You can easily create curves and bends in flat acrylic or plexiglass sheets for your models or miniatures. The tutorial which follows shows how you can make bends with a simple jig and common heat sources. The difficulty with small projects, having tight bends close together, is control of the heat source so the adjoining curve isn't affected. You can see a dollhouse project which used this method to make a miniature 'glass' topped case for a shop counter.
Note: Some types of sheet acrylic are sold as heat withstanding, or plastic which can be embossed from stamp and scrapbook stores.
These types of plastic will not bend when heat is applied. To set up your plastic or acrylic sheet to bend simple curves for your miniature and model projects you need to first remove the protective covering from the material you wish to bend.
Use long thin 1 inch or so in width test strips to practice your technique and learn how your particular heat source affects your chosen thickness of plastic. This will be somewhat determined by the thickness of your plastic. Thicker plastic will need a wider radius curve for most bends.
Use a ruler to check that your sheet of plexiglass or plastic is held squarely clamped beneath your stripwood jig. The stripwood will restrict the application of heat it will catch fire if you overheat the wood and will prevent the plastic beneath it from becoming soft enough to bend.
If possible, leave a long end of your plastic strip where you can easily push up on it with a hand protected by a welding glove or oven glove.
It is far easier to bend the long end of a plastic strip than the short end. Make sure any flammable or heat sensitive material on your clamps is well away from where you will be applying heat to your plexiglass. With your sheet plexiglass clamped securely to your work surface under a straight edge that defines where the bend will be, it is time to heat your material.
The object of heating the sheet is to heat it evenly along a line just in front of the straight edge of your clamped jig. To make sure you apply heat evenly, pass your heat source at an even, slow speed along the line of plastic in front of the jig, keeping it far enough away that the heat source will not singe your wood jig.
If you turn your heat source as you pass across the acrylic, the heat won't be evenly applied across the entire width of your sheet. While you are applying even heat along the bend line, press gently upon the sheet of material you are bending. There will come a point when the material will move easily upwards as it reaches a molten state.
You should be able to feel this point evenly along the full width of the strip you are bending. It should not be softer on one side than on the other.
When you feel that your sheet is allowing you to push up evenly on it, remove your heat source and set it safely aside on a stand or heat resistant surface; the end of your tool will be hot! Holding the sheet material evenly with both hands both in protective gloves push the sheet up gently bending it against the line of the jig as shown in the photo above. You must use two hands to do this with even pressure, or your material will twist slightly as you bend it, unless you are working with a very thin, narrow strip.
When you have your sheet at the correct angle or have bent the curve you want for a window or the front of a curved bakery case, which may not be at 90 Fhold the plastic gently in place for a few seconds until it sets up again.
Allow it to cool still clamped in the jig as shown. Note: You can use the same heat tool you use to bend plastic, to seal and neaten the cut edges of any plastic parts.
Run your heat tool gently back and forth along a cut plastic edge to soften it just enough that it turns clear.Want to bend sheets, tubes, sticks of plastic? Don't want to buy a dollar heating base? Build one for pennies!PASTEL ACRYLIC SHEET BENDING THROUGH LINE HEATER
Did you use this instructable in your classroom? Add a Teacher Note to share how you incorporated it into your lesson. For a totally free unit, dumpster dive for these materials: - Toaster oven cylindrical, rod-like, non bent, heating elements - Sheet metal I used old brass door kick protectors - Outlet plug old extension cord or whatever - Light dimmer - Wiring nuts or soldering gun - Liquid electrical tape optional - metal pipes optional Tools: - Garden Shears or anything that cuts sheet metal - Dremel or drill - Pliers.
Rip apart the toaster oven. Bash it, unscrew the case, use the jaws of life, just dismantle the oven and retrieve the heating elements. Keep as many as possible, because you can make the heating strip as long as required.
Optional: - Mount metal pipes with nuts and bolts or cut tabs on the sheet metal and bend them in towards the pipe parallel to the heating element, with an about 1 inch gap from the element. I used tape. Without the optional metal pipes: - Turn on heating strip, adjust the dimmer for the right temperature I usually turn it on all the way, then reduce the heat.
The edge of your intended bend should be parallel to the heat strip. You may use a jig for definite angle bends. I use square wooden dowels for right angles. I pin one against the bending edge and slide the other dowel under the soft plastic to fold and keep it at a right angle.
With the metal pipes: - Same as before, but you do not have to hold the plastic sheet while the plastic is softening, just leave it resting on the metal pipes. If you feel a heat shield is necessary, it might be safer to use insulated muffler tape rather than full sheets of brass, which is a conductor. Not a particularly good one,but it works.
I would be uneasy with an AC power source and a nichrome heater sitting just above a broad brass plate. Do you think this could be done using "long" halogen floodlight bulbs as the element?
