How do I calibrate hot end thermistor?

[seatlanta]

I finally received a new resistor for the hot end. It is the same as the one included in the original kit. I've assembled the hot end block with the resistor, the 100k thermistor, and the appropriate wiring to the power supply, just for testing. It's not connected to the X-carriage yet—just dangling from the top bars away from everything.

I set the temp to 205. It heated quickly, according to my infrared thermometer, but the indicated temp from the thermistor was way off. When the Kapton tape bubbled and melted, I switched everything off. At that point, the infrared thermometer indicated 385 C. The thermistor reading never reached 200 C. I'm happy it's heating once again, but I clearly need to do something about the runaway high temperature.

Printer
This is a RepRap Mendel with a Melzi board. The nozzle block is aluminum with holes sized for the resistor and for the thermistor.

Software
Pronterface
Slic3r

I've read there is some calibration or adjusting I may do, and I've read about a temperature table. But I still haven't found exactly where I should be doing these things.

I'd appreciate a few tips to get me started.

Thanks.
James in Atlanta

[Alex]

I think you use this

https://github.com/reprap/firmware/blob/master/createTemperatureLookup.py

[Lee]

Hi James, the first thing I would try is to hook up a multimeter directly to the thermistor. Take the thermistor and drop it in boiling water. At this point, if the resistance measurement is not what you expect from the data sheet, the thermistor is bad. Otherwise, you likely have a problem with your connections or possibly with your electronics. Good Luck!

[Larry Knopp]

First thing I'd check is that you definitely have the correct thermistor selected in firmware...

--
 
 

[Lee]

Doh, yea do what Larry says first. I forgot that there are like at least 3 different 100k thermistor options in Marlin. Each with a little different temperature/resistance curves -- and if you've accidentally selected a 50k thermistor, that's definitely a problem.

[seatlanta]

I'm in my shop right now. No boiling water out here, but the resistance of the thermistor at room temperature (75 F. or 24 C.) is 66K Ω.

It's a Honeywell 135-104LAG-J01, an axial glass NTC thermistor.

Product Specifications

Resistance 100,000 Ohm
Tolerance ±10.0%
Accuracy 25 °C [77 °F]
Beta 3974
Operating Temperature -60 °C to 300 °C [-76 °F to 572 °F]
Diameter 2,0 mm [0.080 in]
Termination Material Tinned copper-clad steel
Lead Length 28,6 mm [1.125 in]
Time Constant in Air 4.0 s
Dissipation Constant 2,5 m/W°C
Series Name 135

Is this one that should work?

James in Atlanta

[seatlanta]

Larry wrote: First thing I'd check is that you definitely have the correct thermistor selected in firmware...


Hi Larry:
I've posted the specs for my thermistor (as a reply to another message). I've done more testing in Pronterface, including sending an M301 Wxx statement. The xx refers to various settings for power supplied to the resistor. Why did I do this? Because I read about it on a RepRap page.

But my problem is not with the heating of the resistor. It heats so well that it's out of control in no time at all. It fried my previous thermistor. The thermistor is seeing about 50% of the real temperature as I read it on my cheap infrared thermometer.

I'd like to verify what's selected in firmware, but I don't know what to do. How and where do I access and change things, if necessary?

Thank you.
James (buying resistors and thermistors in bulk)

Thanks,James

[Lee]

If you are using Marlin firmware, look at the Configuration.h file: https://github.com/ErikZalm/Marlin/blob/Marlin_v1/Marlin/Configuration.h

There is a section that looks like this:

//===========================================================================
//=============================Thermal Settings  ============================
//===========================================================================
//
//--NORMAL IS 4.7kohm PULLUP!-- 1kohm pullup can be used on hotend sensor, using correct resistor and table
//
//// Temperature sensor settings:
// -2 is thermocouple with MAX6675 (only for sensor 0)
// -1 is thermocouple with AD595
// 0 is not used
// 1 is 100k thermistor - best choice for EPCOS 100k (4.7k pullup)
// 2 is 200k thermistor - ATC Semitec 204GT-2 (4.7k pullup)
// 3 is mendel-parts thermistor (4.7k pullup)
// 4 is 10k thermistor !! do not use it for a hotend. It gives bad resolution at high temp. !!
// 5 is 100K thermistor - ATC Semitec 104GT-2 (Used in ParCan) (4.7k pullup)
// 6 is 100k EPCOS - Not as accurate as table 1 (created using a fluke thermocouple) (4.7k pullup)
// 7 is 100k Honeywell thermistor 135-104LAG-J01 (4.7k pullup)
//
//    1k ohm pullup tables - This is not normal, you would have to have changed out your 4.7k for 1k 
//                          (but gives greater accuracy and more stable PID)
// 51 is 100k thermistor - EPCOS (1k pullup)
// 52 is 200k thermistor - ATC Semitec 204GT-2 (1k pullup)
// 55 is 100k thermistor - ATC Semitec 104GT-2 (Used in ParCan) (1k pullup)

