Film-Tech Forum ARCHIVE: Cinemeccanica Sound Head Advice

This is topic Cinemeccanica Sound Head Advice in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Mike Pennell (Member # 1692) on 10-02-2003, 03:30 AM:

I have vic 4's at one location and vic 5's at another. I love the projectors, but hate the soundhead design. They are constantly being knocked out of alignment and damaged by brain wraps. The timing of the platters are not an issue as they run fine when i am present at the locations, most of the time the wraps occur when idiot operators leave the tails taped after they move the prints. [Mad]

We are soon to be updating to the reverse scan. Is there options for different soundheads for these projectors or some type of upgrade available from Cinemeccanica? Thanks Mike [beer]

Posted by Pete Naples (Member # 761) on 10-02-2003, 03:41 AM:

Reverse scan on cinemecannica is more robust than forward scan, as you get rid of the fragile SVA cell and replace it with the LED. Have you considered fitting tension sensing failsafe devices to the platters?

Posted by Mike Pennell (Member # 1692) on 10-02-2003, 04:00 AM:

Thanks for the encouraging news on the reverse scan robustness. I would love any information on tension fail safes. mike

Posted by Pete Naples (Member # 761) on 10-02-2003, 04:42 AM:

Typically you can get them from your platter manufacturer, if not I think there are some universal devices available too. usually it consists of three rollers, one of which is mounted on a short pivoting arm. Excessive film tension moves the arm, which pushes a switch, which stops the machine...

Posted by Gordon McLeod (Member # 33) on 10-02-2003, 09:35 AM:

THe BCAP and the Kelmar have a large flywheel that mounts in the centre of the scanner to prevent film dropping in to the centre section

Posted by Thomas Procyk (Member # 1170) on 10-02-2003, 12:04 PM:

We run Victoria 5's and I've noticed some of our machines have a very fragile cell inside the soundrum part. (looks like it's just on a piece of plastic, leaving most of the inside of the sound drum hollow for the film to pull into and snap it off) and some of ours are fitted with a different cell, actually part of a thick piece of metal that's inside the sound drum and fits completely into the hollow center, leaving no room for film to get yanked in there and snap off the cell.

I think if I took pictures, it would be easier to see. [Smile]

=TMP=

Posted by Pete Naples (Member # 761) on 10-02-2003, 01:45 PM:

If they are od dolby manufacture then the thin flimsy thing is an earlier design of cell and arm, the sturdier type is later. They are interchangeable.

Posted by Ken McFall (Member # 845) on 10-02-2003, 02:18 PM:

As Pete say's the reverse scan upgrade is well worth doing. It gives you extra protection against damage if you have a film wrap as the red led mounts are much sturdier than the Dolby cell on its flimsy bracket. Also you are ready for Digital when you can afford to go there [Wink]

It's worth remembering that the bearings for the sound drum are possibly quite old now and would be replaced at the same time as the drum as a matter of routine giving improved performance from the sound head overall.

It is well worth fitting some sort of wrap sensor as this will give protection to the projector, sound head and any wall mounted rollers..... Depending on the type of system you consider there would be no damage to the print at all. Sensors with a sliding roller assembly are the best as they allow time for the projector to stop! No tension between the platter and the projector... just clear the wrap, find the cause and you're back on screen.

A wrap can easily pull rollers out of the wall and cause all sorts of damage, with the real possibility of losing the rest of the show. One wrap with no damage caused would pay for a sensor system in one go!

[ 10-02-2003, 03:23 PM: Message edited by: Ken McFall ]

Posted by Jean-Michel Grin (Member # 1360) on 10-02-2003, 02:48 PM:

Here is two pics of a V8 and a V5 soundhead: They look closely same.

I experienced some brainwarp, with a polyester is a nightmare, even the projector mechanism could be damaged. For this reason we adapted a Strong failsafe switch on ours Cinemeccanica platters this solved the problem. And we added a delayed relay to stop the projector: the failsafe switch was soo sensible, it will shutdown the projector at every splices !

Good luck !

Posted by Kris Brunton (Member # 432) on 10-02-2003, 06:12 PM:

I like to add the larger drum when upgrading with a cinemecanica reverse scan reader. When not using the cinemeccanica reverse scan I like the BACP readers. With these readers the amount of service calls for bent cells, bent led brackets are reduced to virtually nil.

Posted by Rick Long (Member # 213) on 10-02-2003, 10:56 PM:

What Ken McFall said about changing the sound-head bearings is a wise comment. After all, you've got the thing apart anyways, why not take the opportunity to do it?

Also this is an excellent opportunity to clean and lubricate the lay-on rollers.

Posted by Richard Fowler (Member # 893) on 10-03-2003, 10:38 AM:

The complete reverse scan kit from Cinemeccanica includes a new sound drum with the center area filled in save for a slot for the LED bracket. The outside edge which the film travels is also thinner to allow for the optional digital reader to see the Dolby Digital track. If you are not planning for future digital, the BACP utilizes the existing drum, with the thicker film support edges; a spacer ring with set screw is mounted in the middle of the drum to prevent film wraps. Bearings and possibly the top film pressure roller should be replaced if you considering the upgrade.

Posted by Jean-Michel Grin (Member # 1360) on 10-03-2003, 12:00 PM:

That's right: Is realy indicated to change bearings when ugrading a reader, but You will need the original Cinemeccanica tool to remove some parts.

And believe me, it's realy a pain off ass to do the job ! [Big Grin]