DIY Vacuum Forming Machine: How to Source Heating Elements

Vacuum form machines are a staple for creating masks, costume elements, and so much more but they can run over $1,000! If it’s a tool that you won’t be using day in and day out then it’s hard to justify the cost. That’s why so many fabricators look to build their own for less.

There are quite a few designs for building your own vacuum forming machine floating around the internet but when it comes to figuring out the electrical part and how to incorporate a heat source, the details are rather murky. The simplest designs try to jump over that hurdle by just telling you to use your kitchen oven – which is a no, no. When you heat plastics, they emit toxic fumes and you don’t want to be cooking food where you also heat your thermoplastics. Then there are the really nice vacuum form machine designs that often involve welding. If you don’t have a welder then that’s another expense of a few hundred dollars that kind of defeats the purpose of building your own to save money.

When I decided to build my own vacuum forming machine, I wanted to do it in a way that the average beginner could follow with basic tools and no welding. Depending on what you have laying around your shop, I’ll show you how to build your own for less than $150.

Although a vacuum former seems complex, it only consists of a few parts – a heat box to soften the plastic sheet, a vacuum box to form the plastic sheet to your object and a tray to hold your plastic sheet so you can transfer it from the heat source to the vacuum box.

In this DIY Vacuum Form Machine Tutorial:

Sourcing Heating Elements for Vacuum Forming Machines

The first component I built for my vacuform machine was the heat box. In order for it to produce any heat, I’d have to find some kind of heat source that can reach around 400o F so I could work with a wider range of thermoplastics. Heating elements from common household appliances are the best choice for a project like this. Luckily there are a few options and it depends on how much you want to spend and how much work you’re willing to do.

Option 1: Used Toaster Ovens & Space Heaters

You can get heating elements for your DIY vacuum forming machine from a variety of sources. The most economical way is to strip down an old toaster oven or electric space heater and harvest them. The advantage is that you can also take the power circuit and adapt it to your homemade vacuum former with minimal wiring.

This is the option I chose and I’ll take you through how to tear down a toaster oven step-by-step to remove the heating elements safely. But before I do that, it wouldn’t be fair of me not to mention the fact that you can use the toaster oven as is, without tearing anything down if your primary need is for creating small parts. If most of your work can be made with a plastic sheet that fits in the toaster oven, then all you need to do is build the vacuum box. I’ll be covering that process in a later tutorial.

Most toaster oven came with a solid tray to catch crumbs at the bottom. All you need to do is cut a large rectangular hole in the middle and attach your plastic sheet to it using binder clips.

Cut the middle out of the crumb tray and use it to secure your thermoplastic sheet for vacuum forming.

I wanted to create masks and have the flexibility to make medium-sized parts so I knew I’d outgrow the size of the toaster oven pretty quickly.

Option 2: Buying Replacement Heating Elements

You can find replacement heating elements of a kinds online for ovens, dryers, dishwashers, electric stoves, toaster ovens, smokers and more. They all come in different shapes and sizes which will affect how you design your heat box to contain them. If you’re new to wiring or electrical work, choosing one may feel overwhelming because almost all of your options will require you to wire the heating element(s) up, preferably with a switch. You will also have to devise a way to mount the heating element(s) into your heat box.

A replacement heating element for a smoker is easy to use for the heat source of your DIY vacuum forming machine.
Replacement heating elements for smokers come pre-wired and often include mounting hardware.

If this seems a little overwhelming at this point, I have a beginner-friendly bonus option for you. Heating elements made for outdoor smokers and grills usually come pre-wired with a cord you can just plug into the wall. This eliminates the need for any wiring. Plus, many come with mounting hardware of some kind that you can bolt directly into your heat box.

How to Remove Heating Elements from a Toaster Oven

I picked up a used toaster oven from my local thrift shop for $10. Most will be priced at about $30 but mine had caked on grease covering much of the inside and one of the knobs was missing its chrome trim piece. Since I wasn’t looking to win any beauty contests with my homemade vacuum form machine, this cheap toaster oven was a great candidate. If you don’t have a local thrift store, or if the pickings are always slim, another great place to look for used toaster ovens or space heaters is ebay. Just make sure the toaster oven you get has four heating elements so you can work with larger plastic sheets with tour DIY vacuum forming machine.

Toaster oven from a thrift store with heating elements to use in a DIY vacuum form machine.

Once you have your victim …I mean …toaster oven, plug it in to be sure all four heating elements work. It also helps to jump online and see if you can find a user or repair manual for your model toaster oven. There’s often a section on how to replace heating elements so rather than guessing what to take apart, you can follow the steps in the manual. I couldn’t find a repair manual for mine so I’m going to have to wing it!

