8mm Forum: Elmo 1200HD problem

This is topic Elmo 1200HD problem in forum 8mm Forum at 8mm Forum.

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Posted by David Michael Leugers (Member # 166) on April 03, 2004, 05:56 PM:

I hope no one has had this happen to them, but I rather doubt it. Just like the drive belts which turned to goo, the rubber pad on the outer perimeter of the shutter has turned to goo on me. I had just replaced the belts, cleaned and lubed and settled into watching some flicks when the projector just shut down, nothing turning. I opened it up to find the drive tire stuck to the melting goo of the shutter rubber pad. The rubber drive tire maybe bad also, it is difficult to tell at this point. As it is, the projector is useless except for a source of parts. Can anyone fix this or sell the parts I need to fix it? Help!

David M. Leugers

Posted by Rob Young. (Member # 131) on April 04, 2004, 01:53 AM:

David, unfortunately this is becoming a common problem on most ST1200HD's, but there is a fix!

I don't believe that the shutter is available anymore unless you are very, very, lucky, so it's a case of fixing the one you've got.

I was warned a few years back that the rubber was decaying on my Elmo and didn't have long to go. Sure enough it soon fell apart, with the projector suddenly sounding like a road drill!

Amazingly, on my machine, I was able to peel away most of it, leaving a flat surface which got the machine up and running temporarily.

A more permanent fix is to completely remove the rubber, leaving the smooth metal surface of the shutter for the rubber drive disc to rest against (the original ST1200's were actually designed like this, without the rubber). Some people do this with sanding paper, although I think this could be a bit messy. I had my projector serviced recently and the chap used "a chemical" to remove the rubber. I don't know what unfortunately, but I bet someone on this forum with much more technical know-how than me does! Although, whatever it is, I think you'd have to be extra careful not to get it anywhere near any other rubber parts!

The rubber drive discs (don't know proper term for them) do also suffer the same fate as the rubber on the shutter.

With luck, you may be able to get a replacement 24 f.p.s. drive from someone on the forum. Alternatively, the chap who serviced my Elmo lathed off the top surface of decayed rubber, leaving a fresh, smooth surface.

The machine runs very smoothly and very quietly. As the diameter of the shutter has decreased, however, the machine will run a little bit faster. This isn't really noticeable at 24 f.p.s. but you can hear an increase in pitch at 18 f.p.s. But the main thing is that you can get the Elmo back up and running.

Anyone know what chemical he may have used...?

Posted by Chris Quinn (Member # 129) on April 04, 2004, 05:03 AM:

Hi David

No special chemical needed, just use nitromorse,or any good paint stripper. It melts the rubber and you then use a scalpel to remove the rubber.
Basically, a small brush dipped in paint stripper go along about an inch at a time wait for it to take effect, then use a scalpel to remove that bit of the rubber, You must take care not to dig in to the shutter it self as it is only made of a light alloy.
As far as the rubber drive pulley, Tom Photiou has them, and will help you i'm sure.
There is no discerning difference in speed after you have done this.
Chris.

Posted by Tom Photiou (Member # 130) on April 04, 2004, 09:19 AM:

As some of my forum friends will confirm the 24 fps roller is a part which i have managed to get re manufactured, although the first batch has been sold out i am at the moment getting some more orders together to have a 2nd batch made. After the removel of the remaining shutter rubber has been removed you can fit a modified lower motor pulley to compensate for the speed difference, again i did have some made and Kevin,(Mr Elmo) did purchase one of these from me and they worked a treat,however in the States i'm not sure how it would work with the differnt electrical supply, maybe someone could let me know.(it may be fine)
The ones i had made were a size between the large and small diameters of that lower motor pulley and it bought the speed to 23.8 FPS which im sure all would agree is almost perfect.

Posted by David Michael Leugers (Member # 166) on April 05, 2004, 10:13 PM:

Rob, Chris and Tom

Thanks so much for the info! I wondered how much the speed and projection would be affected if I removed the remaining rubber goo from the shutter. I will do that first. Tom, when can I buy a replacement drive wheel? That would insure my old Elmo going on for some time. [Smile]

David M. Leugers

Posted by Tom Photiou (Member # 130) on April 06, 2004, 09:21 AM:

I have had to have these re manufactured as they are no longer availible, although my first batch of 15 is gone i am taking any letters,or e mails of those who would like one and when the list gets to 20-25 names i can get more made up. This is the minimum that the engineers will do for me but i can make it a mix of the 18/ & 24 fps rollers, some of my new found freinds have supported me on this and if you wanted a reference there are some chaps who may be able to pass that on for you, the speed difference can be compensated by fittng new motor belts as the ild ones tend to strecth or a more permanant way is to fit a modified motor pulley which takes up the difference, on the later i am unable to get more at this time.Hope this is of use to.

Posted by David Michael Leugers (Member # 166) on April 08, 2004, 06:26 PM:

Tom

Put me on the list for a 24fps roller!

David M. Leugers

Posted by Tom Photiou (Member # 130) on April 09, 2004, 03:25 AM:

No problem Dave and if you wish to send me your e mail address i'll keep you in touch as to how the list is going and will let you have more details. Thanks. [Wink]

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