Flux Capacitor Vacuum Solenoids
The Round Base
Last Updated (Tuesday, 15 June 2010 12:36)
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Three of the major components inside the flux capacitor are the round metal disk shaped elements. It turns out that they are electrical vacuum solenoids used to switch heavy currents in industrial equipment. They have a glass tube running through the middle and exiting at a right angle. By angling the three glass tubes towards the middle of the box, they form the "Y" of the flux capacitor. They come up on ebay every once in a while but unless you want to drop a few hundred dollars each, you'll need to come up with a substitute. I found the dimensions for the actual solenoids on the web in a BTTF forum. There are also plenty of pictures of these solenoids from all angles, so crafting a replica should be doable. |
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It happens that I have a large stash electrical components and I found a few dc motors with a metal gear box that has the same dimensions as the metal base of the vacuum solenoids. My plan is to transform one of these into a replica of the actual base. Then make a silicone mold of it and crank out several. I have plans on using clear acrylic rod for the glass tube. I used the acrylic rod for a few parts inside my Lost in Space Robot, so I know how versatile it is. |
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I took apart the motor and placed the metal ring on a scrap piece of plastic.
I then put clay around the base to seal it and I filled the center with plastic resin. This will allow me to fashion it into a replica of the solenoid. |
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My replica base is starting to come together. Next I drilled a 9/16 inch hole completely through the middle. I then painted it with primer. After applying the primer, I noticed a few pinholes in the resin. A little automotive Bondo putt filled the holes and I then wet sanded it with 400 grit sandpaper. |
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Here, I've drilled two holes for the soldering posts and a small slot where the electrical wires exit from the solenoid case. The base is about ready to be used as my mold master. That is when the fun begins. |
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I've set in place the soldering posts and added two wires. The wires have one end stripped and wrapped around the top of the posts while the other ends go into the body of the solenoid through the small slot I made. In it's final configuration, the bare wires will be soldered to the posts. |
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Having finished the replica base I could now make a mold of it. I prepared the base by mounting it to a clean flat piece of PVC. I used my tried-and-true Lego method for building a box around the base and mixed up some silicone rubber. I've documents my molding methods in my Silicone Mold Making Guide. After degassing the silicone, I poured it over the base and vibrated any remaining bubbles to the surface where they could pop. I have to wait patiently overnight for it to cure.
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I was tempted to crack it open in the morning to peek but didn't as letting it sit another 9 hours would probably be good for it and I could wait unitl I got home from work. |
MORE TO COME!
Solenoids Solder Posts
Last Updated (Sunday, 29 March 2009 07:24)
 | Two tiny black posts protrude from the surface of the vacuum solenoid. Connected to each is a single black wire. These are posts for soldering the wires that will power the solenoid. The black wires are connected to the coil inside the round metal case. The posts look simple enough but finding something now that matches these would be a trick. |
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| Fortunately they resemble some other electrical components. I have a hand full of test probe sockets that look an awful like what we are looking for. And they are exactly the right size. |
| | Here's the soldering posts placed on my solenoid replica. I added the wires that are wrapped around the top of the posts and go into a hole in the base. |
Those Fluxing Tubes!
Last Updated (Friday, 26 February 2010 21:01)
One of the trickier parts to replicate will be the glass tube which contains the relay elements. I have on order from McMaster-Carr several 6 foot acrylic rods. I used 1/2 inch acrylic rods on my B9 Robot Replica and they are great to work with. I have ordered three different types. I also ordered some 3/4 in. dia. acrylic balls.
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1/2 in. outer dia. Solid |
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1/2 in. outer dia. 1/4 in. internal dia.
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3/4 Acrylic Balls |
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I started by sanding a flat spot on one side ofa 3/4 in. acrylic ball. This allowed me to drill a small 1/8 in. hole part way through. Next I placed the drill bit into the hole. This allowed me to hold the ball against my table sander and sand two more flat spots at right angles to the original and at opposite ends of each other. These flat spots should be exactly 1/2 in dia. I then drilled a 1/8 in. hole completely through from one flat side to the other. |
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I glued sections of the 1/2 OD, 1/4 ID acrylic tubes on the flat spots. The lower right side, which is placed into the solenoid base can be cut flush to the same length as the depth of the hole. This will allow it to sit flush in the hole
I'm still playing with the lengths of the different tubes to get the right look. |
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Here I've put it into the hole and set the two soldering posts in place. I added small copper rods for now, but need to get some other steel ones.
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| More to Come! |
Painting the Solenoid Base
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I finally found time to put some paint on one of the replica solenoid bases. I found a airbrush paint at a local hobby store made by Model Masters (Testors) that is called "Brass - Non-Buffing Metalizer". I gave it a shot and I'm not sure I like the outcome. I've used Chrome air-brush paint in the past and it works quite well. With the chrome, after your primer layer you put on a glass black base. Then the chrome is sprayed on and the gloss black is allowed to show through slightly, giving the chrome a deeper look. |
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The brass paint has no base paint so you are painting over your (gray) primer. You have to completely paint your item. I'll reserve my final opinion until I apply the label and add the tubes. I plan on looking at what other air-brush paint companies offer to see if there is a better option. |
