This is topic My Great Worm-Glop Weekend! in forum 8mm Forum at 8mm Forum.


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Posted by Steve Klare (Member # 12) on November 14, 2014, 03:29 PM:
 
So I had an adventure about a week ago when I was running a film on my Elmo ST-800: every couple of seconds the sound took a nasty dip in pitch.

We’ve all had times like this: when your car starts making a funny vibration, when your girlfriend stops laughing at your jokes, that you know something is wrong but you just can't face it. You blame something, anything else for your problem:

“It’s just the road surface”
“She’s just a little tired from her job”

-rather than face facts that the problem is real, and so are the consequences!

This is NOT denial! (-or IS it?)

In this case I blamed the newly acquired print I was projecting, rather than face having an ailing projector. Since the next film I played was fine I thought I’d been proven right.

(Until the next time…)

The next night I started a known good print and it was even worse: reality smacked me hard in the face. “What is it? Belts? Motor? Power board? I have no TIME to mess with this right now!”

-but all of a sudden, mid-reel it smoothed out and I thought “ST-1200HD!!”

-You see the ST-1200 has a reputation for operating slowly at first and I have one of them too. I’ve been living with running it a couple of minutes from cold for a while to get it up to speed, yet now my ST-800 was doing something similar!

There has been quite a bit of talk about lubrication fixing issues like these, but I’ve never gotten a single definitive answer on what to use, so I’ve put off dealing with it. When you look into it, you find all sorts of alternatives and people swearing up and down that they will either totally destroy the machine or make it better than new. You go out on the 'net in general and it's no better.

-it was now time to find out for certain.

I wrote to a couple of people who repair a lot more projectors than I do and Richard Patchett wrote back that he uses Super Lube when he does projector repairs. I looked it up: It’s among few lubes that specifically states it’s safe with nylon and other plastics. It was available at a local hardware store so I went and grabbed some. (I actually bought it…they don’t let you have films in jail.)

I looked through the gear train on the ST-800. The worst possible point in terms of friction is the worm gear, because two surfaces are continuously sliding on each other at the rotational speed of the worm. So I went at this first. I grabbed a toothpick at the Diner that morning, brought it home and slowly rotated the gear train and dug the old “lube” from within the little valley that spirals around the worm gear.

I call this “lube” because there was a lot more in there than any kind of grease or oil. It was this thick, revolting, contaminated...glop. (-as if the creature from the black lagoon blew his nose!). I’m sure there was dust and film emulsion and who knows what else in there. (There was even some hair! Don’t ask me: I still have all mine!) I just kept doing it until I reached the bottom of the groove and I wasn't wiping worm-glop off the toothpick anymore.

I applied the Super Lube to the worm with a clean fingertip and let it run in a few minutes. I let the machine cool off a few hours to make the experiment real, tried a film and all was well!

I knew from Frank Arnstein that the cam tank lube is another major friction point, so I cleaned out in there and lubed that too. (So much the better.)

The good news is I’ve run every night this week and the ST-800 is still doing fine.

The better news is immediately after I lubed the ST-800 I did the ST-1200HD too.

This machine from the moment I got it has been sluggish when started from cold. The first ten seconds or so the beam is noticeably flickery and for the first three to five minutes the sound is very bassy: music is all minor key, actresses sound disturbingly masculine. There is a little repeating chirp the first 30 seconds which I believe was the drive roller slipping on the shutter wheel. The solution up until now has been turning on the machine with the lamp while I gather prints. Even then it could still be a little slow.

These last few days I’ve been starting it directly from cold and it’s up to sound speed in roughly the time it takes to thread up.

-this is major progress!

Super Lube is excellent for this purpose. It is very gelatinous, so it stays where you put it. The idea of a lube spreading out through the machine and splattering where you don’t want it (optics, film path…) is troubling: no problem here.

I want to run a small commercial for Mr. Patchett to thank him for his help: he sells Super Lube on his website and if you aren’t in a position to go out and find it locally or you just want to help out a fellow film-friend, please order it from him:

Super Lube at RC's Classic 16mm

At the end of the day the nice thing about this is it’s not hard to do, so I will make it like an annual maintenance step. I also think the next few times I clip off the end of Ty-Wraps I’ll save that nice, thin, non-abrasive, sharp piece. It will be a better glop digger than that comparatively blunt toothpick.

