Mistakes were made…

This is yet another post on how to make a silicone mold for resin casting.  Except I didn’t do it all right and you can see how forgiving the process can be.

It all started with my first 3D print – a Boston Terrier from Thingiverse. After removing the supports, there was still some rough areas (like under the chin) that could probably be fixed with printing in a different orientation or different extruder settings.

 

I didn’t worry about that, and I probably should have spent a little more time sanding the model.  I did try to use Magic Sculpt to fill the grain from the printing process.  It did not work.

My mold making materials came from a Smooth-On kit intended for brushing over an original.  This is usually demonstrated on a bust or similar item with a broad, flat base.  Models like mine are usually placed in two part molds.

Having watched a video on that in the last two weeks, I didn’t let any of that stop me.  I proceeded to “clay up” the model and poured silicone over it.  After five hours, I removed the clay and cleaned the model and silicone.  I also added a toothpick to each foot and the chin with a hot glue gun to serve as vents.  I used a large straw as the pour hole.

At this point I made my biggest mistake.  I rewatched the video and read a dozen other articles and found the next step was to spray everything with a mold release agent.  Having none, I searched for alternatives.  Folks talked about oil based ointments (Vaseline, Vicks, and similar) working as long as they weren’t too thick to leave marks.  I decided to use a thinner oil – almond oil.  I poured the second half of the silicone and waited overnight.

My alternative mold release failed miserably.  I could only manage a slight separation at the edges.  After spending most of the day pondering my mistake and options, I took a tomato knife with a long, serrated blade and started into the silicone.  After starting a good groove, I had Mr. Man hold the sides open as I continued to slice.  At about half way, I could see the model inside.  It took the two adults with all hands to “birth” the model out of the sliced silicone.

With that done, I used rubber bands to hold the sliced half together and began pouring resin.  My first cast had a problem with an air bubble at the chin.  I had a vent there, but I left the mold flat. Subsequent casts were done with the head/chin on the downside of a slanted mold.

I also learned a decent way to estimate the resin needed for casting.  I weighed a cast at 25 grams.  I mixed 30 grams of resin (15 grams of part A and 15 grams of part B) to accommodate the sprue vents and pour hole.  It worked perfectly.  For what it’s worth, the 3D printed model weighed 23.5 grams.

Wand Follow Up

I finished that other wand and gave it to an even bigger Harry Potter fan. Knowing I needed to make another one before Halloween, I still managed to put it off and spent the weekend before soldering it together.

Both of them were based on a stick from the yard–first was apricot, second pittosporum. I originally hoped to maintain some part of the natural wood, but I couldn’t find a way to hide the wires, batteries, and reed switch.

I used Magic Sculpt to hide the wire, but rather than blend it in, I just covered the whole stick. The batteries are embedded and not accessible. If it matters, I will bust it open and patch it up again.

I used acryl gouache to paint the “bark”. I mixed some opposing colors to get a couple of different browns. I’m impressed with how realistic the combination of gloved thumbprints and brown paint turned out to be.

I wore a rubbery ring and slipped a neo-dymium magnet underneath.  The wand was actually really handy while walking down dark, crowded streets while the kid collected candy.  I never got a chance to “trick” anyone with the magnet activation though.

Mola Mola beak

One day last summer, my kid and I were strolling along the beach when we found something dead. At first we thought it was a bird, but after much poking we recognized it as a fish. With a little more time, I saw it as a small Mola Mola or Sunfish. The whole thing might have been 18 inches in diameter and was quite decomposed.
I was surprised to find a beak in the carcass. I was able to dislodge it with a stick and we took it home. After a day of drying and de-stinking in the sun, I took these pictures.

Mouse clicking is for wimps

My kid is one of the billions playing Roblox these days.  If you don’t know, Roblox is a MMOG with user generated games.  Being user generated some games are better designed than others.  One game he played recently was Boxing Simulator.  The idea is that you click the mouse to lift weights.  Each click makes you stronger, then you go beat each other up.

