Film-Tech Forum ARCHIVE: RTV-8900 auto shut-off cam alignment

This is topic RTV-8900 auto shut-off cam alignment - help? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jim Henk (Member # 3628) on 12-31-2011, 03:44 AM:

Got a Kelmar film winder a while back, and finally got around to installing it today.

All is well, except for the auto shut-off cam on the camshaft. Have tried various positions, but it doesn't seem to function right. There doesn't seem to be a position that will allow you (manual mode) to start with the arm up, and when the film runs out, the arm drops and shuts off.

At first, I thought the cam was just out of alignment, and needed to be knocked loose and turned on the camshaft. But it's on there pretty tight, and seems to be designed that way to discourage you from doing exactly what I was thinking of doing. (I didn't)

Am including some small images. Am I missing something here? (Aren't I always?) Thanks!

Oh by the way, The 35mm idler wheel on the shut-off arm has seen better days, and I'm shopping for a 70mm idler wheel and shaft for that unit. Anyone have some lying about idly? (each?)

Posted by Chris Slycord (Member # 4239) on 12-31-2011, 04:22 AM:

quote: Jim Henk
There doesn't seem to be a position that will allow you (manual mode) to start with the arm up, and when the film runs out, the arm drops and shuts off.

That's because the switch to auto is what turns on the mechanism for using the auto shutoff arm, unless I'm totally missing something you're trying to say.

Posted by Tony Bandiera Jr (Member # 2365) on 12-31-2011, 12:17 PM:

Chris is spot on..use the AUTO/MANUAL switch.

And why, if you're in Manual mode, would you want or need an auto shutoff when the film runs out? [Confused]

My friend, you are WAAAAYYYY overthinking things. [Big Grin]

Posted by Jim Henk (Member # 3628) on 12-31-2011, 12:31 PM:

Really?

Okay. Then why does Manual mode shut off when the cam switch is in the open position?

Auto mode starts when the inner cam switch is closed, and stops when either the inner cam switch is open, or the Stop button is pressed.

Manual mode starts when the outer cam switch is closed *and* the Start button is pressed, and stops when either the outer cam switch is open, or the Stop button is pressed.

Either mode is wired as auto-shutoff, really. Cam positions are just wonky, that's all.

So what am I over-thinking?

Fraid you lost *me*, now.

Posted by Tony Bandiera Jr (Member # 2365) on 12-31-2011, 01:13 PM:

Ahh, gotcha now. I'm going to UCI today, I'll check out my rewind there and get back on this one.

Posted by Monte L Fullmer (Member # 2797) on 12-31-2011, 07:19 PM:

..and while you got the thing opened up, the ball detents on both assemblies loves to hang up...put a few drops of FG on that ball and push it in a few times to free it .. FG just works wonders on anything you dab it on.

Look inside the control box - comes unbolted from the bottom of the table .. might have some issues inside there...

Posted by Mitchell Dvoskin (Member # 751) on 01-01-2012, 01:20 PM:

Putting aside the exact position of the internal micro switches for the moment, the way Kelmar film tables are supposed to work from an operator's perspective is:

If in MANUAL mode:

The auto-shutoff arm is not intended to be used. If you raise the arm past the point where the micro switch would shut off the power in auto mode, power is cut off above that point and can not be manually turned on until the arm is below that point.

If in AUTO mode:

Raising the arm up as far as it will go triggers the other micro-switch to turn the power on (the "on" button is disabled). When the arm drops below the stop position, the power is turned off.

This applies to all Kelmar tables as far as I know, but specifically to the RTV-7500 thru the RTV-8900 tables that I have personal experience with.

Posted by Jim Henk (Member # 3628) on 01-01-2012, 07:09 PM:

That's it. Thanks Mitchell.

Yep. Cam in perfect position for manual mode, but a former owner screwed up the cam position for auto. Will have to remove it, reposition it ,and put it back on. Damn. It's a *really* tight fit. And to confirm all this, looks like the cam had a new hole drilled and tapped into it, and none of the cam screws are over the real shaft set-screw detente position. Hope the proper hole isn't stripped. That would account for their actions.

Thanks again, everybody. Happy New Years!