hotend no longer heats up

A forum dedicated to the stock LulzBot TAZ 3D Printer
aadamson
Posts: 48
Joined: Wed Jun 05, 2013 2:53 pm

Re: hotend no longer heats up

Post by aadamson » Mon Jun 17, 2013 11:19 am

1013 wrote:this thread has evolved into a general "something is not heating up" thread.

we have a nifty thermal camera at work, so I took some snapshots just now. Its not an even heat up like I remember it to be when I first got the TAZ working (but I did not take any snapshots of it when it was working correctly....doh)

there is nearly a 30 degree defference in spots, and that would account for the discrepancy we are getting. If the thermocouple is in the cool area, that could be our problem.
what would be very cool to know is if on initial heatup that cold area isn't cold until after the initial heat up... I know it sounds strange, but I wonder if the mat is such that it could cool with thermodynamics *after* the first heat up.... or after that area cools to s certain temp...

That would account for why my mat acts the way it does... and it will also account for why the bed heats even tho the sensors is cooling...

Alan

1013
Posts: 339
Joined: Thu May 23, 2013 9:56 am

Re: hotend no longer heats up

Post by 1013 » Mon Jun 17, 2013 11:45 am

I let it completelly cool down and then turned the bed back on.....it looked identical to the pictures I post earlier. Same patern of heating and not-heating.

My guess is that their is a loose connection in the heater, and one or more of the elements is not turning on. But without knowing how it is wired inside, I am not sure if that is correct.

1013
Posts: 339
Joined: Thu May 23, 2013 9:56 am

Re: hotend no longer heats up

Post by 1013 » Mon Jun 17, 2013 12:01 pm

It does look like the bed heater is messing up.

I flipped the bed upside down to get a better look at the element and took some more thermal pictures.
IR_0142.jpg
here you can see 5 out of 6 (I think) traces heating up
IR_0142.jpg (64.22 KiB) Viewed 2193 times
IR_0144.jpg
now this was a few minutes later, and there are only 3 traces heating up.
IR_0144.jpg (57.88 KiB) Viewed 2193 times
notice the hot spot near the connector....it might be burning itself out.....looks like I need to contact lulzbot directly. I am sure they will handle it.

aadamson
Posts: 48
Joined: Wed Jun 05, 2013 2:53 pm

Re: hotend no longer heats up

Post by aadamson » Mon Jun 17, 2013 12:22 pm

1013 wrote:It does look like the bed heater is messing up.

I flipped the bed upside down to get a better look at the element and took some more thermal pictures.
IR_0142.jpg
IR_0144.jpg
notice the hot spot near the connector....it might be burning itself out.....looks like I need to contact lulzbot directly. I am sure they will handle it.
Ok, that is why it could account for the thermistor seeing it cooling (notice how much colder you are even tho the rest of still heating). From looking at the mat side of mine, it appears that the thermistor was placed approx where you show the cool part of the mat, and the cooling part once the mat starts to heat up...

Thanks, that was very helpful... We'll see, they should be getting mine today from the PO... it was attempted on Saturday. And that should tell us something...

1013
Posts: 339
Joined: Thu May 23, 2013 9:56 am

Re: hotend no longer heats up

Post by 1013 » Mon Jun 17, 2013 12:49 pm

I just looked at it again, and only 2 traces are heating now...

I am afraid that the resistance may be changing and could damage the RAMBO, so I am disconnecting it for now until lulzbot gets back to me.

jebba
Site Admin
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Joined: Mon Mar 25, 2013 4:11 pm

Re: hotend no longer heats up

Post by jebba » Mon Jun 17, 2013 2:33 pm

Thanks for all the detailed info, we're looking over it all now.

jebba
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Re: hotend no longer heats up

Post by jebba » Wed Jun 19, 2013 2:54 pm

We just got a nice FLIR today too... research continues...

1013
Posts: 339
Joined: Thu May 23, 2013 9:56 am

Re: hotend no longer heats up

Post by 1013 » Wed Jun 19, 2013 5:08 pm

jebba wrote:We just got a nice FLIR today too... research continues...
it is a useful tool, which one did you get?

jebba
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Joined: Mon Mar 25, 2013 4:11 pm

Re: hotend no longer heats up

Post by jebba » Fri Jun 21, 2013 8:03 am

We got this one:

FLIR Systems E30 160 by 120 Resolution Thermal Imaging IR Camera

http://www.amazon.com/gp/product/B0088LHHOK

It is pretty cool tool so far. We're getting a much better understanding of what is going on. We have contacted the vendor of the silicon pads too, to get their thoughts.

Thanks,

-Jeff

1013
Posts: 339
Joined: Thu May 23, 2013 9:56 am

Re: hotend no longer heats up

Post by 1013 » Fri Jun 21, 2013 8:13 am

nice, that is the same model I used.

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