Either way, you aren't measuring the top of the glass no matter how hard the assertion.... You are reading a distorted view of the bed beneath it and NOT the glass, end of story - so yes it IS useless for reading glass temps.... They tell you right there on the datasheet for a reason

And yes, thermal resistance changes with temp.. Just like resistance does in a piece of wire, often by factors of 5 or 10 or more... the way say, a thermistor does...

Anyway, apologies for trying to set the record straight.... I'll leave everyone to their IR bliss...

Read this...all i know is my dog loves chasing the laser. But really, i think the word "useless" is a little strong. It might not be dead accurate, but when it reads 70 i know I'm good to go...thats useful enough for me.

Heres a little test i just did. Solidoodle is at room temperature. Here are the readings from RH, ir gun, and a thermometer i have in the bottom of the case:

RH= 25.8
Ir gun= 26.0
Cheap window thermometer= about 25

Don't know how the accuracy might change when it heats up, but that seems pretty accurate to me. Not trying to be argumentative. The Fluke article totally agrees with you...so you're totally correct. But the reading is still in the ball park.

Its like saying a car can do 200mph cause that's what the top speed on the speedo is...

Anyway, glass transmits IR straight through, and then distorts the returns, and alu scatters it to the point of irrelevance... At best your reading a skewed sample of a scattered return of the alu... Which the thermistor on the bed is already reporting far more accurately

Right tool for measuring glass temp is direct contact thermocouple or thermistor... Anything else is an approximation distorted by emissivity.

But feel free to remain unconvinced But using an IR/Laser temp probe isn't as easy to operate or accurate as one might think by reading the brochure, and why there is extensive training on interpretation and operation of Thermal Imager Systems

Couple bucks more and you could've gotten this. Think they had a deal a few weeks back that made it a couple bucks cheaper, but its what I'm using and it works great

http://www.amazon.com/gp/product/B000PA … &psc=1

It is a thermometer you are supposed to put directly on a grill to measure the temp. I figure it ought to work sitting on the printer bed too (though now the heater will have to heat up the thermometer as well as the glass). It should let me get a good idea of how long the temp takes to stabilize. At least it is cheaper than a good IR thermometer.

Once I start for the day it's on for 5 to 12 hrs straight so I figure the temp stays fairly steady.

Yeah...I left mine on the print bed with the glass over it; I throw a potholder on top and it usually cranks up to 90 in about 10-12 min.

The underside of your bed reaches 90 in 10-12 mins... the topside, not so sure... Remember where the thermistor is located... so thats whats '90', not the top side of the build plate the other side of the kapton. I'd be easily adding 5 minutes to those times to have the glass stablized to that temp (which wont report on the thermistor, as its a veritable mile away from the top of the glass)

The polyamide itself still gets quite toasty, which is why it still 'works' when its the *very last* layer.... but it doesn't transfer heat worth a damn....

My first part from the acetone vapor dip. Put it in 3x for 30 minutes then let it dry for about 45m each cycle. It was a part that was made using .3mm layer height. I think some of the sand from the sandpaper got in the grooves because it didn't smooth out all the way. Probably hard to tell from the picture, but it almost has a carbon fiber look. I'm sure the whole process would be faster with heat...but overall not to bad for $7 of parts.

Hi muddtt,

If you want it seamless .1 layer height would be best and if you wanted to print with a higher layer height I would
go with 120 grit wet sand paper all the way to 320 wet sand paper lightly and, use a duplicolor filler primer with about 3 to 4 coats with 20 min intervals and sand that down wet between each coat.

It will look spot on like an injection molded part.

I have a commercial tweak that I'm developing to quickly smooth the parts.

I'll post pics soon