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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » What problems do you have with 5 star sound heads? (Page 1)

 
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Author Topic: What problems do you have with 5 star sound heads?
Eric Robinson
Jedi Master Film Handler

Posts: 538
From: Santa Rosa, CA
Registered: Jan 2005


 - posted 04-06-2006 12:07 AM      Profile for Eric Robinson   Email Eric Robinson   Send New Private Message       Edit/Delete Post 
I don't know about you, but considering the relative simplicity of a 5 Star sound head...I seem to encounter quite a few problems.

The number one problem I have is the guide rollers and friction roller binding up on the shaft of the sound arm. I can't tell you how many of these I have had to remove, completely disassemble, clean, and reassemble to restore the spring functionality to the inboard lateral guide roller. Then, (of course), a complete A chain analog and digital alignment.

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Monte L Fullmer
Film God

Posts: 8253
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 04-06-2006 01:45 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
quote: Eric Robinson
guide rollers and friction roller binding up on the shaft of the sound arm.
do you have a humidity, or heat problem up there where there could be some sort of corrosion or gunk buildup on those shafts to bind up that friction pressure roller?

..interesting. I "babysit" 44 of them with no problems at all - outside of the usual maintainence of belt changeouts.. both round tooth variety and the older square tooth variety.

Last month I had to do a scanner drum bearing replacement on one unit.

In the past just keeping an eye on the main drive shaft support bearings - both small and large varieties...and had to only replace one bearing in the many years of playing with 5-star units.

Loved it when STRONG changed out the Bodine motors with Leeson motors..quicker and stronger startups.

..but as for the lateral guide roller assembly: I've never experienced any problems..just changing out the rubber pressure rollers that have started to crack. But, I do take caution of the roller hinge assembly that it swivels properly in its axis.

Only big thing that I have noticed is that, with age, that the large sprocket on the drive shaft that just is positioned on the shaft without an allen set screw, will eventually get its keyway worn some causing the two sprockets to have some slop when starting and running with that keyway play in the large sprocket.

Otherwise, maybe not the best heads out there, but take care of them and they do the job with no hitch..

-monte

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16091
From: Bountiful, Utah
Registered: Jun 99


 - posted 04-06-2006 08:08 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
A good tip with 5 stars and similar lateral guide roller assys. is to lubricate them with LaVezzi oil. This oil is synthetic and does not dry up and beccome gummy as if you used standard projector oil do do the job..... In a pinch you can also use Mobil-1 10W30. I always coat all parts in a projector rebuild with Mobil-1 before re-assembly. Makes getting things back apart at some later date ALOT easier......

For the sprocket shafts on 5 stars use bearinigs with rubber seals....Keeps the grease in and the belt crap out, these bearings typically last longer. On sound drum scanners use bearings that have just the shield so the bearing doesn't add any drag.

Mark

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Eric Robinson
Jedi Master Film Handler

Posts: 538
From: Santa Rosa, CA
Registered: Jan 2005


 - posted 04-06-2006 09:53 AM      Profile for Eric Robinson   Email Eric Robinson   Send New Private Message       Edit/Delete Post 
I have the same problem at multiple locations, some in Northern California, Southern, and even the desert in Nevada. I find that if the inboard lateral guide roller is not working perfectly, you can kiss the lateral position alignment goodbye for digital.

I use TriFlo on just about everything. It is a great cleaning tool which leaves behind a lubricated surface.

quote:

Penetrating lubricant with Teflon, corrosion inhibitors, moisture displacers and solvents to soften and remove dirt and corrosion.

Sounds like I might be better of with LaVezzi oil though?

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Brad Miller
Administrator

Posts: 17657
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 04-06-2006 10:56 AM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
quote: Monte L Fullmer
Loved it when STRONG changed out the Bodine motors with Leeson motors..quicker and stronger startups.
A faster startup is a bad thing, not a good one.

Funny everyone is looking at physical breakdown "problems" of 5 star soundheads, yet physical damage to the films isn't being listed as a problem. Yes I am talking about that stupid pinch roller.

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John Eickhof
Jedi Master Film Handler

Posts: 578
From: Wendell, ID USA
Registered: Jan 2000


 - posted 04-06-2006 11:30 AM      Profile for John Eickhof   Author's Homepage   Email John Eickhof   Send New Private Message       Edit/Delete Post 
I used to call them the 5 star 'film shredder'!! Aside from the early Singer / Graflex design, they have evolved into a pretty decent soundhead, but I would still take a gear drive anyday! The newer models with the metric belts and larger bearings seem to do good. Like Mark noted, the lateral guide roller as well as pad roller shafts should be lightly coated with La Vezzi or Mobil-One synthetic oil and the problems with sticking should be eliminated! Same goes for older simplex & RCA guide rollers. Another thing to check is if the roller assy has been stuck for a while be sure to check the flanges for cuts and grooves from the film, if they are grooved be sure to replace! Or you will have "A chain" nightmares!!!

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Monte L Fullmer
Film God

Posts: 8253
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 04-06-2006 12:54 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
quote: Brad Miller
A faster startup is a bad thing, not a good one.
..at least they don't "snap start" like the old Motiograph Mirrorphonic soundhead units..I always hated those the way you hit the switch and the machine was intant on - due to the units had no flywheel dampening.

.. never had any problems with the Leeson startups...

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Pete Naples
Phenomenal Film Handler

Posts: 1540
From: Dunfermline, Scotland
Registered: Feb 2001


 - posted 04-06-2006 03:23 PM      Profile for Pete Naples   Email Pete Naples   Send New Private Message       Edit/Delete Post 
Leeson motors are awful!

1. They start up too damned fast, many is the shredded main drive gear pair I've had to change on Century machines. We've invented a crude but effective soft start system for these motors.

