Pololu Deaths!

Hi,

Hopefully someone can give me some ideas of things to check here
My Reprap was working well

Suddenly mid print my Extruder stops extruding
Checking the temp all seems good, even a little hand fed extrusion worked no problems
Powered off and swapped X&E motors over,
Extruder moved under X axis driver
X didn’t under the extruder driver
(I presumed overheating)
Fan blowing across my ramps board all along
So I shut her down and left it overnight,
Rebooting it began to work well
Except it did the same trick, this time the Pololu didn’t return

Ive checked:
Connections for shorts (none found)
Ramps/arduno for shorts (none found with magnifying glass)
Firmware re flashed
Re checked voltages

Thought not much else I can check, New Pololu it is

Worked fine for nearly a month
Then same again

I can’t believe I’m killing them with heat as they aren’t warm to the touch

Ramps 1.2, Pololu’s set to 0.4V
So ideas please what might be up with it before I burn another pololu

Rob

Hi Ijmok,

I'd start by checking your end stops for a short.
Mine did the same thing and it turned out to be a pin that worked it's way to the mounting plate and shut down the whole machine.
I couldn't even get it to recognize the com port.

I removed all the stops and it worked so I plugged them back in 1 by 1 and found the problem.

Hope this helps.

Windcatcher

Might be a bad solder joint under the chip. When chips burn out they don't recover but connections can come and go with temperature.

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[www.hydraraptor.blogspot.com]

My soldering of the SMT (bought pre assembled Ive just added headers)

What really odd is its worked ok since May when i first got it, in the last 2 months ive blown 3 chips, one was my fault (loose connection)

Then the second one glitching as above which i replaced figuring id poked it in the wrong way and now this one

Its getting expensive lol

Thanks windcatcher, ill check it but it carries on printing with X,Y&Z just no E

Very strange

Rob

If you keep blowing Pololu drivers, you might want to invest in bigger heatsinks (you do have them, right) or turn down the output current by adjusting those little dials on the drivers(I don't know which way, look it up)

Hi Jamie,

All resolved i think

Seems where id been tidy and heatwraped my wiring id left a little bit uncovered on 2 of the extruder circuits * massive tit i know*

Complete strip down, re terminated everything (crimped, soldered and glue gunned into there holders) and all seems better and more manageable.

Just waiting for a new hot end and were back in business, but XYZ&E look to be doing the right kind of shuffle, went through a "2hr" print with no filament or heat no problems

Fingers crossed

Edited 1 time(s). Last edit at 01/21/2012 06:42AM by ijmok.