Monday, March 23, 2009

Vulcan, God of Fire & Metal

First off:

That---> just happened.
It's a Baretta trike, and it will rule someday.

A lot of stuff has been happening recently. Notably, Dean has let me borrow his 16mm PHBG to replace the 21mm overkill I've been running. -And the Puch is running, indeed. I swapped out the stator for another one, between that and the new harness, the bike seems to be a lot stronger. and with a 16mm carb hooked up, it should be easier to manage the jetting issues. My thanks to Naz, who chopped up a helpless biturbo to make that happen. Finally I'm able to get my machine roadworthy for more than fifty feet at a time.

My folks came out here to visit, and we got to do some touristy stuff, like check out the Museum of Flight down at Boeing Field. Liz briefly trades her Vespa P200 for a SR-71. Mach 3+...not too shabby.

I've also been working on the furnace to make my custom-cast cylinder efforts actually happen.

After a few simple measurements, I modeled a piece of styrofoam to represent the hollow shape in the furnace.

After some shaping of the form, I lay out all the essential parts involved: Crucible, Torch, Bucket, and negative.

From that, I'm able to measure the location of the torch aperature

With that reference I use a hole-saw to cut out the insert for the torch

I then check the hole with the torch head. It's a snug fit.

After popping out the hole for the torch, I fit the styrofoam negative into its position.

I then anchor the negative in place with several large screws. This is necessary to support the refractory mix later and to keep the negative in position, as styrofoam is really really buoyant and will float through the soft refractory mix. I also added 'ears' to the negative; these will be cut-outs for the crucible stays to drop into.

I also add a few footers to raise the furnace off the ground. These are simple hardware store brackets.

With everything in place, I set up out in the garage and mix the mizzou refractory. It has to be mixed up by itself to ensure proper homogenity of elements, then it must be mixed precisely with water by weight, not volume. Because it's somewhat expensive, I use a cheap home-brew refractory in 'filler' areas and only use the mizzou around the critical areas. (the homemade filler refractory is 2 parts portland cement, 1 part perlite, 1 part water, btw)

I've been at this a few days, using different refractory types requires that I wait for them to dry up enough to be firm enough to hold their shape, before pouring in the next layer. It's all poured now, but will be a few days before the refractory will be cured enough to chase out the styrofoam. And then I'll make the lid and brackets for the torch. and then I'll cast some aluminum just in time for my 50th birthday ...weeee!
Puch Gilardoni 75cc


Joel said...

That's looking great! I learned how to cas aluminum at Cornish but when I attempted to make an intake my instructors didn't tell me about the 25% shrinkage until after I was done.

Anybody want a micro-machines intake?

Philip Patrie said...

I'm pretty sure Liz is sitting in the Time Machine from Time Cop starring Jean Claude VanDamme