Sometimes you have to hold a long round cylinder to your workbench. I usually have to hold down a mast for processing into sailing canoe propulsion. The processing process usually demands that you rotate the round object to painfully (sometimes bloodily) smooth its sides or add gear to it. Here's how I made a quickie vice.
See step 1, which is subdivided quite usefully. Linear thinkers will appreciate that. That was not an insult; I am a linear thinker. I have often wondered what parallel thinking would look like, but, of course, how could I know? Would it look like this, by chance? ....
Today I-------And yet-------Do parallel
will work-----I intend to---thinkers
cold fusion----my novel.-----later moments
too----------------------in the day
I----------------------------------see it this way?
Now I'm scared. Believe me, Step 1 is much, much simpler.
Step 1: Build the WP holder in 5 steps, while not ignoring the cautionary statement
(1) Build a V block to hold your object. Just get a block of wood and cut a V in it big enough to hold the object from slipping out of the V as the object (let us call it a workpiece) is rotated. Feeling rather cool, I added an epoxy-graphite blend to the V to let the workpiece (shall call it a WP?) turn smoothly. That was STUPID! It turns well, leaving ugly black streaks on the WP. I made this mistake so that you would not. Trust me.
(2) Drill a hole in your bench. Use a drill, which is 9,763 times faster than training a rat to do this phase. If you are feeling cool, smooth the edges of the hole so it will not fray the cord critical to the next step.
(3) Push a bungee cord up through the hole.
(4) Push the WP through the bungee loop.
(5) tension the bungee cord, which is a fancy way of saying, hook its hooks around something on the bench so that the cord pulls the WP into the V. You are ready to work.
NOTE: Do all the steps this way or else you risk re-arranging the geology of Delaware. Don't ask me how I know this. Whoever thinks about Delaware, by the way? I haven't for years, or decades, until this very instant. --wt