Turn a hub blank on a pole or treadle lathe, mounted between centres, by roughing it to a cylinder and then shaping a taper at each end; without a lathe, saw the blank roughly round and finish with a drawknife and spokeshave, checking against a board template. The finished hub, a cylinder 20-30 cm in diameter and 25-35 cm long, should be symmetrical and smooth, because every later step takes its reference from it.
Part of Wheelwright Craft
Shaping an elm block into the round, tapered body of a wheel hub, either spinning between lathe centres or by hand with a drawknife and spokeshave.
A Round Hub Is Worth A Lathe
Roundness matters because the spoke mortises are spaced by angle around the hub: if the hub is eccentric, equal angles give unequal spacing at the surface and every spoke sits slightly differently. A lathe gives roundness by construction; hand-shaping gives it only by repeated checking.
The finished hub is a cylinder 20-30 cm across and 25-35 cm long. The size of the blank is worth working out before choosing the method. Assume a block of dry elm that is a cylinder 30 cm across and 30 cm long, of about 600 kg per cubic metre (an assumed density for air-dried elm, recalled rather than measured here):
- Volume = π × (0.15 m)² × 0.30 m = 0.0707 × 0.30 = 0.0212 m³
- Mass = 0.0212 m³ × 600 kg/m³ = about 13 kg
Thirteen kilograms is heavy to swing between centres and too much to knock off with a cord-drive cut a shaving at a time. Rough it down with an axe or adze first.
What You Need
- A pole lathe or treadle lathe (Pole Lathe Build, Treadle Lathe)
- Drawknife, spokeshave and adze for the hand route
- A template cut from a board to the finished hub profile
- Chalk or a scribe for centre lines
- A seasoned elm block (Hub Construction)
Method: Turn Or Shave To The Template
Step 1: Rough the blank Hew or saw the corners off until the block is roughly octagonal along its length.
Step 2 (lathe): Mount between centres Mount on the axis you marked at both ends. The block must run true before you take a cut; a wobble means the centres are off.
Step 3 (lathe): Turn the cylinder, then the tapers Take light cuts, moving the tool along. Turn the whole length to the full diameter first, then form the end tapers with the template held against the work.
Step 4 (hand): Shape against the template Pare the block down with a drawknife and spokeshave, rotating it every few strokes, checking it with the template at three or four stations along the length.
Step 5: Check The hub should be symmetrical about the bore axis and smooth enough that mortise marking lines show clearly.
Common Mistakes
- Turning with the pole or cord set too slack — the workpiece chatters and tears the grain.
- Skipping the roughing step — a heavy blank with its corners on is hard on the lathe and hard on you.
- Checking only the diameter — measure at three or four stations; a hub can be round at the middle and tapered by accident.
- Losing the centre marks — the axle bore is drilled from them afterward, so keep both ends marked; a bore started off those marks is eccentric to the turned outside.
Safety
A heavy blank on a lathe
A 13 kg block turning on a lathe can fly out if a centre loosens, and a cord-driven lathe can catch a sleeve or hair. Keep clothing and hair tied back, stand to the side of the line of rotation, set the tool rest close to the work, and stop the lathe before checking with a template.
What’s Next
- Learn next: Mortise Cutting — marking and cutting the spoke holes
- Combine with: Axle Box & Bearings — lining the bore