#define TEMP_SENSOR_0 -1
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 0

Depending on which 100k thermistor you have, you should have set the temp sensor for your hot end to 1,5,6 or 7... unless your electronics use a 1k pullup, in which case you should select 51 or 55.

[vlad]

what resistor value and what voltage are you running?  just want to make sure nothing silly is going on here.  The original thermsitor is #1, but be sure.

[Triffid Hunter]

On Thu, Oct 18, 2012 at 8:50 AM, seatlanta <hyd...@gmail.com> wrote:
> I'm in my shop right now. No boiling water out here, but the resistance of
> the thermistor at room temperature (75 F. or 24 C.) is 66K Ω.
>
> It's a Honeywell 135-104LAG-J01, an axial glass NTC thermistor.

I use these almost exclusively, I find them very reliable. Use table
#6 in marlin/sprinter. However on table #1 it's only about 20c out
@200c, definitely not enough to explain the results you're seeing.

I had one up to 500c (reported by firmware) recently by accident, it
still works correctly.

Sounds like it may be fried, it should read 100k at 25c and drop
rapidly as it warms, see datasheet for exact curve.

[Larry Knopp]

Not to contradict, Triffid, but shouldn't that be the #7 thermistor table?
It's specifically listed for the Honeywell 135-104LAG-J01, as you can see in Lee's cut from Marlin's configuration.h

I use "#1"s, so I don't know for sure...

Other than that, I agree...  it sounds like it may be cooked, with that low resistance reading.

--

[seatlanta]

Triffid Hunter wrote:

I use these almost exclusively, I find them very reliable. Use table
#6 in marlin/sprinter. However on table #1 it's only about 20c out
@200c, definitely not enough to explain the results you're seeing.

Thanks for the info. Makes me feel better about what I bought.

I see that the copy of the Configuration.h file (sent by Lee) actually lists this exact thermistor for table 7. I've never seen this file before, so I'm shocked that I bought a thermistor that's listed there.

What I think I should do
So my next step (maybe) is to track down this file, open it in a text editor, and then make sure I set it (something) to number 7. I have no idea where the file is, but if it's on my shop computer I will find it. Looks like I should enter: # define TEMP_SENSOR_0 7. Is that correct?

I'll also check my newly installed thermistor for its resistance at 25 C.

Questions:

• When I edit the file and save it, is it automatically uploaded to the Melzi board when I plug in the USB cable and start Pronterface (or Slic3r, or whatever)?
• If not, what's the procedure?
• How do I determine whether I have Marlin firmware?
  
• I've had almost no experience with infrared thermometers. I have a cheap one, and I notice that the indicated temperature varies considerably with the distance from the target. I put the laser dot on the heat block, check the temperature, and then move it farther away. The temperature drops. Is that because it is reading the background too? Is it best to be fairly close to the target if the target is small?

Thanks again.
James in Atlanta (learning slowly but surely)

[vlad]

closer to the target, the smaller a point you read. IT will read the average temp in a circleishshape infront of it, think of a flash light.  the further from the wall you are, the bigger of a spot it makes on the wall. Themometer is the same thing, but you are just averaging the temp of everything that would be in that beam of light.
as for updateing the firmware, become familiar with Arduino, that is what you will be using to update firmware, and to change settings permanently. there are temporary ways of doing it through pronterface, but I think that will add to the confusion untill you are more familiar with the basics.

On Wednesday, October 17, 2012 3:51:37 PM UTC-4, seatlanta wrote:

[Larry Knopp]

Ummm...
(pardon me, but...)

