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Author Topic: Elmo ST-1200 Delay in Motor Starting
frank arnstein
Jedi Master Film Handler

Posts: 534
From: Gold Coast. Australia
Registered: Jan 2005


 - posted June 20, 2015 08:30 PM      Profile for frank arnstein   Author's Homepage     Send New Private Message       Edit/Delete Post 
Hi Janice,

The 2 holes you mention are not where to put the oil in.
The rotor shaft will be seen protruding about 2mms from the right hand end of the motor. It is a shiny shaft and it can be seen spinning around when the motor is running. Have a look right in the middle of the end plate of the motor. Then drop oil on the protruding shaft and watch it spin when turned on. Lift up one end of the projector so the oil can run into the bush.

dogtor frankarnstein [Smile]

[ June 21, 2015, 07:37 AM: Message edited by: frank arnstein ]

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Barry Fritz
Phenomenal Film Handler

Posts: 1061
From: Burnsville, MN, USA
Registered: Dec 2009


 - posted June 20, 2015 10:17 PM      Profile for Barry Fritz   Email Barry Fritz   Send New Private Message       Edit/Delete Post 
Janice, does this projector have an inching knob? If it does, and you cannot solve your problem, giving the inching knob a turn while the motor is just humming, would likely get it going.

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011


 - posted June 20, 2015 10:18 PM      Profile for Janice Glesser     Send New Private Message       Edit/Delete Post 
Frank...Things are looking much better for this projector. The oil on the motor bushing really REALLY helped. [Smile] There's now no delay in starting at all. I didn't have to make a belt. The one new belt from the set I bought is working just fine.

I was experiencing slow audio in the beginning of a reel. I noticed the sound improved if I pressed the roller to the shutter wheel. So I added another spring to the top of the clutch as you had mentioned in a previous post. This seemed to do the trick...and in testing a couple of times the sound is now pretty much at the correct speed from the get go.

Frank...I'll keep testing it over the weekend...but so far things look promising.

 -

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted June 20, 2015 11:53 PM      Profile for Andrew Woodcock         Edit/Delete Post 
well done Janice and Frank! I am glad you're machine is getting better and stronger for you now Janice with your every move. Great news! [Smile]

--------------------
"C'mon Baggy..Get with the beat"

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Steve Klare
Film Guy

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From: Long Island, NY, USA
Registered: Jun 2003


 - posted June 21, 2015 08:03 AM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
There is supposed to be a second small belt running between the two rollers' pulleys and I think this is to make up for the smaller area of contact of the drive belt around the 18 FPS pulley.

-BUT

I don't use this machine for 18 FPS so I think it may just contribute drag and slow the frame rate.

I'm going to experiment with leaving it off, especially if 24 FPS comes out noticeably slow.

--------------------
All I ask is a wide screen and a projector to light her by...

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frank arnstein
Jedi Master Film Handler

Posts: 534
From: Gold Coast. Australia
Registered: Jan 2005


 - posted June 21, 2015 08:28 AM      Profile for frank arnstein   Author's Homepage     Send New Private Message       Edit/Delete Post 
Thats great news Janice.
You are going very well on servicing this nice looking Elmo you have. The great pics and video clip you posted made it much easier for all of us here to jointly diagnose.

Here's an interesting small sound function test you can do while in the midst of all the other testing being done.

Have the back off the machine so you can watch the flywheel.
Make sure you can reach the control knob at the front.
Have no film threaded for this test.
Power to the machine is then turned on.
Switch to position 1 so the motor starts running.
While switching from 1 to position 2, observe the stationary flywheel and see if it is sent spinning within a few seconds to full speed. Thats with no film at all.

To try it again, go back to Off, then position 1 and after a few seconds try position 2 again. Every time you go from 1 to position 2, the stationary flywheel should be sent spinning. Then it will slowly stop turning in about 20 secs if no film follows.

Let us know the result Janice and anyone else wanting to do the same simple test on their ST 1200 can report their result as well. Hopefully all the projectors will all pass.

