Adjustable feed carriage for Edison Triumph Phono.
Posted: Wed Aug 23, 2023 11:20 am
I wanted to share a solution I have come up with for playing Indestructible and other celluloid cylinders that have shrunken over time to the point that the reproducer no longer tracks properly and the record begins to skip and sounds distorted. The modification consists of a new two-piece carriage sleave and a cam holding bracket. The left side sleave holds the original feed bar and feed nut. The right side sleave holds the original reproducer holding frame. The cam holding bracket just slips on to the carriage shaft, as you will see in the videos. The two separate carriage sleaves are key together axially, but are free to slide longitudinally on the carriage shaft. The two carriage sleaves are in contact with each other by way of a cam lever, one end of which has a roller that rides on an adjustable cam ramp which is mounted on the cam holding bracket. The left feed carriage sleave actually pushes the reproducer carriage along as the record plays.
So, depending on the slope of the cam ramp, the reproducer carriage can be adjusted to move slower than the feed carriage, (necessary for proper tracking of shrunken cylinders), to move at the same speed as the feed carriage, (for playing wax cylinders that haven't shrunken), or to even move faster than the feed carriage, (possibly for cutting new records for making molds that require additional lead).
The new carriage assembly works very smoothly and I have finally been able to listen to some of my favorite records that previously would begin skipping about two thirds the way through. Making this assembly was rather straightforward, but it did take quite a few hours to complete. I know that a project of this kind may possibly be beyond the capability and/or interest of many collectors, but I wanted to demonstrate that it is possible to compensate for shrunken celluloid cylinders. Also, there may be other ways to accomplish the same adjustments.
I have made four videos to show how the new carriage works. The carriage sleaves and cam bracket are on an Edison Triumph phonograph model D. The original parts can be replaced in less than a minute.
The first video just shows how the feed carriage pushes the reproducer carriage along. The actual contact point between the two carriages is the cam operated lever that follows the adjustable cam ramp. A dial indicator is temporarily clamped to the feed carriage and a target is clamped to the reproducer carriage. Clockwise rotation of the pointer indicates that the reproducer carriage is moving toward the feed carriage. Each mark on the dial represents 1/1000 inch motion. Four minute records have 200 grooves per inch, so each groove is 5/1000 inch. So every five marks shown on the dial means that the reproducer carriage has been retarded one groove. The records that I have tested so far have required about 60/1000 inch retarding or about 12 grooves (60/1000 inch is about 1/16 inch).
The second video shows the action of the cam lever. The adjustable cam ramp and the bracket have been removed for the sake of visibility. The axial keying is also apparent here.
The third video shows a record playing with the dial indicator still in place. As the record plays, you can see the pointer slowly moves clockwise from "0" to about "60", indicating that the reproducer has been retarded about 12 grooves. I imagine that other records may need different amounts of correction. I haven't yet tried any Edison records.
The fourth video shows a cylinder playing with just the new carriage assembly. This particular record previously would always start giving trouble about half to two thirds the way through.
Dan Zalewski
https://www.youtube.com/watch?v=d_dZfq3UDb0
https://www.youtube.com/watch?v=RuswHSKxROo
https://www.youtube.com/watch?v=f12D3gFnuyg&t=66s
https://www.youtube.com/watch?v=3-yBFCvsLHU&t=6s
So, depending on the slope of the cam ramp, the reproducer carriage can be adjusted to move slower than the feed carriage, (necessary for proper tracking of shrunken cylinders), to move at the same speed as the feed carriage, (for playing wax cylinders that haven't shrunken), or to even move faster than the feed carriage, (possibly for cutting new records for making molds that require additional lead).
The new carriage assembly works very smoothly and I have finally been able to listen to some of my favorite records that previously would begin skipping about two thirds the way through. Making this assembly was rather straightforward, but it did take quite a few hours to complete. I know that a project of this kind may possibly be beyond the capability and/or interest of many collectors, but I wanted to demonstrate that it is possible to compensate for shrunken celluloid cylinders. Also, there may be other ways to accomplish the same adjustments.
I have made four videos to show how the new carriage works. The carriage sleaves and cam bracket are on an Edison Triumph phonograph model D. The original parts can be replaced in less than a minute.
The first video just shows how the feed carriage pushes the reproducer carriage along. The actual contact point between the two carriages is the cam operated lever that follows the adjustable cam ramp. A dial indicator is temporarily clamped to the feed carriage and a target is clamped to the reproducer carriage. Clockwise rotation of the pointer indicates that the reproducer carriage is moving toward the feed carriage. Each mark on the dial represents 1/1000 inch motion. Four minute records have 200 grooves per inch, so each groove is 5/1000 inch. So every five marks shown on the dial means that the reproducer carriage has been retarded one groove. The records that I have tested so far have required about 60/1000 inch retarding or about 12 grooves (60/1000 inch is about 1/16 inch).
The second video shows the action of the cam lever. The adjustable cam ramp and the bracket have been removed for the sake of visibility. The axial keying is also apparent here.
The third video shows a record playing with the dial indicator still in place. As the record plays, you can see the pointer slowly moves clockwise from "0" to about "60", indicating that the reproducer has been retarded about 12 grooves. I imagine that other records may need different amounts of correction. I haven't yet tried any Edison records.
The fourth video shows a cylinder playing with just the new carriage assembly. This particular record previously would always start giving trouble about half to two thirds the way through.
Dan Zalewski
https://www.youtube.com/watch?v=d_dZfq3UDb0
https://www.youtube.com/watch?v=RuswHSKxROo
https://www.youtube.com/watch?v=f12D3gFnuyg&t=66s
https://www.youtube.com/watch?v=3-yBFCvsLHU&t=6s