Tool 1 Failure. Temperature Reads are Failing. Check Wiring.

[Elbot]

Tool 1 Failure. Temperature Reads are Failing. Check Wiring. 

I am at wit's end. I have been trying to fix this for months. Please let me know how to fix it. The printer would not print anymore. The last 3 prints, it printed fine for about 30% of the print, then fails. Now, it wouldn't even print at all. I don't know how to "check wiring". I mean, which wire to start with? How to check?

Please advise.

Thanks.

[Ryan Carlyle]

It means the thermocouple wiring.

[Elbot]

which is the thermocouple wiring? How do I check it?

The fan comes on by itself by the way. Even though I haven't turned on the nozzle heaters yet.

Is the following a good plan of action?
1. Even when it was working fine, the wires that go into the green wire connectors that use a screw to secure the wire connections aren't very tight. I am going to solder a thicker wire to all the wire ends and then insert the thicker wire into the wire connectors. That should make a better connection. However, I don't know if any of these are the thermocouple wires? I don't know if any of these wires are loose, so I'll just tighten all of them?
2. Are the wires connecting to the fans and sensors loose? How do I check that?

If this is a bad plan of action, what else should I do instead?

Thanks.

[Jetguy]

Hint, the screw terminals that say "thermocouples" beside them

 

[Jetguy]

Here is a post copied from the Wanhao Duplicator 4 group but applies equally to Flash forge and CTC brands for reference.

Again, the Wanhao board clearly says "thermocouples" next to the screw terminals. So does FlashForge, so does CTC brands.

 

The problem is MOST LIKELY the wiring is loose at the connector. Notice the wire color order. Left to right it is Green then Red for each pair. With the screw terminals, you must loosen the screw, remove the wire (One at a time to NOT mix them up), completely loosen the crew so that the tiny little square metal block lines up with the hole the wire slides into, then insert the wire and then tighten the screw. Notice the wires are in pairs. Because there are 2 extruder nozzles, there are 2 thermocouples and they must not be switched left to right. So gain, from the left, the first two terminals are one thermocouple, the next two are the other thermocouple.

Here is where the sensing end attaches to the heater blocks. Notice the braided wires and then the terminal lug ends that bend around the heater blocks to the side.

here is a front view

Notice the M3 stainless screw and washer attaches them.

[Elbot]

Thanks, that was a GREAT pic. I will try this in a couple hours after work. I'm gonna look for your address. I think I still have it saved here somewhere from a year or so ago. I wanna buy you lunch or something by mailing you a little something (gift certificate, check or something). Thanks again...!

P.S. Do you drink coffee? U near a Starbucks or something?

I will let you know if it works after I try to fix it tonight after work ;0)

You are a genius.

On Wednesday, October 22, 2014 1:00:52 PM UTC-5, Jetguy wrote:

Hint, the screw terminals that say "thermocouples" beside them

 

[Jetguy]

"The fan comes on by itself by the way. Even though I haven't turned on the nozzle heaters yet."

 

Yes, it will do that on purpose, that is a safety function built into the firmware to protect you from yourself since you've said this error hass been happening and yet you keep trying to print. If you notice, the fan comes on whenever the reported temperature of the extruder is above 50C. You'll also notice that if the thermocouple fails, you see a temperature of 1024C displayed. That is the safety so that the heater cannot be turned on and the fan coming on is a secondary function that the reported temp (1024C) is greater than 50C, meaning the fan turns on.

 

On Wednesday, October 22, 2014 1:47:45 PM UTC-4, Elbot wrote:

[Jetguy]

Again, sorry to know that you have had this problem for a while.

Thermocouples are prone to breaking if not installed right. Even if they are perfect before you get the machine, they are wear and tear items because the wires flex every time the extruder moves. So eventually, every owner should know that error message and how to deal with it.

 

I would recommend keeping a set of thermocouples handy as spares and know how to replace them.

[Jetguy]

Also, sorry, the forum nests some of the pictures as quoted text. Be sure to expand the post and see all of it.

On Wednesday, October 22, 2014 2:12:30 PM UTC-4, Jetguy wrote:

[Ryan Carlyle]

Do not solder anything to your TC wires, they require the proper type-K alloys of wire through the full electrical conduction path between the TC and the mainboard. The TC wires should terminate as close to the thermocouple amp as possible. Specifically, any metal junctions need to be at the exact same temp as the TC amp chip. (The error you would introduce with a very short stretch of copper near the board would be minimal, but it's a really bad practice to get into.) 

[Jetguy]

Elbot, It would be good to know exactly which 3D printer you have. The thermocouple may be specific to the brand as far as mounting goes.

Generally you can use any type K thermocouple, it's just that some have different mounting tip systems to the heater block. Some screw into the heater block, some are M3, some are M4 thread, some are TAB style. 

Once we know what printer you have, we can give you specific advice as to what to buy for a replacement.

[Elbot]

Makerbot Replicator 1.

[Joseph Larson]

I had to do this recently for both extruders. The thermocouples died on both of them within a month of each other after replacing the whole extruder assembly with one from Wanahou months earlier. Fortunately I had 2 spares that I had bought to replace my old thermocouples on my old extruder assembly. If you have a new thermocouple you can do the following:

• Turn your bot on it's side and unscrew the bottom panel (it's held on with just one M3 screw) with the hex wrenches that came with your bot. You'll see the connector in the picture that JetGuy's post showed nearest where all the cables enter the back of the bot. 
  
• Use a small flat head screwdriver to unscrew the thermocouple and replace it with the new thermocouple. 
  
• Then turn on the bot (while it's still on it's side) and see if you still get the error. 
  
• If you do then either your new thermocouple is broken or the connector isn't soldered to the board properly or the board is shot. Pray this doesn't happen.
  
• If you don't try preheating your extruder and hold you new thermocouple against the hot end. If the temp numbers go down you've got your thermocouple in backwards (thermocouples are unidirectional). Unscrew the connection, flip it around and try again.
  
• When everything is hooked up you'll need to take the new thermocouple wire around your nerve cluster of wires up to it's new home, unscrew the old one and remove it, and screw the new one in.
  
• Print away.

It's tight work and give yourself an hour at least if this is your first time.

[Elbot]

Joseph, where did you buy those replacement thermocouples for the MBI Rep 1? Thanks.

[Joseph Larson]

Nope. http://wanhaousa.com/collections/hotend-parts/products/thermocouple You have to bend the end to go around the thermoblock but that's what wanhao does for their extruder block.

[Joseph Larson]

Oh, and JetGuy pointed out to me that I forgot to mention you need to turn your extruder heater OFF. Don't just let it go, especially if you're doing it backwards.