Sometimes I have to build something that is different and in my head, this time a solenoid tractor. Firstly I needed to make a more powerful solenoid motor.
We have looked at improving the solenoid motor design previously. Many of these items will be discussed in this design.
The starting point for this model has been the redesign of the coil to make it more powerful. My first attempt used a paper core and end plates that with a mix of cast iron swarf and epoxy resin used to make the “iron core”. The iron core was an outer layer around the copper coil.
The fundamental reasoning was to reduce the distance between the coil and armature. Plus to increase the strength of the coil using an iron core. Laminations of iron are not so easy to shape, hence my idea to mix cast iron swarf into a 20 minute epoxy resin.
I measured the generated force by arranging a pulley system such that the action of the armature lifted a weight off a set of electronic scales.
- Original coil and armature = 0.29N
- Original + steel confinement = 0.45N
- Epoxy Iron Stator = 1.57N
- Final stator + Nd52 core = 2.3N
The epoxy based stator and Neodynium magnet armature using Nd42 magnets increased the force by a factor of 5 over the original design.
I then redesigned the stator using a thin plywood core and endplates. This allowed me to wrap the copper wire along the complete length. Again using the epoxy and iron mix to improve the magnetic field confinement. The final touch was to use Nd52 magnets that were closer in diameter to the hole through the stator. Finally I achieved 2.3N and was very with this increase.