Comments for The Smell of Molten Projects in the Morning

Comment on Makergear M2: Hot End Temperature Profiles by Makergear M2: Extruder Thermistor Recalibration | The Smell of Molten Projects in the Morning

Tue, 21 May 2013 11:18:35 +0000

[…] « Makergear M2: Hot End Temperature Profiles […]

Comment on Makergear M2: Thermistor Tables by Makergear M2: Hot End Temperature Profiles | The Smell of Molten Projects in the Morning

Mon, 20 May 2013 11:08:06 +0000

[…] in the M2 normally uses thermistor Table 1. I adjusted those values to create Table 8, which exactly corrected the mismatch, at least with the earlier, thinner […]

Comment on Thermocouple Ensemble Comparison by Makergear M2: Hot End Temperature Profiles | The Smell of Molten Projects in the Morning

Mon, 20 May 2013 11:08:02 +0000

[…] that all the thermocouples and amps and meters report more-or-less the same values, I tucked several of them around the hot […]

Comment on Thermocouple Ensemble Comparison by Ed

Ed — Sat, 18 May 2013 12:05:27 +0000

EMI from the heater driver PWM

That, at least, seems to not be a problem, as the firmware averages (sorta, kinda) 16 successive temperature measurements. I ran the tests with a DC supply and the results match up with measurements on the extruder, so they're pretty close.

thermocouples depend only on the composition of the wires

For a while, I was expecting to discover, ah, shall we say, melamine contamination, but all of the thermocouple ~~beads~~ nuggets agreed with each other. Definitely a puzzle...

Comment on Furnace Heat Exchanger: Temporary Repair by Capping a Sink Drain Pipe | The Smell of Molten Projects in the Morning

Capping a Sink Drain Pipe | The Smell of Molten Projects in the Morning — Sat, 18 May 2013 11:48:37 +0000

[…] put the new furnace (replacing the old one) closer to the wall with the flue pipe, displacing an ancient slop sink (which vanished from the […]

Comment on Thermocouple Ensemble Comparison by Bill Rutiser

Bill Rutiser — Sat, 18 May 2013 02:12:48 +0000

I took a heat transfer course 50 years ago. Essentially I learned two things. The once maybe useful thing is why the insulation on steam pipes is shaped and sized the way it is. The other was that almost all of the formulas had about as many empirical constants as variables.

If I understand the physics correctly, thermocouples depend only on the composition of the wires so two of the same type should work the same although I suppose impurities might produce a variance. I do wonder though about EMI from the heater driver PWM getting into the thermocouple electronics.

You might consider a rapidly circulating oil bath to speed up stabilization in your calibration experiments.

Don’t give anything I say two much weight particularly if it doesn’t make sense. I have been known to say more than I know but I do try to avoid it.

Comment on Thermocouple Ensemble Comparison by Ed

Ed — Fri, 17 May 2013 16:47:05 +0000

the second degree burn scab

Until you've had that happen, you really don't know why steam burns are so terrible. Just reading about guys who get full-body burns is a queasy experience; it converts the abstract concept of Enthalpy of Condensation into visceral knowledge. Done it a few times, on a very small scale, and that's entirely enough for me.