Film-Tech Forum ARCHIVE: Help with a Norelco problem.

This is topic Help with a Norelco problem. in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Brian D. Whitish (Member # 825) on 05-31-2009, 11:37 PM:

I think Mark might have an idea.I have a AAII that the black inching knob wont turn by hand but will engage with the motor.
Any ideas?

Posted by Mark Gulbrandsen (Member # 72) on 06-01-2009, 01:08 AM:

Brian,

So are you saying that the projector turns freely at the motor but not at all via the big inching knob? Possible sprocket shaft binding or seizure IMHO if this is what you are experiencing. Instead of taking chances I'd be pulling the machine apart to see either what's worn, or what's on it's way to seizing up... It's an easy machine to work on...

Also...
Its normally always more difficult to turn it over at the inching knob thats on the hold back sprocket shaft than it is at the motor itself. Thats because you're turning over the motor armature itself and that's pretty heavy. Also the gear ratios going backwards towards the motor are such that it ads to the difficulty to turn over the motor through the belt and all. Two motor machines are even a bit more difficult to turn over.

Call me if you need any help!

Mark

Posted by Steve Guttag (Member # 268) on 06-01-2009, 08:57 AM:

Brian,

If the intermittent is starting its pull down, it can be rather difficult. Try rocking the machine backwards with the inching knob and then forwards...once you get it moving, it will be loads easier.

As Mark said though, the gearing is such the inching knob really is at a mechanical disadvantage. Look at any AA2 that has been in service a while and look at the gears for the lower sprocket and compare them to the upper...they are night and day on the wear. It is certainly better for the machine to use the motor/transmission than to use the inching knob...though certainly easier/safer for the operator to use the inching knob. The safer part only applies to single motor machines as one has to use their hand on the transmission and in an emergency slow down it isn't safe to slow it down there...hopefully, that doesn't come up often.

I worked for one chain that had the inching knobs removed to avoid the excessive wear on the lower gearing.

Steve

Posted by Brian D. Whitish (Member # 825) on 06-01-2009, 12:44 PM:

Thanks very much guys. Its actually not my projector but one at another one of our theatres. Miles McRae is going out to look at it today.

Posted by Peter Kerchinsky (Member # 1098) on 06-02-2009, 01:58 PM:

There's a first time for everything, right?
Apparently this problem was caused by the framing knob locked in the down position. I worked this machine at this theatre for years and this never happened to me.
Thanks all for the help. That's what
I like about this forum.

Posted by Mark Gulbrandsen (Member # 72) on 06-03-2009, 09:56 PM:

I'll bet that Miles wasn't all smiles after the call...