Oh, shit.
If you don't know what configuration.h is, or where to find it, or if you have Marlin, you better take a step back from this for a minute...

Your Melzi came pre-loaded, yes?
If true, then you can be pretty much 100% certain your firmware is *not* correctly configured for your machine (unless you bought the entire thing from the same source, and they were kind enough to configure it for you).

Start here :
http://reprap.org/wiki/List_of_Firmware

Then here:
http://reprap.org/wiki/Melzi

I'm not at all familiar with Melzi, but it looks like there have been issues even talking to it with the Arduino IDE?  Sorry that's not very helpful.  I would advise not doing anything else until you have gotten to the point where you can connect to, and upload firmware configured specifically for your hardware.

--
 
 

[seatlanta]

Larry wrote:

Oh, shit.

 
James responded:

I completely agree.

Here's a brief history:
My entire kit came from RepRap in Bristol, England. I assembled it quickly (in spite of the instructions). After loading all the software and drivers and libraries, it actually worked for a few minutes, but was problematic. And now I'm wondering if the firmware was not configured correctly.

 

In any event, things went downhill from there, and I burned up the hot-end resistor and thermistor—both of which I've replaced. I also melted the x-carriage. That's why I'm doing my present tests with the hot end separated from the carriage. That's also why I have several resistors and thermistors on my workbench.

 
Meanwhile, I changed computers, reloaded the software, and things are much more stable. I can do 3D practice print runs without any filament. So now, if I can get the temperature under control, I'll be on my way (maybe).

 

You asked: Did the Melzi come pre-loaded? I don't know. I didn't knowingly update its firmware or make any changes. I'm using it as it came out of the box.

 

I'll go to the Wiki sites you list and try to figure out which firmware I have and what to do next. After I do some research, I may have a few more questions, specifically about the procedure for uploading the firmware.

 

Actually, I have a question right now: What's the easiest way to know what firmware I have?

 

I really appreciate all the help from you and everyone else.

 

Best wishes.

James in Atlanta

[Larry Knopp]

Get on the reprap wiki and read about loading firmware...

You need a version of the Arduino IDE.  Try 1.0

When you open pronterface and connect to the printer, you should get some replies such as :

Connecting...
start
Printer is now online.
echo:Marlin: 1.0.0 RC2
echo: Last Updated: 2012-05-02 | Author: erik
echo: Free Memory: 13802  PlannerBufferBytes: 1232

Hopefully...

--
 
 

[Larry Knopp]

Oh, I would definitely also contact your supplier and ask for info.
They should know, right?

[Triffid Hunter]

On Thu, Oct 18, 2012 at 1:15 PM, seatlanta <hyd...@gmail.com> wrote:
> Actually, I have a question right now: What's the easiest way to know what
> firmware I have?

Send M115 from within pronterface

[UK Chris]

Hi James,

Perhaps I'm in a better position to help you here; I have two
Huxleys, one fully functioning and one being put together on the
kitchen table. You may have a Mendel though, but as far as I can see,
the hot-ends look the same. So I just measured my thermistor
(unconnected) at 115K at 22 degs C. Although I haven't finished the
build, I have it communicating with Pronterface and it's all working.
By the way, pronterface reports Marlin 1.0.0 RC2 when connecting. I
haven't a clue how to check config.h either, and don't have the time.
When I put the first kit together - it just works! But I'm happy to
remove the thermistor and send it to you for free - the head is
dangling anyway (OK, I broke the mount). I can easily obtain another
as I'm passing the 'lectric shop tomorrow anyway. I also live about
ten miles from your kit's suppliers in Bath. You've been through
enough and need some help ;)
So send me your address and I'll pop it in an envelope. I'm often in
Delaware, so you can buy me a Yuengling when I'm passing. Any other
checks/measurements you want doing, please don't hesitate to ask - the
kit is only feet away.

Regards

[UK Chris]

James,

Sorry, that was 103K at 22 degs C, I used the wrong range initially.

regards

[seatlanta]

Hi Chris:
Thank your for your very kind offer, but I think I'm OK in the thermistor and resistor department—at least for a while. I just bought and received several of each from Digi-Key.

Today, I'll be in the shop to identify the firmware I'm using. Then I'll go from there.

