Not reaching temperature

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cullymoto
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Joined: Tue Jan 31, 2017 7:32 pm

Not reaching temperature

Postby cullymoto » Fri Mar 03, 2017 4:58 am

Hello. Thanks for looking in.

N2+ V2 hot end, dual extruder all factory except using micro Swiss SS nozzles. Machine running firmware 1.1.1
I've done no modification to the machine, has roughly 100 hours of print with most of that being failed prints.

When I load up a print and the machine is pre heating it always stalls 10c below setpoint.

I can load filament (petg at 270) it reaches set point and loads fine.
I can manually set extruder to 290 if I wish.
Profile requires 270c extruder temp and it sits at 260 + or - 2 degrees for as long as I leave it there.

I've had some success with, after pressing "print" and the machine is preheating, turning up the extrude temp by another 10 (280) then back to set point once it climbs near to 270. At about a 1 out of 5 attempts it will reach set point and print this way.

Once printing it holds setpoint fine and the print is good in respect to extruder temp.

I've double checked that heat cartridge and thermostat set screws are tight, and all cables appear well seated in their respective locations. Heat cartridge sticks out the front of the heat block approx 2 mm, same as the right side.

Anyone have any ideas what's going on?
Thanks

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Vicky@Raise3D
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Re: Not reaching temperature

Postby Vicky@Raise3D » Fri Mar 03, 2017 5:34 am

Do both of the two nozzles have the same problem?
Can nozzle reach lower target for printing? Like 200, 220.

Does the heating bed both have the same heating problem?

What's more, please help check when nozzle stuck at 260C, whether the nozzle heating lights on extruder board is constant-on or flash? HE1 and HE0.
1.png

cullymoto
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Re: Not reaching temperature

Postby cullymoto » Fri Mar 03, 2017 5:12 pm

Hello Vicki. Thanks for your reply.

Both nozzles do not have the same problem. When printing with right nozzle only it reaches setpoint just fine. With both nozzles printing in one print, the left never reaches temp, so the right never tries to heat.
Setting the left nozzle too low for my material (250c) it reaches temp, then heats up the right nozzle to setpoint of 270.

When the left nozzle is stuck +-10C below setpoint the light on the back is flashing.

The heat bed works just fine.

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walshlg
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Re: Not reaching temperature

Postby walshlg » Fri Mar 03, 2017 7:07 pm

pull on the wires to the thermocouple, I had one that looked fine but was unglued and slid around so it didn't stay pressed up against the side of the can

cullymoto
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Re: Not reaching temperature

Postby cullymoto » Sat Mar 04, 2017 3:39 am

Hi walshlg.
If I understand you correctly, your taking about the braided lines between circuitry and thermocouple. They are all snug and secure. Reached in the with tweezers and have each one in there a tug. Temperature sensor braided cable too. No movement anywhere.

Been printing PLA all day without any incident trusted to extrusion temp, however I didn't buy this machine to print materials that a 300$ machine can do... Please help me get this machine back to the higher temps I purchased it for, I'd really rather be running polycarbonate instead of PLA.

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walshlg
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Re: Not reaching temperature

Postby walshlg » Sun Mar 05, 2017 12:26 am

let us know what you figure out, something isn't right!

cullymoto
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Joined: Tue Jan 31, 2017 7:32 pm

Re: Not reaching temperature

Postby cullymoto » Sun Mar 05, 2017 3:11 pm

As I use the machine for pla, max temp 220, once in a white I try to get it up to 270ish to see. It seems to be getting worse, now it struggles to reach a setpoint over 250.
I'm beginning to think that the heat unit (thermocouple right?) Itself is failing.
It's less than a month old with about 100 hours on it now.

Jetguy
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Re: Not reaching temperature

Postby Jetguy » Sun Mar 05, 2017 4:52 pm

No, please understand the difference.
A thermocouple is a temperature sensor. It's nothing more than 2 wires of different metals that create a voltage. There is nothing to "wear out".
The heater cartridge is what produces the heat. It is the larger wire and larger diameter rod. Inside it, it has nichrome heating wire on a ceramic core inserted into the stainless rod.


The first thing I would check is the the screw terminals at the back of the breakout board- maybe going as far as re-terminating the wire (cut, strip, and then tighten in the screw terminal. The heaters are fed via the larger 3 pin connector with black wires. Make sure that connector is fully seated.

I'd also disconnect the heater and use a good multimeter to measure the cold state resistance of both the one that works and the one that doesn't. If the one that doesn't has a higher resistance- there is the answer, higher resistance is less current, less power and wattage.

