Linear motor and workshop heating

Hi folks,
A short week, as will be next week, but no less interesting I hope! I attempt a fix on a linear acutator in a rise and fall column for a piece of opticians equipment, and then on to the workshop heating. I find all the plumbing bits I need and build the heat exchanger for the ducted air heating in the workshop!
Phil, in STILL cold and wet East Yorkshire
• Linear motor and works...