Vacuum Forming an Arc Reactor

If you see me at Maker Faire this weekend, you will likely catch me wearing my vacuum formed goggles and arc reactor.  I was inspired by my vacuum former and this awesome Instructable by dgrover.

Once you have everything set up, this neat little “arc reactor” only uses about 50¢ of materials and doesn’t require any special soldering skillz.1 Here’s how you make your own:

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  1. Make the form
    1. I specifically bought a stack of silver plastic plates for this project.  50 plates for $10 was a pretty good deal. ((In case you care, I use affiliate links))
    2. You could use dgrover’s lasercut files or design your own model.  I designed my own, based on their designs and added 10 degrees of draft to the edges to help it release from the mold.
    3. You’ll also notice lots of little holes in the nooks and crannies of the model.  Those serve a dual purpose of allowing the vacuum to pull the plastic down into those parts and then letting air in when you’re ready to release the 3D printed part.

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  2. Add the LED and Battery
    1. Gather the tools and materials
      1. 5mm fast flashing RGB LED ($7 for 100 LED’s!)
      2. 3V Coin Cell battery, CR2032 ($25 for 100 batteries!)
      3. Push pin
      4. Optional: Hot glue gun and glue
    2. Poke two small holes in the center of the form for the LED leads.
    3. Push the LED through the holes.  I would recommend adding a drop of hot glue just under the LED moments before you pull it against the vacuum formed part.  This will help keep it in place.
    4. Bend the two leads as shown just using your fingers.  Notice the bottom lead is bent roughly 90 degrees and the top lead is curved.
    5. Add the battery.  The LED is polarized, so it will only light up when the battery is properly connected.  So, just put the battery in, then flip it over if it doesn’t light up.  :)
DIY Vacuum Formed Arc Reactors

DIY Vacuum Formed Arc Reactors

I really couldn’t be happier with the results.  It looks way more impressive than the 57¢ worth of materials would suggest.

Bucket Vacuum Former
  1. How to Make a Vacuum Former
  2. How to Use a Vacuum Former
  3. Vacuum Former – Things to Form
  4. Vacuum Former – Ideas to Improve Vacuum Former
  5. Maker Faire 2017 How to Make a Vacuum Former Presentation Slides
  6. Vacuum Forming an Arc Reactor
  7. Maker Faire Application: Vacuum Forming Workshop
  1. You could easily adapt these instructions to add some sweet LED color changing lighting to any other project []

Maker Faire 2017 How to Make a Vacuum Former Presentation Slides


In case you missed me at Maker Faire Bay Area 2017 this year, here are my slides!  Don’t forget to check out all the blog posts with even more detail and pictures.  You can find all the links, including to the 3D printable files, below.

Bucket Vacuum Former
  1. How to Make a Vacuum Former
  2. How to Use a Vacuum Former
  3. Vacuum Former – Things to Form
  4. Vacuum Former – Ideas to Improve Vacuum Former
  5. Maker Faire 2017 How to Make a Vacuum Former Presentation Slides
  6. Vacuum Forming an Arc Reactor
  7. Maker Faire Application: Vacuum Forming Workshop

Vacuum Former – Ideas to Improve Vacuum Former

This is less a post and more about just brainstorming some ideas about how to improve my vacuum formed objects:

  • Main holes, plus smaller holes
    • Perhaps additional, smaller, holes in the center of the vacuum former would allow for additional suction and more detail.
  • Taping unused holes
    • My thinking is the most useful holes in the vacuum former are those that are just under and immediately around the objects being formed.  Other holes beyond those immediately around the object are probably something of a waste of suction power.  Perhaps by placing tape over the extra holes, it would apply a greater vacuum force on the plastic immediately over the object, leading to a more detailed form.
  • Rigid top
    • When the vacuum is turned on, it causes the bottom of the bucket (or, rather, the top surface of the vacuum former) to bow in slightly, going concave.  This hasn’t been a big problem for anything I’ve formed thus far, so I’m not that worried about it.
  • Build a dedicated vacuum box
    • There are tons of plans out there for flat boxes with holes on top and a round hole for a vacuum attachment.  There’s no doubt in my mind, that a dedicated flat vacuum box for a vacuum former would work better than the bucket top I’m using.  That said, the bucket setup is working just find for now.  :)
  • Plastic frame holder and/or a dedicated oven mitt
    • I’m still using mini binder clips and a bent coat hanger.  This works just find for my purposes right now.  However, my fingers get pretty toasty as I’m holding the coat hanger.  Right now I’m just using a large sheet of vinyl shower liner to insulate the coat hanger handle and protect my hands (a little) from the heat.  I’m going to pick up an old oven mitt I can dedicate to this project.  It would be nice if I had a better way of holding the plastic than a coat hanger, but it’s the best I have right now and probably better than most ways for holding a circular piece of plastic.
    • Also, as a public service announcement, if you get a chance, pick up a foot wide sheet of the vinyl shower liner.  It’s cheap and you’ll find all kinds of uses for it.
  • Virgin plastic
    • Plastic plates are great because they’re free/cheap depending on how you use or source them.  But, they’ve already been heated, molded and formed.  That means that when you re-heat and re-mold and re-form them, they’ll be more brittle than they used to be.  I haven’t priced out plastic sheets for vacuum forming, but they can’t be that expensive.
  • Better designed forms
    • I managed to design a 3D printable arc reactor with “draft,” so that the molded parts would release easier from the molded plastic.  I used a draft angle of 10 degrees, which seemed to work pretty well but still required a little effort to remove the part from the molded plastic.  However, I think I’ll design my next part with even more draft; perhaps as much as 15 or 20 degrees.
Bucket Vacuum Former
  1. How to Make a Vacuum Former
  2. How to Use a Vacuum Former
  3. Vacuum Former – Things to Form
  4. Vacuum Former – Ideas to Improve Vacuum Former
  5. Maker Faire 2017 How to Make a Vacuum Former Presentation Slides
  6. Vacuum Forming an Arc Reactor
  7. Maker Faire Application: Vacuum Forming Workshop

Vacuum Former – Things to Form

DIY Vacuum Formed Arc Reactors

DIY Vacuum Formed Arc Reactors

Here’s a list of things I’m thinking about vacuum forming:

  • Arc Reactor parts
  • Star Trek communications badge
  • Cell phone case or cell phone stand
  • Hair clip accessories
  • Replacement emblem
  • Goggles
  • Paint or small part tray
  • Molds from play dough, sculpey, or model magic
  • Molds for soap, candy, ice, lollipops, or popsicles
  • Light switch cover, electrical outlet cover
  • Christmas ornaments
  • Lego toy car shells
  • Rocket nose cone and fins
  • “Shrink wrap” parts to make them smoother and/or watertight
Bucket Vacuum Former
  1. How to Make a Vacuum Former
  2. How to Use a Vacuum Former
  3. Vacuum Former – Things to Form
  4. Vacuum Former – Ideas to Improve Vacuum Former
  5. Maker Faire 2017 How to Make a Vacuum Former Presentation Slides
  6. Vacuum Forming an Arc Reactor
  7. Maker Faire Application: Vacuum Forming Workshop

How to Use a Vacuum Former

This is the second post in a short series about vacuum formers.  You can start with the first post about how to make your own inexpensive and easy to use vacuum former or skip to the bottom of this post with a list of all of the posts in this series.

  1. Theory

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    1. I discussed the theory behind a vacuum former in the prior post.  This post is really about how to actually use a vacuum former in conjunction with a heat source.
  2. Parts

