Film-Tech Forum ARCHIVE: CNR3-35 Platter Calibration

This is topic CNR3-35 Platter Calibration in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Chris Byrne (Member # 1563) on 01-25-2003, 12:21 AM:

Does anyone have any additional tips for calibration of a Cinnemacannica CNR3-35 platter system other than those stipulated in the manual?

I have heard you should check the level (evenness) of the platters, but is this by placing a spirit level on the take up arm or the platter itself? I have been told both.

Posted by Antonio Marcheselli (Member # 373) on 01-25-2003, 07:52 AM:

CINEMECCANICA!!! [Razz]

Antonio

Posted by Darren Briggs (Member # 1071) on 01-25-2003, 02:43 PM:

You must check any platter system is level, not just Cinemeccanica.
As for timing, if i recal the manual states 38 to 42 revolutions per minute with the feeder arm fully across.
And that the first 5 degrees of the feeder arms swing, the plate should remain stopped.

The way I adjusted my platters was run a film, get take up arm/buffer so when the platter has started taking up film, the arm/buffer is six inches from the arm/buffer's resting position, leaving the feeder arm as it was set, adjusting the plate speed preset on the control card to achieve this.
After this you may find when the feeder is inserted into the adjusted plate, when in the stopped position,the plate creeps.
So then adjust the feeder so the plate remains stopped for the first 5 degrees of its travel.
Then place the feeder in the other plates and adjust the control card preset to give the same result 5 degrees resting position as on the first adjusted plate. Now all plates shoudl be set the same.

Hope this makes some kind of sense, but worked for me and the setting acheived by this is able to run at the faster 70mmm speed and standard 35mm speed with perfect payout and a nice tight takeup tension.

Darren

Posted by Brad Miller (Member # 2) on 01-25-2003, 03:21 PM:

I wouldn't say "any" platter system. There are some that need to be tilted and some that don't really care. The SPECO LP-270 for example needs to be just slightly tilted so that the payout arm floats back to stop when there is no film threaded. Also the AW3 (and probably the ST-270 platters) don't care if they are not level.

Posted by Chris Byrne (Member # 1563) on 01-26-2003, 03:52 AM:

Obviously most techs carry out calibration via the way that works and not the manual.

All of my platters are running sweet (bar one) and my gut feeling is that it needs levelling.

it looks pretty simple. Can someone verify that all you have to do is lean the platter back and have someone support it, then adjust the front rubber supports whichever way they need to go? Also it may be a stupid question, but where do you place the spirit level to check for such?

Sorry Antonio - must have been a typo [Wink]

My only other experience in Italian stretches to spaghetti bolognaise. [Big Grin]

CIAO!

Posted by Bill Langfield (Member # 818) on 01-26-2003, 11:39 AM:

Hi Chris,

You never mentioned exactly what is wrong with your platter.

There are several problems that have cropped up for me over the years with the CNR-35/5's.

- Hunting payout arms
- Payout/brain going too slow, in one plate only.
- Hunting takeup/buffer arms
- Take up arms that move out to so close to shut-off, that sometime they DO, at startup.
- Takeup arms that, when activated at thread up swing ALL the way in and bend the slide rollers (happens on early LP-270's too)

Darren's 38-42 rpm on the payout is intersting but pointless, as for I can tell as long as the plate gets up to speed with only say two 'wrap-arounds' I'm happy. (I guess, allow 4 for after a new trailer pack dropped in)

DARREN, does the TRIM POT in the circuit cards effect the payout arm AND the payout arm. It seems too. So now I only touch the adjustment of the payout pot itself, as the pot on the card seems effect the takeup in strange ways. Like if I adjust it for the payout to run perfect for all decks, suddening one (or two) take up arms decide to be 'lazy' at startup.

Brads, 'Levelling' of an LP-270 for the payout to 'float' back to stop position is a good one. Might note thats happening next shift. (The CNR has a light spring to do that even if it is not level)

Bill.

Posted by Bill Langfield (Member # 818) on 01-26-2003, 11:47 AM:

Opps, did I say several 'problems' with CNR's.

Let me say that again, DOZENS!

I'll get a list together, anyone want to make a list too, with solutions!

Posted by Darren Briggs (Member # 1071) on 01-26-2003, 03:58 PM:

Bill,
Yes the Card's speed Pot, effects the feeder's operation as it sets the max speed of the plate.
So increasing the plate speed will probably, when you insert the feeder into that plate, cause the plate to creep even with the feeder in the rest/stopped position.

Various faults mentioned.

- Hunting payout arms
FEEDER SPRING NORMALLY NEEDS REPLACING. A FILM WHICH HAS STATIC BUILD UP ON IT CAN CAUSE THIS EFFECT TOO.

- Payout/brain going too slow, in one plate only.
MAX SPEED OF THAT PLATE IS TOO SLOW, YOU WOULD PROBABLY FIND THE FEEDER DOESNT MAKE THE PLATE MOVE UNTIL THE ARM IS FURTHER OVER THAN WHEN IN THE OTHER PLATES. SPEED UP THE PLATE TO MATCH THE OTHERS, BY MAKING THE PLATE START TO MOVE AT THE SAME FEEDER ARM POSITION AS ON THE GOOD PLATES.

- Hunting takeup/buffer arms
BENT TAKE UP RING??, PLATTER UN LEVEL??

- Take up arms that move out to so close to shut-off, that sometime they DO, at startup.
SPEED OF ALL THE PLATES ARE SET TO SLOW, OR IF IT HAPPENS ON ONE PLATE ONLY, THAT PLATE IS TOO SLOW,
GET AN INVERTER FOR YOU PROJECTOR??

- Takeup arms that, when activated at thread up swing ALL the way in and bend the slide rollers (happens on early LP-270's too)
PLATE SPEED TO FAST SO THE PLATE SPINS SO QUICK WHEN TENSION IS APPLIED, THE PLATE HASN'T GOT TIME TO SLOW AND STOP.
OR WHEN LACING UP THE FILM IS TO SLACK AND IS SLIPPING ON THE TAKEUP RING/COLLAR UNTIL IT GRIPS, BUT THEN THE PLATE IS AT FULL SPEED AND WHEN IT GRIPS IT JUST CANT STOP IN TIME.

Darren's 38-42 rpm on the payout is intersting but pointless, as for I can tell as long as the plate gets up to speed with only say two 'wrap-arounds' I'm happy. (I guess, allow 4 for after a new trailer pack dropped in)
THE 38-42RPM IS IN THE MANUAL , IVE NEVER CHECKED THIS SPEED MYSELF.
IF USING A PROJECTOR WITH A INVERTER, THE FILM SHOULDNT WRAP AROUND AT ALL WHEN SET UP WELL, 4 WRAP AROUNDS I WOULD WORRY LOTS ABOUT THE FILM TENSION SENSOR STOPPING THE SHOW.
MY GUESS IS THAT WHEN THE PLATTER IS WORKING WELL THE MAX PLATE SPEED IS AROUND THESE FIGURES, AS IM SURE CINEMECCANICA WOULD OF TESTED THIS LOTS.

Otherwise im real happy running these CNR3-35/70 platters and are so easy to fix. Also keep an eye on the rubber drive wheels that drive the plates as the spindle they pivot on, i have found can sometimes come loose especially if you are constantly engaging,diss-engaging the plate lots to make up and break down on that plate.

Hope this helps anyone out there a little!

Darren [Smile]