DIY Pneumatic Bearing Press





Introduction: DIY Pneumatic Bearing Press

About: I'm a content creator. I make open source projects and videos for said projects. My goal is to create free and open knowledge for everyone.

I recently had a very successful kickstarter ( and I am now having to assemble thousands of fidget spinners. I first thought I would just assemble them with a cheap hand press, but then soon realized that it would take a really long time to do so, no ideal. I looked online and found desktop pneumatic presses, but they were over $5000! Out of my budget. I decided to make my own press since I knew I could. Also it would be fun. Its made out of laser cut plate steel and overall only cost about $250! I saved thousands and now its saving me thousands of minutes in time also.

Step 1: Watch the Video!

Step 2: Create Your Template for Laser Cutter Place.

Use your favourite CAD software to create your design. If you want to use mine you are free to do so! The zip file contains a PDF (for dimensions) and a DXF file.

Step 3: Get Bearing Holder From Shapeways.

I have created a part that threads onto the pneumatic piston, it holds the bearing with a magnet and centers it exactly where it needs to go. You can order it on Shapeways if you like: Bearing Holder on Shapeways

Step 4: Get the Parts From McMaster-Carr.

I ordered all of the hardware from McMaster-Carr. Here is the list!

  • 5635K63 - Flexible Nylon Tubing HT Pressure, Opaque Red, 0.18" ID, 1/4" OD, 25 ft. Length x 1
  • 5779K109 - Push-to-Connect Tube Fitting for Air Straight Adapter, for 1/4" Tube OD x 1/4 NPT Male x 5
  • 5779K108 Push-to-Connect Tube Fitting for Air Straight Adapter, for 1/4" Tube OD x 1/8 NPT Male x 1

  • 6464K18 Air Directional Control Valve 3-Way, 3 Port, Auto Return, 1/8 NPT, with Palm Button x 2

  • 5862K963 High-Pull Rare Earth Magnetic Disc Nickel-Plated Neodymium, 1/4" Thick, 0.187" Diameter x 3

  • 6498K536 Round Body Air Cylinder Single-Acting, Push Style, 1-1/16" Bore, 4" Stroke x 1

  • 91257A777 Zinc Yellow-Chromate Plated Hex Head Screw Grade 8 Steel, 9/16"-12 Thread Size, 6" Long, Packs of 1 x 1

  • 94895A827 - High-Strength Steel Hex Nut Grade 8, Zinc Yellow-Chromate Plated, 9/16"-12 Thread Size, Packs of 25 x 1

  • 2515T18 - Leveling Mount Easy Adjustable with Cushioned Bottom, 5/16"-18 x 3/4" Long Thread, Packs of 4 x 1

  • 9225K63 - Neoprene Vibration Damping Sandwich Mount Male/Male, M6 Thread, 3/4" High, 3/4" Wide x 4

  • 90591A151 - Zinc-Plated Steel Hex Nut Medium-Strength, Class 8, M6 x 1 mm Thread, Packs of 100 x 1

  • 5779K151 - Push-to-Connect Tube Fitting for Air 90 Degree Swivel Elbow, for 1/4" Tube OD x 1/8 NPT Male x 4

  • 93635A544 - 316 Stainless Steel Hex Head Screw Super-Corrosion-Resistant, M12 x 1.75 mm Thread, 70 mm Long, Packs of 1 x 8

  • 94205A280 - 316 Stainless Steel Nylon-Insert Locknut Super-Corrosion-Resistant, M12 x 1.75 mm Thread, Packs of 10 x 1

  • 91166A290 - Zinc-Plated Steel Washer for M12 Screw Size, 13 mm ID, 24 mm OD, Packs of 100 x 1

Step 5: Paint the Metal.

Apply some paint of your choice so it doesn't rust!

Step 6: Assemble!

Its a pretty simple puzzle, but getting the base on the top mount can be tricky.

Bolt it all together.

Step 7: Admire Your Work.

Admire your DIY tool and the money you have just saved.

Step 8: Test It Out!

It works!

