The Curta.org Bulletin Board

[Pete42]

I just found (and bought) another Type II just like the one in the initial post.

Black body, Delrin crank, plastic clearing lever, bbrbbrbbrbb coloured sliders, large digits - definitely a later model with a black body and collar, not an early Type II retrofitted with red sliders. Serial number is 533801.



I haven't got it here yet, but the seller states that the machine is "as new" and in perfect working order, and from the pictures I have it seems that he might be right - machine and canister look almost pristine.

Have there been significant numbers of spare body/collar parts around, or could it be that there actually were a small batch or custom-made black Type II built by Contina? While I can imagine that some owners "tuned" their older Type II with red sliders it seems strange that someone should use up spare parts for black Type II machines to convert otherwise quite common gray Type II to black.

Not that it mattered much - I bought it because it looks great, not for its collecor's value :-)

[murff]

In your case, only the gray case (part 2.536) and the collar (2.111) were replaced by a black one.
The red adjustment knobs are original for serial #533801.

Or this Curta was assembled with remaining parts after the factory was closed....


... a gray housing



My replacement of the red knobs was based on available spare parts - and since the digits of the older models are small, you can't just
replace the complete part - you have to go one step deeper and replace the knob itself.


... red setting knob complete with large digits
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[Pete42]

I was not referring to your modification of an early II/I with red sliders (pretty beautiful, by the way!) but to the original post by Sebastian. The machine he found matches the one I recently bought exactly, except that there is a large gap in serial numbers (533801 - 561556), which invalidates the theory of a small batch.

On the other hand: Are the bodies and collars of early type II the same (except for the colour) as those of the later, gray ones? I suspect yes, but maybe there are subtle differences - font, spacing, size of the numbers, whatever.

[murff]

Ah yes, I see

OK, number 561556 is definif from the last series of Curtas from the Hilti production (which were also never in the trade) - and thus made from just these remaining individual parts.

#533801 could also be from this period - there would be the inner serial number to check. There are quite a few Curtas from the last series, which do not have a serial number inside. It is certainly not from a small series - this would have been possible only in the transitional phase when changing from black to gray, 510520 +/- 50 pieces...
see also Variations of Curta Type II

Do you know the origin of the Curta Type II #533801 ?
_________________
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[Pete42]

Unfortunately I don't know anything about the machine. As soon as I have it at hand I'll check the internal serial number against the one on the bottom plate.

I'm not so sure 533801 comes from the last batch - at least the type and age calculator on your magnificent web page shows "February 1971" as the manufacturing date for Seastian's and "December 1965" for the one I bought, which is quite a difference.

Would it be of interest for you to get an additional indication to narrow down when the switch between metal and plastic clearing ring occurred? Your variants table is a bit vague about that, but I can definitely say that my 526879 has a metal clearing ring, while 533801 has the plastic one.

[murff]

Unfortunately, it is not known from when the plastic clearing rings were used as standard, hence the "???" in the table. In 1961, it was most likely developed during the development of the Curta Type 1a. However, there are many examples of Curtas after 1961 that have metal clearing rings. On the other hand, it was possible to replace broken metal rings with the plastic version - so you can also find (repaired) Curtas before 1961 with the plastic version.

It is also known that serial numbers of the last series could be arbitrary (on request...) - that is why it is not a guarantee. Since your Curta already does not come along "standard", this could be possible... but without origin history it becomes difficult. However, it is considered certain that this Curta was not offered so in the trade!
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:: curta.li

[Pete42]

The machine arrived today.

First, the seller has described it correctly: It's like new, no traces of use whatsoever, no dents or chips and the container also looks as good as new. Operation is very smooth and so far (I did a number of systematic tests) it works perfectly.

I removed the bottom plate and indeed it does not have a serial number on the inside, the little inset where the serial number plate uses to be is empty and does not look as if it was removed. And, by the way, it also looks as new inside - no dust, no traces of any mishandling or inappropriate use of tools etc.

So the only thing that contradicts the "last series with leftover parts" theory would be the serial number from December 1965 - or have there also been leftover bottom plates with serials from earlier years?

[murff]

Cool - a possible confirmation of my theory...

During the years of production, the serial numbers were assigned without gaps - both on the base plate and inside the Curta. This was necessary for handling warranty and repair services.



It's much simpler: there must have been leftover base plates that were still empty - so any number could be engraved. As mentioned, this was only after the end of the official fabrication period, just in this absolutely last series.


Anyway - a beautiful Curta!
_________________
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[Pete42]

Thanks, that seems to shed some light on the probable history of the little beauty.

So if you're correct in your theory about the blank number plate probably there is another #533801 around somewhere ... it would be really funny to find it one day.

By the way: Currently there is a Type 1 with red knobs and without a serial number for sale on eBay (304638353918). It has a metal crank and clearing lever so it's probably not one of the "leftover parts" batch. Doesn't really look too interesting to me as I think probably someone just modified an old type I.

[Pete42]

I just became aware of a slight difference between the old black body and collar Curta II and the two specimens Sebastian and I found:

On all black machines (Type I and Type II) I've seen so far, the tips on the corrugated of the body and collar rings are black, never blank metal.

On all gray bodies I've seen and the two black ones from this thread, the tips are blank metal.

This would mean that there actually was a later series of black bodies/collars with a slightly different design (blank metal, possibly polished) instead of the completely black anodised metal surface. Or were there black Curta Type II in the original series where the tips of the rings have been polished?

Or were the ring and the body actually two different parts? Your picture of the gray housing seems to indicate otherwise, but it must have been assembpled at some point, so they might have been separate parts.

[murff]

A very good observation

In this combination - black with ground off tips - there is probably no "official" series Curta.

Also this variant belongs (in whatever quantity) to the still possible remaining parts to complete last Curtas - as mentioned, these Curtas didn't have to correspond to the current sales types anymore.

And yes, the case 2.536 consists of two parts, the upper part 2.119 and the lower part 2.115.
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[Pete42]

Thanks a lot for sharing your vast knowledge!

So all in all this seems to be a very special Curta - not necessarily in terms of collector's value (which I don't care too much about), but certainly in terms of beauty and rarity. And the fact that it was probably assembled during the last days or weeks of Curta production makes it even more special, at least for me.

Now on to the search for the "real" #533801

[Pete42]

I became aware of another specimen of the "unusual Curta" Type II with black body and red knobs ... #561563. So now we have three of them, two with serial numbers in the range that is congruent with their properties (Delrin crank/plastic clearing ring/large numbers/ground off tips) and one (mine) with a serial number about five years in the past.

There's always the possibility that somehow the bottom plate of a different type II ended up on mine, but that doesn't make too much sense IMHO - unless someone with an older Type II desperately wanted a high serial number :-)

[murff]

Do you have a link to the #561563 or some pictures





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[Pete42]

No, unfortunately not - the owner (the seller of my machine) wishes to remain private.

But he said the machine is exactly the same as mine (and Sebastian's), and has the plastic clearing ring, Delrin crank and plastic container.