High Strength Pinion Gear

On one of 369a’s Instagram posts it shows that they have a high strength pinion gear. Does anyone know how they do that.

You buy them on vex. They come with little shaft inserts, try not to lose them.

vex sells a wider metal tooth gear on there website.


You’re looking for 276-2251


I never knew that. Okay thanks for the help

Why are the bearings different for pinions? Why can’t all of them just be one piece of metal for all other gears, they would make them much easier to use and insert.

It’s the same thing with all other HS gears. They can fit the HS axle in them too

The pinions have long metal inserts that encompass the entire length of the shaft because they are usually under the highest stress loads as the smallest gear. (For example a 5:1 gear ratio would put all of the force into the pinion)

1 Like

They also used to sell those metal pinions with low strength only (smaller hold) but those are discontinued.

1 Like

You leave the insert out if you want to use a HS shaft and you put them in for LS shafts

How exactly are hs shafts used? They cant seem to fit anywhere

High-strength gears, sprockets, and many wheels (especially newer ones) can all receive the HS shafts. (There are inserts for HS holes to give a 1/8 square or a round hole for free-spinning ordinary shafts). Matching HS bearing flats and HS shaft spacers are available, too (https://www.vexrobotics.com/hs-hardware.html). Lock bars to fit HS shafts can be found at www.robotsource.net . If you want HS shafts to pass through metal, you’ll need to drill out the hole to a larger size. One design feature that VEX had in mind with HS shafts was to make their pre-cut shafts a bit shorter than standoffs, so they could be captured in their bearings between frame elements separated by standard-length spacers. This would be a typical wheel/axle installation.


This is a clever workaround for not having to make major modifications to fit in a high strength axle. But say you need to cut a high strength axle, what is the most effective way to go about doing that?

Probabley a hacksaw or the equivalent in your shop. Power saws would work, but that seems a bit overkill.

My school still has so many of the metal pinions with the smaller holes in them, it makes my life so much easier.

Most basic: hacksaw and vise, clean up end with a file.
More power: use a power band saw and a belt sander to clean up the end.
Most elegant: chuck it on a metal lathe with a 4-jaw chuck or a round collet (HS shaft has a full-cylindrical radius on the corners) and cutoff, face end, and chamfer.

(many people would use a Dremel too with a cut-off wheel, too, but that is rarely our first choice)