Rear Wheel Spokes

The rear wheels of my miniature traction engine needed 32 spokes in total. This is quite a task and so thought I would take you through my process.

cross-cutting brass on bandsaw

I started the rear wheel spokes by cutting out the brass blanks on the bandsaw.

Cutting thin brass on the bandsaw can be a challenge and so I modified the table with the addition of a close fitting MDF table top.

This gave more support for the edges of the brass as the MDF closely fits to the blade.

spoke blanks, hubs and rims

I ended up with 32 brass blanks 43mm x 8.5mm and 0.9mm thick.

I had to stand these altogether so that I could get a feeling for the progress over the next few steps.

I drilled a 2.3mm hole that was stepped in 3mm from each end and centred.

spoke blanks bolted together in sets
Spoke blanks bolted together as four sets of eight spokes.
machining spoke blanks

The sets of brass blanks held in the Soba vice by the ends of the 8BA bolts.

The sides of the blanks were machined using a solid carbide end mill (Rennie tool end mills).

The blocks were rotated 180 degrees and the other side machined.

spokes overall size machined

4 sets of 8 spokes all machined to the same size. Sorry, the last block is in the chuck and ready for the next stage.

spoke sets machined to shape and size
The main spokes machined down to 4mm width with the step wider for the attachment to the rims.
32 spokes

All 32 spokes held in my hand. This now feels like a real achievement.

I had to file the edges to remove the slight flashing from the machining operations. This was particularly prominent on the upper and lower of the spokes in the set of 8.

spokes, hubs and rim

All 32 spokes, 2 hubs and a wheel rim together.

There is still a lot of work to bend each spoke and fix them all in place.

I marked each spoke 4.8mm in from each end and bent them to an angle of 20 degrees each end.

part built rear wheel rim
The spokes are bolted to the rims with 8BA 1/4 inch long round headed bolts.

As soon as the Rear Wheel Spokes started going into place the wheel started to get structure and stability.

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