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    1. “Buck”
      1. The things you’re going to create molds of with your vacuum former are called the “bucks.”
    2. Wire coat hanger
      1. The coat hanger will be bent out of shape and won’t be usable for hanging clothes after this.  A coat hanger from your local dry cleaner would do just fine.
      2. The good news is that this is the only thing, besides the consumable plastic plates, that you can’t put back into its ordinary service as soon as you’re done vacuum forming.
    3. 4 or more binder clips
      1. Pretty much any size binder clips would work, as long as they can get around the thick gauge wire of the coat hanger.  I only had four on hand, (which is probably the minimum necessary) but the more the better.  As you heat the plastic, it will contract and deform.  The more clips you have, the more circular you can keep the plastic as you lay it on top of the object.
    4. Oven mitt
      1. I used a cotton oven mitt that has a silicone rubber grip.  This is probably overkill, but better safe than sorry.
      2. Everything you’ll be touching with the oven mitt will be cool to the touch within about a minute of taking it out of the toaster oven.  I’m pretty sure a thin towel which has been folded over several times would work just fine.
    5. Toaster oven
      1. Preferably one that can do small round pizzas.  If you’re out shopping for one, try and find one that will fit the 10″ diameter plastic plates.  You can find a cheap toaster oven for about $30 on Amazon and about $15-20 on Craigslist.  If you’re short of funds, I’m pretty sure garage sales or Goodwill would have a bargain.
      2. Out of an abundance of caution, I was using my toaster oven outside on the off-chance that heating the plastic was giving off some undesirable fumes.  I’m also utilizing a used toaster oven donated by my brother.  I’m pretty sure the process of heating a few pieces of plastic in the toaster oven don’t make it unsafe for cooking food, but again, I’m erring on the side of caution here.
      3. There’s nothing special about the toaster oven; it’s nothing more than a convenient and cheap heat source.  If you were a more daring sort you could probably use your standard kitchen oven.  I suppose in a pinch you could also use a cheap heat gun, but I haven’t tried this yet.
    6. Pliers (Optional)
      1. I got these out to help shape the coat hanger.  In the end, I didn’t use it very much and it probably wasn’t necessary.
  3. Consumables
    Round plastic plates, 10 - 1/4"

    Round plastic plates, 10 – 1/4″

    1. Round plastic plates (~10″ diameter, without dividers?)
    2. These are just the bulk plastic plates we had left over from Party City.  Next time I’m there, I’ll check and see just what kind of plastic they’re made of.  Their website suggests they carry plastic plates with diameters from 9″ to 10.25″ to 10.5″.  The plates I had were 10.25″ and they worked out really well.  You can probably find a pack of 50 plates for less than $10.  You might be able to do even better by hitting up a dollar store.
  4. Make the Plate Holder

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    1. Using your hands or a pair of pliers, bend the coat hanger as pictured.  The goal is to get it to fit around the underside of the rim of the plate.
  5. Clip the Plate to the Plate Holder

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    1. Using four or more small binder clips, clip the coat hanger to the paper plate.  Put two clips on either side of where the coat hanger handle meets the plate.  Put the other two clips approximately 180 degrees from the first two clips.  If you have more than four binder clips, they would be helpful since the plastic will pull away from the frame as it heats up.  (I only had four on hand)
  6. Turn on the Toaster Oven
    1. Remove all the racks, except for the bottom drip tray, from the inside of the toaster oven.
    2. When it’s empty, turn it all the way up.
  7. Ready the Vacuum Former
    1. Set up your vacuum former as close to your heat source as is practicable.  You want to be able to transfer the molten plastic plate to the vacuum former as quickly as possible so that it doesn’t cool down in transit.
  8. Prepare Buck and Turn on Vacuum Former
    Vacuum former at the ready

    Vacuum former at the ready

    1. Organize the bucks (the things you want to mold) on top of the vacuum former, then turn on the vacuum.
    2. You may notice the vacuum pushes or pulls some of the objects out of the way.  Just rearrange them as necessary.  I try to place things so that they’re surrounded by the holes in the top of the vacuum former.
    3. Basically, you want the vacuum pulling on the hot plastic plate, but not sucking air freely from around it.  If the holes in the top of the vacuum former are spaced out way outside the perimeter of the plate, you’ll want to cover those holes up with some tape.  Regular masking tape worked just fine for me.
  9. Heat and Vacuum!

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    1. Put on your oven mitt, open the toaster oven, and hold the plate in the oven near the top heating element.
    2. The plates I used went through several physical changes before they were ready.  First they softened a little, then they actually flattened all the way out, then then pulled away from the wire frame, then, finally, the plastic got very droopy.  This whole process took less than a minute with the oven at full power.
    3. Once the plastic is nice and droopy, pull the frame out and place it on top of the vacuum former.
    4. The vacuum should pull the hot plastic around your objects.  After a few seconds the plastic should no longer be flexible and warm.  Once it’s cool, turn off the vacuum.

That’s it!

Bucket Vacuum Former
  1. How to Make a Vacuum Former
  2. How to Use a Vacuum Former
  3. Vacuum Former – Things to Form
  4. Vacuum Former – Ideas to Improve Vacuum Former
  5. Maker Faire 2017 How to Make a Vacuum Former Presentation Slides
  6. Vacuum Forming an Arc Reactor
  7. Maker Faire Application: Vacuum Forming Workshop