Magnetic Stop Mechanisms

The magnetic stop mechanisms are based on those supplied by Bolton‘s Bits. These are available as either mechanically or electrically operated versions.

The mechanical versions consist of a magnet mounted on a crank. Connecting a pushrod or wire-in-tube system to the crank allows the magnet to be raised and lowered. The electrical version has an electric motor connected to the crank.

I had a number of the mechanical version in stock so I converted them to electrical operation by building the mounting bracket from plastic card and fitting the necessary gears and motor (obtained from Squires).

Magnetic stop in up (stop) postition.

Magnetic stop in down (proceed) postition.

The motor is rated as 1.5-3.0V so can be operated from one or two standard batteries. You can either use a momentary contact switch to change the magnet‘s position or use a switch that keeps the power on. This will not hurt the motor but, believe it or not, the motor does draw more current when it is stalled (i.e. at the end of the crank‘s travel) than when it is turning. For the motors used on the Bolton‘s Bits units the stall current is in the order of 500mA so if you are running from batteries a momentary contact switch will make them last a ot longer.

The motor, and method of control, is the same as that used for the Junction Mechanisms.