Improved Solenoid Motor

Henk Kaan started with the plans for the solenoid motor, from these he modified and improved the design:

The drawings are clear, and the rest was “improving by doing”.

The microswitch you used seems to be smaller than the switch that I could get. Therefore I looked for a new position for the switch.

The frame was made of standard aluminium strip 50 x 6 mm. The grooves in the base plate were made with a milling machine (a mini-mill table from China)  The roundings for the flywheel and crank are made by means of a circle saw in the milling machine. With a 45 mm flywheel these roundings are not necessary, but they make the model definitely better looking. Furthermore I used the lathe. At first I put the aluminium plate in the four jaw chuck and drilled an opening for the housing of the ball bearings. My largest drill is 14 mm, so I enlarged the opening to the required size by turning. Then I brought the plate into shape using the hacksaw, mill and turn table.

The housing for the bearing was made of aluminium in the lathe. Although it is a push fit in the frame plate I secured it to the frame with two little M2 screws, The outer bearing is fixed by means of a small M2 Allan key. See the added picture. The cam is made of a piece of brass 11 x 11 mm, brought into shape by means of the turntable and milling. The centre hole was drilled on the lathe. The opening in the bearing housing is 0.5 mm larger than the diagonal of the cam, so that the axle with bearings can be taken out.

I made the fixtures for the coil also of 6 mm aluminium plate. At first I drilled and turned the coil side in the four jaw chuck, Then I made a mandrell and fixed the stud with a ring and a M8 screw in the three jaw chuck and turned the plate to 5 mm where required. Then I brought the plates into shape by sawing and milling. 

I made a PVC coil. The coil is a push-fit in the two aluminium studs. I think a push-fit with an ebony coil should damage the wood. However PVC has a disadvantage: the friction between the coil centre and the piston was initially rather high. This was due to the fact that I do not have a 14,3 mm drill and/or reamer. If I should make it again, I might make the cylinder 14 or 15 mm and adapt the piston size to that. And I might make it of PTFE. As an alternative I might make the cylinder of a hardwood  and the rings of PVC. The piston is coromandel.

I made some grooves in the PVC coil front and end so that I could clip the iron strips 5 x 1 mm (I have bent it a millimeter at the ends, like in your video). I made two PVC rings for a temporary push fit, to be replaced by the aluminium fixtures in the final stage. After winding the coil it was necessary to bend the strips a little bit, as the coil had more windings in the middle (in spite of my attempts to get it regularly).

Under the coil is a small diode. I mounted the diode between the connecting screws of the coil. I do not know whether there is any benefit, as I did not try without it.

confining the magnetic field on a solenoid

Confining the Magnetic Field

Confining the magnetic field of the solenoid motor stator is a significant improvement. The force increases and hence the rotational speed increases.

This is the first of a number of improvements to the solenoid motor

After a run-in of about one hour, I reduced the friction by polishing the cylinder with car wax. Although there is almost no friction anymore, the electricity consumption is still rather high. Therefore I made a connection for an auxiliary battery or a transformer (works well!) for long lasting demonstrations.

I used two ball bearings and I glued the cam on the shaft with Loctite. Timing is easy by loosening and fasting the screw of the crank.

I think you will agree that this is a great interpretation and upgrade to the original solenoid motor design.

A huge thanks to Henk for sharing images of the engine and his approach to making parts. It would be great to hear and share other versions of this model that have been made. Please do drop me a line

single piston solenoid motor plan

Single Piston Solenoid Motor Plan

Here we have a pdf download of the plan for the Single Piston Solenoid Motor. An electric motor with a difference. The power output is low, but the action and the sound are fantastic. You can use this as a starting point for a more optimised design or for a multi-piston design.

Henk has made other engines and I just want to share two of these, hopefully we might be able to write more about these engines in future posts.

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