So the kid suggested we use one of those movey thingies (servo) to click the mouse.  So I quickly figured out how to move the servo with a bash script on my new Raspberry Pi.  I knew what to do on an arduino compatible micro controller, but I took this chance to do something Pi.  It was up to him to attach the servo to his mouse.  Rubber bands and museum wax were involved.  It worked, for a while.

Then I looked at using an Adafruit Trinket as a HID to click the mouse.  Using some patterns from other online scripts and resources, I added a button and LED for on/off functionality.  This worked great!

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Then I got a Gemma M0 and I liked the idea of using just this tiny board board with built-in LED and capacitive button on A2.  The on/off switch is nice too.  It was also my first circuit python code.  I’ve done lots of python, but no CP.  Fortunately I had a lot of Arduino experience to give context.

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You can find my Pro Trinket and Gemma M0 code on github.

Total Eclipse

We went to Oregon for the 2017 total eclipse.  We took two weeks and three states to get there.  We spent a week in the Sierras and a couple of days in Northern Nevada.  Then there were a couple of days in the Antelope and Wildlife Refuges of Eastern Oregon.

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By the Friday before the eclipse it was time to enter the band of totality and stake a claim to some part of the landscape to watch it. After a few tries we found a road without dozens of cars already on it.

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I set up a tripod and managed to mount three cameras on it and placed another below. One was an old iPhone 4 just to get our reactions.  I mostly followed the advice of many to just experience the eclipse and save the photography to the experts.  Not to say we weren’t temped, but we didn’t waste too much time on it.

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In the moments of totality, birds stopped singing and insects stopped flying.  We had noted these leaving a stump nearby while waiting.

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Here’s my video of totality with some bits slowed down to show the shadow.  It moves over us to the horizon.  I’d rather it move across the frame, but we didn’t have a great choice of landscape that morning.

This is a time lapse of the whole thing.

We planned to spend another week in Oregon, but when we received word that our cat was on death’s door, we headed South.  Closer to Madras the image below was reversed and we were in the traffic.  It took another night on a random Forest Service road before  we made it home where we had a few more days with our dear kitty.

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Using a Roof Top Tent on a Ridiculously Tall Truck

I managed to capture a time lapse of one of our camping setups on our recent trip.  I’ll keep trying this shot because I’ve thought of improvements already, but in the meantime we have this.

While in Bridgeport for ice and wi-fi earlier that day, we learned that the next day was going to be Friends of Bodie Day when the park was hosting many special events.  We decided to camp along the Aurora Canyon road. We drove up to a spot just under Potato Peak for our second night East of the Sierras.

Pole Camera Mounts

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I was interested in sticking my GoPro camera in places that would otherwise be hard to reach. Then I got the idea to convert two old paint applicators into camera mounts. Both of them attach to broom or mop handles.  The one on the right has the advantage of being capable of sticking way up high or dangling way low.

Jankenstein’s Monster

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As soon as I had the idea for “the project” I decided to start prototyping the controls and interaction with my old Arduino Uno Starter kit.  In the last few weeks I’ve learned a lot and changed almost everything. I started with a LectroBox PC Joystick Shield and an old Microsoft Sidewinder 3D pro I picked up at the thrift store.  Turns out the Sidewinder wasn’t functioning, so I got a cheap SNES knockoff with a 15-pin joystick connection.

That allowed me to control a servo, but controlling two was a challenge due to available power.  Adafruit was to the rescue with the Servo shield that I ended up never using due to a problem with a board change and headers.

By the time the above problem was identified and sorted out, I had moved on to Lady Ada’s non-shield version.  I also discovered the Nunchucky by this time as well. This required code changes to accommodate the different signals from the joysticks.

Once everything was working on my Uno, I moved it all to the fabulous Pro Trinket and added a sound board for the effects.  I added the pan and tilt servo kit to the mix to respond to the joystick. A couple of weeks passed and I knew I needed make this proof of concept fully manifest with a crude mockup.

