Groovemount melting!!!!

[iamthebest235]

So I went for my first print on my prusa mendel, got the hot end heated up to right temp, loaded the ABS plastic in the plastruder, hit the extrude button on pronterface till the plastic squeezed out of the nozzle.  Had to stop there and then came back.  Heated up the hot end upto temp again, and when hit extrude to get the plastic flowing, the brass assembly of the nozzle shifted and saw that the groovemount had separated.  After cooling down the hot end I looked at the hot end assembly and saw that the groovemount had melted and would not thread back in on the brass assembly.

I ordered a new hot end from Rick (great with the shipping btw, I ordered it in the morning and picked it up in the evening...thanx) and he said that it's all assembled and ready to be plugged in.  I trust his assembly more than mine (and it actually looked 50 times better than what I had done with my assembly).  I plugged it in and again same thing happened.  The groovemount (mind that this is a new one) melted when trying to extrude plastic.  How is this possible and how do I fix this?  I don't want to spend $50 everytime I want to try to print something.  

Any suggestions will be helpful!!

[Rick Pollack]

if it is melting the temp is above 250C - you should not be anywhere close to that. what firmware/thermistor table are you using?

Rick

[Triffid Hunter]

On Tue, May 15, 2012 at 1:11 PM, iamthebest235 <iamthe...@gmail.com> wrote:

I ordered a new hot end from Rick (great with the shipping btw, I ordered it in the morning and picked it up in the evening...thanx) and he said that it's all assembled and ready to be plugged in.  I trust his assembly more than mine (and it actually looked 50 times better than what I had done with my assembly).  I plugged it in and again same thing happened.  The groovemount (mind that this is a new one) melted when trying to extrude plastic.  How is this possible and how do I fix this?

stop heating it above 250c - I can print PLA at 180 and ABS at 210 so you shouldn't need to have it anywhere near that hot.

If you're setting a lower temperature than 250, then you've probably selected the wrong thermistor table in your firmware configuration. MakerGear thermistors use table 1

[David Sharp]

Also, if you have not done so, make sure to enable MINTEMP protection in your firmware.  If dodgy connections really were the cause of the accident, then MINTEMP will cause the firmware to shutdown the heater if the thermistor gets disconnected.

Dave

[iamthebest235]

I'm using the sprinter firmware with Thermistor table #1

[Rick Pollack]

what temp is it reporting?

[Rick Pollack]

are you using PID?

[iamthebest235]

I'm using the sprinter firmware with Thermistor Table #1 selected.......

and I'm trying to print @ temps of around 170 - 175 because my ABS actually extrudes at that temp...

I've also got rid of the M109 from the gcode so that the printer doesn't wait for the heater to get to temp when I hit print......I set the printer to 180 and once it gets there I hit print.....

[Rick Pollack]

abs should not be working at 170.

[iamthebest235]

I agree...but when manually (setting the temp and hitting the extrude button in pronterface) extruding it at that temp, I was getting extrusion.  It was flowing nicely out of the nozzle.  So I decided to go ahead and print.  But that still doesn't explain the groovemount melting though.  

Like you and others have suggested I checked my firmware settings and in the Configuration file I have defined my Thermistorheater as #1.......is there anything else that I need to be looking for in the firmware settings?

[iamthebest235]

I'm sorry, I don't understand what you are asking for! I don't know what PID is?

As far as the temp: the pronterface reports somewhere around 168 - 174 when I hit the print button.

[Ross Mosshart]

This may seem like an odd question, but could you post the gcode you were using?

[iamthebest235]

ok found my PID settings in the Configuration.h file:

#ifdef PIDtemp

#define PID_MAX 255

#define PID_INTEGRAL_DRIVE_MAX 220

#define PID_PGAIN 180

#define PID_IGAIN 2

#define PID_DGAIN 100

On Friday, May 18, 2012 10:45:58 AM UTC-4, Rick wrote:

[Rick Pollack]

try turning off PID

[iamthebest235]

Attached please find the gcode i'm using.......it is actually for the 0.5 mm thin wall part the only thing is i took out the M109 line.......

