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Lulzbot heater M305 settings?

Posted by ampapa

ampapa

Lulzbot heater M305 settings?
November 21, 2017 08:21AM

Registered: 7 years ago
Posts: 128

Trying to find the correct Gcode settings for a Lulzbot 24v silicone heater... has a 100k thermistor.

;M305 P0 T100000 R4700               ; Bed thermistor

I think I'm missing a "B" parameter..

Can anyone assist?

ampapa,

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dc42

Re: Lulzbot heater M305 settings?
November 21, 2017 03:56PM

Registered: 10 years ago
Posts: 14,672

Lulzbot is heavily into open source; so if all else fails, find the part number from the bill of materials. Or email them and ask for the part number.

If the manufacturer publishes a resistance Vs temperature table for the thermistor, then it's better to put 3 resistance-temperature pairs into the calculator built into the configuration tool to get both B and C parameters.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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ampapa

Re: Lulzbot heater M305 settings?
November 21, 2017 06:27PM

Registered: 7 years ago
Posts: 128

I found the following in some of the documentation but am unsure where to find that "Table?

"If using Marlin/Sprinter firmware, select temperature table #7 for the correct temperature reading."

IMG_1874.JPG

Thanks,

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dc42

Re: Lulzbot heater M305 settings?
November 22, 2017 04:27AM

Registered: 10 years ago
Posts: 14,672

According to [github.com], table 7 is for a 100k Honeywell 135-104LAG-J01 thermistor. According to [pdf2.datasheet.su], the beta is 3974.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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ampapa

Re: Lulzbot heater M305 settings?
November 22, 2017 08:08AM

Registered: 7 years ago
Posts: 128

Many thanks for the information!

Ampapa,

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ampapa

Re: Lulzbot heater M305 settings?
November 22, 2017 09:21AM

Registered: 7 years ago
Posts: 128

dc42,

Does the beta really matter? most of the config.g files I see only have the T/R parameters is it helpful to have the beta?

ampapa,

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dc42

Re: Lulzbot heater M305 settings?
November 22, 2017 12:44PM

Registered: 10 years ago
Posts: 14,672

There is a default beta value in the firmware. If you use the wrong beta then your temperature readings will be accurate at low temperatures, but not at higher temperatures.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].