How fast is your Elmo St-1200HD or D

[Ken Souza]

Hello All,

I am conducting a survey if you can help me out.

According to the user manual each digit on the film counter represents 18 frames of film. That means after precisely 60 seconds of operation at 24 frames per second the film counter should read 80.

I am curious how fast or slow your Elmo projector runs, so I am conducting a survey. if you own an Elmo I would appreciate if you could perform a brief speed test and let me know your results by posting them here.

All you need to do is zero out the frame counter and then using a stopwatch start the projector and then after precisely 60 seconds stop the projector and look at the number on the film counter. Please be as precise as possible.

Thank you in advance for any information you can give me.

Ken

[Phil Murat]

Hello Ken,

This is a good idea !!!

I suggest you to monitor frame numbers for 5 mn a least to get a confortable accuracy.

However , required precision depends on what you want to do with later.

About GS1200 (and Beaulieu 708EL as well) stability is very good : For a 24fps target , observed fluctuation is from 23,94 to 24,04 for exemple.

Concerning these machines , regulation only acts on Electronic section of main motor without taking account of slippage due to belt transmission.
However , when GS1200 is working in ESS mode (at 25fps for exemple) 25 fps measurement is almost perfect because feed back sensor is installed on camshaft for this application......

If you need a high accuracy for speeds, you need to choose a last generation projector showing an electronic control at least.

GS1200 is a good choice , why ?

-Because main motor is stable with an efficient electronic control

-Because Main shaft is driven by a micro "V" belt (Fiber reinforced belt) which offers a good slippage rate (fare away better than classical round rubber ones)


I don't know too much ST1200 machines. Anyway this machine is fitted with a complex assembly of belt and pulleys. Main motor is certainly stable as AC motor (220 or 110v) with current frequency (50hz or 60hz) is very stable.
So I am not surprized if you find a 20% variation report (means something like 24Fps minus 20%) due to belt slippage only.

[Joe Taffis]

Ken, I no longer have an ST1200 model, but I know a lot of owners that do have them DO NOT have a working counter belt, especially the HD model because that tiny belt is difficult to replace

[Nantawat Kittiwarakul]

I no longer have ST1200, but as far as I remembered the speed was pretty stable. No noticeable fluctuation whatsoever.
Realistically I'd expect anything between 23.5-24.5 fps, as long as it is very consistent.

Currently I also have a 35mm projector in my collection (Cinemeccanica Victoria8 if someone's curious). Even with inverter-driven 3 phase main motor there's still some 0.1% speed variance from time to time. Heck that's already overkill so I don't mind.

[Lee Mannering]

Hello Ken
You will have a few problems with this one as many have removed the outer rubber drive coating on the large shutter drive due to decay aka goo. Without it the st1200 runs faster of course I would say approaching 26 frames per second.
I had a supply of Elmo replacements for these but all used now. I'll be interested to hear your results
Keep well

[Ken Souza]

Thank you to everyone who has responded so far

Ken