3D printing is additive. CNC milling is subtractive. Vacuum forming is transformative. It transforms a sheet of formless flat plastic into extraordinary complex copies. It transforms preconceived limitations about functional part thinness — the interplay between “consumable goods” (foodstuff) and “durable goods”(not food) — and low-volume throughput speeds. It transforms endless eternities (hours) staring at CNC machines into making parts as fast as you can say, “where a heated plastic sheet and replicable shape meet.”

The Mayku Formbox

I got my hands on a cool tool, a molten-melty-makey machine, a device that takes plastic from a boring sheet to oh so neatThe Mayku FormBox!

Unboxing and First Impressions

The design is simple, sturdy, bright, fun, and analog. The unit arrives assembled and ready to go. No tools provided or needed, just plug the power cord into the unit and attach your own vacuum cleaner to provide the suction. The only difficult thing about getting started with the FormBox is patiently waiting by the door after you order one for its arrival. The FormBox looks like a fine piece of retro stereo equipment made by DeWalt. Exhibit A:

Mayku Formbox: The desktop vacuum former that dreams are made of.

And, I LIKE IT. All the interaction points are immediately distinguishable by their bright yellow color. Mayku didn’t go with the classic all-white or all-black aesthetic commonly found on desktop fabrication devices. The soul of the device is infused with that of exuberant industrial designers behind it. It earnestly beckons, “Play with me.”

Vacuum Forming Fundamentals

Vacuum forming isn’t new. Far from it. Heat a sheet of plastic until it starts to melt, then stretch it over (or into) a shape you want to replicate. Repeat as desired. The tooling cost is much lower than injection molding, partially because the tool standards are much less and partially because you have a one-sided tool of two pieces encapsulating the part.  

The tooling cost of injection molding can make it impractical. As tooling cost requirements for a part reach a certain high and production run size reach a certain low the amortization equation worsens until it eventually doesn’t work. This can lead to a project’s death or making significant compromises. One major compromise is often not using plastic parts and consequently not getting the plastic’s lightweight, durable, industrial design and corrosion-resistant benefits. Lowering tooling cost can make the equation work again and vacuum forming can do that.

The Mayku Formbox and all its little bits.

Vacuum Forming Terminology

Template: The object you use as the exterior shape to be formed. Other names include mold, tooling, and master pattern.

Direction of pull: The direction that the template separates from the molded part. Also called direction of removal. This direction is used to determine the draft angle and undercuts.

Tip 1: If you want to get crafty you better get drafty

Draft is the slope of the side walls. Draft allows the molded part and template to easily separate and can extend the usable life of the template. Draft can help in many ways. Draft is like an overly eager friend ready at a moment’s notice to pick you up from the airport or move furniture. As the formed plastic cools, it shrinks and grips tightly around a template with an inadequate draft and hinder separation. The plastic conforms to the shape at the macro-level but also to the texture at a micro-level. The more textured a surface, the more the parts will want to stick together and therefore the more draft that is needed. So, my dumb analogy is, trying to separate surfaces by a parallel sliding action is like trying to pull Velcro apart instead of using draft to peal it back. Draft can reduce friction and rubbing of slide walls. Draft is like the embrace of a pleasant hug that releases after the socially denoted, appropriate amount of time. Ahhhh.

At least three degrees is a sweet spot rule of thumb.

Tip 2: No Ifs, ands, or Undercuts

Here’s a quick hack to recognize undercut features — they will look like good troll hang-outs. Undercuts are ledges, indents, overhangs, holes, cavities, and recessed areas — the type you have a hard time looking directly into. For example, when a template has a hole with a center axis parallel to the direction of pull, it isn’t an undercut. When the feature isn’t aligned with the direction of pull, it becomes an undercut. While I feel I made a valiant effort to explain undercuts, I will allow this simple picture to do it much better.

Undercuts cause material to wrap around a template in a way that the template gets locked in and can’t be removed. If a good draft is a friend’s welcome hug, then undercuts are an anaconda’s unrelenting death squeeze.

Tip 3: No Air, Beware

When it comes to plastic molding, heat and pressure are two sides of the same coin. Like cereal and milk or a car and gas. You can have one without the other, but you aren’t getting what you wanted. That is to say, they are both required inputs.  Compared to other molding modalities, vacuum forming requires much less heat and pressure. This is what allows us to do it in our living room without blowing all the circuits or involving the authorities. Heat and pressure are the proverbial good cop, bad cop. Heat is like, “we have ways to make you talk dirtbag!” And pressure is like, “My partner has a bit of a temper, I think you and I can work this out.” In cases where cavities create an internal seal and block the air paths, the pressure is removed, which eliminates suction and prevents the full transformation process.  Design pathways for air to flow into all cavities. Allow heat and pressure to access all surfaces and you’ll have that crony singing like a stool pigeon.

