Matthew Schultz asked (16.08.18 MMD) if the tracking device in his Schulz player could be modified into a better-working tracker system.  There was a discussion someplace on-line a couple of years ago (I can't find it now) about how to add Amphion-style tracker fingers to the tracker bar.

The drop-down Schulz tracker thingy that rides on the inside of the spool flanges can be disconnected (and left in place for authenticity, if desired).  The double tracker pneumatic and roll-shift mechanism are still used, but controlled by the tracker fingers.

I have attached a couple of photos of the tracker fingers in my Amphion spoolbox.  The tracker fingers are simply pieces of brass wire with one end bent to fit over the tracker bar, and the other end attached to a round flat disc with a leather facing on the bottom side.  The wire fits loosely in a groove in the edge of a small flat block of wood, with a piece of felt for a bushing at each end of the block, and is held in place with an L-shaped metal cap.  The block is screwed to the shelf behind the tracker bar.

The disc rests on the end of a nipple that extends up through the back part of the block.  This forms the valve that controls the tracker.  There is a small set screw (edge of screw head barely visible in the detail photo) that holds the nipple at the right height.

In the online discussion that I referred to earlier, they suggested using a short piece of copper tube filled with solder to make the disc.  The disc needs to be heavy enough to seal the nipple when down.  The nipples extend down through the deck behind the tracker bar and each nipple is tubed to one side of the double tracker pneumatic.

In the Amphion tracker, a suction supply tube runs from the player stack (so suction is supplied when player is in "play") to a hole in the center board of the double tracker pneumatic.  This hole tees into a cross hole that connects to both sides of the tracker pneumatic, so suction is constantly fed to both sides.  But, there is a bleed at each end of the cross hole, so that the suction is restricted to both sides.

So when the edge of the roll paper pushes against the bottom part of the tracker finger, it rotates the wire and lifts the disc slightly, allowing more air to enter that side of the pneumatic than can be exhausted through the bleed, and causing that half of the double pneumatic to open, and therefore the roll to shift.

The problem here is that the Schulz tracker pneumatic only has one tube connected to each side of the pneumatic, so you will need to fashion a junction block with the suction feeding into the center, and then splitting two ways through two bleeds (or maybe adjusting screws set up like needle valves?), then each side teeing into one of the tubes from tracker finger disc to tracker pneumatic.

It has been my experience that, when everything is adjusted correctly, the Amphion system tracks very well, and the fingers are very light and do not damage even very frayed rolls.  They are able to follow the edges of rolls where the paper is curled, where four-hole pneumatic systems would not be able to detect the position of the roll as well.

Bill Luecht

 [ http://www.mmdigest.com/Attachments/16/10/25/161025_152153_Amphion%20Tracker%20fingers.jpg 
 [ http://www.mmdigest.com/Attachments/16/10/25/161025_152153_left%20detail.jpg 
 [ http://www.mmdigest.com/Attachments/16/10/25/161025_152153_Schulz%20tracker.jpg 
 [ http://www.mmdigest.com/Attachments/16/10/25/161025_152153_finger%20dimensions.JPG