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Larry Doe's Scanner BlogPreserving the content of aging piano rolls. June 29 60's Aeolian American perforator up and runningThe past several weeks have been spent completing the punch list on the Aeolian American perforator. For the first time in history, the magnet bank has been assembled with all 100 solenoids. It's obvious the designers of the machine intended for it to have this capability but due to a design error, the holes for mounting the solenoid brackets had been drilled in the wrong location. (one ninth of an inch off) After slotting the holes, the brackets were installed into their correct locations and all 100 magnets are now operational. It's interesting that all the die sets we have were made with 100 holes and there are spaces in the punch ram for 100 interposers. I've seen 3 magnet bank asemblies and they all contain the same mistake.
After assembling the magnet bank, I discovered two different types of solenoids were in use. There was a mix of 32 Ohm and 72 Ohm coils. There were not enough of the 72 Ohm coils to complete one bank and 72 Ohms is the minimum value the magnet driver circuit board can handle without exceeding the current limitation. Guardian still makes these solenoids but todays design has changed to include side terminals and a molded coil form. They won't fit in the available space! Going through some of the spare parts in Bethlehem, I found just enough of the 32 Ohm coils to complete one magnet bank. I surmise Aeolian must have had issues with the 72 Ohm coils being too slow and/or weak and replaced them with an intermittent rated coil which has more speed and strength. The consequence of choosing the 32 Ohm coils is that I must now use an additional relay for each solenoid to handle up to 750 milliamps. I found some nice DIN rail mounted relays with built-in LED indicators and flyback diodes at a reasonable cost. I also made the decision to connectorize each row of 10 solenoids to make future disassembly and servicing easier.
I devised a welded tubular steel frame to hold two bulk paper reels. The ball bearings on the ends of the shafts provide for extremely low friction. So low, in fact, that the paper will fall off the reel under its own weight and pile up on the floor. Not shown in the photos is a friction brake I added over the weekend.
Two optointerrupters are now mounted under the end of one drive shaft. One slot detector triggers the paper advance indexer at top-dead-center. The second detector triggers the chip-enable input of the magnet driver at the proper time during the down-stroke of the punch ram.
This perforator is no longer limited to the fixed ratchet rate used in earlier times when the late Aeolian and Klavier rolls were being manufactured. The old unreliable roller clutches have been retired and the new microstepping indexer has the same capabilities as the modernized Taft Pierce Ampico perforator in use at Keystone. The old roller clutches were worn and did not engage consistently. This is what caused the sustained notes to have inconsistent bridging widths and some notes would repeat inappropriately and primary pouches would flutter. The punch diameter of the installed die set is nearly the same size as is used on Keystones Ampico perforators. A new DuoArt die set was made for this (Aeolian) perforator with .069 diameter note holes and .052 diameter accent holes. I have not yet tried out the DuoArt die set. It's not likely any DuoArt or other reproducing rolls will be made on this perforator for sale to the public due to my non-compete agreement with Keystone. It is very possible we might scan and reissue some of Keystones library of late Aeolian masters and punch them on the 'original' machinery. If there are specific requests (Clyde Ridge fans), contact Richard Groman. My primary intended use for this machine is to make single 'proof' copies for verifying the MIDI punch master files derived from my roll scans. Often, an extra note (caused by a tiny pinhole) which does not belong can be caught without spoiling a whole production run of 15 copies. Once the Chickering Ampico piano is delivered, we can experiment with projects such as the unissued Levitzki notesheet for which no playable roll or master exists. I have a lot of really great and very fragile 88 note rolls worthy of recutting.
Among some spare parts, I found a complete (and rusty) edge trimmer assembly of a different design. This one pushes the edge trimmings down through a hole in the bottom instead of having the narrow strips come out the front of the machine. The edge trimmers (both designs) are of a square shape about one quarter inch in dimension. This makes for extremely smooth edges and this might be why some folks on MMD recently might have thought Aeolian was using pre-trimmed paper. I'm sure the debate on that will continue. Maybe the old trimmer design was causing inconsistent tracking, hence the redesign. I'll try both of them and report the results! Humidity control is also a possible factor.
On the week of June 8th. Anthony Robinson came to Bethlehem and stayed a couple days. He got to see both Taft Pierce perforators in operation. One reads paper stencil masters and the other runs from a MIDI sequencer. He heard the rolls played on Frank Thompson's Knabe Ampico-B and Richard's Lauter Humana foot pumper. Both pianos had just been tuned. We all paid a visit to John Zeiner's piano shop to check the progress on my Chickering. The sound board is finished and the bridges are now being carved and fitted. The key action has all new bushings and felt. The split ivories have been replaced. All keys are polished and gleaming. The dampers have been refinished. (see photos) We said goodbye to Anthony June 10th. and sent him on his way to meet friends in California. April 07 And therewith on his hands and on his knees he went so nigh that he touched the holy vesselSuccess! The new perforator drive system, tested last weekend, has 'touched' the holy grail of piano roll copying! At last, it is now possible to recut ANY original reproducing piano roll with hole-to-hole alignment from beginning to end! Extensive testing has proven the capability of the original Ampico Taft Pierce perforator to manufacture piano rolls having precisely the same step rates and overall length as the original old rolls. In addition, rolls originally cut on Aeolian perforators during the ‘merger’ period can now be manufactured on Keystones Taft Pierce perforating machines thanks to the new motion control system designed by the author.
