At 12:00 AM 2/27/01 -0800, you wrote:
>From: "Mike Eorgoff" <[EMAIL PROTECTED]>
>Normally a manufacturer needs to make a minimum quantity to
>get the unit cost down to a "reasonable" amount that results in a price that
>is acceptable. This portion takes in the manufacturing costs involving
>pattern making, the depreciation on the pattern, raw materials, degree of
>waste produced whose cost must also be recovered, etc. Then there is the
>cost of money involved in fronting the production, and the possibly
>lengthily holding of stock until some hobbiest decides that this part is the
>best thing for his use.
Mike,
I noticed one thing conspicuously missing from your equation . . . Profit.
:-)
Re: lost wax - I don't know the gory details of the economics of
investment or lost wax casting but from my knowledge of the process, which
is hand-labor intensive, I think there are fewer opportunities for gaining
economies of scale than in many other maufacturing operations and costs are
correspondingly high.
As for questions about how patterns could be made, IMHO EDM would be a
good way to do it and it would work this way: Once a wheel design was
chosen the exact shape of the void between the spokes and the radial
degrees of rotation between each spoke could be deteremined. Metal
electrodes would then be made the size of the inter-spoke void. There
would be one full form electrode and then various shortened versions to
form the spokes around the counterweights. The wheel pattern blank (metal)
would be fixed to a rotary or indexing table and mounted in the EDM. The
spokes would be formed as the electrode plunge cut between them. A very
thin spoke and very tiny corners can be fully and cleanly formed this way.
This would get the wheel and spoke geometry spot-on but of course would
have to be followed by a great deal of hand work to get the components to
final shape.
Cheers,
Harry