Again, as shown in the picture below of the board that attaches to the side of the extruder head, the heater output screw terminals are on the right hand side. Also, a common mistake with screw terminals is that if the terminal is screwed tight before the wire is inserted, it may go in but will not make good contact. I literally found my Kickstarter N2 earlybird- one of the first printers ever shipped had this fault and the right heater never even heated because it was a mistake in how the wire was connected in the screw terminal block.
raise3d NuEi headbreakout.jpg.jpg

I've also attached the motion controller board and the same 3 wire black connector labeled "P_HE" is found there for the extruder heaters. Make sure it is seated fully.
Motion board connectors updated2.jpg


This is the heater cartridge-AKA the actual heating element
https://www.raise3d.com/collections/acc ... eating-rod

This is the thermocouple temperature sensor
https://www.raise3d.com/collections/acc ... ure-sensor
The newer style looks like this https://cdn.shopify.com/s/files/1/1069/ ... 1472462463
And the older style looks like a tiny heating rod https://cdn.shopify.com/s/files/1/1069/ ... 1472462462

Jetguy
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Re: Not reaching temperature

Postby Jetguy » Sun Mar 05, 2017 4:57 pm

Again, the most likely answer is actually just an unseated connector or a failed terminal connection at the screw terminals. The next thing down the line is the heater cartridge.

Why? Because if there is resistance at a connection, rather than passing the voltage and current to the heater, that connection will heat up. This causes the tin coatings on the connection to oxidize from the heat and that creates more resistance. That further makes it heat up and oxidize more- maybe even melt and distort the contact- that puts less pressure= more resistance and it just self destructs. That why I said to cut and re-strip the wire end to make sure fresh copper wire is in contact with the screw terminal. If it was oxidized- that contributes to the problem.

The fact you said it degraded over time EXACTLY matches this well known scenario.

cullymoto
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Joined: Tue Jan 31, 2017 7:32 pm

Re: Not reaching temperature

Postby cullymoto » Sun Mar 05, 2017 5:37 pm

Sounds plausible. I'll do some surgery when I get home from work tonight.
Thank you for offering suggestions

cullymoto
Posts: 34
Joined: Tue Jan 31, 2017 7:32 pm

Re: Not reaching temperature

Postby cullymoto » Mon Mar 06, 2017 4:53 am

Removed and shortened wires of the left heater, making sure good contact, resulted in no change.

I then swapped the cables for left and right heater, as well as swapped the position of the left and right heater.
in effect the original Right became the left and visa versa.

new left heater failed to reach setpoint of 260C, stopping at 250c for ten minutes. WHen set to 300 left heater failed to climb above 264 after 20 minutes. while at 264c the setpoint was lowered to 260c. left heater temp fell to 240, climbed back to and stayed at 250.

New right heater reached setpoint of 260c in 30 seconds and stabilized.

read again, original left heater worked fine when installed in the right sockets on the circuit board, while the original right (which worked fine in the original place) failed to reach tempurature when installed in the left circuitry receptacle.

is my board cooked? please advise

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Vicky@Raise3D
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Re: Not reaching temperature

Postby Vicky@Raise3D » Mon Mar 06, 2017 11:10 am

Have you ever checked this part?

What's more, please help check when nozzle stuck at 260C, whether the nozzle heating lights on extruder board is constant-on or flash? HE1 and HE0.
1.png
1.png (158.09 KiB) Viewed 1298 times

cullymoto
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Re: Not reaching temperature

Postby cullymoto » Mon Mar 06, 2017 11:23 am

Vicky@Raise3D wrote:Have you ever checked this part?

What's more, please help check when nozzle stuck at 260C, whether the nozzle heating lights on extruder board is constant-on or flash? HE1 and HE0.
1.png


Yes. Stated above.
The light is solid on until 10°C below setpoint, at which time it begins a rapid blink.
When the temperature has stalled, the light blinks rapidly, the temperature stalls and then falls, the light stays on solid at 11°c below setpoint. Then returns to rapid blinking at 10°C below setpoint.

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Vicky@Raise3D
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Re: Not reaching temperature

Postby Vicky@Raise3D » Mon Mar 06, 2017 11:54 am

cullymoto wrote:
Vicky@Raise3D wrote:Have you ever checked this part?

What's more, please help check when nozzle stuck at 260C, whether the nozzle heating lights on extruder board is constant-on or flash? HE1 and HE0.
1.png


Yes. Stated above.
The light is solid on until 10°C below setpoint, at which time it begins a rapid blink.
When the temperature has stalled, the light blinks rapidly, the temperature stalls and then falls, the light stays on solid at 11°c below setpoint. Then returns to rapid blinking at 10°C below setpoint.


PM sent. Please check.

Jetguy
Posts: 1790
Joined: Tue Mar 22, 2016 1:40 am

Re: Not reaching temperature

Postby Jetguy » Mon Mar 06, 2017 2:12 pm

Again, let's go over the why here.
As you cross the 10C difference threshold, you are now into PID tuning meaning- the firmware baseline values that expect the heater to heat as a certain rate are engaged. If the connections or the resistance of the heater is NOT the same as the factory standard, or if additional airflow is cooling the heating block- then yes, a heater might not reach set temp.

Which is why breaking out the multimeter, measuring the heater cartridge cold resistance, re-terminating- not just checking the wiring is required. And yes, pushing the upper limits temp on the stock firmware without individual machine tuning of PID- this is the problem one would expect to see.
There may be NOTHING "wrong" with your machine or wiring- just that pushing above 250C is not specifically tuned in stock firmware and minor variations in the heater cartridges could easily explain this. As could non insulated heater blocks with air from the fans blowing on them.

