Monotype Composition Caster Pot Temperature Controller

Over the past few months, I’ve had to replace the old Partlow temperature controller on the pot of my Monotype Composition Caster.

On my caster the old mechanical controller has failed; each time I ran the caster I found that the metal temperature had gone up from where it was set, sometimes 50°F hotter than the setting, despite recalibrating the controller.

Rather than replacing it with a possibly just as bad spare controller from my parts pile, I chose to replace it with a modern electronic controller that uses a thermocouple to measure the temperature of the molten metal. Just as with the original controller, this switches power to an electrical contactor which in turn switches the power to the electrical heating elements.

I’ve used the caster a few times with the new controller, and so far the only problem I’m having is visibility. Its location is the same as the original controller, on a post above the pivot that the pot swings on. This means that from my normal operator’s position, sort of facing the tool tray, I have to peer around/through the ingot feeder to see the display. Furthermore, to avoid having the controls face all those visual obstacles, I’ve turned the enclosure to face more to the right, so you can see it well if you’re standing by the galley. I don’t have to consult the temperature readout much, and it is a self-illuminated display so easily visible, but when I’m casting display fonts I want to keep an eye on the pump stroke counter. This is an LCD display and so difficult to see from an angle. I might turn the enclosure to the left to face my normal position to improve visibility. I think a bit of experimentation will be required here.

I recently gave a short presentation about this project at the 2023 ATF Conference in Maine, and I have posted a YouTube video showing the construction and installation of this new controller.

I’ve already made a post about the custom enclosure I made for this.

Leave a Reply

Your email address will not be published. Required fields are marked *