CNC Machining Skateboard Trucks and Hardware from Billet Aluminum

Skateboard trucks are small, precision, load-bearing aluminum parts — exactly the kind of job a desktop CNC router with a halfway rigid aluminum setup can actually do well, as long as you respect that a router isn't a mill and plan the operations accordingly. This guide covers truck anatomy, material and heat-treatment choices, the toolpaths for machining a hanger and baseplate from billet stock, and the fixturing problems that come from machining an intentionally asymmetric part.

Truck Anatomy and What Each Part Actually Needs

A skateboard truck has four machined components that each have different requirements:

• Baseplate — mounts to the deck, holds the pivot cup and kingpin. Needs flat, accurate mounting-hole spacing (matched to standard deck hole patterns) and a precisely located pivot cup bore.
• Hanger — the part that actually turns; holds the axle and rides on the bushings around the kingpin. This is the highest-stress part and the one most worth machining from a stronger alloy.
• Kingpin and bushings — buy these; they're cheap, standardized, and not worth machining.
• Pivot cup — a precision bore and matching boss; needs a tight, repeatable fit or the truck will feel loose and unpredictable regardless of bushing setup.

Material and Heat Treatment

AlloyRelative strengthMachinabilityNotes 6061-T6GoodExcellent — forgiving for a router setupThe right default choice for a first attempt 7075-T6Significantly higher fatigue strengthGood, but gummier and harder on toolingWorth it for the hanger once your process is proven on 6061

Buy pre-tempered (T6) bar stock rather than trying to heat-treat your own aluminum at hobby scale — getting a proper T6 temper requires controlled solution heat treating and aging that isn't practical in a home shop, and this is exactly the kind of structural, under-your-feet part where guessing at heat treatment is a bad idea.

Toolpaths

Treat this as a two-sided job on most desktop routers unless yours has real 4th-axis or has enough Z travel for a deep pocketing operation from one side:

1. Rough the hanger's outer profile and the baseplate's mounting-hole pattern with an adaptive clearing toolpath in 6061 — adaptive strategies keep chip load consistent around the hanger's curved profile, which a simple contour pass struggles with on a part this shape-irregular.
2. Drill and ream the pivot cup bore as a dedicated operation, not as part of a general pocket — bore straightness and diameter tolerance here directly determine how the truck feels to ride. A single-flute or finishing end mill for the final pass, run slow, gives a better surface finish than trying to hit tolerance on a roughing pass alone.
3. Drill the kingpin hole and axle holes with a spotting drill first to prevent walk, then a standard drill cycle — these need to be straight and perpendicular to the mounting face or the truck will ride crooked.
4. Flip and fixture for the second side (typically deburring the back face and finishing any through-features) using dowel pins registered to the first-side mounting holes, so the second operation stays aligned to the first.

Fixturing an Asymmetric Part

Hangers and baseplates don't have convenient flat, rectangular stock to clamp — this is the part of the job most likely to go wrong on a desktop machine. A dedicated fixture plate with pockets machined to match the rough part's silhouette (cut this fixture from MDF or HDPE as a first operation, then use it to hold every subsequent part in the batch) solves this far better than trying to clamp an irregular shape with standard toe clamps each time. Leave sacrificial tabs connecting the part to the surrounding stock during roughing, and cut them free as the final operation — trying to hold a fully-freed irregular aluminum part through multiple tool changes invites a part that shifts mid-cut.

Finishing

Deburr every edge by hand before anything else — aluminum machining leaves sharp burrs exactly where your fingers and clothing will contact the truck constantly. Anodizing (Type II, done at home or sent to a local shop) gives both a durable, corrosion-resistant finish and the color customization skateboard trucks are known for; bead blast before anodizing for a consistent matte finish, since raw end-mill tool marks will show through clear or lightly tinted anodize.

Skateboard trucks are a good "graduate project" for a desktop CNC router once you've got feeds, speeds, and aluminum workholding comfortable on simpler parts — the tolerances that matter (pivot bore, axle straightness, hole alignment) are achievable on a rigid desktop machine, and the asymmetric fixturing problem is a useful skill that transfers directly to a lot of other small-batch aluminum part machining.