Film-Tech Forum ARCHIVE: "Motorboating" with Simplex soundhead

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Posted by Gary Crawford (Member # 2038) on 04-28-2004, 01:38 PM:

A recent problem with an older Simplex SH1000 optical soundhead. It seems the lateral guide roller will sometimes allow Dolby or another soundtrack to get close enough to the light path where it will "motorboat."

I found that pushing on the inside edge of the guide roller "guard rail" will let the film ride where it's supposed to. My relief man didn't know that trick.

The roller has a very small amount of side play but will run okay once you adjust it. I also noticed that a quick tap of the edge of the film with my fingernail will put it back where it belongs. It hasn't gotten any worse, but what are the long-term potential problems? Need a new lateral guide roller maybe?

Thanks...Gary

Posted by Dominic Espinosa (Member # 2122) on 04-28-2004, 02:10 PM:

I would check that the flange on the guide roller isn't worn or anything, this could point to a long-term misallignment.
I noticed this sort of problem on one of mine once when the nut that retains it became slightly loose. Check to see if the roller is allowing the film to slip, or if it's guiding it off in one direction or the other. Unless you've got a different head than I'm thinking of there shouldn't be any play whatsoever on that roller.

Posted by Gary Crawford (Member # 2038) on 04-28-2004, 02:22 PM:

Thank you Dominic.

From what I can see, the roller has a very slight side play, mere millimeters if that, but just enough to let the film run off enough to allow the Dolby track to scan in the exciter path.

The roller edges seem okay (I didn't mic them) and are not pizza-cutter sharp. Once I push it inward it clamps down on the film just fine and the whole reel runs like it's supposed to.

I'm thinking maybe a small adjustment is the problem but I haven't found it yet.

Posted by Randy Stankey (Member # 64) on 04-28-2004, 02:41 PM:

I suggest that the lateral guide and associated parts be given a good cleaning and realignment. Replace any worn or damaged parts.

One thing that I have found is that people apply WD-40 or other unsuitable lubricants to the lateral guide's shaft. Over time, the stuff hardens or gathers dirt and starts to get stiff.

The lateral guide holds its place by spring pressure against the adjustment knob. Same thing goes for the flanges on the sides of the roller. Every time you thread the proejector you unconsciously move those parts side to side. It may not be very much but it doesn't have to be. Tolerances are tight in there.

Now, if the parts are dirty, worn or not assembled correctly, the springs won't be able to push their associated parts back into the correct position. If those parts aren't in the right position, the film won't be in the right position. And, of course, if the film isn't right, the sound won't be right.

A cleaning, check and realignment of the lateral guide assembly will allow all of these parts to "float" around the way they need to and find their "home" positions after you thread the projector.

If you are careful when you disassemble, you should be able to get everything back together again without needing to perform a full A-Chain alignment. (At least not right away.) If done carefully all you should need is a piece of Buzz Track film to reset the lateral alignment. If you accidentally bump the cell/CCD or the slit lens and knock them out of whack, you'll have a problem on your hands. You probably won't be able to solve it without a full A-Chain. If you don't have the equipment, you are screwed.

When you clean that shaft and assocated parts, be sure to get all the old, crusty oil or grease out. I don't believe the thing needs lube at all but if you feel the need to lube it, use one or two drops of 3-In-1 or similar.

Posted by Mark Gulbrandsen (Member # 72) on 04-28-2004, 02:46 PM:

"When you clean that shaft and assocated parts, be sure to get all the old, crusty oil or grease out. I don't believe the thing needs lube at all but if you feel the need to lube it, use one or two drops of 3-In-1 or similar."

Randy,
Shame, shame, shame!!! I bet thet you also carry a can of WD-40 with you on your calls......

This is THE MOST COMMON problem with sound reproducers that use a spring loaded flange!!!! The oil evaporates and leaves a film of goo.
Realistically......
ONLY use some sort of light synthetic oil on the lateral guide shaft and parts....3 in 1 will evaporate before you get home that night and you'll be stuck again!! 3 in 1 is crap oil of the highest magnitude.