My analysis (probably flawed)

• I built the RepRap Mendel from a kit that included the correct thermistor. At that time, the temperature control seemed to function and the printer extruded a thin strand of filament.
• The nozzle clogged, and while taking the head apart, I broke the thermistor.
• I ordered another thermistor—the Honeywell model—which is OK to use but may require different settings in the firmware. That's something I know nothing about.
• The system overheated with this setup, and I fried that thermistor, the resistor, and melted the carriage—and all the while it indicated that the temp was OK.
• Purchased infrared laser thermometer
  
• During further troubleshooting, I was treated to the spectacle of my wiring bursting in flames (literally). I've attached a photo of the wires I pulled from the system.

Today, I'll move forward and try to learn more about the firmware issue. Thanks again for the help and advice. It's much appreciated.

[Misha]

Man, wiring catching on fire is my greatest fear with my machine.  Especially since I build my own heated bed from scratch using nichrome that runs on 110V.

 

Switching to a 24v kapton heater soon.

[UK Chris]

James,

Suppose I'll have to get my Yuengling someplace else then.

Misha,

Sounds like one of those toys where it buzzes if you touch the bent
wires - but an adult version. Lets all pray for the kapton heater
delivery.

Regards

[seatlanta]

Here's what I get when I connect with Pronterface. Looks like it's Marlin 1.0.1.

Connecting...
start
Printer is now online.

echo:Marlin 1.0.1 RRP
echo: Last Updated: 2012-09-19-1-JMG | Author: RepRapPro
echo: Free Memory: 11527  PlannerBufferBytes: 1232
echo:Using Default settings:
echo:Steps per unit:
echo:  M92 X91.429 Y91.429 Z4000.000 E875.000
echo:Maximum feedrates (mm/s):
echo:  M203 X300.000 Y300.000 Z3.000 E45.000
echo:Maximum Acceleration (mm/s2):
echo:  M201 X800 Y800 Z30 E800
echo:Acceleration: S=acceleration, T=retract acceleration
echo:  M204 S1000.000 T1000.000
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum xY jerk (mm/s),  Z=maximum Z jerk (mm/s), K=advance_k
echo:  M205 S0.000 T0.000 B20000 X15.000 Z0.400 E15.000
echo:  M206 X0.000 Y0.000 Z0.000
echo:  M208 X210.000 Y210.000 Z140.000
echo:PID settings:
echo:   M301 P12.000 I2.200 D80.000 W125
echo:Thermistor settings: M304 Hh Bb Rr Tt, H0=Bed, H1..n=nozzle, b=thermistor beta value, r=series resistor, t=thermistor resistance as 25C
echo: M304 H0
 B3480 R10000 T10000 M304 H1
 B3960 R10000 T100000
 FPU Enabled no
transform correction not enabledecho:SD init fail
Entering skeinforge settings:  Slic3r/slic3r.exe --load Slic3r/config.ini 

GitHub files
I've extracted all of the configuration.h files downloaded from Github. This includes a configuration_adv.h file. This directory is in my Python27 directory.

Now what?
I guess I need to change the thermistor code to 7 and upload the firmware to my Melzi motherboard. Right now, I'm staring at the screen and wondering how to do this.

I'll begin my research on the Wiki pages, but if anyone has a short-and-sweet procedure for me, please let me know.

James (still in Atlanta)

[Triffid Hunter]

On Fri, Oct 19, 2012 at 2:12 AM, seatlanta <hyd...@gmail.com> wrote:
> I ordered another thermistor—the Honeywell model—which is OK to use but may
> require different settings in the firmware. That's something I know nothing
> about.

I've used the honeywell thermistors with table #1, as I said
previously they simply throw your temperatures out by about 20c,
enough to make your prints look a bit funny but nowhere near enough to
cause problems like the ones you report

> The system overheated with this setup, and I fried that thermistor, the
> resistor, and melted the carriage—and all the while it indicated that the
> temp was OK.

sounds like a wiring fault

> During further troubleshooting, I was treated to the spectacle of my wiring
> bursting in flames (literally). I've attached a photo of the wires I pulled
> from the system.

again, sounds like a wiring fault- specifically something shorting out
to something else

If your thermistor wires have ever shorted to +12v (or +24v) even
momentarily then the ADC input on your mega will be destroyed. you'll
have to change pins.h to use one of the other available inputs.

hooking up a known good thermistor will tell you if that's the case.