[iamthebest235]

what does this do anyways?

 Plus I can't really operate the the printer as of right now because no way to thread the groovemount on the nozzle assembly.....its melted....I currently don't have access to a tap and die set......just ordered a new V3 groovemount from u guys...will be able to operate the printer again once I install the new groovemount

[iamthebest235]

Oh btw sorry just double checked the PID settings:

The first line : #define PIDTEMP is 'commented'......so it was off

On Friday, May 18, 2012 11:58:08 AM UTC-4, Rick wrote:

[Triffid Hunter]

please post a decent quality photo of how you have mounted your thermistor to the hot-end

if the thermistor is poorly mounted, it will report temperatures significantly lower than the real temperature, which will cause the issues you're experiencing

[iamthebest235]

I currently dont have access to the printer over the weekend (will get you a pic on monday). But the new one was pre-assembled by rick so it was and should be perfect.

[Rick Pollack]

the new one melted?

[iamthebest235]

yes...it melted....but this time the damage was mainly just the groovemount thankfully...the brass piece with threads looks good no damage to that (the previous one had all the melted groovemount plastic cooled and hardened on the threads.....

I just received the new groovemount that I had ordered on Fri.....I will hook that up on Mon.  but this time would like to really thoughtfully diagnose the problem before turning on the printer and starting another print while getting the same problem......can't really afford to keep spending $27 for new groovemount every time.....

that is why I need all of your help that I can get to diagnose it.......do you suggest that I upload new sprinter firmware and go through all the settings again??? because like I had said I have sprinter (from around Dec/Jan.) and thermistorhead #1 defined.....

[Rick Pollack]

there is something very wrong with the temperature management system.

[David Sharp]

Where do you have the thermistor mounted?  It sounds like you don't have it located in the correct location and is measuring lower than it should.  I would not attempt any more prints until this is sorted.

Dave

[NCBob]

In line with what triffid hunter asked, a good quality picture of your thermistor mounting will go a long way to determine that it's ok and not the cause of the problems.

[iamthebest235]

I will get a good picture on monday...but again in regards to the mounting/assembling of the thermistor...the new hot end that I purchased (and which still melted the groovemount) was fully assembled from MakerGear by Rick......and therefore it should be as close to perfect as it could get......I did no messing around with that piece...Rick said that it should be ready to be plugged in and therefore thats what I did.......

I agree with Rick's comment above: there has to be something wrong with the temperature management system.......I'm going to try to upload the firmware and go through the Getting started (posted in these forum) guide again to make sure it is not the firmware......

[Rick Pollack]

that hot end was fine. were the electronics fully assembled?

[iamthebest235]

Yes the electronics (ramps) were fully assembled

[brw_racing]

Good luck sorting this all out...
I think if it were me I would do all the testing from here on out with the previously melted hot end parts. Cant hurt them much more now. You may even find you can clean the melted plastic off the threads better if you can heat it up again? Hope you get it fixed soon.

[Rick Pollack]

you can send the electronics to us and we can check them. which psu are you using?

[iamthebest235]

I'm using the Eagle PSU that originally came with the kit.  Attached find the pics of the 'new' hot-end and groovemount that melted and also pics of the PSU board (the red PCB board) assembly.

[Mike511]

Interesting thread - I've been having a similar issue with my prusa.  Hotend temp is stable until after I start a print.  Then it rises without control.  I'm working on some diagnostics and will post when I've sorted it out...

Mike

[Ross Mosshart]

Possibly unrelated, I had this happen (uncontrolled temperature spikes) a few times on my Cupcake when I was still running Gen3 electronics. I traced it back to lag/interference on the USB cable. After I changed over to RAMPs I no longer had this issue.

[Triffid Hunter]

On Sat, May 26, 2012 at 12:01 AM, Mike511 <michael...@gmail.com> wrote:

Interesting thread - I've been having a similar issue with my prusa.  Hotend temp is stable until after I start a print.  Then it rises without control.  I'm working on some diagnostics and will post when I've sorted it out...

this sounds like you have a really high temperature set in your gcode

[iamthebest235]

The thing is my hot-end temp does not rise out of control at all.....all the melting of groovemount occurs between 150-180 C...I haven't worked on the printer this past week...wanted to just walk away from it for a while...will get back to it this week though....

