8mm Forum: Sears Tower Film Speed Problem

This is topic Sears Tower Film Speed Problem in forum 8mm Forum at 8mm Forum.

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Posted by Gerald Santana (Member # 2362) on September 26, 2012, 07:54 PM:

I have a Sears Tower Super Automatic, a nice projector that ran very steady until the belt became very worn. I finally had the chance to convert this projector (with a 1.2 lens and variable speed)to a halogen lamp and replaced the belt.

The lamp conversion worked just fine however, now the projector is running at around 18-20 fps, stuck there, speed decreases when it's supposed to go up! [Confused]

Does anyone know here how to fix this, the belt was supposed to be the right one, I got one here: http://www.turntableneedles.com/Round-Belt-Large-98-Inch_p_538.html

Could it be that the belt is to loose or the wrong one? Any help would be appreciated.

Posted by Pasquale DAlessio (Member # 2052) on September 26, 2012, 07:58 PM:

Could the new b ulb conversion be drawing too much current?

Posted by Winbert Hutahaean (Member # 58) on September 26, 2012, 08:23 PM:

quote:

Could the new b ulb conversion be drawing too much current?

If that is the case, try projector running with and without the lamp. Do you notice the speed changes? If it does not, then I doubt that is the case, Pat.

Posted by Manuel Tapia (Member # 3249) on September 26, 2012, 09:45 PM:

I don't think so, but could be a possibility.

Did you check the temp before and after the conversion ?

If the new one is getting hotter that the old one, the band could get soft and lose friction.

But i think the possibility to be the a lack of current.

When i did the conversion I checked both parameters, current and temp.

Posted by Janice Glesser (Member # 2758) on September 26, 2012, 11:06 PM:

The problem Gerald is DO NOT USE THE EJL BULB . It's 24V 200W . Again... you can only use A 21V bulb 150W like I have said previously...the EKE or EJV.

[ September 27, 2012, 12:49 AM: Message edited by: Janice Glesser ]

Posted by Gerald Santana (Member # 2362) on September 27, 2012, 09:55 PM:

Hi Folks,

I've put in a EKE lamp and it looks really good but, ever since changing the belt over, I've noticed the reduction in speed.

It's still running at about 18- 20 fps with the new belt. When I try to turn up the speed, it slows down. I wonder what it could be? [Confused]

I don't have a way to check the current but, noticed this happening with the old lamp and belt.

Thanks to all for the advice!

Posted by Richard Bock (Member # 1926) on September 27, 2012, 10:04 PM:

Gerald I don't know if this will help you or if you already know about Al Lasher's Electronic Store on University avenue in Berkeley. They have an assort ent of turntable belts there.

Posted by Gerald Santana (Member # 2362) on September 27, 2012, 10:18 PM:

Yes Richard, I've been to Al Lashers. Only problem there is belts are non-returnable and I think I have the right one. However, I'll go there again this weekend and try a smaller one.

Posted by Hugh Thompson Scott (Member # 2922) on September 28, 2012, 06:21 AM:

I'm just having a wild guess Gerald,but on some projectors,they
have potentiometers for the control of current, is it possible
that it has been moved.Or maybe the transformer is on it's way
out.Even with no belts attatched you would have an idea if the
machine is running to correct speed.Is there another belt in there
that alters the cycles that has been overlooked?

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