CURTA 2000

CurtaBy George E Heath

Curt Herzstark envisioned a world free of unnecessary thinking when his Liechtenstein jewels first appeared in 1947. The original design was so nearly perfect that very few changes were ever introduced during its 23 years in production. Back then, Y2K was a part number for a vacuum tube. But time and progress do not stand still and if Curt were alive today, he would be producing the Curta 2000 model. Alas, Curt is not alive to carry out this significant product improvement, so I have taken up the challenge and developed a modification for your type I and II Curta calculators.

Curt eliminated unnecessary thinking - now the drudgery of manual cranking is going to be a thing of the past. This article provides the details to convert your low-tech pepper grinder into the motor-driven Curta 2000. It's like upgrading your 286 computer to a Pentium III - and nearly as easy.

Stage 1 Modification - The Motor Drive

For the stage one upgrade, you'll need the following tools and materials;

See Note 1 before beginning any work on your Curta.
  1. Take a 2-inch piece of the duct tape and place it on the top of the calculator, under the crank handle. This will protect the fine finish from being marred by the subsequent sawing and filing.
  2. Locate a line 4mm from the crank axis and cut off the crank with the hacksaw.
    *Curt's Tip #1 - Save time and labour! Just saw 3/4 of the way through and pry up on the crank with the screwdriver - it'll break right off. You've just saved about 15 saw strokes and 20 seconds of time!
  3. Use the flat bastard file to clean up the cut surface of the crank - remember appearance is important.
    *Curt's Tip #2 - Try to prevent too many of the metal particles generated from the preceding steps from entering the calculator - they can cause rough operation and binding of the gears. If your unit does seize - just force the crank to work the chunks through. Use vice-grips if the crank has already been removed.
  4. Apply a bit of black paint to the exposed metal on the crank (and any plier marks) - it gives a nice finished appearance.
  5. If you have one of the early calculators with a rounded dome at the crank axis, flatten it with the file.
  6. Apply a generous gob of hot glue to the crank stub, and quickly press the drive end of the Nikon motor drive into the soft glue.
  7. Wrap about 4 turns of duct tape around the now joined calculator and motor drive to permanently connect them together.
    *Curt's Tip #3 - Position the motor drive so that it does not interfere with the movement of the setting knobs or the counting dials.

It's just that easy folks! Each time you press the shutter release button on the MD4 your Curta goes through one crank cycle. Now you don't have to think or work! The future we all dreamed of is here - the Curta 2000.

Stage 2 Modification - High Speed Operation

Curt says "if some's good, more's better, and too much is just enough!" And who can argue with that? You've already made a big improvement to your calculator with the Curta 2000 modification- but why stop there? You can get more - much more - from this transformation.

The Nikon MD4 is powered by 4 AA cells, which provides 6 volts DC at fairly low amperage. In stock trim, the MD4 will cycle in about 3/4 seconds - faster than hand cranking, but still not fast enough. Tool Time's Tim Allen would tell ya' - this baby needs more power! Using the booster cables from your trunk, connect your car battery to the motor drive. You've doubled the voltage and hooked into virtual limitless amperage.

*Curt's Tip #4 - Watch the polarity! If you've reversed the connection, you'll drive the calculator backwards. This setup has the power to overcome the ratcheting mechanism that normally prevents this condition. If the calculator makes a crunching sound and metal bits fall out when you cycle the motor drive - it's reversed. Also, you may want to wear oven mitts when using the 12 volt connection - it tends to get hot. If thick smoke or flames appear, discontinue use momentarily.

Stage 3 Modification - Appearance Upgrades

You've completed the mechanical and electrical mods to your Curta, or should I say - your Curta 2000 - now its time give the ascetics a kick into the third millennium. The possibilities are endless but here are few tasteful changes that are real head turners. American car and motorcycle manufacturers learned long ago that you can't beat chrome plating (the more the better) to give your product the right look. The drab satin black finish on the Type I can be completely concealed under a luxurious layer of bright chrome. Just take the whole unit to an automotive bumper shop and have them throw it in their plating tank. Presto - like magic you have a gleaming icon of fine industrial design. Note: This process can obliterate all the numbers on the unit. If this happens to yours, just reestablish them with an ink marker.

In addition to, or as a separate option, what about speed stripes. You choose the colour and size - express your individuality. Stripping tape is available at auto parts stores.

Interior lighting, engraved initials, digital interface, drilled lightning holes, anti-theft alarm, shot peening, Â…you name it. I'll bet some of you creative types are thinking of mods right now that you could make to improve the performance and appearance of your Curta.

Machine ready!

Editor's Note: Mr. Heath is currently working on a mechanical/electronic hybrid version of the Curta 2000. The output digits will be replaced with LED displays and the input sliders will be covered by a numeric keypad! The unit will retain the gear based mechanical CPU. It may be powered by a small wind generator, but early experiments have proved disappointing. The minimum 11 mile per hour air flow is seldom present in indoor settings. One of the possible solutions is to increase the diameter of the turbine from 6 inches to 4 feet, but this would add an extra 45 pounds and considerable bulk to the once pocket sized calculator.

Mr. Heath is interested in obtaining type I and II Curtas (by donation) to further his research. Your unit will be returned as a prototype when completed.

Note 1. Do not carry out any of these modifications on your calculator!

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