Introduction: DIY Pneumatic Bearing Press

Picture of DIY Pneumatic Bearing Press

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.

Picture of 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.

Picture of 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.

Picture of 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.

Picture of Paint the Metal.

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

Step 6: Assemble!

Picture of 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.

Picture of Admire Your Work.

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

Step 8: Test It Out!

Picture of 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.

Picture of 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.

Picture of I Think It Looks Cool.

Build one!

Step 11: Support These Projects!

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

YouTube SeanHodgins

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Be informed the moment a new project comes out!


evanandkatelyn (author)2017-06-14

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

bgreen3 (author)2017-06-06

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.

DennisS4 (author)bgreen32017-06-13

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

bgreen3 (author)DennisS42017-06-13

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.

seanhodgins (author)bgreen32017-06-06

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.

bgreen3 (author)seanhodgins2017-06-06

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.

Yonatan24 (author)bgreen32017-06-07

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

snappytaco (author)2017-06-07

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

Makernaut (author)2017-06-07

Real life problem solving :D

Yonatan24 (author)2017-06-06

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

seanhodgins (author)Yonatan242017-06-06

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.

Yonatan24 (author)seanhodgins2017-06-07

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

Same here :)

EcoExpatMike (author)2017-06-05


seanhodgins (author)EcoExpatMike2017-06-06

I'm glad you think so!

pcollado199 (author)2017-06-06

Excellent well done

seanhodgins (author)pcollado1992017-06-06


MikeW30 (author)2017-06-06

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.

seanhodgins (author)MikeW302017-06-06

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.

clazman (author)2017-06-06

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.

seanhodgins (author)clazman2017-06-06

How very engineery of you, are you a real live engineer? ;)

Some would think(myself included) that stress analysis on 1/4" steel being used to install a press fit bearing in a plastic part would be overkill. Not really a good use of time considering the forces would need to be magnitudes higher to make any real impact on the frame.

But I'm glad you think it works well!

gm280 (author)2017-06-05

Bravo sir, bravo. Seem you have become an entrepreneur now and that is great thing. Ingenuity is always great to see in action. I have a suggestion that you probably have already thought about. Watching the video, it seems to take two plunges to seat the bearing in properly. If you can make it seat in one plunge, your time would decrease a heck of a lot. And therefore you can produce more fidget spinners in the same amount of time while saving the wear on the equipment. Just a suggestion. Also start working towards your next product because fidget spinners will fade out eventually and then you will have the next product to rely on. Always looking forward Thumbs Up!

seanhodgins (author)gm2802017-06-05

Thanks! Yeah, I mention that in the video, the part line stops the bearing and then it often takes another push to get it in. Basically its because my air compressor goes to 200psi, which would easily provide the power to drive the bearing in, but the regulator on it only goes to 125psi! I specifically got this compressor for the 200psi rating and got it home to find that its max regulator power is 125.

However there is another factor for the second punch which I learned. When it forces the bearing past the parting line, if it has enough force it actually makes the part jump past the bearing by about 0.5mm on occasion which is pretty strange/interesting. So I have to flip the bearing and then give it another push to center it(this time it doesn't have momentum). I think with more power it would make that bounce even higher. I think some industrial machines first put down a brace on the part, then force the second part it, that way the first part doesn't jump. Its an interesting phenomenon.

I can't wait to get onto the next product, too many fidgets around me!

Thanks again.

About This Instructable




Bio: M.a.Sc in Mechanical Engineering. Pretty much designing a new circuit board every day, and I have made a few inventions of my own ... More »
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