I have no reason to believe this is only an Elmo thing either. The next time you have the back off any machine you own please give this a try.

-Only YOU can prevent Worm Glop!!

[ August 31, 2015, 02:39 PM: Message edited by: Steve Klare ]
 
Posted by Timothy Duncan (Member # 4461) on November 14, 2014, 03:43 PM:
 
Thank you so very much for that helpful info Steve! I suppose we all have projector troubles on occasion, so I don't feel so alone anymore.
 
Posted by Andrew Woodcock (Member # 3260) on November 14, 2014, 03:52 PM:
 
Well it is an Elmo Steve, only to be expected from a primitive AC belt driven drive chain including a crude drive wheel rubber friction clutch arrangement and no electronic drive circuit to keep the speed constant at either 18 or 24 fps at the flick of an electronic switch or button.

Ah well, at least you have found a solution to at least attempt to keep these machines wow and flutter free, or at the very least, reduced compared to regular performance levels.

Thank heavens for super lube eh!

I don't think I have ever seen any other manufacture of S8 projectors that uses the main drive to directly drive the shutter wheel. In fact does any other manufacture even use a shutter wheel?
 
Posted by Steve Klare (Member # 12) on November 14, 2014, 04:08 PM:
 
Actually, the ST-1200 is AC motor driven and friction drive but the ST-800 has a speed regulated DC motor and belt drive.

I blame much of the ST-1200's troubles on the fact that basically all the machines have lost their rubber shutter wheel surface. The ST-1200s AC motor is great, but unfortunately this newly established rubber on metal contact just causes a lot of slippage. (-imagine what driving would be like if the roads were all steel plates instead of pavement?)

-I have to think as new these were much better in this department.
 
Posted by Andrew Woodcock (Member # 3260) on November 14, 2014, 04:13 PM:
 
Better, almost certainly Steve, perfect never. I don't get how the DC drive would give you similar symptoms if it is electronically governed??

I would have to see the drive chain on one of these but going through a worm gear on a DC drive seems ridiculous as surely it can just drive the shutter directly via a belt in the manner that the GS 1200 does? Then of course.. no such problems.
 
Posted by Steve Klare (Member # 12) on November 14, 2014, 04:15 PM:
 
I'd say the glopped rotational load was maxing out the regulator.

When the gas pedal is fully to the floor, you will have to slow down if the hill is steep enough.

"Cap'n! She's givin' all she has!!"
 
Posted by Janice Glesser (Member # 2758) on November 14, 2014, 05:23 PM:
 
Steve...Here's a pic I posted in another thread earlier this month. I use both these lubes depending on the part.

 -
 
Posted by Steve Klare (Member # 12) on November 14, 2014, 05:31 PM:
 
Aye! That's the stuff!

PS: The ST-800 does direct drive of the shutter using a belt from the motor. The worm on both machines is on the shaft from the shutter and the top and bottom of it drive gears sending torque to the upper and lower sprockets.

The thing is when that regulator circuit saturates the power transistor controlling the motor, if the available voltage is not high enough to maintain 24 FPS, you will drop out of regulation.

"I canna change the laws of physics!"
 
Posted by Andrew Woodcock (Member # 3260) on November 14, 2014, 05:50 PM:
 
Good points Steve! But surely you would design that DC drive chain different to what Elmo did back then? The GS1200 is the only Elmo machine that got it right as far as I can see!
 
Posted by Graham Ritchie (Member # 559) on November 14, 2014, 07:01 PM:
 
That's good advice Steve and thanks Janice for posting that photo....will have to get some [Cool]
 
Posted by Steve Klare (Member # 12) on November 14, 2014, 08:56 PM:
 
Andrew,

We live in an imperfect world and everything is compromise. An AC motor is simple, efficient, fixed speed and pretty rugged. If you could make a 24 FPS only projector you could belt it or gear it and life would be good.

-but...

We need to run machines at two different frame rates with two different line frequencies so now your belt or gears become a variable speed transmission, and simplicity goes out the window.