[seatlanta]

Hi Triffid:
Thanks again for your suggestions.

The fire was due to my resistor getting so hot that the ribbon cable's insulation reached its flash point; it smoked and flashed almost instantly. Of course, at that time, I did not know I had an overheating issue—or should I say, a temperature-control issue.

All the wiring is correct, as far as I can tell. All the tests (voltage and resistance) continue to be in range. The machine operates and goes through the motions of printing, albeit without a print head. The only thing I need to resolve is how to make my Honeywell thermistor read the temperature correctly. If I could get it to within 20 degrees, I'd be happy. Right now, when the thermistor thinks the temp is 180, it's really 350.

I feel like I'm being a pain because I simply don't have the knowledge (yet) to change the firmware. Most of the instructions I find online are several years old and quite confusing. The ones that are clear (to me) have not helped. Yesterday, I worked on it for eight hours, into the night, until my wife said to come in out of the shop.

I've read everything I could find about the subject. I downloaded the latest version of the Arduino software and opened the config.h files. I edited the file, changing the resistor value to 7, as listed in the file's comments. But I could not get it to compile and upload. It said I had listed the wrong board, because my board's CPU was not listed. I have the Atmega 1284p. I entered the Atmega 1280, which was the closest option. I declined to override the error message and upload it anyway.

Next, I downloaded additional files that included the Atmega 1284p (speeds of 16mhz and 20mhz), and they showed up in the board options. I tried both speeds, but could not get an error-free upload. I quit and reinstalled the Arduino software and a different version of the configuration.h file.

Now, the Arduino software says I can't open any sketch file unless it has an .ino extension. I screamed and awakened the neighbors.

Right now, the original firmware is intact and everything still functions. I'm about to brew a thermos of coffee and return to the shop. Maybe I really need something stronger than coffee.

Thanks again.
James

[Gert van den Berg (MoHaG)]

On Friday, October 19, 2012 3:10:00 PM UTC+2, seatlanta wrote:

I've read everything I could find about the subject. I downloaded the latest version of the Arduino software and opened the config.h files. I edited the file, changing the resistor value to 7, as listed in the file's comments. But I could not get it to compile and upload. It said I had listed the wrong board, because my board's CPU was not listed. I have the Atmega 1284p. I entered the Atmega 1280, which was the closest option. I declined to override the error message and upload it anyway.

Next, I downloaded additional files that included the Atmega 1284p (speeds of 16mhz and 20mhz), and they showed up in the board options. I tried both speeds, but could not get an error-free upload. I quit and reinstalled the Arduino software and a different version of the configuration.h file.

Now, the Arduino software says I can't open any sketch file unless it has an .ino extension. I screamed and awakened the neighbors.

The .ino is basically a "Project" file that has all the files relevant to compiling the firmware.

Some of the firmwares have problems on some of the newer Arduino versions. 0.23 are often recommended for those... (Don't change thart if you aren't having problems)

If the right processor is selected, it should involve clicking the upload button after setting up the configuration. The first time you try to move anything after loading a different firmware, it miught be a good idea to have a finger on the reset button, in case it decides to move too far.

Check all the basics once the firmware is changed (movement in all directions, endstops (if you are using them)), temperatures. Then switch on the heater to a low temperature (< 100 degrees and try to monitor it...) If it seems ok, you can try a higher temperature and actually try to extrude...

The list G code command on the reprap wiki is handy.... http://reprap.org/wiki/G_code (There are commands to check the endstop status, etc...)

Gert

[UK Chris]

James,

Isn't this really simple,

You say "I'm in my shop right now. No boiling water out here, but the resistance of the thermistor at room temperature (75 F. or 24 C.) is 66K Ω"

My thermistor, from your original kit's supplier (same hot end) says 103K at 22 degs C.  Spec says 100K at 25 degs C.  Therefore you have a duff thermistor - again.  Mine in now loose on the kitchen table - want me to put it in an envelope?  or get another and check it's around 100K at room temp.

Happy to do boiling/freezing measurements if it would help.