This function is interesting and important as it provides full speed to the flywheel straight away so the sound from the projector is almost perfect right away. No hearing wow in the sound while waiting for the flywheel to catch up to the film speed. Its already spinning fast, well before the film actually takes over as the means of driving the flywheel and spinning at a steady speed.

dogtor frankarnstein

[Smile] [Wink]

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Dominique De Bast
Film God

Posts: 4486
From: Brussels, Belgium
Registered: Jun 2013


 - posted June 21, 2015 09:12 AM      Profile for Dominique De Bast   Email Dominique De Bast   Send New Private Message       Edit/Delete Post 
I removed the final film path that is used for 180 m (600 ft) reels as it tended to unlock during the projection and touch a larger reel. I use this projector for 360 m (1200 ft) anyway. I Wonder if it's a common fault on this projector.

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Dominique

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Maurice Leakey
Film God

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From: Bristol. United Kingdom
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 - posted June 21, 2015 11:14 AM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
The projector does have an inching knob (at the front.)
http://super8data.com/database/projectors_list/projectors_elmo/elmo_st1200dmo.htm

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Maurice

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frank arnstein
Jedi Master Film Handler

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From: Gold Coast. Australia
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 - posted June 22, 2015 04:05 AM      Profile for frank arnstein   Author's Homepage     Send New Private Message       Edit/Delete Post 
Janice, Steve, Tom and the others following the "St-1200 low starting torque saga", thread.

After repeated testing of my ST-1200d all weekend, I am happy to report that it appears to now be completely cured of the dreaded syndrome which has plagued it ever since I bought it.

Even on cold start, it responds immediately and the motor spins without delay. I cannot make it stall anymore by quickly turning from Off to Project. There is no need to wait for the motor to spin up before switching from 1 to Project because it responds so fast. It also sounds smoother and quieter.

So I hope that Janice's 1200HD also gets a similar positive report from her. We will wait and see what she says but I am hoping we have now got this problem finally solved for the benefit of all Elmo ST 1200 owners.

dogtor frankarnstein [Smile] [Wink]

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Janice Glesser
Film Goddess

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From: Sunnyvale, CA USA
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 - posted June 22, 2015 09:45 AM      Profile for Janice Glesser     Send New Private Message       Edit/Delete Post 
Terrific Frank!!! It shows it can be done [Smile] Out of the several steps I took, which ones specifically solved the problem for you Frank or did you do something else?...AND I invite Steve, Tom and other members to post here which steps worked or didn't work for them on the ST-1200.

I'm going to do the last test today that you recommended of observing the flywheel. I don't recall seeing the flywheel move without film running thru it, but then I wasn't looking for it at the time. I wanted to let the projector sit for a day to see if the audio delay was actually improved from a cold start.

--------------------
Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Steve Klare
Film Guy

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From: Long Island, NY, USA
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 - posted June 22, 2015 10:05 AM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
I plan to do a thread on my experiences restoring the rubber surface to the shutter wheel (especially if it works out!). So far it looks good, but I haven't run it for more than a 10 minutes at a time yet.

Something I'm not clear on: I don't see a motor shaft poking out the right (non-fan and pulley) end of the motor. My machine looks exactly like Janice's so I think I'm just misinterpreting. Maybe I need to look more carefully. (Everything is packed so close together!)

I've never had the delayed start problem with my machine, but have suffered from the gradual rise towards (never quite "to") 24 FPS.

-so I would like to find this lube point and kill off yet another contributing factor to pokey-projection.

This is an irritating problem: you project reel #1 and everything sounds bassy, musical tempos a little downbeat, and actresses a little masculine sounding, but your ear and your brain compensate. Now you do a changeover to a second machine for reel #2 and until you re-compensate the actors sound like there's just a pinch of helium in the air!

