The Curta.org Bulletin Board

[HansO]

I have a Curta I #17606 with two errors. The clearing lever is broken, and the curta is gritty inside. After having studied the disassembly guides on the net, I feel that I'll soon move on to tear down the machine. It will receive a new clearing lever - laser cut out lever, fastened with screw and nut, according to the old repair methodology.

When the Curta is disassembled, I would also like to take the opportunity not only to remove grit and fasten the lever, but also to lubricate where appropriate. However, I do not possess the facsimile of the service manual, and wonder if such info is found there. I have seen the manuals on Ebay, but I am a bit reluctant to buy one given the excellent tear-down manual readily avaliable on the net.

So the question is: does anyone know if the lubrication info is included? Any tips much appreciated!

/Hans

[Jack]

Hans,

I'd be please to guide you on lubricating your Curta. However, the details are too complicated to explain properly on this bulletin board. Perhaps you'd be willing to discuss this personally. Send me an email or call me one evening.
_________________
Jack Christensen
Timewise
32 Old Barn Road
Hawthorn Woods, ILLINOIS 60047
USA
847-550-5052 (evenings)
curta.info@gmail.com

[roger]

I just obtained my first Curta (Type I) and it appears to be in very good condition. It also appears that it has not been used in a long time. Most of the sliders didn't move at all, and the rest of them were very hard to move.

After taking off the bottom and the housing I noticed that the sliders were stuck on the posts (not the "cork screw" ones in front but the ones behind them). I managed to lubricate these posts using a very small brush and a minute amount of vegetable oil (didn't have anything else available), and now the sliders are moving very smoothly. Everything is working very well.

I realize that for long term lubrication vegetable oil is not a good choice, but it got the sliders unstuck. What is the recommended type of lubricant I should use to properly lubricate my machine? Also, are there any readable scans of the Curta oiling chart somewhere? Jan Meyer has one on his site but the resolution is very low and it is hard to make anything out.

When operating my machine, the crank moves very smoothly with hardly any resistance when adding. When subtracting, I notice that there is some resistance when the digits carry over. I wonder how much resistance is expected and when I should consider taking the machine apart more to lubricate more. I currently don't have a properly sized tool to push out the pin to remove the handle, i.e. this will have to wait until I do.