US1M sailboat ballast bulb and mold

I have created a set of files for use by everyone interested in making their own US1M bulb. these bulbs may also suit other one-meter sailboats as well.

There is a dimensioned PDF file of two bulbs and two casting molds. There are also 3d versions in STL format.

The two versions have different finished weights. One is the "standard" ~4 lb bulb, the other is a "lite" version at ~3lb 6oz. (This second bulb may be a good choice for DF95/US1M conversions also)

These molds are designed as half molds for open pouring. You cast each bulb half, then epoxy them together, fill the seam with body filler, sand smooth, and machine the plug for the fin and mounting hardware, then finish as desired. By varying the depth of lead fill during casting or drilling out a bit of lead from the finished halves, you can fine tune the weight.

---You will notice in the PDF the weights are listed slightly higher than the finished weights. Those annotations are the raw bulb weights from a 100% filled mold. The mold and plug are slightly oversized to account for shrinkage and machining lead away for the fin slot and mounting hardware.