Clutch pedal

[Martyn Nutland 1Participant @martynnutland1]

Hello Everyone,

I wonder if someone could advise me as the best way to do the following?

I'm making a clutch pedal for an Austin Seven. Before we start, let me say, I do realise the easy way is to buy one from an autojumble or the 'usual suspects', but Seven addicts will appreciate that while the Ruby type pedal that secures with a pinch-bolt are two-a-penny, the earlier cotter-pin secured variety are much rarer hence my approach.

For machining simplicity, I elected to make the pedal in four pieces. A boss to fit the spindle where it emeges from the gearbox; the lever, the pedal stalk and the foot-pad. I've cut a boss 35 x 35 x 40mm from mild steel, radiused the corners for appearance and drilled a hole (about 15mm diameter) to slip over the spindle, plus a cross hole for the cotter pin.

The difficulty is there's a round section (collar if you like, about 20mm O/D) on the gearbox side of the boss. This takes the return spring – the coil fits over the round part and one end passes around the lever and the tail locates in a small hole in the gearbox casing.

How can I best make the round section on the boss? I've thought of holding the rectangular piece in a four jaw chuck on the lathe and doing an interupted cut; I thought, perhaps setting it up on a rotary table and rotating the block against an end mill, but I don't have a four jaw chuck for my rotary table; or perhaps shaping it on a belt sander?

As always, expert guidance would be very much appreciated.

Best, as always from snowy Paris! Martyn

[Martyn Nutland 1Participant @martynnutland1]

Round boss on square stock

[Chris Evans 6Participant @chrisevans6]

Lathe and four jaw look most likely given your equipment availability. Good luck and if possible post a picture of the completed item.

[Howard LewisParticipant @howardlewis46836]

Lathe and 4 jaw would be my choice, also.

If it needs to be said, the car will be to Imperial dimensions, and Whitworth form threads, not Metric (Excepting the spark plugs ).

At a guess, the clutch throwout shaft will be 19/32" diameter, and the boss for the spring possibly 7/8"

Howard.

[Speedy Builder5Participant @speedybuilder5]

I think Martyn is trying to make the pedal as shown on bottom right of the sketch. The 20mm collar supports the clutch release coiled spring.

[Martyn Nutland 1Participant @martynnutland1]

Thanks so much for the very prompt replies.

Yes…I'm coming to settle on the interupted cut approach. Reduce the area first with saw cuts; then shape it on the lathe.

Exactly as in the picture.

Imperial dimensions, of course. BSF on the early models BSW towards the end of production.

Thanks again everybody

Martyn

[Howard LewisParticipant @howardlewis46836]

Giving a pedal travel that must be almost an inch!

the pinch bolt arrangement made adjustment of free play so much easier!

Howard

[Author]

Posts