8mm Forum: Eiki MS 860 Series Vs Eiki RM/ST Series

This is topic Eiki MS 860 Series Vs Eiki RM/ST Series in forum 16mm Forum at 8mm Forum.

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Posted by Robert Tucker (Member # 386) on February 11, 2009, 04:55 AM:

Wondered if any one can tell me the differences between the earlier Eiki MS 860 series compared to the RM/ST models?

Two factors come to mind firstly there is 3 sprockets compared to just two on the RM models. They are also situated differently as compared to MS series as you have one above the film gate and one directly below along with a third one, before or after the sound stage?

Can anyone tell me if the 3-sprocket system design is better then the two sprockets (one being at the top of the film gate and one being towards the back of the projector well after the sound stage.

I have also noted on the MS series that they use the larger more powerful lamp 120v 1000w bulb how does this compare to the commonly used halogen reflectors that were used in the RM models of 200w,

Posted by Stuart Reid (Member # 1460) on February 11, 2009, 05:03 AM:

Not sure about what difference a 3-sprocket design would make, but I can tell you that a 1000w incandescent bulm is far more inefficient than a modern 200w halogen.

Posted by John Whittle (Member # 22) on February 11, 2009, 10:30 AM:

I have always like the MS-860 series with it's open manual threading and three sprocket control with better control of the film over the sound drum.

There are a couple of things to know about this projector at this point in time.

The amp is a weak point with old style transistors and a "flaky" phase splitter (there was a service bulletin on this), the power for the amp and exciter lamp comes off of windings in the motor rather than a transformer (this is also the case on the ST series) such that a load change on the motor can change the power to the amp and affect volume.

The lamp was mentioned as a problem and it does give off a lot of heat and not as much light as a EJL lamp. Also the early projectors had a white plastic on the sprocket drums which split. The later plastic used on the ST/RM/NT machines is more stable. You can press on new drums, but then they need to be trued up in a lathe. Also there is a belt that drives the take-up arm from the top sprocket drive. This belt was used only on the 860 series and the X-1500/10/20 machines so it would have to be custom cut today. For a while we could get the Xenon projector part, but it was at an extreme cost increase. A better solution would be to mount torque motors for the take-up and rewind and remove the drag from the main projector motor.

I also modified the lamp house to use an EJL lamp and used transformers off of RT machines to power the lamp. I rebuilt the amp into just a pre-amp using the circuits used in the RT machines with it's better exciter lamp voltage regulation with lower ripple giving better hum free sound.

Someone at IAV in the US (which was the Eiki distributor back in the early 1970s) told me that the MS-860 was built with the EJL lamp for ELF. I've never been able to confirm this, but if any exist they'd be on your side of the pond.

John

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