On Jun 14, 5:44*pm, "Lew Hodgett" wrote:
"eganders" wrote:
I need to make a spiral groove in a couple of columns. *I only have
to
do it in two columns and I may not do another for a LONG time, so a
complex jig that will take room and time to build is not an
attractive
approach.

Find somebody with a Sears & Roebuck "Router Crafter".

It was an accessory for a router to do specifically what you want to
do.

Lew

Thanks folks. You all gave good ideas. I will look up the router
crafter. The thin plywood guide may be a way to go also. I don't
have all the details yet (my daughter in law is asking for it for
their new house and we don't have dimensions yet). I believe it will
be a minimum of about 2 ft high and about a minimum of 3 inches in
diameter. I don't know how long--12 to 18 inches is a guess.