Remove the Outer Cover

My toaster oven had a black metal cover holding together the wall panels so this had to come off first. It was attached with small screws so it took me no time to get through them with a power drill.

The outer cover of the toaster oven is held together by screws.
The outer cover of the toaster oven may also be attached with other fasteners like torx screws.

With all the fasteners gone, the outer cover of the toaster oven can be removed.

Instead of screws, your toaster oven might be riveted together in some areas. In this case you’ll have to drill through the rivets. It’s not a difficult process but it will slow you down a bit. The only weirdness I had with my outer black cover was two torx screws on one side instead of regular screws.

With the outer cover gone, you should now be able to get a look at how your heating elements are attached and formulate a plan for their escape.

The heating elements of a toaster oven held in place with tabs.
The heating elements of a toaster oven held in place with tabs.

As you can see, my heating elements are held in place with tabs that are bent down. At this point, it looks like all I have to do is cut some wires, unbend the tabs and pull out the heating elements. But there are still a few panels and components in my way.

Remove Inner Panels & Heat Shields

Depending on your toaster oven’s design, you may be able to start removing your heating elements at this point. In my case, I had heat shields covering my element tubes making it difficult to maneuver my hands around them. In order to remove the heat shields I had to at least loosen some of the remaining inner panels. Plus, I wanted to harvest the power circuit so I opted for a complete tear down. I’ll cover in detail how I removed the power circuit and repurpose it for my DIY vacuum forming machine in a tutorial later in this series.

Removing the inner panel of a toaster oven to access the heating elements for my DIY vacuum form machine.
Removing the inner panel of a toaster oven to access the heating elements for my DIY vacuum forming machine.

With more of the inner panels gone, I now have access to the heat shields covering the toaster oven’s heating elements. The more panels you remove, the easier it is for components to be pulled out. I found some additional screws inside the toaster oven and once removed, the whole structure was loose and ready to come apart.

Removing the inner panel of a toaster oven to access the heating elements for my DIY vacuum form machine.
Removing the inner panel of a toaster oven to access the heating elements for my DIY vacuum forming machine.

Remove the Heating Elements

The only thing now holding the heating elements in place are a few bent tabs. Start by unbending all the tabs and straightening them out as much as possible. I also had small retaining plates I had to pop off.

The heating elements on a toaster oven held in place by bent tabs.

With the retaining plates off, I was able to turn the white insulator so it could slide through the hole. But first I had to cut the blue and white wires to be able to pull them through.

Some wires may have to be cut in order to remove the heating elements from the toaster oven for your DIY vacuum form machine.
Some wires may have to be cut in order to remove the heating elements from the toaster oven for your DIY vacuum forming machine.

With everything ready to go on this side, I could pull out the heating elements in pairs from the other side. I decided to do it this way because I didn’t want to mess with the metal rods holding each pair together.

Work slowly to wiggle them out. Once you get to the end, you’ll have to twist the insulator caps so they align with the holes to be able to pull them out completely.

As careful as I was, they made a nails-on-chalkboard screeching sound as they came out!

Examine the Heating Elements

My heating elements looked as expected for a used toaster oven. There were minor white patches of corrosion along the tubes but nothing too concerning. The white insulator caps also looked good. Look closely for cracks along the surface of the tubes. The insulators should look nice and white with no yellowing or burn marks. All these indicators could pose a safety issue down the line. In addition, your heating elements probably won’t last that long and it would be a shame to have to replace them so soon after going through all the work of building your own homemade vacuum forming machine.

Examine your heating elements before using them in your homemade DIY vacuum forming machine.

It’s a good idea to save your disassembled toaster oven and every part you removed until you complete your DIY vacuum forming machine. There could be some useful things you can repurpose like screws, brackets, and panels. The retaining clips I removed from the heating elements will probably come in handy for attaching them to my heat box.

I hope this guide has made the process of sourcing heating elements from toaster ovens or space heaters for your DIY vacuum forming machine less daunting. Re-purposing these common household items is not only economically smart, but it’s also an exercise in sustainability and ingenuity. After going through this process, you’ll start looking at all the appliances and electronics you have around you as a treasure trove of useful parts! The journey to create your own tools for building motorized props, animatronics and robots can seem intimidating, but as I’ve shown, it’s within reach when you take your time and proceed step-by-step. After all, the heart of craftsmanship lies in innovation, resourcefulness, and the joy of creating with your own hands.

Join me for Part 2 of this DIY Vacuum Forming Machine series, where we design and build the heat box that will house the heating elements we just removed.

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