Tips on building a master

Lonnie Sweet · Post by **Lonnie Sweet** » Sat Dec 19, 2009 6:50 pm

Hi all, I'm finishing up the treads for my TIE crawler and was wondering.
I've made a 2 piece master, one is the inside of the entire side pylons, and the other is the outside. I screwed two pieces of MDF together then cut the shape so that each side would be a mirror of the other. This worked perfectly. I plan on using corrugated styrene from evergreen for the treads, which can be cut and attached after. My question is: I was thinking it would be easier to have the two halves cast separately to allow a one piece mold, but is there any advantage to joining them, attaching the treads and using a two-piece mold? Each half is almost 1/2 inch thick.

Stu Pidasso · Post by **Stu Pidasso** » Sat Dec 19, 2009 7:13 pm

The one down side I see with two sided tread patterns is seams. When you do the open face mold, inevitably, with the heat generated by resin curing, you'll get very slight size differences in halves, causing that annoying tread seam up the middle. I say if it can be done, cast them as one piece. Better to remove a pour stub than sand for hours trying to remove that groove.

Wait a minute.... a TIE master? oooOOOooo.... PM me if you need a caster.

Lonnie Sweet · Post by **Lonnie Sweet** » Sat Dec 19, 2009 8:33 pm

You were 1st on the list to contact actually. One other option I just thought of is simply leave the treads off the halves and simply cut the corrugated styrene to fit and glue it on afterwards. I'm concerned about air bubbles on the face of the upper half if it's a two piece mold.