Heater For Bending Acrylic

We like using acrylic in our projects but there are a couple of tricky techniques, particularly getting clean cuts for glued edges and bending the material into curves. [Giorgos Lazaridis] has a great solution to the latter, a dedicated acrylic heater. Instead of using an oven to warm the material for bending he’s using localized heat produced by a high-powered lamp pulled from an old laser printer. The next part of his solution is to keep the heated area of the acrylic as small as possible. This was achieved by creating heat sinks on either side of the bulb. The metal bars seen above have water running through them to help isolate the softening of the material to a narrow strip. See how well this system works in the video after the break.

[youtube=http://www.youtube.com/watch?v=kmYRmPYFovc&w=470]

22 thoughts on “Heater For Bending Acrylic

  1. man… I was trying to build one to bend pieces to act as a guard against my new puppys teeth and the door. He was chewing the door to the kitchen we would put him in when we would leave the house. I needed to put a 2 inch bend in a 3 foot piece. Maybe I can use multiple bulbs and scale this design up

  2. My dad used to form acrylic 20 – 30 years ago. He used nichrome heating elements (probably scrounged out of a dryer) surrounded by asbestos cement board. Asbestos cement board is probably a little too hard to come by and I cant reccomend cutting it without serious personal protecive gear. But as I recall timimg was everything, you overheat it and it would bubble or even burn with that setup.

    For some large radius curves he built a form and used gas burners to create an oven of sorts.

    A recent article in Rod & Custom magazine showed how to do bubble tops for custom cars as was popular in the 60’s. Check it out on this link –

    http://www.rodandcustommagazine.com/techarticles/1101rc_star_kustom_shop_bubbletop_fabrication/index.html

    Overall great approach. I especially like the water cooled heat sinks, excellent way to control the heat.

  3. You don’t actually need water-cooling for this. You can very effectively bend acrylic with the quartz heating element from a space heater and a sliding sheet-metal shutter on top of it to reduce the heated area. You want to only heat the material up enough to just barely reach the plastic point, and if you get it that hot in the center the metal shields will keep the rest cool enough to not deform.

  4. macw, the very first design was like this (check the worklog in the site), but had some problems with overheating, and also was completely inefficient. As a matter of fact, the design that i have right now can operate without water cooling for about 7 to 8 minutes before the bars get hot. With air cooling it could run more, enough to make 3 plastics. And if you polish the bars, can further increase it. The design you describe will work as well, but after some time (depending on how good the design is) it will overheat, unless you have a means of dissipating the energy losses.

    And after all, without water cooling it would not have fun building it, would it? ;)

  5. It’s a nice bit of DIY, but that design is eons old.

    I used something nearly identical back in the late 1990’s at secondary school in the UK (age 11 to 16), and the bit of kit I was using was definitly from the 80’s, if not the 70’s (not unexpected due to age of school buildings). The element was most definitely something akin to what you’d find in a space heater.

    I recall it had that lovely finish on the tool that you get on old kit which is basically cast metal that’s been painted. Lots of depth.

    As for the acrylic, best to heat it and flex it with the protective covering on, because that bubbles just before the acrylic does. Although once it bubbles it’s royal PITA to remove all the covering so you’ve got a narrow window.

    Also he needs to make some forming molds.

  6. Beautiful, simple and efficient clean design. I have been looking for a way to bend acrylic for custom built computers and models that reduced warpage and bubbling. Thank you for the idea.

  7. Nice! I’ll pass this on to a friend who uses acrylic for his laser engraving business.

    Three things that I’d do, though:

    1. Build two heaters/coolers (not permanently attached), so the acrylic can be sandwiched between them and both sides heated at once.

    2. Permit the cooling rails to move apart, and have the heating section be made up of short segments that can pivot (connected zig-zag fashion?), so that the user can select the width of the heated area. Perhaps nichrome wire that runs past pins connected to alternating cooling racks? It would be spooled underneath the rig, and powered from the first and last pins, that only the desired length would be heated. (Would that work?)

    3. Perhaps have the cooling rails clamp the acrylic, and be hinged, with springs, so that, as the acrylic softens, the springs automatically bend it to the desired angle, set with stops.

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