1 May
2014
1 May
'14
4:59 p.m.
once the resistor gets hotter than it should, it probably burns away
whatever paste is conducting its heat to the block, and runs away, so of
course there is no thermal glue there now..
I believe putting a cyindrical resistor in a cylindrical hole in an
aluminum block is a recipe for disaster, unless you have magic thermal
glue that is also pliable, since everything is expanding and contracting
with every thermal cycle.
I don't have any reason to believe there's anything wrong with the
thermistor, which is the temperature sensor.
i'll probably be there on saturday. Do you know if JB weld is a good
choice for gluing the resistor in place?
-jake
On Thu, 1 May 2014, Hol Gaskill wrote:
just popped by the space and noticed the air gap -
should probably use
some kind of high temp thermal grease. my bet is that the heater was
getting significantly above max temp but that heat wasn't getting
conducted into the block and into the thermistor. i'll check mine and
bring in on saturday for omni hackathon with a side of 3ding - will you
be around? would also like to learn how to work with thermistors.
cheers
on May 01, 2014, Jake <jake(a)spaz.org> wrote:
> if the TAZ we has now has the 2.0 schnozzle then it might use the 4.7 ohm
>resistor as seen
here:>http://www.lulzbot.com/products/heat-resistor-47-ohm>>of course the printer
will work with a different resistor as long as it >provides enough heat to print. Worst
case we have to insert M220 S50 to >slow it down to half speed printing until we get a
better resistor...>>what value resistors do you have? any special glue?>>On
Thu, 1 May 2014, Hol Gaskill wrote:>>> this is what i pull up for the part - 6.8
ohm:>> http://www.lulzbot.com/products/heat-resistor-68-ohm>>>> sounds
like the most common reason for these failing is over temp from
miscalibrated>thermistor - i did find those 3 i got for the type a machine and if
it's the same>part i'll bring them in.>>>> on May 01, 2014, Jake
<jake(a)spaz.org> wrote:>>> so i spent all evening (and some of last night)
to finally spool up the >gigantic>pile of black filament for the TAZ 3D
printer.>>i finally got it hung from the wall>with a!
dust cover over it
and ready to >feed smoothly into the printer, and then>i discovered that the heating
>element in its extruder head is dead.>>oh well.>>so,>we need a new
resistor to go in there. I don't know what the original >spec is, but>since the
whole thing runs on 24VDC and assuming 24 watts of >heat, that would be>a 24 ohm
resistor or so.>>Is someone other than me interested in contacting Lulzbot>and
asking >whether they want to send us a new resistor, or if they can tell us
what>>part number of resistor we should get as a
replacement?>>-jake>>P.S. yes i tested>the resistor and it's dead,
infinite ohms, it's burned >out. When we get a replacement>we can glue it in
there better than they >apparently did. If the glue goes bad
it>dies.>>>