Maltese Cross

[Stephen RowleyParticipant @stephenrowley13300]

As I once was a cinema engineer and until 2006 had a large collection of old cinema projectors I thought I might have a go at making a 1/3 scale model of one of the odd British projectors from 1947. All simple enough but to make it work I need to make a Maltese cross from MS and about 7/8 across by 1/4.

Any advice please.

jsk

P.S. I can make a Maltese cross by hitting him!

[Stephen RowleyParticipant @stephenrowley13300]

How to machine a Maltese cross

[Robert DoddsParticipant @robertdodds43397]

Hi,

The more correct name for the film advance mechanism you seek is Geneva wheel mechanism. Right sort of area but wrong country

If you look on this site there is most of the design parameters set out and a little animated bit as well . There are lots more to google under Geneva mechanism so go and explore.

 

http://www.meadinfo.org/2009/05/geneva-wheel-design.html

 

http://www-bsac.eecs.berkeley.edu/~pister/245/project/KumaresanVidya.pdf

Regards

Bob Dodds

[Stephen RowleyParticipant @stephenrowley13300]

If I were to go in to any cinema in this county and say Geneva wheel mechanism no one would know what I was talking a but, if I said cross box or intermittent unit as the Americans call it that would be different.

In the book by the S.M.P.T.E. it is described as a Maltese cross and Geneva pin movement.

JSK

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