A warning story to finish your DIY projects

[luka]

Just a small warning story how a 99% finished DIY project almost turned into a disaster because of my laziness to do the final step.

About 6 months ago I built a cold-finger cooling for my Canon 450D. The camera modification was done and I finished a custom-built TEC controller (using microcontroller for PWM). I was just finalising the last part which was the cable when I realised that I did not have a connector that can carry enough current (5A). The local shop was closed and I had to try it out right then... so I figured out that it is winter and cold so that the TEC won't be running at full power and that I can use a lower rated 3A connector... only for a quick test and I'll be monitoring the temperature at all times...

Everything worked great and the connector did not even get warm (PWM was under 40%). So I tried the DSLR at night and it worked beautifully. Again no heat on the connector... and again the next night and so on. I kept telling myself to replace the connector but there were other things to do and build... eventually I forgot.

Fast forward 6 months to a hot summer Perth night and TEC running at almost full power. I was messing with the guiding for a long time when I noticed a smell of burning plastic. Eventually I started feeling in the dark until I burned my finger on the melted plastic housing of the connectors... only then it hit me what I did. The plastic was completely melted and the connector contacts were all black and burned.

I think I have learned my lesson that night. I am still thinking how things could have been if the guiding worked straight away and I went to bed and left the DSLR imaging overnight (in my backyard), how the whole thing could have started a fire.

[traveller (Bo)]

Ouch, a lesson learnt the hard way.
Thanks for the timely warning Luka. Guess the safest option is not to complete the DIY projects, that way there is no way they will stuff up
Bo

[luka]

Can't do so Bo, the DIY is in the blood

The lesson is just to be more careful and not to be lazy to do the hard, boring bit at the end. In the end we have more control what and how we do the things than if we buy finished product off the shelf.

And I am not sure about the safety of the commercial projects anyway, Samsung Galaxy Note 7 comes to mind