Posted by Gary Crawford (Member # 2038) on 04-28-2004, 02:47 PM:

Thank you Randy and Mark. I'll see what I can find tonight. These are old machines here and they do need TLC but problems are few and far between.

Posted by Scott Norwood (Member # 30) on 04-28-2004, 02:56 PM:

Mark -- what kind of "light synthetic oil" is best for this? Would Century projector oil work? I run a pair of SH-1000s from time to time, though I haven't had this problem (yet).

Posted by Randy Stankey (Member # 64) on 04-28-2004, 03:16 PM:

No, I don't lube those parts, nor do I use WD-40 very often at all. (A can of WD-40 and a cigarette lighter makes a great flame thrower! [Big Grin]

)

I suppose I should rephrase and say that *IF* you feel the need to lube those parts a light oil that won't gum up is the thing to use. I don't remember the brand but I remember a certain kind of gun lube that worked really well. You were supposed to use a small amount of the stuff and wipe off the excess before assembling the parts. It worked great even when temperatures went below freezing. Other lubes would get sticky when cold. This stuff supposedly worked when temperatures were below zero. The only thing I remember is that it had a very "sweet" smell to it. I think it had Teflon in it or something.

Posted by Steve Kraus (Member # 476) on 04-28-2004, 03:47 PM:

Amazing that these machines ran for six decades without synthetic oil.

Randy, I think you're thinking of Tri-Flow which has a peculiar banana scent to it. We used to use it on the heated printhead of Acmade edge numbering machines.

Posted by Mark Gulbrandsen (Member # 72) on 04-28-2004, 04:07 PM:

Steve said......
"Amazing that these machines ran for six decades without synthetic oil."

Actually they didn't run for six decades without alot of assistance. The majority of them had regular maintainance from RCA Service, ALTEC Service and many other servicing agents while you were growing up and watching movies at Park Forest Mall and film was being done right. Indeed some theatres running these reproducers even had monthly service contracts in busy locations in large citys. Aside from the fact that they were the best reproducers made the frequent service is really why they are still with us.

On a first time service run the last two weeks through Wyoming and Montana out of 14 locations there were 5 stuck lateral guide rollers and two completely frozen lateral guide assys. with stuck bearings and the shaft trying to spin in the bore of the bearings!! I wonder how much film these reproducers scratched????

Its best to coat shafts and other parts excluding rubber surfaces with a light film of oil and yes, projector oil is ok.... Living in a very dry climate I just happen to prefer synthetics as they don't evaporate at all and the lateral guide roller will run longer without attention.... some of our customers only have yearly service done. You will also have far less corrosion in humid areas. Either the LaVezzi oil which comes in a convenient 4 ounce bottle or the lightest grade of Mobil-1 is fine. I believe its only available in multi grade from AP stores but the 10-30 works very good... The LaVezzi is around 20 weight straight synthetic, probably nothing more than a good grade of compressor oil.

I also coat all shafts and bearings of ANYTHING that I am assembling, or re-assembling with Mobil-1 as it allows the assy. to come apart much much easier years later as the oil is still flowing and not a sticky dried up film!! Bearings will slide right off the shafts, etc years later.

Mark

Posted by Randy Stankey (Member # 64) on 04-28-2004, 04:49 PM:

That's the stuff! Tri-Flow! Thanks for jogging the memory, Steve! [Smile]

Posted by Bill Enos (Member # 440) on 04-28-2004, 05:31 PM:

About 15 years ago when I was servicing office machines, IBM Selectrics in particular, we tried Triflow on the print shafts of these machines. The print shaft is the shaft that the carrier rides on. Triflow was very slick at first, but in about a month it gummed so badly that the carriers were moving very sluggishly, we got recalls on every machine treated with this stuff. Mayonnaise would be better, and at least you could put it on a sandwich. On our SH1000s I wipe the guide roller shafts with projector oil when I assemble them, never had a problem in 18 years, it probably serves only to prevent rust.