My plan of attack:

- re-flash the sprinter firmware

- use the old burnt up groovemounts and see if the temp that pronterface says is correct by measuring the actual temp (i need to find a temp gage that I can use in that space)

- 

[Jay Couture]

I think it's clear that there is an issue with your temp sensor. In Sprinter configuration.h look for

#define THERMISTORHEATER X 

The X should be: 1 is 100k thermistor

Next with the (12V power off) and the USB plugged in. Connect to the Arduino with the Pronterface and check the temp reading. In Pronterface you just click a button to issue the command M105. In my house the temp is 27.73C (81.9F and yes my thermostat is set to 82). Yours should be in the same neighborhood. 

It's possible that you have a poor connection to your termistor (is it the same one or did you get a new one when you ordered the replacement hotend?). If you are melting the PEEK (from wikipedia: PEEK has a glass transition temperature at around 143 °C (289 °F) and melts around 343 °C (662 °F).)

FWIW,

Jay

[Triffid Hunter]

On Thu, May 31, 2012 at 2:44 PM, Jay Couture <jay.c...@gmail.com> wrote:

It's possible that you have a poor connection to your termistor (is it the same one or did you get a new one when you ordered the replacement hotend?). If you are melting the PEEK (from wikipedia: PEEK has a glass transition temperature at around 143 °C (289 °F) and melts around 343 °C (662 °F).)

for some reason those numbers don't correlate well with reality.. the makergear groovemount is perfectly fine at 235-240 but will drop the barrel at 250+ so it actually behaves like it has a glass transition in the 240-250 zone.. not sure how that works, but there it is *shrug*

[John Yang]

most likely it is simply increased creep occuring at the lower temps
below the glass transition temp

[Jay Couture]

Or it may be that it's not pure peek and any reinforcement increases it's temperature profile (For unreinforced PEEK, the HDT is 160"C (320"F). The addition of 30% glass or carbon fiber reinforcement results in a dramatic increase to 315"C (599"F).). 

Not that it matters. Hundreds of these hotends have been sold and used so we know the material is up to the task. And that two of them have done the same thing for the same person/machine tells us, it's not the hotend.

-Jay

[iamthebest235]

Great suggestions everyone thank you for taking notice into this problem of mine.  Jay, I will perform the diagnostics you suggested and the thermistor is new on the new hot-end and was assembled by Rick so it should be perfect.  As far as # define THERMISTORHEATER X the 'X' is 1 in my config file.

[iamthebest235]

I uploaded the firmware again (will have to calibrate the machine again later).....and connected to the arduino via pronterface with the ATX power supply off...upon clicking the Check Temp button it shows 40-41 C.........that is way too much....and when i touch the nozzle end....it does not feel any warm......I'm currently trying to acquire some kind of temperature probe to check the measurements........will keep everyone updated.....

So with the 12 V power supply off...

[iamthebest235]

Ok I'm really confused now...as I said in the previous post that with everything off and the nozzle sitting @ room temp for a long time reads 40-41 C in pronterface but 22-23 on my temp probe (room temp)....but when i turn on the heater for the extruder and set to the default for abs in pronterface (230).....both the temp. probe and pronterface temp are pretty much the same...3-5 degree difference.......probably because of the temp. probe its not the greatest but the best i could get my hands on for now..........

Need help big time now.......I have one more new groovemount and I don't want to mess that up...but I can't really test cuz the old groovemounts are messed up and can't be threaded to the brass end of the nozzle.....what should I do......I've a deadline for this to be printing by Friday (i don't need good prints......i just need to show that this machine works and prints by friday)........

Any and all help is welcomed and greatly appreciated!

[Joshua Wills]

Do not use the Pronterface default for ABS - it is too hot. Try 205
first. For quicker help, join the IRC channel on efnet, #makergearv2
.