The "Printer" was and always has been capable of printing the material you desire- however, since that is the upper limit- care and consideration by you the user may be required to hand tune the system.

Jetguy
Posts: 1790
Joined: Tue Mar 22, 2016 1:40 am

Re: Not reaching temperature

Postby Jetguy » Mon Mar 06, 2017 2:21 pm

Again, step 1, actual measure and identify the problem. Since this only happens on one extruder in particular, the question is what is different about THAT heater and wiring. Resistance of the cartridge determines the wattage and thus rate it will heat because of the fixed 24V source. If the firmware or the voltage was the issue, neither heater could reach temp. But, you have one that does and one that doesn't. Also knowing that both heaters share the same 24V source wire in the 3 wire larger connector, that means at least we know the 24V + source is present. Then the flashing of the LEDs indicates that you are in the PID controlled region of the temp range and so the MOSFET is working, and fairly good indication that the total system is working.

But, again, the question is what is different about YOUR specific heater that is not reaching temp on stock PID tuning.
Of the things a user could do it would be:
#1 Again measure the cartridge and identify that it is a different cold resistance than the other cartridge- that explains the why?
#2 OR, identify that airflow is different for the second extruder and is blowing on the heater block and thus preventing it from reaching temp.
#3 and finally, short of replacing the heater cartridge and/or fixing the airflow- simply tune the PID values to match that heater. The issue there is stock firmware does not enable EEPROM storage of firmware parameters so you either have to flash new firmware from edited source or alternatively, put a PID value in the starting gcode sequence of every print file by editing the slicing profile.

Jetguy
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Joined: Tue Mar 22, 2016 1:40 am

Re: Not reaching temperature

Postby Jetguy » Mon Mar 06, 2017 2:26 pm

PID tuning information viewtopic.php?f=2&t=549&p=5294&hilit=PID#p5294

Here I explain PID tuning values in an answer to another question viewtopic.php?f=7&t=1499&p=12900&hilit=PID#p12899

Here is a thread about insulating the heater block- something you should probably do with a block radiating those kinds of temps to the nearby fans. viewtopic.php?f=2&t=1418&p=12401&hilit=Insulation#p12401

cullymoto
Posts: 34
Joined: Tue Jan 31, 2017 7:32 pm

Re: Not reaching temperature

Postby cullymoto » Mon Mar 06, 2017 4:16 pm

Jetguy wrote:Again, step 1, actual measure and identify the problem. Since this only happens on one extruder in particular, the question is what is different about THAT heater and wiring.


I appreciate your input my friend.
After swapping the left heater with the right, as well as their respective wiring, and seeing the issue remain on the left it tells me that it is not a heater cartridge issue, the fault is somewhere in front of that.
As far as cooling is concerned, both fan side fan setups are identical.

If it isn't hardware, and rather software, why did I not have this issue when I printed nylon at 280°C on the left extruder in the past?
I have done no updates to any software since unboxing and initial installation.
Can software deteriorate like that?

I think you were right initially jetguy, there is something in the system hardware that is degrading over time.
I'll be buying and learning to use a multimeter. Then comparing break out board output voltage to left cartridge vs. right.
Vicki has through pm given me something to try. I will report on this in the near future.

turbo_lew
Posts: 1
Joined: Mon Mar 06, 2017 7:58 pm

Re: Not reaching temperature

Postby turbo_lew » Tue Mar 07, 2017 12:05 pm

Hi there, I'm new to the raise3d N2, I've had my 2 weeks and I have the same issue. set the temp to 250 and it stops at 240. Some times it will sit there a few minute and them reach the set point and print. Some time I can wait 20min or more and nothing, just sit 10c below set point. The heater led is the same as you, Solid when heating up to 10c below then flashing.
I know the printer can heat well above this and hold it fine.
To get the printer to start I'm having the heat the extruder 15c above my print temp and quickly start the print. While printing it will hold the set temp fine.
On a side note it also happen when heating the extruder for filament change, I have to heat above the set point then restart at the temp I want to begin the load / unload.

I've not tried the right extruder, will test tonight.

I did find that the ribbon cable had come loss last night and after pressing it back in, it was working fine for the print I did last night. This morning I tried to run a 4 hour print and it was back to playing up. The cable hadn't come lose, checking the rest of the cables on the extruder seem fine. I think this was just coincidence.

The printer is standard, I'm printing with the left head, using pet-g at 240c. I have the feeling that it might be software as it's bang on 10c from set point. If it was hardware or loss wiring it would be more random. I'll try printing PLA around 190 - 200 tonight to see if lower temp affect it.

Any other suggestion / solution would be greatly welcomed

Lewis.

cullymoto
Posts: 34
Joined: Tue Jan 31, 2017 7:32 pm

Re: Not reaching temperature

Postby cullymoto » Tue Mar 07, 2017 12:26 pm

One quick test that I've discovered in all this, block the fan on the side your trying to heat. It has helped me.
Still not working right, but I have a long print underway for a customer so I can't do much else.
Once the extruder reaches temp, let the fan breathe for your cooling needs and it should hold temperate.
I gently stuck the raise scraper blade between hot end and fan duct. Only takes a minute or so than you can take the scraper away.


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