This series of threads could actually turn out to be important: I know a number of us that have been limping along with these problems for years, just maybe we're going to get these machines back up to 24 FPS at last. I'm sure 40 years ago when they left the factory, they were all full speed.

--------------------
All I ask is a wide screen and a projector to light her by...

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Janice Glesser
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From: Sunnyvale, CA USA
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 - posted June 22, 2015 10:42 AM      Profile for Janice Glesser     Send New Private Message       Edit/Delete Post 
Steve...Here is a close-up of where I placed a few drops of oil at the far most center point on the motor. I then tilted the projector to allow the oil to penetrate a little further inside.

 -

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Steve Klare
Film Guy

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From: Long Island, NY, USA
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 - posted June 22, 2015 10:59 AM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
I see it!

I assume we're talking something like 3 in 1 oil?

--------------------
All I ask is a wide screen and a projector to light her by...

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011


 - posted June 22, 2015 11:09 AM      Profile for Janice Glesser     Send New Private Message       Edit/Delete Post 
Steve...This is what I used. It's probably the same as 3 in 1.

 -

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Tom Photiou
Film God

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From: Plymouth U.K
Registered: Dec 2003


 - posted June 22, 2015 12:00 PM      Profile for Tom Photiou     Send New Private Message       Edit/Delete Post 
Janice, you did very well there, I cant even see that rear part of the motor, its buried.
The flywheel spinning without film quite often doesn't work properly on these, Hence if you have a short leader the sound can be very wobbly for a couple of seconds until the film goes through and spins that flywheel. This is called the rapid start up mechanism & was designed to get the flywheel running as the switch is put into forward before film gets through, this was to cause less stress to the film on threading and also to give the sound an instant,(or near instant) play with no warble. Its actually quite an intricate set up, if any oil or grease what so ever gets onto the rubber roller below the flywheel that starts the flywheel spinning it just wont work without stripping it and cleaning it all, it relies on friction to get going.

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Steve Klare
Film Guy

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From: Long Island, NY, USA
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 - posted June 22, 2015 12:45 PM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
I'm thinking of putting something thin like a coffee stirrer or the end of a Ty-Wrap in there and letting the droplet slide down it to the lube point.

-counting applying the lube, tilting the projector and aiming the flashlight, we are up to at least four hands!

(Shame I didn't know while I had the back of the motor exposed...)

None of the other STs and many other manufacturer's machines don't have a driven flywheel, yet life still goes on! (The GS(s) must at this rate, right?)

--------------------
All I ask is a wide screen and a projector to light her by...

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted June 22, 2015 02:37 PM      Profile for Andrew Woodcock         Edit/Delete Post 
That's the beauty of the capstan driven machines. Perfectly matched running speed between sound track and film running speed from the second the rubber roller comes into contact with the capstan roller. More manufacturers should have adopted this fine design principle.

No dancers, no loss of loops, no noticeable Wow or Flutter. Very good idea indeed.

The GS goes someway to fixing these issues by taking a feed of one of its drives onto the capstan drum to get it up to speed before threading.

[ June 22, 2015, 04:33 PM: Message edited by: Andrew Woodcock ]

--------------------
"C'mon Baggy..Get with the beat"

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Barry Fritz
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Posts: 1061
From: Burnsville, MN, USA
Registered: Dec 2009


 - posted June 22, 2015 04:32 PM      Profile for Barry Fritz   Email Barry Fritz   Send New Private Message       Edit/Delete Post 
I like Zoom turbine oil. Penetrates well and withstands high temps. It has a long flexible retractable nozzle for reaching hard to get at areas. It is available at Ace Hardware stores and online. Most projector repairmen do not recommend 3 in 1 oil.

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted June 22, 2015 04:40 PM      Profile for Andrew Woodcock         Edit/Delete Post 
It does have it uses Barry, just not as a one for all solution.

It is particularly good on the two tiny roller shafts at the top sprocket shoe on the ST1200.

Without, the rollers WILL at some stage or another cease turning and then DO scratch film here.