[John Yang]

since I assume you have a barrel heater nozzle thermistor setup from
the burnt out failure from before, I'd just connect the broken setup
to your machine, but have it sit on a metal or other heat resistant
surface. then run the heater to a set point, and use an external
thermometer to check the readings from the thermistor. So basically
test out the termistor readings on a bare barrel setup so you don't
mess up another insulator if you're worried.

[iamthebest235]

Thanks for the suggestions.

LJ: I did exactly the same to see if the thermistor reading was correct and it was pretty accurate after I turned on the heater (withing 3-5 deg C of the temp. probe reading).  With the PSU off and nozzle end cooled to room temp. it read 40-41 deg C (which I thought was odd) but when the heater is on the temp rise and fall is pretty decent to what I observed on the thermometer.

Joshua:  I will join the IRC channel soon in a couple hours.  But I didnt heat the ABS on pronterface to the default value.  In my initial runs (when everything failed) I changed my defaults temp on pronterface to 200C; fed the abs @ around 130C; and it started extruding at arond 180C; which is when the groovemount melted too.

[iamthebest235]

Ok so I think I've found out the problem I just don't know how to solve...

Today I tried to heat up the nozzle (without the groovemount attached) to 190 C.  In pronterface it took about 13 mins to get to 156 C and then dropped to 149 C.  It stayed constant at 149 C for a while.  So I got my temp probe, and touched it to the end of the nozzle (near the thermistor) to get the reading.  The temp probe read 205 C and was climbing.

This tells me that the hot end temp keeps rising but pronterface (software) stalls at 150 C.  

(1) I would be inclined to say that its the thermistor that's not installed/working properly, but again this is the new hot-end assembled by Rick.  

(2) Next, maybe the sprinter setting is not correct, but it is: Thermistor is defined as # 1 (as it should be)

(3) When I tested to ohms on the room temp thermistor connections (they read: 98.7 kohms), keep in mind at that time the hot end temp in software read 40 C.

What do you guys think are the possible solutions/culprits for this problem?

Once again, thanks for all your help.

[Rick Pollack]

do you want to send the hot end and electronics to us?

[iamthebest235]

Yes, how long is it going to be for the diagnostics though? Let's say if I can get them to you tomorrow morning.

[Jay Couture]

The common denominator is your controller. Your RAMPS to be more exact. If you ahve a v1.3 or higher there are multiple temperature pins. T0 to your extruder, T1 to your HPB, and T2 to a second extruder if you have one. Have you posted a close up photo of your RAMPS before? ( http://reprap.org/wiki/File:Rampswire14.svg ) 

Only issue, I don't see the second termp probe T2 assigned to an analog input in the pins.h file.

-Jay

[Rick Pollack]

not long, day or two.

[iamthebest235]

I don't think I've posted a pic of the Ramps but I've a fully assembled Ramps 1.4 board from makergear.  I had a v1.2 before that I assembled and had some bad soldering job so I just got a new one pre-assembled from Makergear to play it safe.  

It could also be the PSU.  I've attached pics of my PSU setup (I will attach it to this post too) if you could please check that and let me know if its correct or not.  It's the Eagle PSU.  

[iamthebest235]

Great, I'll try to get it to you possibly today evening (between 5 & 5:30pm), drop it off personally.  If not then definitely tomorrow morning I'll drop it off.

Thanks for looking into this, I appreciate it a lot.

[Charles Steinkuehler]

On 6/6/2012 9:24 AM, iamthebest235 wrote:
> (2) Next, maybe the sprinter setting is not correct, but it is: Thermistor
> is defined as # 1 (as it should be)

You might want to review this.

I got a hot-end kit from MakerGear that includes a 100K thermistor with
a beta value of 4066. I don't know the exact part number of this
thermistor (Rick?), but based on the RepRap wiki, the only thermistor
listed with this beta is the EPCOS 100K thermister:

http://reprap.org/wiki/Thermistor

...which is thermistor table #6, according to the Sprinter source code:

https://github.com/kliment/Sprinter/blob/master/Sprinter/Configuration.h

--
Charles Steinkuehler

[iamthebest235]

Hmm...so I checked the part list i got with the new hot-end and it says: 'Modular Thermistor Kit - thermistor is 3mm (beta value 4066)'

Maybe this could be the easy (kinda stupid) problem that is fixable via one easy step (changing the thermistor definition in firmware.  I'll try to upload the new value on the board and run a simple heating test again.  See if that yields anything.  Do one last test before I turn the electronics and ramps over to Rick.