Posted by Steve Kraus (Member # 476) on 04-28-2004, 06:44 PM:

Re: 18 years, 15 years: No wonder those typewriters were malfunctioning...they'd been serviced by a projector technician! They shoulda called a typewriter expert! [Razz]

Posted by Christopher Seo (Member # 7) on 04-28-2004, 09:36 PM:

FWIW, I used Tri-Flow to lube the lateral guide roller shaft of an RCA 1040 and it's still running fine after over half a year.

Posted by Mark Gulbrandsen (Member # 72) on 04-28-2004, 11:38 PM:

Some day perhaps some of you will deal with the hundreds of these reproducers that I do every year. Then you will understand the meaning of synthetic!!

Mark

Posted by Lindsay Morris (Member # 1430) on 04-30-2004, 04:53 AM:

On all those little rollers and in particular the ones on the rotary stabiliser soundheads that hold the film in contact with the drum I use neat Slik 50 motor or gear oil.
This stuff is Teflon based and only the smallest drop is needed and lasts and lasts and lasts with very little if any gooey build up and best of all no oily deposits to work out the ends and drop down onto film etc.
Slik 50 comes from USA and maybe is known under a different name over there but it works a treat. It is Teflon based.
Prior to pulling out the pair of Simplex standards that is all I ever used throughout the entire machine even in the Intermittent mixed 50/50 with normal oil. These ran beautifully for 7 summer seasons and never missed a beat and never dripped oil onto the floor which most of the other Simplexes of this vintage I had ever worked on always did... great pools in fact... one was so bad it would empty the intermittent in about 2 days and had a film can lid on the floor to catch the stuff.
The rollers in the upper and lower fire traps were always difficult to lube the inside pivots and I started using Slik 50 on those initially on some other machines as to do them properly you had to pull the spool boxes off to get to the oilers.
When I set up my own outfit I used Slik 50 there and in the 7 seasons they ran I never took the spool boxes off to lube the rollers that stuff stayed there for the whole time and never once had a roller seize up.
The soundhead tension rollers in the newer Century/Westrex combo also got the same treatment as those do work hard with the tension on the film at that point so some form of good lube that stays there is essential.
The lateral guide roller is critical in ensuring correct stereo and must revolve very freely and not be allowed to develop flats or grooves in the flanges.
Lindsay

[ 05-01-2004, 04:01 AM: Message edited by: Lindsay Morris ]

Posted by Mark Gulbrandsen (Member # 72) on 04-30-2004, 02:08 PM:

Lindsay,

How thick is Slick 50 compared to SAE weight and is it 100% synthetic or are just the teflon particles synthetic?

Mark

Posted by Steve Kraus (Member # 476) on 04-30-2004, 08:34 PM:

http://www.slick50.com/

Posted by Mark Gulbrandsen (Member # 72) on 04-30-2004, 08:43 PM:

Donno, That link told me less than Lindsay did about it. I do use Slick 50 grease on AW-3 platter bearings though.

Mark

Posted by Lindsay Morris (Member # 1430) on 05-01-2004, 03:55 AM:

Mark,

Not sure of the exact specs for Slik 50 but is used by a few motor mech friends of mine extensively in gearbox and engine rebuilds and they almost put their life on the line for the stuff. I put it into my diesel ute motor and gearbox and although have not really noticed any change in the engine the gear changes are a lot smoother since adding it.
It does not say much about it on the bottle and there are 3 types marketted here.. for Engine, Gearbox and Diff NOT for Auto boxes and NOT for Hypoid diffs though.
I think the recommended mix for a gearbox is 1 litre for 5 litres of gear oil and on an oil change you just whack the required amount in first and then top up with whatever oil you are using and there are no notes about any differences between use with mineral or synthetic oils...seems to be compatible with most. About to buy another gearbox shot soon so will look more closely at the label as I am only going from memory now.
Viscosity looks similar to about SAE 20 and for a while we could get it in small squeeze packs as a GP oil for general workshop use with about 3-4 oz in the bottle.
When I started using it in the ute I just used some of that Gearbox mix in the projector oil can and as I said did a mix of 50/50 with the normal Capella oil we had for the intermittents and used about an almost neat Slik 50 mix for any other spots.
I tried the intermittents one at a time watching for wear any unusual noise and picture shake on the first one and it seemed to run a lot quieter than the untreated mate. So I then did that one and it too became quieter... if that is possible with a Simplex of these vintages... Like 1929 and still going.
I was never worried about stuffing an intermittent as I have box full of spare units on hand so if I screwed one up I was ready to replace it but after observing the performance on most of the other oiling points I reckoned that the intermittent would not have a problem. Best thing was virtually no oil drips from either machine as these Simplex have oil holes everywhere and a lot of it escapes and with Slik 50 you use very little.
Have since put the Century CC on a 50/50 mix at the start of the season and after about 100 sessions this season no sign or sound of anything unusual in that one either.
On the Century there is one quite small roller after the final sprocket of the Westrex soundhead and that one really works hard as the film wraps around that one quite tight as it heads off to the first large roller on the machine prior to getting onto the transport rollers across to the MUT. If I use anything else in that roller it begins to squeal like a pig after 3 or 4 sessions .. use Slik 50 and it goes for weeks before it looks like it could do with another dose.
In my case I only run one session a night being outdoor so things may well be a little different on a complex machine going all day but try it and see how you go.. a little experimentation may well show up any problems that I have missed.
When you get the stuff on your fingers you can certainly tell the difference in "slipperyness" IF that is the word between Slik 50 treated oil and normal oil.
Lindsay

Posted by Bill Enos (Member # 440) on 05-01-2004, 09:17 AM:

The suspended solids in Slik 50 and other similar products will melt and clump in extreme overheats. It happened to a coworker about 15 years ago. A rad. hose blew at high speed on the interstate and all the steam, water went behind the vehicle, by the time the light came on the damage was done. Some bearings had run dry. The shop that did the rebuild dug out some plastic material blocking an oil passage, lab analysis proved it to be teflon. The additive was not Slik 50 but another national brand. On being presented with the evidence they paid the claim for the related damage without much protest.

Posted by Lindsay Morris (Member # 1430) on 05-02-2004, 07:46 PM:

Bill,

I dont think much would have saved a motor when all the coolant goes as the retained heat in the block takes the temps way up and really weird things happen then.
In my own case ages ago my father in-law and I were jogging back from the goldfields after a non productive gold hunt with a metal detector.. but a very pleasant few days camping out. At the sedate speed of 80kmh (50mph) his manifold heating hose on the Holden HR blew and we did not notice anything at all until he said he thought he was loosing power [Eek!]

When he stopped steam went everywhere and when it all cooled down the motor was locked solid. When we got that apart 2 pistons had melted crowns with quite a bit of metal in the sump so obviously the temps in there were horrific and I doubt whether any additive would have saved that motor.
The makers of a lot of this stuff claim that once treated one could drain the sump and run a 1000kms or more without any futher oil and suffer no damage.... hmm I wonder... not quite game to try that one myself.
A whole lot different in a much slower moving piece of machinery such as a projector with far less extremes of temps from hot to cold and my experience in the Simplexes and now the Century is that I use very little oil and it stays there for a long long time and I do not need drip cans on the floor. [thumbsup]

Lindsay

Posted by Mark Gulbrandsen (Member # 72) on 05-02-2004, 08:03 PM:

Reminds me of the deomonstration years ago in which a bottle of Marvel Mystrey Oil was to a 1957 Pontiac with a hige V-8 in it. The car with Marvel added to it was left to idle for about 30 min. and then the oil drained out. The car was then sucessfully driven across Death Valley with out it seizing up which considering how big some of those engines were is pretty amazing. Perhaps thats why Marvel Mystery Oil is still a favorite of Cinematographers to oil camera movements. Use 40% pure Mineral oil and 60% Marvel.

Mark

Posted by Gary Crawford (Member # 2038) on 05-05-2004, 11:50 AM:

Thank you for all the suggestions guys.

Gary