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» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Kinoton FP30 and Strong Alpha Platters - timing and adjustments (Page 1)

 
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Author Topic: Kinoton FP30 and Strong Alpha Platters - timing and adjustments
Matthew Nock
Film Handler

Posts: 82
From: Bairnsdale, Victoria, Australia
Registered: Jan 2003


 - posted 02-13-2003 06:53 AM      Profile for Matthew Nock   Email Matthew Nock   Send New Private Message       Edit/Delete Post 
Hi all!

We have just installed two very nice little Kinoton FP30's to replace our Simplex projectors.

However, we have run into a little bit of a problem...

The Kinotons stop a lot quicker than our simplex machines did, and and such, the "dancer arm", "Yo-yo", "jockey" (whatever else you wanna call it) comes up very suddenly, and the takeup platter does not slow down quick enough.

How do we change where in the path the platter should commence its slow down? I know that we can adjust the variac to change where it has its failsafe cut-off, but I couldnt find anything in the manual about what I am trying to do.

Any help, suggestions?

Cheers,

M@

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Richard Fowler
Film God

Posts: 2392
From: Ft. Lauderdale, FL, USA
Registered: Jun 2001


 - posted 02-13-2003 10:43 AM      Profile for Richard Fowler   Email Richard Fowler   Send New Private Message       Edit/Delete Post 
If this projector is a fairly recent model with the invertor drive system ( which Kinoton was first to implement into most of their systems [Smile] ) the drive controller ramp down speed could be adjusted to slow more gradually. electromechanical variac platters such as Potts, Strong, et cetera are not able to stop smoothly during the initial 5 to 10 minutes of operation. Call your tech to do the adjustments.
Richard Fowler
Kinoton America Inc.

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Matthew Nock
Film Handler

Posts: 82
From: Bairnsdale, Victoria, Australia
Registered: Jan 2003


 - posted 02-14-2003 10:06 AM      Profile for Matthew Nock   Email Matthew Nock   Send New Private Message       Edit/Delete Post 
Hi Richard,

Thanks for the quick response. I have a feeling that our machines will not be using the invertor drive system - the machines where manufactured in 1987.

It seems that the problem is very much more platter related than anything else. I noticed tonight that the unstable "dancer-arm" movement was also apparent upon starting a show. As you have said, the take a while to stabalise..

It appears that because the start and shutdown of the projector is so quick, it seems that the platter isnt able to "keep up".

Anyone had any experience with these sort of problems with strong platters?? There must be a work around for this [Smile]

Cheers,

M@

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Daryl C. W. O'Shea
Film God

Posts: 3977
From: Midland Ontario Canada (where Panavision & IMAX lenses come from)
Registered: Jun 2002


 - posted 02-14-2003 10:19 AM      Profile for Daryl C. W. O'Shea   Author's Homepage   Email Daryl C. W. O'Shea   Send New Private Message       Edit/Delete Post 
A question... why is the projector stopping with film in the machine? Does it not tail out at the end of the show?

To stop a projector manually while using Strong platters (or any variac controlled platter) I usually just grab the take-up deck to slow it down when I hit the stop button. Sometimes this requires a bit of running... or a bit of a dash to the platter.

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 02-14-2003 11:51 AM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
I think Matthew is trying to thread up the film, then motor down to the starting point. Sounds to me like his automation simply can't operate off of a start cue.

So long as you have Strong platters, you are pretty much screwed in this regard. What kind of automation do you have? Maybe it could be set up for a start cue, which would eliminate your problem.

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Dave Macaulay
Film God

Posts: 2321
From: Toronto, Canada
Registered: Apr 2001


 - posted 02-14-2003 12:15 PM      Profile for Dave Macaulay   Email Dave Macaulay   Send New Private Message       Edit/Delete Post 
This is usually a problem with Cinemeccanica V4s as well, they stop fast too. Stopping with the supply platter full is not good, starting up is OK as long as it doesn't pull totally tight or drop the platter dancer to shutoff, the dancer will ride around a lot but should settle down. The drive motors have a lot of power but not much drag to stop a turning platter!
Altering your startup routine to avoid stopping - using start cues or adjusting leaders and start delay time - is your best approach.
You can add an accumulator between the projector and platter but this is a pain to get/build/install and to use.
Or attach a big flywheel to the projector motor, like Simplex does.

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Rick Long
Jedi Master Film Handler

Posts: 759
From: Toronto, Ontario, Canada
Registered: Nov 1999


 - posted 02-15-2003 11:02 PM      Profile for Rick Long   Email Rick Long   Send New Private Message       Edit/Delete Post 
As Dave says, Cinemeccanica projectors (including Vic 5's and Vic 8's have this problem when used with Strong platters.

