pic: Vertical Drum Climber


We considered, but never prototyped a vertical, or angled climber. Our concern was “bunching” up of the rope near the top.

How has this worked so far?

Can’t speak for 2077, but I know that 1425 has a vertical drum climber that worked amazingly. In addition sufficiently powerful climbers seem to be able to power though any bunching.

Aside from better packaging for some designs, are there any other benefits over a horizontal drum?

I would imagine that grabbing the rope could be simpler with a vertical climber than a horizontal one. With a vertical one, your rotation is perpendicular to the rope, allowing hooks like those in the picture to very easily grab it as you drive into it. A horizontal climber has its rotation parallel to the rope, requiring a different type of attachment mechanism (velcro, hooks that have to line up precisely on either side of a knot in the rope, etc).

Right. This has worked extremely well for us. Climbing the rope, once it’s around the drum, is simply a matter of torque/speed/gearing, etc. The hard part is getting it around the drum to begin with, and this is the huge edge this geometry brings. Just drive into the rope and you’re up. The students pitch it to the judges by likening it to how a person grabs a hanging rope by sweeping the hand horizontally.

The angled piece of polycarbonate at the top of the drum redirects the rope (heavy paracord) at about an inch away from the drum, allowing it to spread a bit and keeping it away from pinch point at the very end of the drum.

We developed a vertical spool for 3 primary reasons:

  • Compact packaging
  • Easy rope capture, large effective capture radius
  • Effective friction grip on bare rope

The simple, compact packaging made it easy to design it as a modular subsystem. It is just one hitch pin and one Anderson connector to swap, ~ 1 min replacement.

Grabbing the rope is very effective for all the reasons Buchanan listed. Similar to acquiring game pieces, fast and effective acquisition of the rope is what separates average climbers from great ones - past that it is a simple matter of motors and gear ratio to drive climb speed.

Grip force on the rope in our case comes from friction generated by several overlapping wraps of the rope cinching up on the spool. This only increases as we climb. There’s no need for catching knots, loops, or Velcro on the rope to grip it.

To SenorZ’s point, bunching can be an issue, as well as having the rope wrap up and over the end of the spool. We controlled the incoming path of the rope by using a U-bolt much like the bail arm on a fishing reel. Early testing showed that thick 1" tubular webbing would spool in a neat roll, decreasing effective pulley diameter as we climbed to the point that the motor would struggle. Switching to 5/8" tubular webbing resolved this, as it is narrow enough to prevent spooling from being so uniform.

We have been very happy with our climber this year. We’ve also been very surprised at how rare a vertical spool is.