How to Make a Strip Heater for Forming Acrylic Sheet - BriskHeat
I'm just thinking they give out alot of heat, with the electric safely contained inside a nice glass case. I think I may have just thought of my first instructable.
Reply 2 years ago. Lol when I read Halogen lamp my thought went towards the Easy Bake ovens. Actually if you could come up with an instructable for such a lamp along with easy to use jigs to curve plastics as opposed to a 90 degree crease. While using an iso-transformer could be a nice safety measure it is not necessary.In addition to being an online editor for MAKE Magazine, Michael Colombo works in fabrication, electronics, sound design, music production and performance Yes.
All that. In the past he has also been a childrens' educator and entertainer, and holds a Masters degree from NYU's Interactive Telecommunications Program. Acrylic has great potential as a building material for would-be makers. It has a very clean look, is easily cut dremel, table saw, scroll saw, band saw, to name a fewand is durable.
This can be easily done using little more than scrap wood, a Dremel, circular saw, heat gun, and a vise. Geometrically, this consists of a triangle with vertical legs extending from it.
Time to bust out the old high school trigonometry. Now I need to find the length of the vertical side. If you need a review, check out this site for a good explanation. Put it together with the sides of the triangle we found, and we know how long to cut our acrylic. Now square up your measurements and mark them out on the acrylic. You can cut using many different types of tools. I chose a Dremel with a cut-off wheel. At this point you should drill or cut any holes you want for your project.
Make sure to use a small drill bit to start and work your way up in size. Set your circular or table saw to twenty degrees and cut your piece. Mount this in a vise with the acrylic sandwiched between the jig and another board for protection. Push back and down on the acrylic at the same time with a flat piece of wood. The point is to have even heat and pressure so the bend is as straight as possible.
It will start to bend a little at first, and then much more quickly. As the bend goes further, switch to more downward force so the bend is crisp. For the back of the enclosure, we found the triangle height to be 2. Add two inches for the overhang, and cut another jig with a height of 4. Repeat the bending process for this piece. Now flip the enclosure on its side and trace the contours of the bends you made on a fresh piece of acrylic.
I find that a fine-tipped Sharpie works best for this. Make sure to do this separately for both sides as the shape will be slightly different. Use acrylic glue and a needle-nose applicator to attach the sides to the body of the enclosure. This is the best adhesive to use because it actually chemically bonds the acrylic pieces to each other, almost like a weld.Technical Editor at Maker Media.
Sometimes Scientist. Builder of things. Maker of stuff. Acrylic is a wonderful plastic that can be used for all sorts of different projects. It comes in both transparent and colored options, and can be machined, laser cut, or heated and bent into almost any shape. Acrylic comes in two varieties: extruded and cast.
While they may look identical, there are reasons you may choose one over the other based on your fabrication plans. Extruded acrylic has a lower melting temperature than cast acrylic, which makes it ideal for vector cutting on a laser cutter. When laser engraving, cast acrylic is preferred, as the resulting engraving will be a frosty white color that contrasts against the rest of the acrylic.
While it takes some practice to get right, slowly brushing the flame from a propane or MAP gas torch across the edges to melt them slightly can give them a transparent, polished appearance. Just be sure not to polish edges that must be glued, as the resulting joint may not be as strong.
Using a strip heater, acrylic can be heated and bent at different angles. Store-bought strip heaters can be quite expensive, but there are ways to make do without them. Place the part of the acrylic to be bent just above the open door, wait for it to soften enough, and then bend it to the angle desired. Place the iron handle-first into its holder, plug it in, and then use a set of third hands to hold the strip just above the iron. For straight cuts in acrylic, a plastic-scoring blade can be used.
With a straightedge as a guide, pull the blade toward you, leaving a score mark. Score the acrylic several more times along the same line, then place the acrylic on the edge of the table and use light, quick pressure to snap the piece in two.
You can also cut acrylic with more traditional blade tools such as a jigsaw, band saw, or table saw. High tooth-count plastic-cutting blades are available for these tools, and are recommended. Acrylic is typically glued using solvent-based glues, such as Weld-On 4.
Unlike many other gluing processes, acrylic glue softens the surfaces of the acrylic and welds them together, chemically bonding the two pieces into one. To glue acrylic with solvent glue, typically a squeeze-bottle applicator with a needle tip is used. Put the acrylic on the edge where you want it, and place the needle of the glue-filled applicator where the two pieces meet.During these challenging times, we guarantee we will work tirelessly to support you.