In the spirit of “get it done” I sat down with some materials and committed myself to having something by the end of the day. With foam core, duct tape and open-cell foam I put it all together as you see here.

The Reception

I have shared these incremental steps with my 10 year old son and he nods appreciatively.  The might make a small comment like “Cool” only to add “when will it walk.  These don’t upset me, I remember being that same kid amazed at my dad’s ability to make things and wondering why he hadn’t made me an Astromech droid in his workshop already.  Oh and can you make it so I can fit inside?

Once I presented the final model in all it’s jank and crudeness, he gushed!  It was the best thing ever.  Better than the U-Command AT-AT that does walk.  I asked why and it was because the controls were much more responsive.  I received many spontaneous hugs since then.  He’s showed his friends. It has survived being alone with them (mostly).  I’m quite satisfied.

Now it’s time to move on to the full size project.

Minions of the Blue Istari

I had started some analogy with Gandalf and Gwaihir, Saruman and his corvid spies, and Radagast and all his minions. It was all to build up to the forgotten blue wizards and their affinity for Jays. But like most things Tolkien, it was all too deep and complex. [1]


And it was all to tell the story and share some pictures of the Scrub Jay family that has taken to demanding peanuts from us. They started coming around in February, and we got the peanuts soon after. They were already accustomed to our neighbor doing the same, so it isn’t like we’re the originators of the idea.
It started with a peanut left on the fence while we went back inside. But now they come down when we take the dog out to piddle. They are a family, or at least an adult and a juvie. The young one will sit higher while the adult will come down to grab the peanuts. I’ve tried holding out a handful of shelled peanuts while Mama Jay tries to crack open a nut in the shell. She stops to check out my offering, but she’s never dared to go for the easy takings. She will come right next to me while I sit in chair on the porch.

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Mama will often peak over the eaves to see if we’re around with peanuts.

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I know some folks aren’t fans of Jays because they bully other birds. In our yard the Mockingbirds are the bullies and they often are bombing the Jays during their brief appearances in our yard.

 

 

 

1. That’s no insult. I’m a huge fan. I’ve read the appendices to ROTK. I was not able to finish the Simarillion.

YAIC – Yet another insect colony

A couple of years ago I established a dermestid beetle colony. I bought the starter bugs from a guy on the internet. This seemed cleaner than collecting from carrion in the wild, but on second thought it’s all dead stuff.IMG_4643
I fed them canned dog food to start, but soon I found a dead garter snake on the road. It was not damaged except for a puncture or two which led me to deduce that it was dropped by a raptor. Silly as it sounds I had my son pick it up for me.
I put the snake on an open cereal box inside the colony container. After a day, I noticed that the bugs seemed to only enter through the punctures. I got my gloves on and tied my hair back, it was time to gut this snake. The scalpel was sufficient, but slicing across the belly scales was harder than I expected.
Once open the snake’s anatomy was mostly recognizable after I adjusted to seeing paired organs offset. Lungs and kidneys were not side by side, but rather one after the other. I put the offal next to the flayed snake. The pile was gone in three days.
It took many more days, but I was surprised with the thoroughness of the dermestids. They ate almost every scale and truly left only the bones. There were a few scales left on the head and I didn’t want to wait for them to flake off on their own.


This is a fragile specimen and half of the jaw came loose as I moved it. I first sprayed peroxide to clean and whiten, but then I noticed that the bones were softening while wet and a couple of ribs were dislodged. I moved the skeleton to some parchment paper and let that dry in the sun. Before it was too dry I arranged the snake to a more manageable configuration with a slight coil.
My riskiest move paid off when I used aerosol spray fixative as a final step. This seems to have done the trick with holding the tiny pieces together without discoloration.

Other Specimens

I have added other creatures found dead in our yard, but I haven’t had as an amazing success as I did with the snake. Everything else has been mammal and I haven’t taken the time to gut or flense the bodies. Where they ate the snake scales, they don’t eat fur and it leave a mess in the colony box. They also smell a lot more. My family is wonderfully patient with me.