to get the temp from the glass than the bed ring, since it is the glass that the filament is sitting on?

[geneb]

He covered the hole in the Onyx from the bottom and then poked a tiny hole in the tape, then shoved the thermistor back through the hole.

g.

[skyjuice]

He covered the hole in the Onyx from the bottom and then poked a tiny hole in the tape, then shoved the thermistor back through the hole.

g.

You got it

[aodhan]

Thumbs up to this. I had the same problem at my hot end yesterday. DEF in the middle of a five hour print. Removed the thermistor clamp screw, lined it with kapton, laid the thermistor back down and replaced the screw. Temp went from reading about 19C to 27C (19C must be the value it reads when one leg is shorted, because whenever it's 19C it doesn't budge even when heat is applied.

The thing I wonder, though, is why when they go DEF the printer keeps moving. Without temperature control it just keeps going trying to extrude material. I can't imagine that's very good for the machinery.

[skyjuice]

Awesome! I finally contributed something glad that little trick worked for you!

[Zob]

Great tip skyjuice, thanks!

I've been having this problem intermittently for months and that's sorted it. My thermistor legs were also a fraction too long so I just bowed them out a little to get the tip right in the centre of the hole.

Zob