2. They tend to hunt, or at least they do on 50Hz, combine that with the inadequate fixings of the drive pulleys to the shafts (look at the grub screws, there is only one, so the pulley tends to sit slightly eccentrically to the shaft), and you get a lovely throbbing vibration through the machine. So bad it'll make the film guidance rollers on the top visibly shudder and audibly rattle. I'm sure I don't need to explain what that does to the picture.

That said, the few Simplex installations we have here, the Leeson motors are better on them than they are on Century mechs.

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John Eickhof
Jedi Master Film Handler

Posts: 578
From: Wendell, ID USA
Registered: Jan 2000


 - posted 04-06-2006 03:47 PM      Profile for John Eickhof   Author's Homepage   Email John Eickhof   Send New Private Message       Edit/Delete Post 
I remember the best test of young vs experienced in a booth..the Crest Theatre in Sacramento Cal. Had Motio SH-7500s with Brenkert BX-80s on them! They would startup so hard and fast the shearpins were snapping almost every reel change! ( They had an envelop of pins on the booth wall by each control station, and a screwdriver! )Andy Field the Manager finally set up some good old 5KW hand operated Variacs on each SH and the Union Operator would use the variac to start the machine! (2000ft changeovers! w/ Strong Excelite arc lamps!) Finally I convinced Andy into replacing the motios with XL soundheads..the shear pin problem went away! Well about 2 years later they were running a private employee show, and the film stopped..for quite a while..( younger IA operator and staff on duty ) After about 20 minutes! A friend of mine (life IA operator) finally went to the booth ..they had two Service techs and three operators there ) and they could not figure out why the picture head would not operate although the soundhead would! So Guy pointed out the shearpin on the Brenkert, showed them all how to replace it and the show was back on the screen! I also have seen the rubber motor couplings on the Motio soundheads 'ripped' apart from the sudden start!

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Louis Bornwasser
Film God

Posts: 4424
From: prospect ky usa
Registered: Mar 2005


 - posted 04-06-2006 08:21 PM      Profile for Louis Bornwasser   Author's Homepage   Email Louis Bornwasser   Send New Private Message       Edit/Delete Post 
We used 200 watt 5 ohm adjustable resistors on the Motiograph to slow the starting time. Louis

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Gordon McLeod
Film God

Posts: 9435
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 04-06-2006 09:09 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
Most single phase motors I usually put a 1.5 ohm 200watt resistor in serries with it to rob the motor of some starting torque as standard install

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16091
From: Bountiful, Utah
Registered: Jun 99


 - posted 04-06-2006 10:35 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
quote: Eric Robinson
I use TriFlo on just about everything. It is a great cleaning tool which leaves behind a lubricated surface

You are not a very good tech if you are doing that. NEVER spray any solvent or supposed lubricant into any assembly. I guarantee that you are dong more damage than good and its certainly not the correct fix. Thats as bad a habbit as any tech an develop! Tear down the assembly , clean the parts, properly libricate them, and then re-assemble it. Coating shafts, etc. with a light true synthetic oil will cause you and your customer alot less grief in the long run than if you use regular projector oil.

Last October I had to dismantle and clean 10 Simplex lateral guide rollers because a theatre manager had repeatedly sprayed the stuff in them. Caused them all to rust, apparently the Tri-Flow reacted with what ever was on the shafts.... I posted pictures of the damage it did back about that time so a search might turn them up.

This is a list of the things not to spray into assembled Moving Picture Machines.....

Tri-Flow
WD-40
Lubri-Plate
Liquid Wrench...... Not for use on film either;).....
Carburator Cleaner*
Mr. Misty*

*I do use the last two items to clean dissassembled individual parts and bearings though.... they are powerful cleaners to be used following proper safety procedures.

My saying is DO IT RIGHT, IF YOU CAN'T THEN GET SOMEONE THAT CAN

Mark

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Pete Naples
Phenomenal Film Handler

Posts: 1540
From: Dunfermline, Scotland
Registered: Feb 2001


 - posted 04-07-2006 02:21 AM      Profile for Pete Naples   Email Pete Naples   Send New Private Message       Edit/Delete Post 
What the hell are;

Tri-Flow
Lubri-Plate
Liquid Wrench
Mr. Misty
? [Confused]

Automotive carb/brake cleaner is good stuff for shifting old gunged up grease. Even WD40 has it's uses, but READ the label, it's NOT a lubricant!
There's an orange based product we use in teh workshop, you just throw the parts in a bucket of it and have a coffee. Rinse in hot water, dry thoroughly and you're done. Smells nice too.

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Monte L Fullmer
Film God

Posts: 8253
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 04-07-2006 02:55 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
quote: Pete Naples
Tri-Flow
Lubri-Plate

..1-Tri-Flow is a lubricant spray with teflon in the mixture. You find this stuff in bicycle and key shops.

I used to use this stuff in lubricating the ruby jewel bearings that supported the double roller lateral guides in Christie P-35 traps.

Seen a lot of techs carry a small can of Tri-Flow in their workbags..

2- Lubri-plate.. is a white grease paste in a vinyl squeeze tube to lube the small spindle roller bearings assemblies on the Christie AW3(r) platter hubs.

3-Liquid Wrench .. if you got a stuck and rusted nut on a bolt..stuff was sprayed on the nut and was fluid enough to pass between the threads to looses a stuck nut.

(as for the other stuff..haven't a clue..)

-Monte

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Dan Lyons
Jedi Master Film Handler

Posts: 698
From: Seal Beach, CA
Registered: Sep 2002


 - posted 04-07-2006 01:39 PM      Profile for Dan Lyons   Email Dan Lyons   Send New Private Message       Edit/Delete Post 
But it says it will make your old junk like new! [Wink] [uhoh]
 -

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