Flux Capacitor from Scratch

[xyster101]

I have the opportunity to meet Christopher Lloyd after a screening of Back to the Future. So I decided to make a Flux Capacitor! I did not want to spend the $150 on the real electrical box so I built one out of wood, MDF board and other bits.

First up, to make anything you need a plan. I usually make a CAD drawing, but this time just a sketch.



I built a box out of poplar with some extra wood in the corners. I sanded them to 220 grit paper. The box is roughly 12"x10".



I used a socket to trace an arch and then used the belt sander on the corners.



Using a hole saw I cut out and glued together wood pieces to make the solenoids. These are 2" in diameter and 3/4" thick. Final thickness ended up being 1 1/8" after I sanded them down.



I bought a piece of flat acrylic from Amazon that was 6"x6"x3/4" for $7 and some acrylic rods off Ebay that are 1/2" outer diameter and 1/4" inner diameter and some acrylic balls. I cut them and sanded the parts with 220, 400, 600 grit paper. Then polished it on a wheel. You could use a dremel for this as most people don't have a buff wheel.











The top is made from 1/4" press board that is used for the bottom of drawers. I put some wood around the edge to give it thickness. Then I cut a window and plexiglass to go in it. The rubber trim was a pain to do and expensive. I bought it from https://www.mcmaster.com/ it is 7/8" I think and comes in a 5' length for $15.



I primed the solenoids and drilled holes to put the electrical connectors on. I bought those Terminal Binding posts off Amazon for $10 and had to remove the top portion (on the right side of the pic) and that went into the wood cylinders.



Then it was onto the ACCEL 3009ACC 7mm Super Stock spark plug wires. These were $40 and really expensive. They came in a set of 6, so you can make two Flux Capacitors if you want.




After polishing the acrylic blocks I taped the edges and sprayed them silver. They look sweet, but reduce the light from the LEDs on the final version. I would recommend not doing this even though it is movie accurate.



Attaching the solenoids together had me thinking for a few days. I needed to connect acrylic to itself and then to wood that was painted. Usually gluing to paint is only as strong as the paint. So I put a 1/4" acrylic rod piece inside the solenoid. I used plastic weld glue #16 (great name right) off Amazon to glue the acrylic flux tubes to the acrylic balls. I then glued the flux tube to the top of the flux block while at the same time the ball to the rod inside the wood wheel and at the same time epoxy to attach the flux block to the wheel. So three things glued at the same time and I held them for a few minutes while they set.



I used 1 1/2" plumbing pipe for the pipes on the outside. I painted them silver and then used epoxy to attach a wood disk to the top of the box then attach the pipe. The side pipe has a piece of pipe epoxied to the box and then the side piece can be removed. I will be putting a switch here. My father also had an old school Emboss Label maker. You can still buy these at Staples or Amazon, but from the reviews they are not as sturdy as the original ones.



This whole time I was working on this I spent the evenings working on the Arduino code. I had never programmed before and spent around 20 hours learning how to code. I used another guy's code and added a lot to it. I bought an Arduino starter kit for $35 off Amazon then went to the interwebz to learn.

https://create.arduino.cc/editor/xyster101/b07817c4-bae8-4c78-a75a-271cdacb2fe7/preview



Some features of my code include:
4 LEDS chasing
Motion sensor so it activates when you enter the room
3 codes to choose from: Time Travel chase where it speeds up, steady chase, and steady on.

Then it was onto hot glue the LEDs down. Two important things I learned from this:
Each LED needs it's' own resistor
Switches need a resistor when they are wired up or the Arduino board well get "false" on triggers.




When it is all assembled:





Video of it working:

https://youtu.be/dbO3RTeSHmQ

 

[cjchiu]

Wow. Very nice! Any vid of it "fluxing"?

 

[Confused85]

Awesomeness! Another one for my build list. Subbed!

Sent from my Nexus 5 using Tapatalk

 

[Revol2]

Ho Ho ! Its fantastic. Like!
But background box - black color.

 

[Gixxerfool]

xyster101 instead of using hardware for your switch denounce you can add it into your sketch.

 

[xyster101]

@xyster101 instead of using hardware for your switch denounce you can add it into your sketch.

I could not figure out how to interrupt the sketch when it was in the middle of a program. The main light chase program lasts about 30 seconds and I could not get it to interrupt. After 20 hours of programming, which is not my thing, I went with what I could figure out.
Check the code and let me know how to change it.
Thanks

 

[Gixxerfool]

I could not figure out how to interrupt the sketch when it was in the middle of a program. The main light chase program lasts about 30 seconds and I could not get it to interrupt. After 20 hours of programming, which is not my thing, I went with what I could figure out.
Check the code and let me know how to change it.
Thanks

The problem is the use of delay(). Delay() literally stops all other functions in the sketch until the time has passed for that delay. The way timing is handled in sketches is either through delay() or millis(). Easiest way to explain the difference is think of being in the kitchen. You need to wash dishes, stir spaghetti sauce and microwave an item. In delay() you would wash the dishes until they're done, then stir the sauce until it is cooked and then microwave something to completion. In millis() you would wash a dish, stir the sauce once and check the microwave in that order until all take are complete. In code Arduinos can't multitask so it needs to either finish a task then move to the next or do a little of each to get closer to the end in really rapid succession in order to appear to multitask. So your approach for a hardware debounce was perfect for this code. The root of the problem is it will likely miss the button press since it's not looking for it all the time.

You would need to literally rewrite all the code from the ground up to put it into a millis() timing scheme. It's called a state machine. Since you solved the problem in hardware, good show.

 

[xyster101]

You would need to literally rewrite all the code from the ground up to put it into a millis() timing scheme. It's called a state machine. Since you solved the problem in hardware, good show.

Thanks. I was able to figure out how to do a blink without using a delay, but I did not write the code for the chasing sequence speeding up. As a result I don't fully understand how it works and I don't know enough about coding to re-write it. I did wire it with a button first and yes I had to hold the button until the end of the code to change to the next sequence.

Thanks for the props. It was quiet the learning experience!

- - - Updated - - -




I finally finished everything up. I added a few more lights and made the requested video. First time using iMovie which I liked, but I did not like working on a Mac. I was not familiar with how things work and it is very different from a PC. What do you think?

https://youtu.be/dbO3RTeSHmQ

 

[Gixxerfool]

Thanks. I was able to figure out how to do a blink without using a delay, but I did not write the code for the chasing sequence speeding up. As a result I don't fully understand how it works and I don't know enough about coding to re-write it. I did wire it with a button first and yes I had to hold the button until the end of the code to change to the next sequence.

Thanks for the props. It was quiet the learning experience!

- - - Updated - - -


http://i462.photobucket.com/albums/...tor/ChristopherLloyd with Max_zpsq0bxv2ps.jpg

I finally finished everything up. I added a few more lights and made the requested video. First time using iMovie which I liked, but I did not like working on a Mac. I was not familiar with how things work and it is very different from a PC. What do you think?

https://youtu.be/dbO3RTeSHmQ

I still don't understand it completely. I have a slight grasp on it. My code needed it and I'm still not done. The nice thing about it is I added more lights to mine so I only needed to add two lines of code since it's calling the same functions as the others. Your prop looks great. Good work.