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Topic: Shape of intermittent cam.

Jeff Stricker
Master Film Handler

Posts: 481
From: Calumet, Mi USA
Registered: Nov 1999

posted 07-03-2002 11:57 AM

John P. any way you could scan and post a sketch of the mods. so we could get an idea of how it works?

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Josh Jones
Redhat

Posts: 1207
From: Plano, TX
Registered: Apr 2000

posted 07-03-2002 12:00 PM

Sounds like something an old telecine would have.

Josh

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 07-03-2002 12:48 PM

You can see the Kodak patent on line at the US Patent Office website:
http://patft.uspto.gov/netahtml/srchnum.htm

Do a search on patent number 6,183,087

Essentially, the Kodak invention uses a unique profile to the starwheel slots to allow the cam pin to provide greater acceleration. Unlike other high speed intermittents, there are no additional linkages or complexity --- just a different shape to the cam and starwheel that can be retrofitted to existing intermittents.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

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Brian Tristam Williams
Film Handler

Posts: 93
From: Johannesburg, South Africa
Registered: Apr 2002

posted 07-03-2002 02:43 PM

German, where did your boss get that picture? Do you have a larger one? Very interesting.

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000

posted 07-03-2002 05:55 PM

I edited my orginal post, but I am curious what it was used in or for. It looks kind of "shipboard-ish" to me....

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Will Kutler
Phenomenal Film Handler

Posts: 1506
From: Tucson, AZ, USA
Registered: Feb 2001

posted 07-03-2002 07:34 PM

Geneva mechanisms are used for many things. In fact, Berg...a major gear manufacturer out of NY produces some and lists them in their catalog.

One very wise and experienced projectionist and tech. once told me that a competitent machinist or toolmaker would have no problem making the parts. Assembling and adjusting an intermittent is another matter...unless you have been properly trained...

As a competitent machinist and die maker, I concour that the parts are straight forward to make...just time consuming!

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German Marin
Expert Film Handler

Posts: 227
From: Verbania (VB), Italy
Registered: Jul 2001

posted 07-03-2002 10:20 PM

Paul, I think that the Maltese Cross (a six arm star) is a sample just to show how it work but I'm not sure.
Brian, I've not seen the large one but I'll try to find it, that's a very rare maltese cross, the piece look as big as 3' or more.

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 07-04-2002 02:56 AM

I rather doubt the average machinist could make the parts in the precision required. There is a reason LaVezzi supplies almost every manufacturer.

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Brian Tristam Williams
Film Handler

Posts: 93
From: Johannesburg, South Africa
Registered: Apr 2002

posted 07-04-2002 06:29 PM

Well, I don't think, for training, you need that precision. Just make a large mock-up of the little thing.

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Will Kutler
Phenomenal Film Handler

Posts: 1506
From: Tucson, AZ, USA
Registered: Feb 2001

posted 07-05-2002 05:52 PM

Steve K. says that the average machinist could not make these parts?

Well, Steve....what do you know about machining?

These parts can either be cast then finish ground, or made entirely from stock...these parts have, I believe, .0002 tolorance, which is the norm w/precision grinding.

Some of the grinding equipment needed for these parts would be common to an injection mold or tool and die shop rather than just a job shop...such a a jig grinder and what not...

Non the less, a competitent machinist should be able to make said parts...I have made complicated precision ground parts with similar tolorances as class projects...

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 07-05-2002 09:23 PM

The fact the Charlie Wolk didn't have the boys in the back room make stars and cams tells me something.

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John Hawkinson
Film God

Posts: 2273
From: Cambridge, MA, USA
Registered: Feb 2002

posted 07-05-2002 09:48 PM

'seems to me it's less about whether your average machinist can machine parts to this tollerance, and more about whether they can do so quickly and cheaply, or whether someone who specializes can do it less expensively and more efficiently.

--jhawk

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Gerard S. Cohen
Jedi Master Film Handler

Posts: 975
From: Forest Hills, NY, USA
Registered: Sep 2001

posted 07-06-2002 10:59 AM

I made my intermittant
It's housing's made of clay
The star is from the deep blue sky,
the c(l)am from Sheepshead Bay.

My Pa was not La Vezzi
Nor I, Will Kutler Two
My grinder only sharpens knives,
Micrometer's plastic, (blue.)

My intermittant doesn't pull
Film down like projector claw--
Selective memory is its thing
It skips three of every four.

It shows me highlights of my life
That make me laugh and sing--
If I keep writing crap like this,
I'll earn my straightjacket - Bing!

Gerard

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Will Kutler
Phenomenal Film Handler

Posts: 1506
From: Tucson, AZ, USA
Registered: Feb 2001

posted 07-08-2002 07:50 PM

John

you hit the head on the nail.

It is a matter of specialized set up so that the parts can be made in masse...and cheaply....mass production.

Today, CNC has become a catch phrase that for some reason CNC means quality... This is just not so...in a nutshell, CNC = effeciency for long mass production runs. Lord knows how many messed up CNC parts I have seen because of improper inspection and monitoring of the system...or CNC programmers who have made mistakes...or computers that like to crash

I have personally been witness to the fact that by the time a CNC program has been written and the machine set up, the parts could have been made plentyfold with manual set-ups!

Today, young people are cluelsee to what pentagraphs, tracer mills and lathes, turret lathes, screw machines etc were, and how mass production was efficiently accomplished before the days of computers!

Anyhow, not to crash on CNC, it does have its place...

Love the Dreidel Song Mr. Cohen, Sir!

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 07-11-2002 10:32 PM

Will said >Today, CNC has become a catch phrase that for some reason CNC means quality... This is just not so...in a nutshell, CNC = effeciency for long mass production runs. Lord knows how many messed up CNC parts I have seen because of improper inspection and monitoring of the system...or CNC programmers who have made mistakes...or computers that like to crash <

Gee, seems like they've got those three letter bastards in every industry. You could almost substitute the letters DLP in that paragraph!

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