More plaster disasters and CAD

I haven't written for a few days...it's taken me some time to get over the disappointment of my molding failure. Here's what happened

Got ready to mix the ceramit.


Tried to pour it and everything went wrong. It was too thick, and my pour hole was too small. It kept on getting clogged in the gate. I didn't get a complete fill before the material dried. In retrospect, the gate and vent were poorly placed, I was never going to get a complete fill. Furthermore, I should probably study material sciences. The ceramit was a little harder than the plaster, so despite using olive oil as a mold release agent, the pour did not want to come free. When I finally saw the writing on the wall, I knocked it out with a hammer. This is what I got.




Here are my four attempts


Anyways, this failure led me to rethink my design process. I decided to give a go at designing the car in CAD. I'm amazed! Here are my results:










Total: 114 h

Tooling

I know this is long so bear with me

First I've got the box I made. I laid the car on it's side, and marked where the guide pins should be to not interfere with the form.



Drilled holes for the guide pins



Had to open up the holes a little bit with a file as I did not have a drill bit large enough.



Then put the guide pins in place. I accidentally bought one 2cm short, so oh well, there is a short one.



Then I drilled holes and placed the bolts that will hold the blank and act as the gate and vent in the finished tool



Painted the mating surfaces of the frame with wax so they wouldn't leak.



Placed my blank on the bolts I installed



And painted it with a light coat of olive oil. (probably didn't need to be extra virgin, but probably didn't hurt either!)



Then I assembled the side of the box with the attached blank



Getting the screws in place, just some final checks



We are ready for the first pour



The goal was to pour plaster halfway up onto the blank. This was much harder than it looks. I didn't mix enough plaster, so I had to make another batch.



I waited for this pour to dry, then painted it with olive oil as well



Second pour for the other half...jeez, again I mixed too little plaster. Next time I'll do some math and calculate volume before mixing



So here's what we got. I attached nuts to the top of the guide pins to hold it together (just in case)



First, I took the bolts for the gate and vent out of the side





Then removed the guide pins





Took off the bottom





And the sides



This is the result of my pours of plaster



Put a bolt back in a gave it a decided whack with a hammer (now that took confidence!)



Pryed the two halves apart with my hands, as I imagined that it was still quite delicate



And wouldn't you believe it worked



Ladies and gentlemen there you have it, I have made a tool



Pounded the guide pins back in place



Tightened them down, and will let this dry for a while



Total: 82 h

Evolution

I've come pretty far in a couple of weeks

Modeling the blank with wax

I set about to smoothing out the wax that I applied yesterday by brush and making adjustments to make sure that the blank is slightly oversized.

I thought I would heat up a blade and use it to smooth the wax. That didn't work. The wax is soft enough that it can be smoothed out using regular sculpting tools


As all of us, I'm my own worst critic. I know the areas of the car that I think are poorly done, or could be better. I've had a change of heart after seeing this pictures. I've found that the pictures don't lie, and pic up details one might not notice with the eye. The pics of my styrofoam/wax blank are fantastic. I can't wait to get it into plaster.












Total: 77 h

new shirt

I got the shirt that I ordered off of ebay.it. Man it's the real deal. It's a bit big on me, but hell, I actually got a team shirt from a formula one team that raced in 1993.



If this picture is accurate, it means that I can use the shirt as a color reference for painting the model. I have to say that pictures do not do the colors on the sleeves justice. This red/orange is loud and florescent, as is the yellow