Build A Flux Capacitor Replica

bttf 001sm Well, I finally finished building my Back To The Future - Flux Capacitor prop replica. I put it off for some time because of so many other projects. My last project was my Lost in Space B9 Robot and that took over 4 years to build. During that project, I learned how make silicone molds, cast plastic resin and work with many different types of materials. Those skills were put to use on this project. While my wife won't let me display my robot in the living room, maybe she'll let me install the Flux Capacitor in the family vehicle.

My goal with this site is to document the process I went through to make my flux capacitor and hopefully help others along the way. Check out the build progress I went through on the menu at the left.

Please let me know what you think of my site and how I can make it better. Send me your questions and comments. Pictures, I want pictures of your Flux Capacitor replicas, even before you are done. Let me know if you've found a better way of building any of the parts. To the right is my nephew Ben when he opened my prototype Flux Capacitor replica which I had given to him as a gift. That story is below.

shield eyes from light1sm
  • Is it a Gigawatt or a Jigawatt?
  • Flux Capacitor Part II
  • ...a Flux Cap in a pear tree


We all know what Doc Brown said in the first movie. "I need a nuclear reaction to generate the 1.21 gigawatts of electricity I need". But he pronounced gigawatts as if it were spelled with a "j", as in jigawatts (or jigowatts). Being an electrical engineer, I had heard the prefix "Giga" pronounced many times before, but always with the hard "g" sound, as in gigabyte.

I always figured that the word "Jigawatt" was made up just for the movie and meant to sound like a really large amount. It wasn't unit I started researching this Flux Capacitor Replica project that I stumbled across a few references to the actual term. It turns out that the original pronunciation of "Giga" was with a "j" sound (really a soft "g").

Looking at the entry on they give two valid pronunciations ji-g-wät and gi-g-wät . They even have a neat audio clip of each being spoken.

UPDATE Merriam-Webster has pulled their alternate pronunciation for gigawatt. Now they only have the "J" sounding version, as used in BTTF. I don't know if they have changed their minds on the alternate or Doc Brown went back in time to correct it. The two pronunciation links above still work though.

I am certainly happy that they used the original, older sounding pronunciation of the word since the story involved time travel and Doc Brown conceived of the Flux Capacitor on November 5th in 1955 after slipping and hitting his head on the toilet. Ironically, most references point to the early 1960's as the first time the term was used. That's okay at the start of the film as it's set in 1985, but in 1955, the younger Doc Brown should have said "1.21 gigawatts? What's a gigawatt Marty?

The saying over the years has taken on a life of its own. I've heard people say it without even knowing where it came from. What's even more fun is the debate that follows on whether a gigawatt is an actual term. People would rather debate the pronunciation of the word then ponder the possibilities of time travel. Here's hoping for a Back to the Future 4. Let's make it a reality while we still can.

So, how much is 1.21 gigawatts you ask? Well, a gigawatt is equal to one billion (10 9) watts or 1 gigawatt = 1000 megawatts. If your typical 100 watt incandescent light bulb (at least what used to be typical before they outlawed them here in the US) draws 100 watts of energy, 1.21 gigawatts would be able to light over 12 million 100 watt light bulbs. 1.21 gigawatts is also equivalent to 1,621,400 horse power.

Read More

I've decided to start my second Flux Capacitor replica. I learned plenty building my first (which went to my nephew Ben). I plan on updating my web site with newer, more detailed pictures of construction details I may have glossed over the first time. I've have also had requests to supply some parts and while I don't really want to spend all my spare time making parts for others, I may offer a few, starting first with the solenoid bases, since I made a mold of my replicas. Let me know if you are interested.

Flux Capacitor - Part II

Read More

The two months before Christmas were very busy. I'd been wanting to finish my first Flux Capacitor to give as a Xmas present for my nephew Ben.ben with flux capacitor xm I can happily say that it was finished in time and was a big hit on Christmas. He was very surprised when he opened the packaged and could not believe what was inside.

I took many pictures over the last several weeks of construction and I will be updating all of the sections with the final details. There are a few tweaks I will be making on my next one (for me) but I could not be more pleased with how it turned out. Keep checking back. If you have any specific questions, please let me know.

Read More