Hi All
A couple of posts about what to charge for making master patterns
missed the point I think.
when making a standard hand made piece of jewellery there are a
number of hopefully obvious things to consider regarding form and
quality. when making a master pattern the specifications require a
more technical approach. Only experience and a lot more training can
help you understand this. You have to take into account shrinkage of
the ring and settings so that your stones will still fit and finger
size will be correct. A higher level of skill and understanding of
manufacturing process’s is required if you want your end result to
be of good quality. i’ve seen a lot of master patterns that are a
pain to clean up, polish and set because the pattern maker did not
use his brain. A clever pattern maker can decrease the labour content
and increase quality of a casting by the way they construct the
master. Even simple things like putting locking pins on settings
where they contact a ring so you dont have to fiddle around trying to
hold them in place while you solder them. Some masters I make I put a
very slightly convex surface where i want a flat one because a flat
surface often casts slightly concave. The placement and even the
shape of a sprue can make a lot of difference to how the metal flows
into the flask. Some patterns i’ve seen have a very untidy join to
the sprue. If you have jagged edges on a master you will have the
same on the investment when its cast, this can result in very thin
pieces of investment(a bit like flashing on a casting) these can
break off as the metal flows in and they end up near the top of your
casting embedded in the metal. For those who still have not got it
Good Masters can save large manufacturers 100s of labour hours per
year.
Phil W