Hobbing a Pulley for driving accessories for Model Steam Engines or Toy Steam En

[Blue HeelerParticipant @blueheeler]

Hobbing a Pulley for driving accessories for Model Steam Engines or Toy Steam Engines
This worked out really well for a first attempt, I’ve been wanting to try this for ages to stop belt slippage on pulleys and drive wheels when running accessories off steam engines under load which can very often be a problem as some engines lack the power to be able to put a lot of tension on a small round drive belt.
It’s a great hobby and pastime working on your metal lathe or metal milling machine making parts for model engines and model or toy steam engines.

https://www.youtube.com/watch?v=adQg7KxkGf8

 

[Blue HeelerParticipant @blueheeler]

I’ve been able to ‘retrohobb’ many previous drive pulleys that I have made now over the years by making up some more jigs for different sized axles. Happy that in aluminium, brass and one mild steel drive pulley I’m getting the same results shown in the video.

I am extremely happy to be able to duplicate now on my DIY drive pulleys what Wilesco has always done.

A Wilesco stock standard drive pulley –

 

 

[Blue HeelerParticipant @blueheeler]

Here’s some photos of a vertical transmission that I made some years ago that I have ‘retrohobbed’ one side of the drive pulleys on this morning.

 

 

 

[Michael GilliganParticipant @michaelgilligan61133]

Well-done

… I presume that hobbing is a much gentler process than knurling would be.

MichaelG.

[Blue HeelerParticipant @blueheeler]

G’day Michael, knurling like that would be beyond my paygrade (well and truly).

This is very gentle, the drive wheel being hobbed automatically turns by the action of the tap spinning (for me the lathe at 400rpm is perfect) and you can let it go around as many revolutions as you’d like slowly giving more depth to the cut.

I’ve found that once you are at the preferred depth, I let it do 3-4 revolutions until the tap is no longer removing any material. I then put the piece on a mandrel and use some very fine wet & dry.

[Michael GilliganParticipant @michaelgilligan61133]

An appreciative frame-grab from the video:

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MichaelG.

[Blue HeelerParticipant @blueheeler]

Thanks Michael.

[Blue HeelerParticipant @blueheeler]

[Blue HeelerParticipant @blueheeler]

Retro Hobbing…..(Worm Gearing) I’ve been busy hobbing my vertical and horizontal transmissions I made some years ago plus a few other accessories.

Things I’ve learned from doing many now – what works for me.

Lathe 400rpm
Use lots of WD40 and a toothbrush to keep clearing away the chips
Very critical is to have the tap centered perfectly in the middle (spend some time eyeballing this) if there’s any chatter whatsoever the tap is either trying ride up or down
Don’t put too much pressure on the tap, its not needed and just keep going in a couple of thou at a time. When you’re at the depth you want, let the piece rotate at least another 4x for a really clean cut.

 

[Blue HeelerParticipant @blueheeler]

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