Andrew.
On 10-Nov-09, at 10:18 AM, Zach 'Hoeken' Smith wrote:
> Hmm. This is NOT GOOD. I had thought the manufacturer just changed
> the thermistor a bit, but I guess its a slightly different one. The
> good news: we can easily generate a new lookup table and the
> existing small thermistors will be just fine.
>
> This is documented here: http://www.reprap.org/bin/view/Main/Temperature_Sensor_2_0
> The thermistor in question is this one: http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=495-2125-ND
>
> First one to post the updated lookup table that properly reports
> values wins. Hint: you can get most of the values from the
> datasheet or measure them directly.
>
> In the meantime, I'll try and find a better thermistor replacement
> (the original flavor was discontinued)
>
> Cheers,
> Zach
--
"The future is already here. It's just not very evenly distributed"
-- William Gibson
I opened up my "\reprap-gen3-firmware-1.6\ArduinoSlaveExtruder" and
located a file by the name of "ThermistorTable.cpp".
This file appears to be written in plaintext and the content has a
series of entries that resemble your post.
I copied and pasted the text from your post and created a new
"ThermistorTable.cpp" file.
I open the Arduino IDE.
I select the Arduino Decimlia board.
I load "reprap-gen3-firmware-1.6/ArduinoSlaveExtruder/
ArduinoSlaveExtruder.pde"
But, hitting compile causes an error - saying "26: error:
SimplePacket.h: No such file or directory"
<I have not yet connected my computer to the plastruder board via the
TTL to USB cable>
Suggestions?
Thank you,
MakerBlock
On Nov 28, 8:08 am, jet <allartbu...@gmail.com> wrote:
> It looks like I have the 1mm bead, so I tested Zach's more and less
> conservative examples with a Fluke 88 using a temp probe under the
> insulation at the head of the nozzle:
>
> "./createTemperatureLookup.py --r0=100000 --t0=25 --r1=0 --r2=4700
> --beta=4198 --max-adc=1023" with a target temp of 220 and a Current Temp
> of 221, held steady on the Fluke at 169
>
> "./createTemperatureLookup.py --r0=100000 --t0=25 --r1=0 --r2=4700
> --beta=4315 --max-adc=1023" @ 220 held steady at 197, 240 held steady
> around 212C
>
> So I scrounged another multimeter and tested the resistance at 24C (room
> temp) and 150C (was easy to get it stable there), for values of 93.7K
> and .704K, then used reprap's calculator got a beta of 4881. Plugged
> all that in to the script for a new .ccp and hit/held 212C on the next try.
>
> Here's my table, if anyone else wants to try it. I suggest ramping up
> the temp slowly in case the values are too hot for your unit.
>
> // Thermistor lookup table for RepRap Temperature Sensor Boards
> (http://make.rrrf.org/ts)
> // Made with createTemperatureLookup.py
> (http://svn.reprap.org/trunk/reprap/firmware/Arduino/utilities/createT...)
<http://www.flatline.net/journal/2009/12/28/thermistortable-for-1mm-thermistors/>
And by "simple", I mean it has links to the detailed instructions
written by other people. :-)
The short of it is, follow the wiki tutorial on upgrading firmware.
When you get that working with the stock software, try swapping out the
thermistortable file and build again.
--jet
> --
>
> You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
> To post to this group, send email to make...@googlegroups.com.
> To unsubscribe from this group, send email to makerbot+u...@googlegroups.com.
> For more options, visit this group at http://groups.google.com/group/makerbot?hl=en.
On Dec 28, 1:12 pm, jet <allartbu...@gmail.com> wrote:
> okedoke, just wrote a simple set of instructions on how to swap out
> ThermistorTable.cpp:
>
> <http://www.flatline.net/journal/2009/12/28/thermistortable-for-1mm-th...>
> > For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.
You have to copy those library files into your Arduino build environment.
http://www.reprap.org/bin/view/Main/Generation3Firmware
-ethan
I've been looking on at this thermistor thing for a while...
Recently I rebuilt my extruder heater barrel assembly with one of the
new thermistors and also bought an assembly from Rick with the smaller
thermistor... and chose to make the leap to the modified thermistor
table.
After a few false starts due to not following the instructions on how
to compile the project properly, I got it done.
I can vouch the instructions are all there in the key pages (already
listed in this thread)...
You just have to read them fully... and not skim like I am prone to
do ;)
Anyway...
The point of my post is to provide a plot comparing the different
thermistor parameter sets I've come across (mostly on this thread).
Here's the link: http://docs.google.com/Doc?docid=0AXwI5ZZe0UmWZGM1cGZwZ3hfMGZn
You might recognise it as an excel chart... sorry to die hard
opensorcerers (sic)..., M$ is omnipresent in my work world ;)
I'm happy to share the associated spreadsheet if anyone wants it...
I'm mostly just reproducing the calcs of the python script and
including datasheet data.
I was curious about how the different number sets compared and...
picture, 1000 words etc...
The chart has linear scaled axes and is zoomed to show the temperature
range 150-350 degrees C.
This corresponds to the ADC range 0-250 (out of 1023) for most
parameter sets posted for this thermistor/resistor config.
I've shown the more/less conservatives from Zach, TeamTeamUSA's
numbers and Jet's numbers.
I've compared these to:
The distribution numbers (for 3mm thermistor) for v1.6 firmware.
