Saturday, May 4, 2013

Time for a Mold Test Run

OK, I'm finally finished with the parts.  I'm not sure if they are done but I am definitely finished!

After the last sanding and filling primer round I hit them with some plain grey primer and then with a few coats of gloss clear.  They look surprisingly good and I'm sure will produce excellent castings.  I'm going to start with the 2 easier parts and see how the process goes.  Once we get it worked out I'll move on to the next 2 parts that have a bit more complex geometry, especially the large part which may freak them out a bit due to its size.

The brown shafts are teflon impregnated delrin inserts that will be used in the mold to create the core for the swingarm pivot shaft and also to add support to the mold assembly by providing a rigid interlocking piece in the middle of the mold.  This will help prevent the rubber from shifting during injection due to the pressure of the molten wax.  The I used teflon impregnated material to allow easy removal from the wax pattern without marring.

I'm going to drop it off at my jeweler buddy's business on Monday and he'll see what the moldmakers say to doing such a large piece.  They usually deal with ring sized parts with a bracelet every now and then.  The molds look like these shown below.
The extremely jagged cut is on purpose to help keep the mold halves aligned during repeated injections.  These small molds are usually held together with small blocks of wood and a rubber band but I think we will have to make wooden boxes to hold my larger mold halves.  Let's see what the guys with a lot of experience say.  Hopefully it will be 'no problem'.

That's all for now.