You will need to make your own fixture for whatever you are installing a bearing(or other things!) into. Since mine is one of my fidget spinner designs, its exclusive to this part and what I'm using it for. If you have your own designs you just need to make them fit into the base fixture.

Step 9: Be Your Own Assembly Line.

Seriously, I couldn't even imagine doing this manually. My arms hurt just from pushing the buttons 5000 times. I put myself in robot mode.

Step 10: I Think It Looks Cool.

Build one!

Step 11: Support These Projects!

Consider subscribing to my YouTube, becoming a Patron, and following on Instagram.

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    23 Discussions

    McMaster-Carr FTW!! Fun looking project. I hope to have this problem sometime and know there is a great solution out there

    Cool project but for most people this is complete overkill. You can get a 1 ton arbor press from Harbor Freight that does the same thing for $60. Just need to 3D print the bearing holder and the part fixture.

    6 replies

    I have to also disagree, I would rather push 2 buttons and be done.

    I didn't say this wasn't easier. I said that for small volumes you can do the same thing for $60. I posted the info for people who may not be aware of the existence of an 'arbor press.'

    I'd like to have a Haas VF-3, but I'm not going to be able to afford that anytime soon. For now a bench top CNC will have to do.

    Thanks, I don't disagree that it would be overkill if you were just doing a couple, but I have 8000 to do now, and another 7000 frames in inventory. No way I'm doing that by hand! haha

    Also, overkill is fun sometimes, and I might automate the system some more, so pneumatics are necessary for that.

    You are right, that is faster! It's a really cool project, just wanted to give readers more options if their jobs are less than multiple thousand units. :D And I agree, the more automation the better! Congrats on your recent Kickstarter success. I'm launching an Indiegogo myself, soon.

    And don't forget about juice squeezers! They might work too.

    excellent work. "tool and die makers" are the untold hero's of manufacturing.

    Real life problem solving :D

    Wow! Just from a quick Google search I found this:
    Listening to the Making it Podcast would make the time pass quickly for me! :)

    2 replies

    I considered one of those(searching alibaba actually), but shipping to Canada, and $350US is quite a bit more than $250CAD and some fun time building something! Also I think the majority of them that I found were 220V which I don't have in my shop.

    I will generally always opt to build something myself if it is possible. You always learn and have fun. Plus I like making videos as well.

    Of course it's better to make one, I just saw that you mentioned that they cost around $5000...

    Same here :)

    Your air pressure is more than enough. You need an air cylinder with a larger bore. You current cylinder at 125 psi is applying about 110 pounds force (lbf) at the rod end. A 1.5 bore at at the same pressure will double that to 220 lbf.

    The press thru of the bearing is the fixtures fault.placing a dime or penny in the bottom to stop the bearing might do it.

    1 reply

    Yes, a larger cylinder would definitely increase the force. The fact is, I tested the force required to install the bearing before I decided on this size cylinder, but my tests were done on my prototypes. My prototypes were SLS Nylon material that was 3D printed, my injection mold pieces are PA66 Nylon. The 3D printed parts did not have the parting line inside the bearing bore and therefore required slightly less force. The parting line is what threw off the force requirement, but I'm making due.

    I can't put a penny or dime under where the bearing would sit or it would definitely cause it not to seat all of the way into the part(it would be a penny or dime short of seating). Right now the fixture has a perfectly flat added piece of plastic to stop the bounce through by seating the plastic and the bearing at exactly the same place.The bounce through(I don't know the technical term) doesn't happen every time so my method of flipping it when I notice it seems to work well. Also, to further back that its not the fixture, if I press the bearing several times after it has seated properly it won't bounce through, its only the initial press when it "Pops" with momentum. Refer to the slow motion in the video, that has a good pop.

    As I mentioned I believe most machines put pressure on the base part receiving the bearing before pushing it through to avoid this. A two step process. Or they use more force and a slower motion.

    Surprised it works so well. Obviously it is over designed.
    Since from my taking a cursory visual stress analysis this frame is a disaster in machine design. A lot of material in minimally loaded areas and very little material in highly loaded areas.