Rule 4: One Size Doesn’t Fit All

Some manufacturing processes cut excess material away and some have a limitless reservoir to pump material in. With vacuum forming, you don’t start with much, and that’s all you get. As the material stretches over the template it pulls and thins out the adjacent areas. The bigger and taller the part, the thinner it will be. You can form the same size sheet around a lime or a coconut. The lime-molded part will be almost as thick as the starting sheet while the coconut-molded part may be barely thick enough to survive the rigors of a Jimmy Buffet concert. Like blowing up a balloon, stretch the material too much and the party’s over. Experiment with starting thicknesses of different increments and cut a cross-section of a sample part to observe the resulting sheet thicknesses and variability. 

Mayku Formbox Specs

  • Height: 315mm
  • Length (With Handles): 466mm
  • Width: 274mm
  • Forming bed: 200mm x 200mm
  • Draw Depth: 130mm
  • Weight: 13kgs
  • Price: $699 (Mayku | Amazon)

Mayku Formbox: The Rating

If you’re new to vacuum forming, the Mayku Formbox makes the learning process easy. You can be up and making nearly as fast as you’re asked, “Why is our vacuum cleaner hooked up to that toaster oven???” ?‍♂️ And, if you lack templates, you can actually cut your template out of a potato (seriously).

The FormBox is a primer on vacuum forming. Mastering the intricacies of industrial vacuum forming would take a lifetime of learning about materials, fastening, joining techniques, secondary operations and so on. Though the FormBox isn’t upgradable or hackable, it is exceptionally simple by design. The mastery gained will be compounded by secondary avenues of knowledge exploration in 3D modeling and 3D printing, which you can use to design better templates. One may choose, for instance, to learn about molding chocolate or soaps, stepping stones or cosplay costume making, farm equipment or industrial waste systems. Maybe not an industrial waste system.

Pong Score – 4
Rams Score – 5

Is It Awesome?

Totes McGoats. Just check out the Mayku gallery of beautiful and fun stuff made directly or indirectly using the FormBox.  I’m outraged at myself for not having washed my body with soap shaped like a Nintendo controller. FOR SHAME.

The Project

Step 1: Buy a small frozen pizza

Step 2: Buy another small frozen pizza because the first one you bought was eaten after you didn’t label it as being for a very important project (actually happened).

Step 3: Bake the pizza per the manufacturer’s instructions.

Thats’a nice’a pizza!

Step 4: Freeze the cooked pizza. “No!” YES.

Step 5: Fire up your Mayku FormBox!

Note: The Mayku Formbox does not cook pizza.

Step 6: Use the cooked and refrozen pizza as your template. “For real?” YES.

Looks better than the first pizza of the day at the deli counter!

Step 7: With the cooked and re-frozen pizza as your template, separate the molded plastic from the now semi-frozen pizza.

Delicious! You could almost eat it! (Not recommended.)

Step 9: Trim the excess material off the molded plastic pizza.

Step 10: Paint the molded plastic pizza with a plastic primer.

Step 11: Commission your friend Pete Kim to realistically paint your part.

That pizza. Why hello, you look sizzlin’.

Step 12: Adhere your pizza masterpiece to an RC car. “What?” YES.

A little glue, and…

Step 13: Play tricks on unsuspecting people.


Who Should Buy This?

There are endless applications for the Mayku Vacuum Former. Those who would benefit from its capabilities include architecture modelers, terrarium aficionados, soapers, chocolatiers, RC hobbyists, pet haberdashers, cosplayers, makerspaces, creepy mask makers, universities, cool people that want to make customized gifts, preppers or prototypers, and folks prone to great ideas. For professional engineering, the applications that come to mind are those where something needs to be clear and very thin. For example, clear environmental covers for electronics or lights, household items, packaging, displays, and more.

Deep Thoughts

There existed a void between kids’ toy and factory-grade industrial machines in the vacuum forming space. What Mayku has done with the FormBox is to execute a triple-lindy into that gap, making vacuum forming simple, affordable, and much more accessible. Making vacuum forming fun and hip is what draws that new audience in. Thankyu, Mayku.

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Dan Slaski is the Lead Renegade for Renegade Prototyping and your new secret weapon/best friend for design domination. A Virginia Tech Mechanical Engineer with a long list of credentials to accompany his years of industry experience in fields including the medical, robotics, and military sectors. He has designed assemblies with hundreds of unique parts and moving components that have gone high into the earth's atmosphere, deep below the oceans and everything in between. All of this has contributed to his vast portfolio of knowledge dealing with difficult engineering problems, and a wide repertoire of skills in prototyping, manufacturing, and sourcing. Yet he still finds a way to remain humble. If you have a project that demands success you need to get on his client list ASAP.