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Monday 1 October 2018

The best laid plans of mice and man... Fellows A75 laminator continued ...

If you've been following this for a while, you'll know I modified a Fellows A75 laminator to get a more reliable way to make toner transfer PCB's. (You can find the original articles here and here.)

As I had predicted, we were now using the item way outside of it's specification, and that's it's life expectancy was certainly going to be, erm, compromised....

Well, tonight it happened. It stopped getting warm. Now I've got a commercial prototype to get out, and I need it. Let's see what's happened.....


So, the poor thing is once again disassembled. Those two red wires you can see running from the other side of the PCB are connected to the element.... A quick check with the meter, and ... it's open circuit. Damn.

Now, in the last modification I decided to raise the temperature by modifying the controller. So what if there's one of those non-resetable thermal fuse things on the element somewhere....





And there is! Mounted against the lower heating element...

It's duly removed, the two wires soldered together, and insulated with a piece of heatshrink...









Back in business!

Now, we've removed an essential safety device, so I'll re-iterate my previous warning... We're putting paper in here, which is being exposed to higher temperatures for more time than it would be in normal use.... If it should jam, there's a risk it could smoulder and catch fire, and ruin your day... DON'T USE IT UNATTENDED!

... you nkow what , I may just build a combined speed/ temperature controller for it, and have done ...