Three different punch-row spacings were tested and parameters were adjusted in order to ‘dial-in’ the length of the finished roll. In every case, the final result was within one-sixteenth inch of the original roll. The rolls tested were 28 to 35 feet long. It is quite amazing to lay down the original roll over the recut on the floor of the long hallway and see every hole in perfect alignment from beginning to end! One must remember, old rolls DO shrink over the ages. Environmental exposure, paper quality and the age of a particular roll are all factors in determining how much a given roll will have shrunk. Therefore, it is not necessarily important to exactly match the length of the original roll. More importantly, the roll copies should be of the CORRECT length. When played at the marked tempo, the song should play to its end in the prescribed amount of time. Equally important is punching the correct hole size in order to maximize the strength of chain perforations. How many recutting houses are able to deliver on ALL of these requirements?
In keeping with the traditions established by Charles Stoddard and Clarence Hickman, the research and development that has gone into the achievement of the above-mentioned accomplishments has been done at great expense by the principals of the Keystone Music Roll Company.
On Monday, Frank Thompson and I visited the John Zeiner piano shop to see how the 1926 Chickering restoration is progressing. Enjoy the photos! Completion could be as soon as mid summer. Some new leather arrived for the restoration of the pneumatic components and we have restocked on paper for the perforators. March 29 Never leave a glass of wine on nightstand next to laptop.Since our last episode, a rare unissued Levitzki Ampico notesheet has been scanned, perforator components were tested, more perforator components were ordered, leather for Chickering restoration arrived and mass extermination of poison ivy was carried out.
On May 24, 1926, Mischa Levitzki returned to the Ampico recording piano and recorded the 2nd. movement of Beethoven's Waldstein sonata Op. 53. The notesheet seen in the accompanying photos is the actual original master made on the line marker in the Ampico recording studio nearly 83 years ago. You can clearly see every perforation is hand-punched. There are 3 punches at the start of every note and a single punch at the end. A pencil mark connects these perforations on sustained notes. The numbers written next to the start of every note are probably the intensity values and might be proof the spark chronograph was in use at this early date. Some lighter vertical pencil marks show the locations of the expression tracks and the stack division. There are some horizontal lines from beginning to end with numbers written in on the treble side which might correspond to measure or beat numbers. The very first chord is numbered '1'. There are areas where evenly spaced horizontal lines are drawn in and areas of notes are encircled with a comment to even them up. There are many thousands of small yellow and white bits of paper pasted over note holes. Many have been punched through. This lends credence to the stories of many of the classical performances needing a month or more of editing. There may have been a second go-round of editing which could explain why two colors of editing tape were used. The note sheet would have to be run on the (now nonexistent) stencil machine in order to create a playable roll. It's interesting to note, the editors had little control over which exact punch row an event would fall into. The automated stencil machine had to make that decision. Perhaps the many bits of paper tape were an attempt by the editors (Miss Volavy in this case) to move an event to a different punch row. I don't know of any surviving trial rolls of this performance and we will have to manually insert all of the chaining into the Scanimage MIDI file. Won't it be interesting to hear how polished this performance was? The photos show entire sections of paper having been spliced in. Could this be be some of Miss Volavys 'assisting'?
By the time I arrive at Keystone April 4th. to install the stepper advance unit, I will know just how effective my protective clothing was for preventing contact with the many poison ivy vines which were cut down yesterday. My face was covered with Ivy Block lotion and a face shield. There was no other exposed skin and all gloves and protective clothing were put into the trash. No tools were handled after the gloves came off. I devised this experimental way of killing the roots by wrapping the ends of the vines with a paper towel and dipping it into herbicide. The ends were then encapsulated with urethane foam. This will contain the poison and prevent it from being washed away by rain. It also keeps the poison from killing the host Arbor Vitae bushes. Time will tell whether this method is effective.
The Z-tronics organ rank driver board set has been bench tested successfully and a second set of stepper drive components has been ordered for the late Aeolian perforator.