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We will get through this together. Updated: September 14, References. Bending acrylic is something you might do if you are building a case or enclosure for an object, for example. There are different methods for doing this, and each helps you to easily bend acrylic.
acrylic bending heater
Just be sure that you have the necessary tools and supplies for your chosen method, and you will be on your way to mastering this craftsman skill. Before you bend acrylic, set it between 2 pieces of scrap wood and clamp them together with a vice. Then, aim a heat gun at the point on the acrylic you want to bend. As the acrylic heats up, move the heat gun from side to side and steadily push on it with a piece of scrap wood to help it bend.
If you need to make further bends, let the first bend cool before continuing so you don't lose it. To make side pieces, trace the sides of your newly-bent acrylic onto a flat piece and cut them out with a saw. For tips on how to bend acrylic with a strip heater and how to determine dimensions when bending acrylic, read on!
Quickly soften acrylic sheets for easy bending, Plastic photos frames, Arts and crafts, Custom work shop fabricating. Note: Bending material before it is thoroughly heated will result in stress crazing small internal fractures along the bend Practice on scrap material first. Do not leave strip heater unattended. Work in a well-ventilated area. Have a general purpose ABC rated dry power fire extinguisher nearby. Do not heat acrylic sheet with an open flame or in kitchen ovens—such ovens are not equipped with adequate temperature controls and safety devices for this type of work.
Yes We Heat That…. Toggle navigation. How to Make a Strip Heater for Forming Acrylic Sheet Quickly soften acrylic sheets for easy bending, Plastic photos frames, Arts and crafts, Custom work shop fabricating Instructions for Strip Heat Forming Acrylic Sheet Note: Bending material before it is thoroughly heated will result in stress crazing small internal fractures along the bend Practice on scrap material first. Note: The ground wire should be long enough to attach to a common ground such as the corner plate screw on an electrical outlet.
Tape edge of fiberglass cloth and foil down to sides of wood to prevent fraying of edges. Attach ground wire to common ground Plug the strip heater into V outlet. Acrylic sheet may be formed along a straight line by strip heating. Remove protective masking paper. Place acrylic sheet on the supporting frame with the area to be formed directly above the heating element—do not let the sheet touch the heating element. Surface overheating will cause scorching and bubbling; if this occurs, increase the distance between the heating element and the sheet.
Allow the material to heat thoroughly until it softens or welt in the area to be formed. Bend gently to the desired angle, keeping heated side of the material on the outside of the bend, and hold firmly until cool.
Dust and other particles will greatly affect surface quality of the finished product. Thermoforming refers to the process of heating and shaping a plastic sheet on a mold. Thermoforming can range in complexity from manual operations to highly automated, large scale ones. Thermoforming offers processing advantages over competitive processes such as blow molding and injection molding. Relatively low forming pressures are needed and large size can be economically fabricated.
Since the molds are exposed to relatively low forces, they can be made of inexpensive materials. Mold fabrication time is therefore very short, minimizing lead times. Thermoforming is often selected for fabricating prototype and display parts due to its low tooling costs. However as part volumes increase, processes such as injection molding become more economical. Below is a chart that compares the cost of making a part using pressure forming one type of thermoforming and injection molding.
Higher molecular weight acrylic has better heat strength during forming but is more difficult to form due to its higher melt strength and elastic memory. Lower molecular weight acrylic forms more easily and with great detail but is more sensitive to differential heating.
In designing a part for thermoforming, several things must be taken into consideration to ensure the successful forming.
Certain materials might not be suitable for some applications. However, slight modifications to part design can make forming of some parts more feasible. Tight tolerances can be met with the proper process and tooling. However, tighter tolerances make the forming process more expensive. Keep in mind that with thermoforming, details can be obtained only on one side. Therefore a temperature must be specified with the required tolerances.
Draft angles are important to incorporate when designing a part. The draft angle is the degree of taper on the mold sidewall which allows for easier removal from the mold. Radii can facilitate forming to a large degree. Radii in this case refer to any corners in the part.
Radii reduce draw ratios, giving more uniform wall thickness and reducing the molded-in-stress. For example, parts with small depth of draws can be formed with simple processes such as vacuum or pressure forming. Parts with larger depth of draws require multi-step processes which allow for such deep draw.
Wall thickness of the formed part is a function of initial thickness, depth of draw, type of mold, and the shape of the part. Prestretching the sheet prior to forming yields more uniform wall thickness.
Acrylic Strip Heaters & Line Benders
The deeper the draw, the thinner the sidewalls. Molds for thermoforming can be made out of many materials ranging from wood or plaster to aluminum or steel.
Material selection depends on the number of parts to be formed and on pressure and temperature requirements. Another major factor influencing material selection is cost. Cost refers not only to material cost, but also to costs associated with fabrication, maintenance, storage, and other aspects of working with the material. Wood, plaster, and plastics are usually used for prototype production molds.
Molds for applications such as signs, containers, and displays are usually made out of these materials. They are inexpensive to build but are not very durable.