Most stationary engines are on a trolley, hence I though I should make a set of Whippet trolley wheels.
As it happened we visited Wimpole Hall and there in the farmyard were some vehicles that might give some inspiration.
The design that feels more in keeping with a trolley wheel is the one on the right, however, I do like the 5 spokes of the wheels on the plough (centre).
I wasn’t sure at first of the diameter for the wheels. 2.5″ felt roughly right, but I didn’t have enough material.
Then I thought about using 1/4″ thick mild steel plate. A bit thin, but this would work if I didn’t machine anything off the thickness.
A piece of 2″ diameter mild steel (offcut that was lying around) was mounted in the 3 jaw. This was then faced, centre drilled, drilled through with a 5mm bit and then threaded 6x1mm.
All of the machining has to be done with the mandrel not being moved in the chuck. Thus making the alignment easy to achieve.
The mandrel allowed the wheels to be fixed with the 6mm caphead bolt and easily swapped around to machine both sides.
I always mounted two wheels together so as to give a bit more support to the outer edge. This doubling up helped as the mandrel was a smaller diameter than the wheels.
Once I had four wheel blanks with the correct profile I then had to machine the spokes. For this I stepped across to the Sieg SX2.7 milling machine and rotary table.
Again the mandrel is mounted in the four jaw chuck that is itself mounted to the HV4 rotary table. I then used a dial indicator to adjust the 4 jaws until the mandrel rotated on centre.
This HV4 rotary table has a set of indexing plates and so with some calculations it is easy to set it up for 5 indexed positions. See our free workshop excel calculations download that has lots of different sheets, one of which is for rotary index tables.
Machining the spokes did take some time. The design of the spokes for these wheels did mean that all of the indexing and machining was done from one side.
Still takes around 3 hours to machine each wheel, lots of time to listen to audio books.
A set of 4 finished wheels. Not perfect, but are trolley wheels perfect? I filed the rough edges off and then tumbled these with ceramic balls for a few hours to clean them up.