Bare Bones Vacuum Forming, Just Add Plastic Plates

Vacuum forming is a handy thing to be able to do, and [3DSage] demonstrates how to do a bare-bones system that can form anything smaller than a dinner plate with little more than a 3D printed fitting to a vacuum cleaner, a heat gun, and a trip to the dollar store.

Plastic plates from the dollar store make excellent forming sheets, and in a variety of colors.

The 3D printed piece is a perforated table that connects to a vacuum cleaner hose, and [3DSage] mentions elsewhere that he tried a few different designs and this one worked the best. A cardboard box makes an expedient stand. The object being molded goes on the table, and when the vacuum is turned on, air gets sucked down into the holes.

As for the thermoforming itself, all that takes is some cheap plastic plates and a heat gun. Heat the plastic until it begins to droop, then slap it down onto the vacuum table and watch the magic happen. Using plastic plates like this is brilliant. Not only are they economical, but their rim serves as a built-in handle and helps support the sagging plastic.

Thermoforming plastic on a 3D-printed vacuum table and using 3D-printed molds definitely isn’t a system that will be cranking parts out all day long, but as long as one allows time for everything to cool off in between activations, it’ll get the job done. Nylon will hold up best but even PLA can be serviceable.

Watch it in action in the video embedded below. The video is actually about [3DSage] making adorable Game Boy themed s’mores, but here’s a link to the exact moment the vacuum forming part happens.

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Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

Make Better 3D Printed Molds, For Thermoforming Plastics

Thermoforming — which includes vacuum-forming — has its place in a well-rounded workshop, and Mayku (makers of desktop thermoforming machines) have a short list of tips for getting the best results when 3D printing molds on filament-based printers.

A mold is put into direct, prolonged contact with a hot sheet of semi-molten plastic. If one needs a mold to work more than once, there are a few considerations to take into account. The good news is that a few simple guidelines will help get excellent results. Here are the biggest ones:

  1. The smoother the vertical surfaces, the better. Since thermoforming sucks (or pushes) plastic onto and into a mold like a second skin, keeping layer heights between 0.1 mm and 0.2 mm will make de-molding considerably easier.
  2. Generous draft angles. Aim for a 5 degree draft angle. Draft angles of 1-2 degrees are common in injection molding, but a more aggressive one is appropriate due to layer lines giving FDM prints an inherently non-smooth surface.
  3. Thick perimeters and top layers for added strength. The outside of a mold is in contact with the most heat for the longest time. Mayku suggests walls and top layer between 3 mm to 5 mm thick. Don’t forget vent holes!
  4. Use a high infill to better resist stress. Molds need to stand up to mechanical stress as well as heat. Aim for a 50% or higher infill to make a robust part that helps resist deformation.
  5. Ensure your printer can do the job. 3D printing big pieces with high infill can sometimes lift or warp during printing. Use enclosures or draft shields as needed, depending on your printer and material.
  6. Make the mold out of the right material. Mayku recommends that production molds be printed in nylon, which stands up best to the heat and stress a thermoforming mold will be put under. That being said, other materials will work for prototyping. In my experience, even a PLA mold (which deforms readily under thermoforming heat) is good for at least one molding.

Thermoforming open doors for an enterprising hacker, and 3D printing molds is a great complement. If you’re happy being limited to small parts, small “dental” formers like the one pictured here are available from every discount overseas retailer.  And of course, thermoforming is great for costumes and props. If you want to get more unusual with your application, how about forming your very own custom-shaped mirrors by thermoforming laminated polystyrene?

Ice Wrenchers, Wrencher Chocolates, And The Vaquform DT2

What do you do when you find some friends have bought a vacuum forming machine? Make novelty chocolates and ice cubes, of course! This was my response when I had the opportunity to play with a Vaquform DT2 all-in-one vacuum forming machine, so what follows is partly a short review of an exciting machine, and partly an account of my adventures in edible merchandise creation.

The vaquform machine, on a neutral white background
The Vaquform machine in all its glory.

Vacuum forming, the practice of drawing a sheet of heat-softened plastic film over a model to make a plastic shell copy of it, is nothing new in our community. It’s most often found in hackerspaces in the form of home made vacuum forming tables, and usually requires quite a bit of experimentation to get good results. The Vaquform machine I was lucky enough to be able to try is an all in one machine that puts the whole process into a compact desktop machine of similar size to a typical 3D printer. It’s a machine of two parts with a moveable carriage between them for the plastic sheet; a vacuum table on its base, and a heater unit suspended above it. The unique selling point is that it’s an all-in-one computer controlled unit that does as much as possible for you, it simply requires the user to place a sheet in the carriage and follow the instructions.

When I first saw the machine I didn’t really have anything to try it with, so of course I resorted to producing a Wrencher or two. Because what it makes are essentially moulds, it made sense to produce something Wrencher-shaped with them, and thus the chocolate and ice plan formed. The first mould was made with laser-cut Wrenchers in 2mm acrylic, stacked on two more layers of uncut acrylic to make a bar with an inset Wrencher on top, while the second one used a 3D-printed array of larger stand-alone Wrenchers with channels between them. Would my first attempt at vacuum forming make usable moulds or not? Only one way to find out. Continue reading “Ice Wrenchers, Wrencher Chocolates, And The Vaquform DT2”

6 panel diagram of process

Add Conductive Traces On Vacuum Formed Plastic With 3D Printing

Surface conductors on vacuum formed parts appear in many hacks, from cosplay armor to 3D touch pads and smart objects. But making them has always been painful. Either they had to be hand painted after forming, which looked sloppy and was labor intensive, or they had to be printed with some difficult to use stretchable ink tech. [Freddie Hong] and his group have another solution, using tech most hackers already have – a 3D printer and a vacuum former.

plastic tray with electrodes to sense foil wrapped chocolates
Smart tray created by this method.

