feeds and speed

[rtbcomp]

Missed that bit - a trimmer usually refers to trimming capacitor, a trimpot best describes a variable resistor!

Those on the Maplin link are trimming capacitors.

This may be a better bet http://www.maplin.co.uk/Search.aspx?menuno=12464&MenuName=Potentiometers

The capacitor will be an open circuit so if it makes no difference looks like we're in the right ballpark at least.

 

[CRAIGPERRY]

so, by my reackoning I need a N48BR Preset Potentiometer ??

I notice in the photo it has two terminals but the one I'll take off has 3, however two go to the same connection on the PCB so this should not be an issue ???????