Regards

[j...@250hacks.net]

Hi James,

I think just selecting the ATMega 1280 should work when programming your arduino board. Here is the steps I go through to flash new Marlin firmware to my board:

• Open Arduino and go to File -> Open, navigate to your Marlin directory and open the main project file (Marlin.pde). This will open tabs for all the source files of the Marlin firmware.
• Select the correct board under Tools -> Board. Also select the correct serial port for flashing.
  
• Click on the "Configuration.h" tab -- this is the header file that contains all the setttings that you need to set. NOTE: I'm not sure where you got the original firmware that is on your arduino board -- did it come pre-flashed? if so, you will want to figure out what values are currently set (I believe there is a command for this, maybe someone can chime in) and make sure you update the configuration.h with the correct values. There are a lot of settings in this file, so you need to carefully go through each of them and figure out what they should be set to. I suspect you have the wrong thermistor selected, which is why you are getting incorrect temperature settings.
• When you are confident in the changes, click the "Save" button in arduino. We are now ready to upload the firmware.
• Make sure any programs that could be talking to your printer are closed or disconnected. For example, if you are using Pronterface, click the disconnect button so it will close the serial connection to your printer (it could conflict while flashing.) I've had errors like timeouts when leaving pronterface connected and trying to flash at the same time.
  
• Click the Upload button in arduino. It should first compile everything and then start uploading (assuming there are no errors.)
• Once arduino indicates "Done Uploading", then connect to your printer again in Pronterface.

If the thermistor is working, you should see an ambient temperature of about 25deg C (room temperature) in pronterface, without the hot end on. You should be able to debug from here -- if the value is incorrect, try changing the thermistor value in Configuration.h above and reflash.

You should also check to make sure your board is wired up correctly -- specifically that the thermistor is connected to the correct pins on your RAMPS board. See this link:

http://reprap.org/mediawiki/images/6/6d/Rampswire14.svg

Hope this helps.

joe

On 10/19/2012 06:10 AM, seatlanta wrote:

Hi Triffid:
Thanks again for your suggestions.

The fire was due to my resistor getting so hot that the ribbon cable's insulation reached its flash point; it smoked and flashed almost instantly. Of course, at that time, I did not know I had an overheating issue�or should I say, a temperature-control issue.

All the wiring is correct, as far as I can tell. All the tests (voltage and resistance) continue to be in range. The machine operates and goes through the motions of printing, albeit without a print head. The only thing I need to resolve is how to make my Honeywell thermistor read the temperature correctly. If I could get it to within 20 degrees, I'd be happy. Right now, when the thermistor thinks the temp is 180, it's really 350.

I feel like I'm being a pain because I simply don't have the knowledge (yet) to change the firmware. Most of the instructions I find online are several years old and quite confusing. The ones that are clear (to me) have not helped. Yesterday, I worked on it for eight hours, into the night, until my wife said to come in out of the shop.

I've read everything I could find about the subject. I downloaded the latest version of the Arduino software and opened the config.h files. I edited the file, changing the resistor value to 7, as listed in the file's comments. But I could not get it to compile and upload. It said I had listed the wrong board, because my board's CPU was not listed. I have the Atmega 1284p. I entered the Atmega 1280, which was the closest option. I declined to override the error message and upload it anyway.

Next, I downloaded additional files that included the Atmega 1284p (speeds of 16mhz and 20mhz), and they showed up in the board options. I tried both speeds, but could not get an error-free upload. I quit and reinstalled the Arduino software and a different version of the configuration.h file.

Now, the Arduino software says I can't open any sketch file unless it has an .ino extension. I screamed and awakened the neighbors.

Right now, the original firmware is intact and everything still functions. I'm about to brew a thermos of coffee and return to the shop. Maybe I really need something stronger than coffee.

Thanks again.
James

--
�
�

[seatlanta]

Thanks, Joe, for the step-by-step procedure. I'll give it a try today.

I'm confident about all the wiring; I've rechecked it several times. By the way, my board is a Melzi version 2.0 (see photo). The two white wires at the upper right are the thermistor leads.

 

Everything seems to work perfectly except for the temperature control. I'm waiting for a response from RepRap about their thermistor's manufacturer and part number.

 

Thanks again.

