I have written to MMD a couple of times over the years about the
reproduction musical box I have been working on.  This year I brought
my prototype with me to the MBSI convention in Morristown and have
improved it since.  I will be starting to make my product in small
batches now and am thinking about buying my materials in slightly
higher quantity.

I have always been dissatisfied with the quality of mainsprings made in
India that I have gotten from clock supply shops and would prefer an
American-made product that I can get in exactly the width I want.  It
is easy to get spring stock slit to custom widths, but the setup costs
are high, as you can imagine.

I was wondering if any other music box workers would be interested in
buying some material with me.  The larger the order, the lower the cost
per pound.  If we can arrange a joint order, prepaid, then I am happy
to pass material on to others for the cost of shipping and 10% over the
purchase price.  This would be coiled strip stock.  It would be up to
you to cut it to length, anneal the ends and cut rivet holes.

I will, in any case, place a large order for myself and be willing to
sell to other restorers as needed, but in that case I would be financing
inventory and interest costs, so my markup would be more like a typical
retail markup.

My springmotor is typical of medium sized cartel cylinder boxes (13"
cylinder).  I have averaged the measurements of a few antique boxes and
found that the most typical size for their spring is 0.028" thick and
1.25" wide.  The material is a blued C1095 carbon steel strip hardened
to Rc 48 to 51.  The edges will be fully dressed and rounded.

Are there other opinions about a "typical" spring thickness and width for
this size of springmotor?  My sample size was only about 4 mainsprings
and there was variation.

I would be happy to hear from anyone with a more extensive collection
of sample original springs or if anyone knows of any rule-of-thumb
methods for sizing a spring thickness to a given spring barrel size.
My spring barrel is 2-3/8" id with 3/4" winding arbor.  You can contact
me at:

Jonathan Herz - Herz Music Box Co.
2 Loomis St.
Montpelier, VT 05602 USA
tel: 1-802-223-5049
email: jherz@sover.net.geentroep [delete ".geentroep" to reply]