DIY Air Bearings, No Machining Required

Seeing a heavy load slide around on nearly frictionless air bearings is pretty cool; it’s a little like how the puck levitates on an air hockey table. Commercial air bearings are available, of course, but when you can build these open-source air bearings, why bother buying?

One of the nice things about [Diffraction Limited]’s design is that these bearings can be built using only simple tools. No machining is needed past what can be easily accomplished with a hand drill, thanks to some clever 3D-printed jigs that allow you to drill holes with precision into stainless steel discs you can buy on the cheap. An extremely flat surface is added to the underside of these discs thanks to another jig, some JB Weld epoxy, and a sheet of float glass to serve as an ultra-flat reference. Yet more jigs make it easy to scribe air channels into the flat surface and connect them to the air holes through a bit of plaster of Paris, which acts as a flow restriction. The video below shows the whole process and a demo of the bearings in action.

[Diffraction Limited] mentions a few applications for these air bearings, but the one that interests us most is their potential use in linear bearings; a big CNC cutter using these air bearings would be pretty cool. We seen similar budget-friendly DIY air bearings before, including a set made from used graphite EDM electrodes.

26 thoughts on “DIY Air Bearings, No Machining Required

    1. Imagine how nice it would be if air bearings on the bottom of heavy furniture and appliances was standard.
      Need to pull out the fridge? Clip on the air line and it’s easy as can be.
      Need to slide a bookshelf over? Clip on the air line and give a gentle nudge.
      etc.

    1. As long as it’s DEstructive – no matter how much air pressure you have, you’re not going to be building many skyscrapers with it. Cutting them in half, on the other hand…

  1. Brings memories of picking ungodly weights at a prior job. 8bar air pressure, 300mm square air pucks to lift 5 tons each, on a mostly smooth concrete surface. Push 50 tons with a finger, but you gotta remember there is a LOT of momentum once it is moving, and that as level as the floor was, it had 0.5 to 1mm variation that could play hob on a move. Emergency brake was a solenoid air valve that cut from supply to dump position with a spring and several E-stop remotes. The system tripped on occasion when a crew member was blocked by the load. Failsafe, tripped on loss of signal for an active remote. Fun times.

    Similar system was used for several hundred tons on some jobs.

  2. Amazing video! This is the best kind of engineeeing content. The kind that is documented and reproducable. I wonder how much harder it would be to lap the stainless steel disk directly?

  3. Scale it down a little, and it might make a fun bed level indicator for a 3D printer (provided the entire printer is itself level). Raise whatever side the puck slides towards.

  4. Printing industry uses balls in those low pressure air holes. Big heavystack of paper pushes those balls down, they let air out that lifts the paper. If it lifts too much or it slides away, the ball closes. It’s self regulating!

    1. For the 30 to 50 ton moves on good, flat, smooth (to the scale of the lifting pad) surfaces, we used smaller portable compressors, like the larger ones you could pick up at a box store. maybe 5HP to 10HP. Heavier moves, especially on less smooth surfaces where a skirt was needed, more like a traditional hovercraft, a trailer with a screw compressor would be used, but rarely run much above idle other than at places like expansion gaps, where the filler or bridging material wasn’t always a great match.

      Yes, we rode the planks (two air caster units under a steel channel) like surfboards for shi*s and giggles. No, it was not safe.

  5. This is quite a neat way to make these complicated parts. I don’t have use for it now, but it can be a great solution for projects to come. One small suggestion, can we leverage existing technology to mass produce a type of air bearing? I’m guessing you could get quite close with an ENIG coated maskless PCB.

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