Universal Mounting Hub - 5mm Aluminum

The universal aluminum mounting hub allows you to mount custom wheels and mechanisms to 5 mm motor shafts. The hubs are sold in pairs. The set includes one Allen wrench and two 4-40 set screws for securing the hubs to motor shafts.

Universal Mounting Hub - 5mm Aluminum Product Help and Resources

Core Skill: Robotics

This skill concerns mechanical and robotics knowledge. You may need to know how mechanical parts interact, how motors work, or how to use motor drivers and controllers.

1 Robotics

Skill Level: Noob - You will be required to put together a robotics kit. Necessary parts are included and steps will be easy to follow. You also might encounter basic robotics components like bearings, mounts, or other hardware and need a general idea of how it goes together.
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Core Skill: DIY

Whether it's for assembling a kit, hacking an enclosure, or creating your own parts; the DIY skill is all about knowing how to use tools and the techniques associated with them.


Skill Level: Noob - Basic assembly is required. You may need to provide your own basic tools like a screwdriver, hammer or scissors. Power tools or custom parts are not required. Instructions will be included and easy to follow. Sewing may be required, but only with included patterns.
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Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Dr. DFTBA / about 12 years ago / 3

    So, could I connect a threaded rod for a 3D printer?

  • Rob Schwartz / about 10 years ago / 2

    I just created 3D files for this part- they are now on SparkFun's 3D Models GitHub repository. Feel free to download them and use them here :)

  • Rcrowley / about 14 years ago / 2

    Now if we only had something like this for the standard splined servo shaft...

  • R0B0T1CS / about 14 years ago / 2

    You now officially have every item I ever had to go to Jameco for. Thank you... for blowing them out of the water.

  • Member #482835 / about 10 years ago * / 1

    I ordered a few pairs of these knowing that the set screw size was 4-40 and that they came with set screws, however, I had expected the hub screw holes to be 6-32. I suppose I shouldn't have expected this since it doesn't mention 6-32 in the description, yet, at the same time, it DOESN'T mention the size of the screw holes on the hub AT ALL in the description anyway. So, just FYI to everyone who doesn't have a habit of looking at every dimensional drawing for every part ordered, the screw hole sizes on the hub are 4-40 as well. Plus, you may also want to note that these hubs are NOT at all compatible with the Actobotics product line. The holes do not line up no matter how you orient them. These hubs are manufactured by Pololu, not Actobotics. This fact isn't stated in the description and was another contributor to my confusion. But, I know now. And, despite all the confusion, it's a pretty nice hub. It holds tight.

    • Member #482835 / about 10 years ago / 1

      The 4-40 screw hole size in the hub is in the dimensional drawing. Too bad it wasn't in the description. But it still is not compatible with Actobotics.

  • Member #131173 / about 11 years ago / 1

    I really like that I can just pop over to You-Do-It-Electronics and buy these now. It simplifies things massively.

  • Member #394828 / about 11 years ago / 1

    Would it work with a 4mm shaft motor?

  • pmarchesi / about 11 years ago / 1

    Hi, I lose allen key. Which is the size of allen key?

    • Kamiquasi / about 11 years ago / 1

      Try an 0.05" one. Though if you're thinking of running out and picking one up, just get a set and add to your toolbox :)

      • pmarchesi / about 11 years ago / 1

        Thanks!!! I hope find 0.05" key. I live in Uruguay, The allen key in inch are uncommon. Bye

        • Kamiquasi / about 11 years ago / 1

          If the metric ones are more common, look for a 1.25mm (metricized) or 1.3mm (proper metric) one, or a kit with one. Either should be close enough to the 0.05" to work.

  • LineKernel / about 12 years ago / 1

    hi can someone confirm that the allen wrench that comes with the item is 1mm allen wrench ?

  • ThinkerT / about 13 years ago / 1

    Helpful Note: I purchased something similar to these and I ended up buying a threaded rod of the same size from McMaster to replace the itty bitty screws that come with this.

  • Vegard / about 14 years ago / 1

    so i bought 5 of these, and when i got them i realised there was no screws in the bags to mount the two hubs together. And the holes are so damn small i cant find matching screws..
    Really bad they dont come with the hubs...

    • There should have been set screws. Please contact customerservice@sparkfun.com.

      • Ben9 / about 14 years ago / 1

        Vegard said there were no screws "to mount the two hubs together", so it doesn't sound like he's complaining about missing set screws (the set screws are for mounting the hub to a shaft, not to another hub). The threaded holes for mounting the hub to another object are for common #4-40 screws, which can be found in whatever length is best for your project at most hardware stores (e.g. Home Depot, Lowes, etc).

  • mcuaust / about 14 years ago / 1

    In Australia we refer to those "two 4-40 set screws" using the British term, Grub Screws.

Customer Reviews

4.5 out of 5

Based on 4 ratings:

Currently viewing all customer reviews.

Nothing to complain about

Everything came just fine in the package, and the included hex key for the grub screws was very well made. The hubs sit very tightly on D- or round shafts and seem to be quite sturdy. I wouldn't hesitate to buy more if I needed them in the future.

Exactly what was ordered and work just great!

I hope they come up with some larger 5mm ones for bigger projects. They are VERY tough to find.

Works perfect!

I'm using this on a Halloween prop that doesn't require a lot of torque, and it's working perfectly. :-)

Oh yeah, I wasn't sure what length screws I needed until I assembled everything, so I bought the screws from the local hardware store as the screws are a common size.

Good product, but not what I needed

Solid product. Well-made and light, but I won't have the chance to try them in my project.

I purchased these under the mistaken impression that they would work with the Actobotics sprockets I bought to mount to them. Alas, they do not. Reading the comments, it seems I'm not alone in this discovery. I don't fault the manufacturer or Sparkfun at all; I blame myself for getting lazy and making assumptions.

Sorry to hear they won't work for your application. If you contact our tech support team, they'll be able to arrange a refund for you if you'd like.