Simple marking gauge, and simple marking question

[Aram]

I'm making poplar models for my next piece. I have these legs with rounded profiles, where the upper part is smaller than the lower part. They are rounded, might be hard to tell in the picture. Cutting the ledge, and rounding the top and bottom, are not terribly difficult. 



But I wanted an angled bevel at the transition, not a ledge. How to mark a parallel line to define the bottom of the bevel? The world's simplest marking gauge. Scrap wood, a few seconds at the router table, and an Xacto blade with a little epoxy on it. Works perfectly. See scribed line (darkened with pencil) above.



Now the question. Looking at the top pic, pretend I have rounded the top, but the bottom is still square. I need to mark on the ledge, evenly, 1/8" (or thereabouts, but must be consistent all the way around) away from the rounded top part. That defines the bottom profile I will plane down to.

If I had a 1/8" thick flexible.... thing... that I could wrap around and trace with a pencil, boom. Done. Probably some ordinary household object, but I'm out of ideas. Thoughts?

Thanks in advance.

[DaveR1]

Do you have a sketch of what the leg is supposed to look like when it is finished?

[Aram]

Do you have a sketch of what the leg is supposed to look like when it is finished?

Not really. Still designing it! 

[DaveR1]

I have ideas but I expect they are wrong because I'm pretty sure I'm not understanding what it is you are making or how it is supposed to look.

[bandit571]

Couple wraps of tape, and a pencil...done.

[Aram]

Couple wraps of tape, and a pencil...done.

Hmm. Maybe. It would take a couple dozen wraps to get around 1/8". Could work, though.

[bandit571]

Even Derek's Blue tape....cheap...

[Aram]

Even Derek's Blue tape....cheap...

Well, sure. If I use Derek's. But then we have another problem... 

[bandit571]

Hmmm, thought "everybody" went out and bought a roll
 

Maybe do things bass-ackwards?   If the mountain won't come to.....

Instead of moving the marker....move the part against a stationary marker?  Like putting a knife in the vise, add a stop block the required distance from the knife, and rotate the part against the knife....

[Aram]

Maybe do things bass-ackwards?   If the mountain won't come to.....

Instead of moving the marker....move the part against a stationary marker?  Like putting a knife in the vise, add a stop block the required distance from the knife, and rotate the part against the knife....

That could work. It still seems easier to wrap something around the top, mark with a pencil, and move on. A stack of blue tape might be the easiest answer. This is not joinery, just aesthetics. Slightly uneven marking here or there won't matter.