The distribution numbers using higher resolution table in the lower
ADC end.
The T-R numbers for the extruder circuit based on the data table in
the datasheet for B57540G0104F000 (the small thermistor)
Most striking observation:
All the curves suffer from accuracy problems around the working
temperatures for ABS (200-250C).
This is due to the even spacing of the table, really.
I havent checked, but assume the table doesnt have to be evenly spaced
so I think it would be a good thing to increase resolution down low in
the ADC range... at the expense of temps 0-100C, say... or even use
logarithmic/geometric spacing...
I havent ever used python... cant be too hard... looks kind of
familiar... I might have a crack ;)
To avoid adding more confusion through more different tables I'm
asking what other think before posting a table...
I suggest the table be based on Zach's 255/220 parameters but use a
resolution of 16 "ADC units" above 200C, with wider steps to
compensate around 0-150C... or a bit less, maybe, to fully cover the
PLA range?
Stating the obvious: determining what temperature is best to print at
is going to differ slightly with every extruder and a certain amount
of calibration is necessary... The exact temperature profile will
differ with many things, the thermistor positioning and degree of
insulation from the barrel and ambient air will be different etc etc
etc.
That said, I think it makes sense to have a "recommended" table/
parameter set for each thermistor type... to help other indecisive
people like me to commit to something ;)
Cheers,
Tim.
OK, I chose to manually pick a profile biased towards resolution at
both (less linear) ends of the thermistor curve for twenty point
lookup.
I went with:
5,5,10,10,20,50,100,100,120,150,120,100,100,50,20,10,10,5,5
Starting at 25 and going through to 1010...
This is based on the 25C/220C parameters posted by Zach earlier.
Can easily apply to any other Beta/R0 etc or email the spreadsheet on
request.
It gives a bit of improvement in the range 200-250 as well as at the
low temperature end.
Graphical comparison to other parameter sets at:
http://docs.google.com/Doc?docid=0AXwI5ZZe0UmWZGM1cGZwZ3hfMmQ5M2JuMmc2&hl=en
Cheers,
Tim.
Thermistor table file (ThermistorTable.cpp) snippet:
//=================================================
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 4198
// max adc: 1023
#define NUMTEMPS 20
short temptable[NUMTEMPS][2] = {
{20, 317.6},
{25, 299.2},
{30, 284.9},
{40, 263.7},
{50, 248.1},
{70, 226},
{120, 193.1},
{220, 158.5},
{320, 137},
{440, 117.7},
{590, 97.4},
{710, 81.5},
{810, 66.7},
{910, 47.3},
{960, 32.6},
{980, 24},
{990, 18.5},
{1000, 11.4},
{1005, 6.9},
{1010, 1.2},
};
//=================================================
On Dec 30 2009, 7:41 am, ErisianFront <erisianfr...@gmail.com> wrote:
> Hi Fellas.
>
> OK, I chose to manually pick a profile biased towards resolution at
> both (less linear) ends of the thermistor curve for twenty point
> lookup.
> I went with:
> 5,5,10,10,20,50,100,100,120,150,120,100,100,50,20,10,10,5,5
> Starting at 25 and going through to 1010...
>
> This is based on the 25C/220C parameters posted by Zach earlier.
> Can easily apply to any other Beta/R0 etc or email the spreadsheet on
> request.
>
> It gives a bit of improvement in the range 200-250 as well as at the
> low temperature end.
> Graphical comparison to other parameter sets at:http://docs.google.com/Doc?docid=0AXwI5ZZe0UmWZGM1cGZwZ3hfMmQ5M2JuMmc...
The following two parameter sets use the same parameters as used by
Zach previously in this thread:
Both use r0=100000, t0=25, r1=0, r2=4700.
Ones uses beta=4198, the other, beta=4315.
Cheers,
Tim.
Thermistor table file (ThermistorTable.cpp) snippet:
//=================================================
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 4198
// max adc: 1023
#define NUMTEMPS 20
short temptable[NUMTEMPS][2] = {
{25, 299.2},
{49, 249.5},
{56, 240.5},
{65, 230.7},
{76, 220.8},
{89, 211},
{104, 201.6},
{121, 192.6},
{157, 177.6},
{222, 157.9},
{311, 138.7},
{431, 119.1},
{570, 100},
{685, 84.9},
{756, 75},
{819, 65.2},
{873, 55.4},
{936, 40.4},
{987, 20.3},
{1010, 1.2}
};
//=================================================
Thermistor table file (ThermistorTable.cpp) snippet:
//=================================================
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 4315
// max adc: 1023
#define NUMTEMPS 20
short temptable[NUMTEMPS][2] = {
{25, 285.3},
{49, 239.1},
{56, 230.6},
{65, 221.5},
{76, 212.2},
{89, 203},
{104, 194.1},
{121, 185.6},
{157, 171.4},
{222, 152.8},
{311, 134.5},
{431, 115.7},
{570, 97.5},
{685, 82.9},
{756, 73.4},
{819, 64},
{873, 54.5},
{936, 40},
{987, 20.4},
{1010, 1.8}
};
//=================================================
From http://www.flatline.net/journal/2009/12/28/thermistortable-for-1mm-thermistors/
// r0: 93700
// t0: 24
// r1: 0
// r2: 4700
// beta: 4881
// max adc: 1023
Thanks!
-Dave