Bushing #3713 and Pin #3673: Small Parts, Big Difference

Quick answer

Buy Bushing #3713 when a rotating shaft needs a stable, low-wear seat inside a compatible build. Buy Pin #3673 when you need a plain locating pin that lets parts move without friction holding them back. Both are single-unit replacement parts from Circuit Cubes | Tenka Inc., so order the quantity your build actually needs.

What each part actually does in a build

Bushing #3713 is a single replacement bushing listed under Parts with SKU 3713. In practice, a bushing gives a rotating shaft a defined seat, which helps keep motion centered and reduces the slop that shows up when a shaft sits loosely in a hole. Pin #3673 is a single replacement pin identified by part number #3673 and described as without friction. That wording matters: a low-friction pin is meant to let connected parts move freely rather than grip or bind.

Neither part is a motor, a battery, or a switch, so neither one powers anything on its own. They are the small interface pieces that decide whether a mechanism spins smoothly or fights itself. If you are troubleshooting a build that binds, stalls, or wobbles, these two parts are often the cheapest variables to change first.

How to choose between them

Start with the motion you need. If a shaft rotates inside a fixed frame, the bushing is the part that manages that interface. If two pieces need to pivot or slide past each other with minimal drag, the friction-free pin is the better fit. Buying both is reasonable when a single assembly has one rotating joint and one free-moving linkage, because they solve different problems.

Check your existing hardware before ordering. Both listings are for one unit each, and the catalog does not supply dimensions, material, or a compatibility list. That absence is a real limitation: measure or compare against the part you are replacing, and contact the seller by email if you are unsure. Guessing on fit is the most common way a 6-cent or 7-cent part turns into a wasted shipping cycle.

Gear #94925 is the part people forget

If your build uses a 16-tooth gear and the shaft it rides on wobbles, replacing the bushing or pin alone may not fix the problem. Gear #94925 is a single 16-tooth replacement gear, part number #94925, and it is the third small part worth checking when a drivetrain feels rough. A worn or mismatched gear can mimic a bad bushing, so inspect the gear teeth and the shaft seat together before you decide what to order.

This is also where buying single units helps. You can replace only the part that failed instead of buying a whole assembly, which keeps repair costs low on parts that cost cents rather than dollars.

Ordering and quantity rules

Each listing includes one piece. A build with four rotating joints needs four bushings, not one, and a linkage with two pivot points needs two pins. Count the interfaces first, then add one spare of the part you are most likely to lose. Small parts disappear on carpets and workbenches, and a spare costs less than a second shipment.

Keep the part number visible when you order. Bushing #3713, Pin #3673, and Gear #94925 are distinct SKUs, and the store lists them under Parts rather than Circuit Cube. If you also need a switching or control component, that is a different category and a different purchase decision.

Decision rules for small-part buys

• Rotating shaft in a fixed frame: Choose Bushing #3713 when a shaft turns inside a frame and you want a defined seat rather than a loose hole. Order one per rotating joint.
• Pivot or sliding link: Choose Pin #3673 when parts need to move past each other with minimal drag and the low-friction behavior is the point. Order one per pivot point.
• Drivetrain still feels rough: Inspect Gear #94925 alongside the bushing and pin, because a worn 16-tooth gear can imitate a bad shaft seat. Replace the failed part, not the whole assembly.
• Fit is uncertain: The catalog does not list dimensions, material, or a compatibility list for these parts, so compare against the part you are replacing or contact the seller by email. Do not guess on fit; ask first.

Product facts

• Bushing - #3713: Bushing #3713 is a single-unit replacement part listed under Parts with SKU 3713 and the Tenka Inc. brand. You get exactly one bushing per order, so count every rotating joint before checkout.
• Pin - without friction - #3673: Pin #3673 is a single replacement pin identified by part number #3673 and described as without friction. The low-friction design suits pivot points and sliding links where drag would stall the motion.
• Gear - 16 Teeth - #94925: Gear #94925 is a single 16-tooth replacement gear, part number #94925, listed under Parts. If a drivetrain still binds after a bushing or pin swap, the gear is the next small part to inspect.
• NO/NC Switch Cube: The NO/NC Switch Cube uses a slide switch: in the NO position, pressing the lever arm closes the circuit, and in the NC position, the circuit stays closed until you press the lever arm to open it. It is a control part, not a mechanical fix, so buy it only when your build needs switching rather than smoother motion.

Who should buy which part

Best for

• Builders replacing a worn or missing bushing at a single rotating joint
• Makers who need a low-friction pin so a linkage pivots or slides freely
• Anyone repairing one interface instead of replacing a whole assembly

Not for

• Builds that need power, control, or switching, which require a Circuit Cube component such as the NO/NC Switch Cube
• Buyers who cannot confirm fit, since dimensions and a compatibility list are not supplied in the catalog