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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. TrackbacksThe trackback URL for this entry is: http://doesigns.spaces.live.com/blog/cns!7F5B5518D772B529!2029.trak Weblogs that reference this entry
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