Clock or Spit Jack

13 posts in this topic

Posted · Report post

Anyone seen a good drawing,photographs or a plan for an 18th century spitjack.

I'd like to build one like this..



Any info appreciated

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Posted · Report post

Joseph Moxon's "Mechanicks Exercises" has plans for a spit jack It was published in 1703 though a lot of the data is earlier.

Make sure you get the full book and not just the printing section that is commonly sold. I got a copy put out by Astragal Press.

Haven't tried his plan...yet.

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Posted · Report post

They've made them at Colonial Williamsburg but I don't know if plans are available.

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Posted · Report post

Excuse my ignorance, but what is the purpose of a spitjack / clockjack?

Looks like a shop winch, but there has to be more to it than that.

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Posted · Report post

It turns a spit over a fire.

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Posted · Report post

Hello Chainsaw,

Hope you are still active and reading posts.

I am planning to make a 'Clock Jack' too, we call it a 'Spit Engine' here in the UK.

Did you have any luck getting plans and do you have any advice to pass on?

Thanks.

G.

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Posted · Report post

There are some dwgs in Seymour Lindsay's book of domestic ironwork. I'll try to scan them if you don't have access to a copy.

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Posted · Report post

Hello Sam,

Thanks for the offer, but I have a copy of that excellent book (and reviewed it on the forum some time ago).

A scan of the plans and text in Moxon's book would be most welcome if you have a copy!

I have many, many illustrations and photo's of spit engines and some video of the mechanisms working - courtesy of another posting on IFI. But... I am very keen to find plans/blueprints from the correct period.

The reason for this is that I am pretty sure that there is a certain ratio that experience has proved to work best in the gearing; comments from local horologists give strength to this thought. It would be soul destroying to hand cut all the cogs etc. just to find I had discovered a poorly functioning ratio!

I have been in touch with Ivan Day (food historan), he built a copy of the spit engine in the kitchen at the castle museum in York. He is abroad for a couple of weeks but I'll have a chat with him on his return and will pass on any good advice to all who are interested.

Regards,

G.

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Posted · Report post

I saw a travel show yesterday that was touring Bath, England. They were visiting an 18th century kitchen that had a dog powered spit turner. You actually put a dog in a suspended "hamster wheel" looking thing and he would run/walk for a two hour shift and then you swap dogs. The wheel was shafted and geared to turn the spit over the cook fire.

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Posted · Report post

Some of them had vanes that rotated in the flue gases and turned the mechanism.

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Posted (edited) · Report post

Hello all,

I have finally tracked down and bought a fairly ropey copy of Moxon's book (the prices most sellers were asking were crazy!).

The good news is that the title is well and truly out of copyright.

The book does indeed contain a basic plan and quite detailed instructions for the construction of a spit jack ('clock jack' to brother Jonathan). Given time - and some luck with my techno-skills - I shall add the scanned-in chapter.

Hope this will be of help to some.

Please keep me posted if you have a go at making this according to the instructions. Any tips learnt along the way will be most welcome.

G.

Edited by GNJC

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Posted · Report post

Here, I hope, are the scans of Moxon's plan.

G.

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