[Rick Pollack]

just use thermistor table #1 in sprinter/marlin

[Charles Steinkuehler]

Not a big surprise, but it looks like Rick knows what he's talking
about! :)

I found the thermistor part number on his website (B57560G104F) and the
values in Sprinter/Marlin table 1 match what I calculate from using the
data sheet temp/resistance values. Table 6 looks like it's for a
different part.

...so probably no easy fix. :(

On 6/6/2012 10:32 AM, Rick Pollack wrote:
> just use thermistor table #1 in sprinter/marlin
>
> On Wed, Jun 6, 2012 at 11:30 AM, iamthebest235 <iamthe...@gmail.com>wrote:
>
>> Hmm...so I checked the part list i got with the new hot-end and it says:
>> 'Modular Thermistor Kit - thermistor is 3mm (beta value 4066)'
>>
>> Maybe this could be the easy (kinda stupid) problem that is fixable via
>> one easy step (changing the thermistor definition in firmware. I'll try to
>> upload the new value on the board and run a simple heating test again. See
>> if that yields anything. Do one last test before I turn the electronics
>> and ramps over to Rick.
>>
>>
>> On Wednesday, June 6, 2012 11:16:28 AM UTC-4, Charles Steinkuehler wrote:
>>>
>>> On 6/6/2012 9:24 AM, iamthebest235 wrote:
>>>> (2) Next, maybe the sprinter setting is not correct, but it is:
>>> Thermistor
>>>> is defined as # 1 (as it should be)
>>>
>>> You might want to review this.
>>>
>>> I got a hot-end kit from MakerGear that includes a 100K thermistor with
>>> a beta value of 4066. I don't know the exact part number of this
>>> thermistor (Rick?), but based on the RepRap wiki, the only thermistor
>>> listed with this beta is the EPCOS 100K thermister:
>>>

>>> http://reprap.org/wiki/**Thermistor <http://reprap.org/wiki/Thermistor>

>>>
>>> ...which is thermistor table #6, according to the Sprinter source code:
>>>

>>> https://github.com/kliment/**Sprinter/blob/master/Sprinter/**
>>> Configuration.h<https://github.com/kliment/Sprinter/blob/master/Sprinter/Configuration.h>
>>>
>>> --
>>> Charles Steinkuehler
>>>
>>
>

[Triffid Hunter]

On Thu, Jun 7, 2012 at 12:38 AM, Jay Couture <jay.c...@gmail.com> wrote:

The common denominator is your controller.

and wiring! 

[iamthebest235]

Rick i've mailed the ramps board and the hot-end back to you, you should receive it by noon tomorrow.  If you get done with the diagnostics early just let me know and I should be around cleveland downtown for the weekend and I can just come by and pick it up.

Thanks again for looking into this and really appreciate the help.

[Josh Williams]

Hey hey iamthebest235,

I realize this is an old thread, but it's got some good information in it relevant to our problem : )

We have been having ongoing issues that result in the groovemount dropping out after the temperature apparently getting too hot. We're on our 4th one! For about 6 months we did not have this problem. The past two months it's been troublesome : )

We have replaced the the thermistor and rebuilt the heater core. 

The one thing that we have seen is the temperature drop significantly once or twice in a very short time, ie: It will read 212c steady for a few minutes, and as fast as pronterface can update it will jump as much as 30c, down to ~180c. This sounds like a loose wire connection somewhere, but I was curious if you had any final resolution as to the problem?

Our next steps will be:

1) Monitor temperature with an external thermometer to see how the pronterface readout compares.

2) Redo the wiring between the ramps board and the thermistor / heatcore.

Thanks!