Upgraded thermistor reads way above actual temperature

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dsl158
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Upgraded thermistor reads way above actual temperature

Post by dsl158 »

Ive tried everything and I am so desperate. I bought a E3D V6 hot end. I never updated the firmware because I had no Idea I had to but then it broke. I bought a pack of new ones http://www.amazon.com/gp/product/B00GD4 ... ge_o00_s00

I installed the new one and updated the firmware exactly as instructed on the wiki I even calibrated the PID. PLEASE HELP IM RIPPING MY HAIR OUT. Do you think I should just buy a new thermistor?
BenTheRighteous
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Re: Upgraded thermistor reads way above actual temperature

Post by BenTheRighteous »

How do you know your temperature is reading wrong?
(It probably IS wrong, and I'm hoping you'll say you have a thermocouple)
What did you set your EXT0_TEMPSENSOR_TYPE to in your firmware?

I don't see an entry in the comments for what you bought so what you probably need to change are these:
EXT0_TEMPSENSOR_TYPE 97
GENERIC_THERM1_T0 25
GENERIC_THERM1_R0 100000
GENERIC_THERM1_BETA 3950

That's just based off what Amazon says. You probably need to look up the actual spec sheet to verify those numbers are right.

Assuming you've got that thermocouple I mentioned, you can tweak the beta value to bring the printer's temperature readout into precise agreement with the actual temperature.
nitewatchman wrote:it was much cleaner and easier than killing a chicken on top of the printer.
dsl158
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Re: Upgraded thermistor reads way above actual temperature

Post by dsl158 »

BenTheRighteous wrote:How do you know your temperature is reading wrong?
(It probably IS wrong, and I'm hoping you'll say you have a thermocouple)
What did you set your EXT0_TEMPSENSOR_TYPE to in your firmware?

I don't see an entry in the comments for what you bought so what you probably need to change are these:
EXT0_TEMPSENSOR_TYPE 97
GENERIC_THERM1_T0 25
GENERIC_THERM1_R0 100000
GENERIC_THERM1_BETA 3950

That's just based off what Amazon says. You probably need to look up the actual spec sheet to verify those numbers are right.

Assuming you've got that thermocouple I mentioned, you can tweak the beta value to bring the printer's temperature readout into precise agreement with the actual temperature.

Do you think if I just buy a new thermistor it will work? and i know because if I can put my finger on the extruder at "240" then im either a super hero or the hot end isnt hot and my config file already has all that
Last edited by dsl158 on Tue Jul 07, 2015 10:51 pm, edited 1 time in total.
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Jimustanguitar
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Re: Upgraded thermistor reads way above actual temperature

Post by Jimustanguitar »

240 at room temp sounds like a bad wiring connection. Check if the resistance measurement across the thermistor itself is the same reading that you get when you measure it at the Rambo connections. If this is different, you've got a loose connection somewhere that's giving you poor continuity. If that seems fine, measure it at the Rambo while you wiggle the wires going to the hot-end, it may be loose and intermittent.
dsl158
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Re: Upgraded thermistor reads way above actual temperature

Post by dsl158 »

Jimustanguitar wrote:240 at room temp sounds like a bad wiring connection. Check if the resistance measurement across the thermistor itself is the same reading that you get when you measure it at the Rambo connections. If this is different, you've got a loose connection somewhere that's giving you poor continuity. If that seems fine, measure it at the Rambo while you wiggle the wires going to the hot-end, it may be loose and intermittent.
it goes to 240 when its target temp is 240. It will have room temperature and when you set it to preheat it will go up very quickly. after it thinks its at 240 abs still wont come out. Its not a jam either ive checked multiple times
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Re: Upgraded thermistor reads way above actual temperature

Post by Jimustanguitar »

The cartridge in an E3D will heat up quite quickly, so that doesn't sound wrong, but not extruding anything does. Any chance there's a snag somewhere on the inside? Perhaps the bowden tube is canted and doesn't align with the hole through the heat-break and the filament is hitting that 'ledge' and not feeding through any further? Can you see light through the bore of the hot-end?
dsl158
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Re: Upgraded thermistor reads way above actual temperature

Post by dsl158 »

Jimustanguitar wrote:The cartridge in an E3D will heat up quite quickly, so that doesn't sound wrong, but not extruding anything does. Any chance there's a snag somewhere on the inside? Perhaps the bowden tube is canted and doesn't align with the hole through the heat-break and the filament is hitting that 'ledge' and not feeding through any further? Can you see light through the bore of the hot-end?
The bowden tube goes through the heat break
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