They 3D print the traces with conductive PLA filament directly onto a base plastic sheet, and then vacuum form the whole thing. The filament is happy to deform when heated – it’s printer filament.

We like this process.  We’ve found conductive filament isn’t reliably resistive across vertical layers, but is reliable in the XY plane. Their method only requires one layer. Also, they suggest 3D printing a layer of non conductive PLA atop most of the conductor, like a PCB solder mask.

Conductive filament has a fair bulk resistance. They suggest electroplating it before applying the top mask layer. They also are exploring 3D printing logos, stripes, and such with colored filament, or even making surface detail like rivets on model parts or adding thickness where the plastic thins during vacuum forming.

Designing the 3D print requires guessing what bit of plastic sheet ends up where in the vacuum formed final part.  His group used a commercial program, t-sim,  to do the prediction and Grasshopper to import the result into Rhino3D. This seems a lot for a home hacker. Drawing lines on a test sheet and vacuum forming seems simpler.

We’ve looked at vacuum forming before. We did a piece on 3D printing bucks , and covered [Ted Brull]’s Kevo vacuum former back in 2015.

Thanks to [howielowe] for the tip.

Vacuum Forming With 3D Printer Filament

Even if they don’t have one themselves, we’d wager the average Hackaday reader is at least vaguely aware of how a vacuum former works on a fundamental level. You heat up a plastic sheet until it’s soft, then use a vacuum pump to pull the ductile material down onto an object and hold it there while it cools off. It’s easy to build a vacuum forming rig yourself, but small commercial units are cheap enough that it might not be worth your time. If everything goes to plan, the technique is a quick and effective way of duplicating items around the home and shop.

But we were recently tipped off to a variation of this classic technique that’s certainly worth further research. As demonstrated in a recent video, [Nathan Martinez] shows how 3D printed sheets can be used in place of the 5″ x 5″ squares of thermoplastic film that his imported vacuum former was designed to use. It’s easy enough to do: just model up a square with the appropriate 2D dimensions in your CAD package of choice, and extrude it to a height of about .5 mm.

A printed mesh pattern could be used to form custom shaped filters or strainers.

So what’s the advantage? Well for one thing, it’s cheaper. Though admittedly, not by much. Going rate on Amazon seems to be about 90 cents per sheet for the real stuff, and some back of the envelope math shows the printed version coming in at around 30 cents given nominal filament costs. Whether or not those savings are worth the extra effort is certainly debatable.

But that’s not really the most interesting part. With printed sheets loaded into the vacuum former, you’ve got access to a much wider array of materials to work with. For example, [Nathan] shows off some very interesting flexible pieces he was able to produce using sheets of TPU. You can also experiment with different surface textures. These can not only be used to give your vacuum formed pieces a bit of interesting visual flair, but could actually have some practical applications. In the video we see how a printed mesh could be formed over a piece to create a conformal air vent or filter.

To be sure, there’s some room for improvement here. Not all the pulls were successes, and [Nathan] says getting the printed sheets up to the proper temperature can be tricky. But when it works, it works quite well, and we think there could be some untapped potential in this unexpected melding of new and old methods of at-home plastic production.

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Vacuum Forming With 3D Printed Buck Tutorial

[Matterhackers] has a nice video tutorial on using vacuum forming to create plastic items. Sure, you have a 3D printer, but vacuum forming has some advantages if you are making thin and flexible items quickly. But don’t feel bad. The master item in the process is from a 3D printer. Like a mold, the forming won’t produce a duplicate of the master, called a buck. Rather, the buck provides something like a die that the plastic wraps around.

While obvious vacuum-formed items include such things as take-out food containers and plastic blister packaging for retail items, you can also make more substantial items. Apparently, all theStar Wars movies in the original trilogy used vacuum forming to create stormtrooper armor.

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Making Custom Curved Mirrors At Home

Generally speaking, creating custom mirrors is a complex task that involves a lot of careful grinding, and isn’t something to be taken lightly if you need precision results. Just ask the folks who provided NASA with a wonky mirror for the Hubble. But assuming you’re not working on an orbital space telescope (or even a ground based one, for that matter), [volzo] has recently documented some techniques for producing single and double curved mirrors of reasonable quality using common workshop tools.

The first step is finding something that’s a bit easier to work with than glass. After testing various reflective materials such as PVC foil and painted PETG sheets by comparing the reflections of projected test patterns, [volzo] found that laminated polystyrene gave the most accurate results. If you just want to make a simple bent mirror, he shows how you can pop one of these sheets on a CNC router, make the appropriate cuts, and fold them into shape.

That part might seem a bit obvious, but what about a more complex shape? Here, [volzo] points to how the thin sheets of polystyrene also lend themselves to vacuum forming. As demonstrated in the video below, all it takes is a 3D printed plug and some basic equipment to rapidly produce mirrors in arbitrary shapes.

Now obviously the optical properties of such mirrors will leave something to be desired, but depending on your application, that might not be such a big deal. As examples [volzo] shows off a few projects using these custom mirrors, such as a tabletop camera that captures both sides of the table simultaneously and a circular projector. Laminated polystyrene could potentially even be used to create low-cost variable mirrors.

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