9 mm.	11 mm.

Overview

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9 mm.
(#3473)

Front View	Rear View	Top View

Technical Details

I made this Prusik Comealong in 2021.

This Comealong, 9 mm. is 45 mm. tall, 25 mm. wide, 23 mm. thick, and weighs 41 g. The central rope channel is 11 mm. in diameter, and the slot opening is 8.4 mm. wide.

Comments

In 2009, Marty Karabin sent me a copy of an ad from an old issue of Summit Magazine (June 1970, p. 32). In the ad, Tommy Taylor of Bessemer Alabama was selling the "Prusik Comealong." This was a simple device for lifting a Prusik Knot, but neither one of us had seen one, and I didn't pursue the matter at the time.

In 2021, Marty acquired an original Prusik Comealong in an estate sale, and he sent me three pictures.

Original Prusik Comealong. Photos by Marty Karabin.

It was time for me to do something, and so the next day I went out to the shop and made two. I reduced the rope channel and slot dimensions on this one so that it would fit 9 mm. PMI Pit Rope. Mushier 9 mm. ropes should easily fit through the slot.

Drilling the rope hole on the lathe and cutting the slots on the bandsaw was easy, but it took a few trials to get the sling hole right. A 45° angle starting slightly over-center seems to work well. The slot dimensions are also critical: too narrow and it is hard to get the rope inserted, too loose and the Comealong won't stay on the rope. I made them a bit narrow and then widened them by trial and error until they seemed right.

The Comealong can help drag a Prusik, but it seems to work better with other knots like the Helical and the Pemberthy. It requires that the main rope be tensioned below. It also seems to work better on stiffer ropes because the ascender knot will slide more easily and the rope is less likely to slip out through the slot.

The Comealong may be silly device, at least for cavers and climbers. Rather than adding weight to a Prusik, we would probably prefer to just get an ascender. Arborists might like it, since it basically does what the Rope-Tek Hitch Hiker does.

[ Top | 9 mm. | Return to Semi-mechanical Ascenders ]

11 mm.
(#3474)

Front View	Rear View	Top View

Technical Details

I made this Prusik Comealong in 2021.

This Comealong is 45 mm. tall, 25 mm. wide, 22 mm. thick, and weighs 36 g. The central rope channel is 12.9 mm. in diameter, and the slot opening is 10.6 mm. wide.

Comments

This comealong was made for 11 mm. rope. I adjusted the slot width to admit new Goldline, a very stiff laid rope formerly common among cavers and climbers. I scaled the remaining dimensions from Marty’s photos.

[ Top | 9 mm. | 11 mm. ]