One night while in dreamland, I thrashed around enough to knock half a glass of wine off my nightstand and onto the keyboard of the new Toshiba laptop computer. The wine poured through the computer and out the CD ROM slot into a pool on the floor. A bath towel came to the immediate rescue but did little to improve the condition of the computer. I avoided powering it up and proceeded to disassemble the entire laptop the next morning. Luckily, only a few drops made it into the hard drive and CD ROM and did not touch the motherboard at all! The worst case scenario was avoided and only the keyboard would need replacing. I decided to try my luck disassembling the keyboard. There were enough eyelashes in there to reconstruct Marilyn Monroe! The trick will be in discovering how to unsnap the keytops from the tiny scissor hinges without breaking anything. There are a few decorative divider strips which must be broken off before the sheet of flexible rubber buttons can be lifted off the circuit board membrane. There are no active ICs in the keyboard assembly except a few LEDs and all switch contacts are hermetically sealed within the membrane. After washing and drying all parts, the keyboard was carefully reassembled and the laptop has been working reliably for more than a week. March 08 Ampico stepper drive system finishedFor the past three hours, I have been exercising the newly completed stepper drive system for Keystone's original Ampico Taft Pierce perforating machines. The last week was spent designing, fabricating, assembling, wiring and programming the new device. See accompanying photos. It will now be possible to perforate piano rolls with virtually any punch row spacing. The immediate goal is to be able to punch Ampico rolls made during the 'merger' period when the rolls were manufactured on Aeolian perforators with .030" punch row spacing. Instead of physically changing gear ratios, it will now be possible to select the desired punch row spacing with a simple thumbwheel switch. The number of microsteps per punch row has been calculated using an Excel spreadsheet designed by the author. This spreadsheet contains equations which model the physical characteristics of the perforator mechanism along with the gear reduction ratio of the drive motor. All cells enclosed in heavy borders are the input parameters. The most important calculated result is the number of microsteps per punch row which is programmed into the motion controller and selected by the thumbwheel switch. The rest is a matter of calculating the proper acceleration and deceleration rates which will produce smooth indexing movements without any undesirable harmonics.
One crescendo pneumatic has been restored and a few progress photos are included. I plan to make another visit to Keystone in a few weeks to install the new motion controller and will check on the progress of the Chickering piano restoration at the John Zeiner & Sons shop during that trip.
February 15 The great summitThe Keystone crew was in Frederick, Maryland Feb. 6th to attend a screening of the lost (and now found) silent film "Beyond The Rocks" starring Rudolph Valentino and Gloria Swanson. Accompanying on the mighty Wurlitzer was Ray Brubacher. We arrived early for Richard Groman to assist Doug Miller in tuning the pipes numbering over 600. We were fortunate to be joined by Spencer Chase, Warren Trachtman and Joe and Lauren Orens. There was time for us all to have dinner at the local brew pub before showtime.
Warrren and Spencer followed us back to Bethlehem, PA after the show and were guests of Richard Groman for most of the weekend during which many of the nuances of roll mastering, editing and technological advancement were discussed. Warren gave us a demo of his new USB scanning software and was present while several 88 note rolls were edited, perforated and played on the Lauter foot pumper. Spencer showed us many of the utilities he has written relating to scanning and rendering. He is now testing a new perforator control program which could allow a PC to replace the older MIDI sequencer which depends on (sometimes unreliable) floppy disk technology. There was considerable discussion on paper characteristics, lyric printing and web hosting. On the latter subject, I would expect to see some progress soon since some new people are becoming involved. The response to the latest printed catalog has been excellent and we're hearing very positive feedback about the product quality.
The next technological advancement will be the addition of a modern programmable motion controller and stepper motor with gearhead to the now computerized Ampico perforator. Classical enthusiasts need not worry. The number 2 perforator is untouched and still operates from the traditional paper stencil masters and is making beautiful rolls with its brand new die set. Today, I finished the bench testing of the motion controller. It is able to read a BCD thumbwheel switch and execute any of 10 different pre-programmed step rates. We have effectively surmounted the limitations of the available change gears and should now be able to perforate many more piano roll formats including the Aeolian/Ampico titles issued during the merger period. With microstepping, the overall length of a remastered roll can be matched to the original roll with a precision of one sixteenth inch. The holy grail of hole-to-hole roll copying is now within our grasp!
On the home front, the Chickering Ampico restoration is moving forward. The piano was picked up today by Modern Piano Moving. The 40 foot trailer was filled with 20 pianos and one Ford Ranger which will be employed on a challenging delivery in Maine. Russ, Joe, Ken and (dog) Maggie will be making stops in Rhode Island, Massachussetts and Maine before heading back to NY and Allentown, PA where my Chickering will be delivered to John Zeiner and Sons for full restoration and refinishing. That will take at least until early Summer to complete. So far, I've rehinged, covered and sealed four of the larger pneumatics and will start on the crescendos next. Will try and get some progress photos for the next blog entry. |
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