Congratulations to John for getting a laser perforator up and running!



A few thoughts based on information learned by those who designed and

built the laser perforator at Valley Forge:



1) They used an existing laser perforator as the core of the system.  As

such, there was a large exposed area available at any given time and they

had both X and Y axis control.  They found that cutting panels was much

faster than rastering.  For a small unit like the one pictured in John's

posting, rastering makes sense, but may take more time to create a roll.



2) For tracking accuracy, cutting the edge of the roll at the same time

as cutting the perforations might be worth considering, if the edge will

not be too "scalloped" as a result.  Slitting after the fact will give a

cleaner edge but may result in accumulated tracking errors.



3) This may be the most important lesson.  Yes, the laser is unlikely to

catch the paper on fire as long as there is adequate airflow.  However,

the vapors, which contain paper dust, are flammable.  While experimenting,

attempts were made to cut multiple copies like is done on most perforators.

What was found is that the vapors got trapped between the layers of paper

and the result was fire!  Do not attempt to cut multiple layers with a laser

and be sure to have adequate airflow to prevent accumulation of the vapors.



I would be interested in more details of the project, if John is willing

to document and share them.  I am sure others will want to make their own

device, much like the way scanners started a few years ago.



Hope this helps.



Jack Breen

Southborough, MA



  [ I wonder whether John is in contact with Donald Neilson, Sr.,

  [ Norristown, Pa., who owns the laser perforator that was operated

  [ for several years for him by Frank Himpsl under the firm name

  [ Valley Forge Music Rolls?  Frank should have a wealth of first-

  [ hand experience in laser perforation of music rolls.

  [ --Relief Editor.