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Front Rear
Front Rear
Open for Rigging
Open for Rigging

Technical Details

Andrzej Mistela donated this ascender in 2006, but he says that it probably dates from the 1970s.

The shell is made from 3 mm. gold-anodized aluminum, bent to form a U-shaped rope channel. The shell is 147 mm. high and 58 mm. wide, and the rope channel is 17.2 mm. wide (i.d.). The top of the rope channel was chamfered by stamping prior to bending the shell. This eliminated a potential sharp edge against the rope, and creates a slight lip on the outside of the shell as a byproduct.

The cam is made from cast aluminum. It has nine rounded teeth. The eye is 14.8 mm. in diameter (i.d.). All surfaces on the cam are well-rounded.

The cam axis is made from three parts. The pin itself is 43.4 mm. long piece of 8.5 mm. steel rod, threaded at one end. It screws into the knob. The knob is stamped from 1.5 mm. steel. It has ten crenellations that remind me of a bottle cap. The axle has a cross pin to hold the axle in place (see the right-hand arrow in the second photo).

The axle hole on the right side of the ascender has a small slot at the top to clear the cross pin, and a stamped dimple below to capture the pin so that the axle assembly cannot rotate when the ascender is in use (the left-hand arrow in the second photo points to the dimple).

A red cord riveted to the cam, shell and axle assembly serves as a keeper. The rivets are all steel.

There are no markings on this ascender.


The workmanship on this ascender is rather good. I find the axle assembly rather interesting. The distance between the cross pin and the knob is carefully set to give some significant resistance to turning the axle assembly. Once the ascender is placed on rope and the axle turned so that the pin rides in the dimple, it should stay securely in place.