It's a weird combination of me just being slow, a perfectionist, and also just having a hard time finding time to work on the thing. Cuz you know I have all those other pressing priorities like winning arguments on facebook and updating my blog. Wah wah. Sad_trombone.gif.
With that in mind, I have made a lot more progress in the past week on the side mechs. For those who are following along, you will recall that this type of work is literally my least favorite type of all maker work. The process of putty, sand, primer, repeat is pure madness. But let's get to it.
I spent a couple weeks working out of the model shop at Fonco Creative Services, as it was close to my place, but had to bug out as they suddenly got a big piece of work in. A simple relocation to my workshop and setting up of a spare table got me back up and running in no time.
The bat signal is always watching over me, of course. I mean, come on.
I refer to this piece as "the coffee can" and there are two of them, one for each side and they are mirrors of each other. After looking at the way the whole thing assembles together, I realized a good time saving maneuver is to plug up the open end with a disk of styrene. That will save me some time cleaning out the existing recess, and will also make the mold less complicated. It will also give a nice surface to which I can glue or bolt other parts of the side mechs.
This little gasket-looking connector piece was not originally a stand alone part. There is a piece of the side mechs that is basically like a 90 degree curved and tapered tube. You can see it in a photo below. The white part. Much like the coffee can, there is one for each side, but the ONLY difference between the two pieces is the orientation of this gasket on the tip of it. So I made the strategic and money saving decision to only mold one in it's entirety, but then mold this piece as a separate piece, thus allowing me to create the mirror version of that tube without having to make a separate mold for the entire thing.
What you're seeing here is the early phases of my clean up process. I cut a styrene disk to fit into it, glued it in with super glue gel, then laid down a coat of spot filler putty.
And here is the final product, with a little bit of love and spray primer later.
Let's jump ahead and take a look at this assembly:
See the big white part? And the tip over on the left? That's where I cut off the gasket you see me working on above. Now check out the other end. See the grey, bigger gasket sitting on the table? As originally modelled, that too was a part of the white angle tube. It was all connected. In order to make it easier to mold and cast, and to further my goal of only making one large mold for the tube, that gasket was separated and will be cast as a separate part. This gasked needed treatment similar to the smaller one shown above.
So I cut a styrene disk, glued it in.
Then started cleaning up the seam. A little putty, a little sanding, and it's all but invisible. This will make attaching the gasket to castings of the tube super easy. Previously, all it would have is a micro thin lip to attach glue to, making the bond fairly week. Now I can just bore drywall screws through it if I wanted to.
This piece is proving to be difficult to work with just because the quality of the print wasn't super good. Lots of clean up around the edges and lips.
I did two passes at it today and made a lot of progress. This is also another example of a piece that has a drivers side and passenger side version, both mirrors of each other. Much like with the tube above, I chopped off the little flange that makes the pieces unique, and will cast everything separately. So instead of two large, complex and unweildy molds, I will have one medium complexity mold that can be optimized to use the minimal amount of rubber, and then a tiny mold for the flange that can easily be flipped and attached to create the mirror versions.
This next little piece is proving to be one of the most difficult to clean up. Just lots of tiny corners to get into and perfectly cylindrical parts are always hard to get right. I had the idea of just rebuilding most of it using tube stock and my lathe, but thought better of it. It's coming along. Probably another 2 or 3 sessions with it and it will be ready for molding.
At the end of the days work, here are three parts that are ready for molding. The two gaskets, and also the little flange that I spoke about earlier.
I decided to make my mold boxes out of corrugated cardboard this time, instead of foam core, which saved me the trouble of cutting all those little slits in a strip as I had done before so that I can get a rounded shape out of it. It worked great.
See that little black sharpie mark on the inside of the box? That's my fill line. Before building out the boxes, I measure the height of the piece I am going to mold, then I add about a 1/4" to it, and I use that measurement to mark the fill line. I have never been good with eyeballing how much rubber to pour into a box, and always end up using WAY more rubber than needed, so I developed this method as a helper for my own personal shortcomings. Of which I have many, of course.
Lastly, here's all the piece super glued down to the surface. I try to give about a half inch of border around each piece. Maybe a little less. I defintely don't need more, and maybe less would be ok. I really define the height of the fill and the thickness of the borders based on the shape I am molding, and how well the mold will hold it's own shape when it is empty. It varies a lot based on the complexity of the part. Something you just get with experience, I suppose.
Ok that's all I have to show off for now. Thank you for taking the time to read it, I greatly appreciate all the good folks who are keeping up with my blog, are asking questions, and maybe are even learning a thing or two from my ramblings. Until the next time!!!
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