Hello fellow MMD subscribers.  This is my first posting after many
months of lurking in the MMD Archives section.  I have found the
Archives to be a tremendous resource.

I have been interested in mechanical instruments ever since my parents
took me to "Al Svoboda's Nickelodeon Tavern" in Chicago Heights over
30 years ago.  The experience of hearing those wonderful instruments
made an indelible impression on my young mind.  Now, 30 years later,
I am trying to share that experience with my own two sons.  My wife and
I own a player piano and a small roll collection.  I have just completed
the Bob Essex punch machine and I am set to begin construction of a
small Dutch street organ.

Building the punch machine has been very satisfying.  The instruction
booklet is exceptional: it covers all aspects of construction and
operation.  The booklet, as Mr. Essex explains in the introduction,
is not a specific set of plans; the final configuration of the machine
is left up to you.  Images of the prototype can be found on the MIDster
Punch web site (http://members.aol.com/MIDPUNCH/index.htm).  I have
sent an image of my machine to <editor@foxtail.com>.

My version is made largely of cast aluminum plate.  It is driven by two
50 oz/in stepper motors.  The punch traverse motor is coupled directly
to a 5 turns-per-inch anti-backlash ball screw.  This yields .001-inch
resolution.  The paper advance roller is driven through a 5:1 timing
belt.  I have temporarily mounted a solenoid in the punch frame.  I
will change this to an air cylinder to punch thick book stock.

The section of the booklet describing the electronics is very clear and
specific.  My only change in the electronics has been to use a pair of
stepper motor driver cards I had left over from another project.  The
electronics as designed are optically isolated from the PC.  This is
a very good protective feature.

The software is easy to use and very adaptable.  It is hard to
imagine a format it could not be configured to punch.  Mr. Essex has
been very helpful in responding to questions regarding a glitch I was
experiencing.  (My hardware was at fault).  Included with the software
are a number of sample tunes as well as alignment aids.

If you have had some experience with electronics and have access to
modest shop facilities, I am certain you can build a very useful
machine.

Next I will begin a keyless version of the Johan de Vries street organ
(http://www.psy.vu.nl/homes/johan/orgels/draaiorgel/kistdraaiorgel.uk.html).
I will let everyone know how it turns out.

Sincerely,

Craig Johnson
Orland Park, Illinois

 [ Nice photo of your nice construction, Craig.  I'll place it at the
 [ MMD Pictures site, http://mmd.foxtail.com/Pictures/  -- Robbie