James

[j...@250hacks.net]

James,

Actually, I am not sure Marlin will run on the Melzi board, but I am not familiar with it at all. Sorry, I should have asked about your hardware -- I prematurely assumed you were running with a RAMPS board..

joe

--
 
 

[Triffid Hunter]

On Sat, Oct 20, 2012 at 7:42 AM, j...@250hacks.net <j...@250hacks.net> wrote:
> Actually, I am not sure Marlin will run on the Melzi board, but I am not
> familiar with it at all. Sorry, I should have asked about your hardware -- I
> prematurely assumed you were running with a RAMPS board..

as far as I know, melzi is a surface mount version of a sanguinololu
so Marlin should work fine

[Larry Knopp]

James,

This kit is from Reprappro??

--

[seatlanta]

Larry asked: This kit is from Reprappro??

Yup, directly to me from Bath, England. I send them emails when I have questions, but they can be a bit slow with their replies. My most recent query was a request for the manufacturer and part number of the Mendel thermistor. I'm waiting.

James

================================

[Larry Knopp]

Okay...

http://reprap.org/wiki/RepRapPro_Huxley_commissioning#Step_1:_Communication

Almost at the bottom of the page :

Step 4: Heaters

Hot end

N.B. Some RepRapPro Huxley kits shipped with a Melzi controller between August 2012 and the first week of October 2012 have an error in the firmware. Please see this forum topic for a solution http://forums.reprap.org/read.php?214,123839,159857#msg-159857

That issue is *not* yours (but makes me wonder...), however, it has this link from Jean-Marc...
http://reprap.org/wiki/RepRapPro_Huxley_maintenance#Uploading_new_firmware

Which may assist in figuring out that Melzi.

Hope it helps!!!

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[seatlanta]

Larry: This could be some good information, and it's something I have not yet seen. I thought I'd found it all during the last two days of research. I have a Mendel, but the possibility of a firmware error could account for some of the problems. I'd settle for any explanation at this point.

The part about the reset jumper on the board intrigues me because so far, I have not been able to upload any compiled firmware changes. I've tried almost every option available in the list of boards, including a few that I knew were wrong. But I figured what the hell, I'll try anything.

I've downloaded and tried four different iterations of the Arduino software, from old to the newest. I've extracted at least three versions of the Marlin/Sprinter firmware, and a few bootstrap patches. The frustrating part is that the Melzi is not listed as an option on the Tools/Boards menu. I often get a message telling me to select sanguino from the list, but it's not there either. The Atmega 1284p is not listed with a Melzi version, and the 1280 gives me an address error.

It's near midnight here, and I'm finished for the day. Tomorrow, I'll be trying again and I'll carefully read the items you sent. Thank you for your research.

James in Atlanta

 

[Tim A. King, Jr]

James...what processor does your board have?  I assume a 1284p, but let me know..I might have a solution for you if you are supposed to choose Sanguino...

Tim

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[seatlanta]

Yes, it's a 1284p. Any suggestions are appreciated.

James

[Tim A. King, Jr]

James...I am sending you a file off-list...

Tim 

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[Calabus]

I melted a few heads with the exact same problem. I have a Rostock Max by the way. After months of troubleshooting I found out it was a bad port on the Rambo board. It was the port the thermistor plugs into. Here is the thread from the Rostock forums where we went through troubleshooting...
http://forum.seemecnc.com/viewtopic.php?f=37&t=2641



On Wednesday, October 17, 2012 3:51:37 PM UTC-4, seatlanta wrote:

I finally received a new resistor for the hot end. It is the same as the one included in the original kit. I've assembled the hot end block with the resistor, the 100k thermistor, and the appropriate wiring to the power supply, just for testing. It's not connected to the X-carriage yet—just dangling from the top bars away from everything.

I set the temp to 205. It heated quickly, according to my infrared thermometer, but the indicated temp from the thermistor was way off. When the Kapton tape bubbled and melted, I switched everything off. At that point, the infrared thermometer indicated 385 C. The thermistor reading never reached 200 C. I'm happy it's heating once again, but I clearly need to do something about the runaway high temperature.

Printer
This is a RepRap Mendel with a Melzi board. The nozzle block is aluminum with holes sized for the resistor and for the thermistor.

Software
Pronterface
Slic3r

I've read there is some calibration or adjusting I may do, and I've read about a temperature table. But I still haven't found exactly where I should be doing these things.

I'd appreciate a few tips to get me started.

Thanks.
James in Atlanta