Mk5 wont Heat

[C.Cotter 24/7]

I did 2 prints yesterday and today I can't get the mk5 to heat up??

[James McCracken]

Have you tried flowers and whispering sweet nothings?

Get it? heat up??? lol its funneh...

Srsly though... have you checked the power resistors? They should
read the right ohmage and have good electrical connections to the rest
of the circuit.

Also check the thermistor. I haven't debugged any Mk5s so I don't
know how exactly to do it with the bot off - but with the bot on, in
the control panel, you should get a temperature reading. If its 0 or
255, there's a problem with the thermistor or how its connected...

If you directly connect the power resistors to 12V for a moment does it heat up?

[Luis Esteban]

On Dec 22, 12:09 pm, "C.Cotter 24/7" <ccotter...@gmail.com> wrote:
> I did 2 prints yesterday and today I can't get the mk5 to heat up??

What appears in the control panel? In the temperature. If you have a
multimeter check the ohms. in you MK5 by connecting the two red and
black cables you would connect to the relay to you multimeter. It
should read anywhere from 2.5 ohms to 3ohms. That's fine. It'll
probably be your relay, thats what happened to me. Does your relay
click on when your send the command to heat up. It can click but still
not be working. Check the soldering on your relay.
Hope this helps,
Luis Azmouz

[Zip Zap]

Is your print head wrapped up with Kapton tape?  If so, check your wiring.  Loose wiring, loose soldered points, are big contributers.  I found that solder melts and droops easily as it gets close to 200C.  I find that clamping the connectings works better.  I myself have reverted to wiring the resistors together with 16 gauge solid copper wire and just using pliers to sandwich clamp them to the resistors and adding a little dab of solder.  The thin wires that MBI provides are just too weak and burns up easily.  Use thick solid copper wire at the printhead and then extend out to regular braided wiring to your extruder board.

---

From: Luis Esteban <dlpla...@gmail.com>
To: MakerBot Operators <make...@googlegroups.com>
Sent: Thu, December 23, 2010 7:00:13 AM
Subject: [MakerBot] Re: Mk5 wont Heat

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[The Ruttmeister]

Odds are its just the solder having died.... quite why MBI did such
exellent work designing the Mk5 without replacing the solder I don't
know... Even the high temp stuff isn't really up to the job.

There's a simple solution though. Clean off the solder and instead
use some female spade crimps. I could only find 1/4" ones. They work
but 1/8" might be a better fit. You probably want to wrap the
insulation before you connect the crimps to the resistors though. (And
just to be super clear, I mean crimp the crimps to your ptfe coated
wire, then push fit those onto the ends of the resistors).


On Dec 22 2010, 9:09 am, "C.Cotter 24/7" <ccotter...@gmail.com> wrote:
> I did 2 prints yesterday and today I can't get the mk5 to heat up??Z

[David]

I did the same modification except I used the male ring and a bolted
connection. So far so good.