The best way, if possible, it to re-work your automation so that it doesn't stop till the film tails out (as long as the change-over closes when it should).

Failing this, another solution used, is to manally switch the motor to manual over-ride during the credits. The motor will continue running until you return the switch to the auto position.

With one type of automation we had, which allowed projectors to stop with a cue, the cue was put on the tail-piece about 3 frames from the very end of the print. As it was a peg-board automation, all other functions happened at the appropriate time.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 02-16-2003 11:27 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
This is actually a problem with using any machine that slows down quickly when using with the Strong/Potts platter. You cannot compensate for it unless you have the invertor drive feature on your machine. You will have to act as the brake and slow down the deck by helping it stop yourself.
There are alot of machines that have this unfortunate rundown problem.
Mark @ CLACO

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 02-16-2003 11:42 AM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
Use the bigger Strong center ring for takeup at all times instead of the pansie-assed wimpy small ring that is included with the platters. It was mentioned in my review that the platters should come with the bigger rings instead of the small ones.

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 02-16-2003 12:12 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Good one Joe. I had forgotten about that. However, I will warn Matthew that if he uses the large center rings, he has to be extremely careful when he is threading and pulls tension on the takeup elevator, as it will take off and break rollers off of the platter if you are not careful.

What a great design. [puke]
You know, all Strong has to do is extend the height of the elevator! [Mad]

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Jack Ondracek
Film God

Posts: 2348
From: Port Orchard, WA, USA
Registered: Oct 2002


 - posted 02-16-2003 03:59 PM      Profile for Jack Ondracek   Author's Homepage   Email Jack Ondracek   Send New Private Message       Edit/Delete Post 
quote:
You know, all Strong has to do is extend the height of the elevator!
I don't think it would be that simple, Brad.

Platters that use gear reduction motors have a much more positive control over momentum, both starting and stopping, which is the basic problem here. The Strong/Potts/CFS/D&M platters, are challenging because the motor does little to slow the platter down once voltage is removed... and they take so long to build up speed that they're doing the 50 yard dash by the time they catch up to the projector... all this well known to everyone here.

The problem with extending the elevator rails is the variac itself. It's already at zero output by the time it hits the top right now. You'd have to rework the linkage somehow(?) or come up with some spring loaded arrangement that would allow the elevator to continue traveling past the variac's stop point.

Basically, these vacuum cleaner motors just don't have enough starting torque to allow the takeup platter to keep up with a fast starting projector... and I'm just waiting for the day the feed platter tries to frisbee the print! [Eek!]

Give this one to ORC & their herky Bodine rim drives... I never had that problem with that part of their design. Those gear reduction motors have a lot more control over the platters & have no problem keeping up with the projector.

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 02-16-2003 04:44 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
I'm not suggesting Strong extend the length of the elevator's travel in relation to the variac, only extend the top so there is a few extra feet of play where the speed is at 0. It shouldn't be too difficult to redesign the arm that couples to the variac to allow for an extended elevator. Heck, they could even make it so that the variac has a counterweighted arm that protrudes from the control box and the elevator literally pushes it down (increasing it's speed). Then they could make the rods as long as they wanted because once the elevator rollers reached a certain height, it would raise up off of the arm. A simple modification like this would definitely be cheaper for Strong to do then redesign the takeup entirely, hence my comment.

If nothing else, add a spring to the top of the elevator to help slow down the platter. While I don't really like that idea, it's better than the way it is now.

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 02-16-2003 05:12 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
Actually the red specos and the teco platters also had problems with fast starting and stopping machines

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Jack Ondracek
Film God

Posts: 2348
From: Port Orchard, WA, USA
Registered: Oct 2002


 - posted 02-16-2003 07:00 PM      Profile for Jack Ondracek   Author's Homepage   Email Jack Ondracek   Send New Private Message       Edit/Delete Post 
quote:
from Brad:
I'm not suggesting Strong extend the length of the elevator's travel in relation to the variac, only extend the top so there is a few extra feet of play where the speed is at 0.

Guess that's where you lose me.

If the variac is a zero, and is against its stop, you could have 20 feet of extra rail, but the rollers couldn't use it because of the variac limits preventing further upward movement.... yes??? no??? ???

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 02-16-2003 07:15 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Now you've lost me.

Let's say the current rails are one foot tall (which is about right). If they were extended to be 3 feet tall, but only the bottom foot would make the motors spin and the top 2 feet were "zero speed", that would give enough stop time. Alternatively they could add one more roller like SPECO did on their later LP270s. The idea here is to get more spindown time before the elevator crashes.

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