Elmo gave us two wheels rolling on their circumferences, Eumig gave us a ball and a wheel with the ball rolling on the side of the wheel.

-neither has aged well.

As far as I know, the main transport drive of the GS-1200 is exactly the same as the DC driven GS-800, ST-800, ST-600 and ST-180 (theory of operation if not the exact components). I think where the GS separates itself is the auxiliary motors for the arms. (I'll be sure if I ever take one apart...)

-but this is still a thread about the value of de-glopping the worm. I'm so pleased with this I'm saying even if you don't have problems like these you should crack them open and do this: if nothing else it will reduce the strain on your motor and supporting electronics. As I said: it's easy. So why not?

If your neighbors have a long abandoned projector in their attic, wait until they are away, break in and do this fix! (maybe steal their jewelry as cover...)

Someday they'll thank you! (or maybe not...) [Wink]
 
Posted by Andrew Woodcock (Member # 3260) on November 15, 2014, 05:39 AM:
 
Yes very good advice Steve. I always replenish all aging lube on any machine I acquire and find regular lubrication to the cam and claw is essential to the good working health of at least two of my machines. As you quite correctly point out Steve, old "baked" grease does more damage than good on unused machines that have been in storage for many years

[ November 15, 2014, 12:02 PM: Message edited by: Andrew Woodcock ]
 
Posted by Gary Crawford (Member # 67) on November 19, 2014, 07:32 AM:
 
Also Steve Osborne of The Reel Image sells what he calls Moly Lube....probably the same kind of stuff. I've used that on my machines with good success. On the rubber on the shutter wheel of the St1200HD. I once bought a machine cheap on ebay. All rubber was looking more like Super Lube, than rubber...including the rubber on the shutter wheel. It took me a few days, but I got all the belt glop out of the machine and all the rubber off the wheel. I was concerned that with no rubber on there, it would be a non operational machine. I was wrong. It turned out to be in perfect running shape...with the steadiest picture and best sound of all the hd's in my arsenal. It now is one of the two permanent St1200HD machines in my booth at home. It makes a slight bit more noise than the others.(the rubber on the wheel dampens the sound somewhat), but it comes up to speed ...picture steady...and if there is a change in running speed(and pitch of sound) due to the small reduction in the diameter of the shutter wheel, I have not noticed it But that kind of lube is good stuff and thank you, Steve, for another nice, informative and witty contribution to us collectors.
 
Posted by Steve Klare (Member # 12) on November 19, 2014, 08:59 AM:
 
You are welcome Mr. Crawford!

I doubt the thickness of the shutter rubber makes any noticeable difference in the running speed of the machine, but I'm betting back in the old days the added traction when it was there helped the machine get up to speed a lot easier.

The ST-1200 is a beast: built like a tank. If you can cope with the Fred Flintstone designed speed control they are excellent!
 
Posted by Osi Osgood (Member # 424) on November 19, 2014, 01:26 PM:
 
Great post!!!
 
Posted by Mathew James (Member # 4581) on August 31, 2015, 02:04 PM:
 
Great thread btw! Surprisingly, they have this lube at home depot in canada. I want to try this on my ST1200.
Where is this part to lube that Frank mentioned? ("cam tank lube is another major friction point") I am not sure what part this is? Thanx.
 
Posted by Steve Klare (Member # 12) on August 31, 2015, 02:38 PM:
 
The cam tank is located behind the gate. It's what makes the claw jump up and down. It is pretty sheltered in there. You'll probably need a flashlight to look in while you move the transport to see the follower riding up and down on the cam. It's no joy to access for cleaning purposes either.

Characteristically all the parts involved in the cam tank are the same color: "old, dirty grease", so they are a little hard to see in the darkness of Elmo Innards!
 
Posted by Mathew James (Member # 4581) on August 31, 2015, 02:41 PM:
 
Thanx!
I am going to try this very soon....next time i am at home depot(which is often in the summer) I will get this lube!
Cheers,
Matt
 
Posted by Steve Klare (Member # 12) on August 31, 2015, 02:43 PM:
 
For a long time I loathed the Home Despot!

For a few weeks after we got the house it felt like we were there more than we were at home!
 


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