When a local remodeler approached me about reproducing five
porch posts for a 140-year-old house in Boulder, Colo., my
interest was piqued. Despite the fact that I didn't have a
lathe — much less one that could turn 10-foot posts
— I took the contract, figuring I could build my own to
do the job.
I made the lathe's 12-foot-long bed from 16-inch LVL; the legs
are cobbled together from 2x6s and scrap ply. The head and tail
stocks are blocks of Douglas fir with Baltic birch plywood
bases that clamp to the bed.
To hold the post blanks, I lag-bolted pillow-block bearings
(Grainger, 888/361-8649,
www.grainger.com; item
#2X405) to the stocks. The bearings have a 3/4-inch bore,
through which I slipped 3/4-inch-by-6-inch lag bolts that screw
into the post's top and bottom.
The 19-inch-diameter plywood pulley screws securely to the end
of each post and is turned with a 70-inch V-belt driven by a
salvaged 1/2-hp 1,725-rpm motor. I mounted the motor on a
hinged platform, which allows me to easily change the drive
pulley on its shaft. Using a range of pulleys from 1 1/2 to 4
inches in diameter, I'm able to get shaft speeds from 136 to
363 rpm, with enough torque to do the job.
Possibly the toughest part of the whole project was drilling
level and centered holes in the end of the blanks to receive
the large lags. To do this, I used my radial drill press and
blocked up the post blanks to the right height. I had to grind
down a 3/4-inch spade bit to accommodate the lag-screw
threads.
It was with some apprehension that I first flipped the switch;
spinning a 70-pound, 10-foot blank on a homemade lathe is not
something to take lightly. To my relief, the machine ran very
smoothly. With the blank turning, I wasted most of the stock
with a hand-held power-plane (below, left). The posts have a
long, straight taper; to cut this I ran my router along a
sloping jig made from aluminum channel and MDF, with a plastic
skate wheel attached to the router base for smooth milling
(below, right). I used standard turning tools and an MDF tool
rest to make the coves and beads (bottom).
I spent less than $250 for materials and hardware to build the
lathe. Once it was complete, turning a blank into a finished,
sanded post took about seven hours.
William Allen is an occasional wood turner
in Nederland, Colo.