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Rostock V2 hotend not hot

Posted: Mon May 19, 2014 10:58 pm
by Max
This is informative, and no longer a problem.

I've been printing away for the last week with no problems. I've got hotend temp, retraction, bed temp, disappearing purple glue all working great.

This afternoon I started to prep for a print. Preheating the bed to 85, heat up the hotend to 220 (ABS), and then normally run 20-30 mm of filament through the extruder to prime everything.

But this time the hotend maxed out at 170C. I thought maybe with the V3 bed plate, and questions about the power supply not being big enough, something burned out something in the power supply. I was ready with an old 700W power supply, and extra wires to run to the bed.

Just as I was about to start taking everything apart, I checked the thermistor. Just by dumb random luck, I noticed a bad solder on a wire to one power resister in the hot end. Soldered it back together, and everything is perfect again.

So FYI. If everything was working just fine and then the hotend just can't get up to temp and hovers around 170C... You might have a broken wire. Or a broken power resistor. But just one. Because one will heat to ~170C.

-Max

Re: Rostock V2 hotend not hot

Posted: Tue May 20, 2014 11:59 am
by geneb
Soldering the resistors is a great way to drip solder on your parts. That's why crimp connectors are specified for the heating resistors.

g.

Re: Rostock V2 hotend not hot

Posted: Tue May 20, 2014 1:56 pm
by Max
Good point Gene, and that's why I used silver solder. I didn't have a good crimper, but I had the silver solder. As soon as I realized we were using 220+C temps I knew I couldn't use my normal stuff.

The real problem is that I need new glasses, because I didn't look close enough when I did the work the first time. I also routed the wires a little differently to keep more distance from the thermistor wiring. That made it hard to use a crimp.

Re: Rostock V2 hotend not hot

Posted: Tue May 20, 2014 3:55 pm
by geneb
Ahh, good point! I'm not used to anyone but my wife using silver solder (she's a jewelry designer - teaches a HS class in it even!).

Max, I don't touch a soldering iron any more without a pair of these on: http://www.amazon.com/gp/product/B005VI ... UTF8&psc=1

I use the 3.5 diopter lenses. They're excellent.

g.