With it applied to the roller shafts, as a very light machine oil, it keeps these tiny rollers free and constantly turning in between timely maintenance interventions and therefore prevents scratching to films at this particularly vulnerable area of these machines.

I find the early silver coloured steel ones are better than the later white plastic ones on these machines.

--------------------
"C'mon Baggy..Get with the beat"

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011


 - posted June 22, 2015 06:35 PM      Profile for Janice Glesser     Send New Private Message       Edit/Delete Post 
After letting the projector sit idle for a day...the motor had a little delay in starting...but a drastic improvement. Once the motor starts the first time... it will continue to start instantly and it's start-up speed is right on. I think the extra tension of the added spring helped with the speed issue. Years of non-use and poor storage is probably the cause for the motor seizing and the oil on the bushing has helped loosen things up.

Frank...I did your test... and yes...the flywheel turns when going from position 1 to project. Yeah! [Smile]

--------------------
Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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frank arnstein
Jedi Master Film Handler

Posts: 534
From: Gold Coast. Australia
Registered: Jan 2005


 - posted June 22, 2015 09:36 PM      Profile for frank arnstein   Author's Homepage     Send New Private Message       Edit/Delete Post 
Hi Janice,

I think that the one single thing which restored the projector operation to normal was the lubrication to the tight rear motor plate bush.
The application of more oil to the bush on the next day has improved it even more.
So give yours a second oil treatment and see if it further improves.

This has made such a difference to my Elmo that I can't resist testing it every hour to convince myself that it really is fixed. Then I do some more watching of movies to listen to the great sound and terrific picture.
At night before bed, I set it up ready to do another motor torque test in the morning.

Happy Days.

dogtor frankarnstein [Smile] [Smile] [Wink] [Wink]

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Steve Klare
Film Guy

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From: Long Island, NY, USA
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 - posted June 22, 2015 09:58 PM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
Awwwww great!

Now mine is stalling from start up.

I do believe my new belts are a little bit...tight!

Well...Guess I'd better get some oil.

--------------------
All I ask is a wide screen and a projector to light her by...

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Mathew James
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Posts: 740
From: Hamilton, Ontario, Canada
Registered: Dec 2014


 - posted June 22, 2015 10:10 PM      Profile for Mathew James   Email Mathew James   Send New Private Message       Edit/Delete Post 
I may have to do this to mine as well as I think I have a similar issue, but less drastic as Janice had.
So thankful for all your help solving this Frank so we all benefit in the log run. Janice, thanx for your perseverance!
Cheers,
Matt

--------------------
--
Cheers,
Matt 📽

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frank arnstein
Jedi Master Film Handler

Posts: 534
From: Gold Coast. Australia
Registered: Jan 2005


 - posted June 23, 2015 03:19 AM      Profile for frank arnstein   Author's Homepage     Send New Private Message       Edit/Delete Post 
Janice.....

Glad you got a positive result with the fast spin to the flywheel. As Tom has just told us, if the slightest bit of oil gets onto the small rubber roller that drives the flywheel shaft, then the friction is lost and it wont work again till its sprayed with evaporative cleaner then dries clean and bone dry.

The interesting thing about this "all mechanical" sub device, is the way it is engineered to turn itself off after about 10 seconds of friction drive to the flywheel shaft.
Pathescope Baby projector owners like Janice will soon recognize the familiar "worm shaft and peg" design that is used in this Elmo to ensure the device switches off after a short but precise time. Its is fascinating to watch it in action, just behind the flywheel.

Good Luck with your Elmo's Steve and Matt. Keep us informed with progress.

dogtor frankarnstein

[Wink] [Wink] [Smile]

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted June 23, 2015 04:53 AM      Profile for Andrew Woodcock         Edit/Delete Post 
Great results all round Frank. Brilliant knowledge sharing, well done once again!

This type of activity is what keeps our community rolling in the world of real film for yet another 30 years hopefully!

--------------------
"C'mon Baggy..Get with the beat"

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