One of my Curta I the lifting of the carriage is not smooth like the others. It feels very 'rubbery' or 'sticky' with considerable resistance. Probably due to age.

Where do I oil this if this happens? Do I need to open up the entire Curta?

Yes you have to open the upper part of the Curta...

There is some dirt in one of the six possible positions where the Carriage locating pin has to snap in to the Carriage casting.
Only cleaning - no lubrication.


Not knowing your mechanical skills... this is not an easy task - good luck!




[ 10.027 Carriage locating pin ]


[ 10.040 Carriage casting ]

Murff, is it also possible that the ball that prevents the carriage from lifting mid-turn is sticking? Either way, getting in there to that point will expose all of these things.

Yes that's also a possibility... depends of the kind of stickiness.

I think if the whole movement of about 2.5mm is sticky then it's probably in the carriage positioning (and slightly different stickiness on each position)

If the problem is on a shorter way then it could be the carriage locking ball as you described (and on each position the same kind)

It's difficult to estimate without the Curta in the hands...