slide rule magnifiers

[Al]

Notwithstanding other drawbacks/virtues of slide rules, they are still around, they can get to be the bane of "old eyes". I remember, years ago, seeing an elderly engineer, he had gray hair, using his K & E Log Log rule, which had a clip on magnifier that rode the cursor.

Anyone here know where one might obtain one of these today. Thanks in advance for information or direction.

Al

[Garth Wilson]

I wonder if you could make one with a lens that's all cyclinder and no sphere from Edmund. They have stuff like that, high quality, but not exactly cheap. Try http://www.edmundoptics.com/optics/optical-lenses/cylinder-lenses/cylinder-lenses/2110 Note that there are seven pages of these.

[Geoff Quickfall]

Bye your self a plexi half cylinder 12" magnifier. Get some uv light activated epoxy (the type they use to glue magnifiers to watch crystals).

Cut to size, sand edges, apply even coat of liquid epoxy insuring there are no bubbles. Position and when ready apply uv light.

Cheers, Geoff

Edited: 16 Sept 2013, 9:58 p.m.

[Geoff Quickfall]

Here is a Summit magnifying calculator lens shaped and polished and fitted to my HP01. Compare that to the second photo with a stock lens.

My eyes need the help now:

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Edited: 16 Sept 2013, 10:04 p.m.

[sjthomas]

Quote:

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My eyes need the help now:

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And you're a pilot?!?!?!?! :-)

[Mike (Stgt)]

If the lense is to distinguish figures like 1 and 7 or 0 and 8, my consent. But if you try to make a more precise reading, sorry for that, it will not work. The extent you magnify the scale the same extend you will boost the reading error too. So the lense is just a helper for bad eyes, not to spread the slide rule's scale.

It is like HP-67 and HP-97, the one with the bigger display is not more acurate.

[aurelio]

Quote:

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It is like HP-67 and HP-97, the one with the bigger display is not more acurate.

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Excuse me Mike, I don't understand that

Edited: 17 Sept 2013, 4:44 p.m.

[Mike (Stgt)]

If you write with a pencil on a piece of paper the letter 'A' and once more 'A' but twice as big as before, well, in both cases it is the letter 'A', there is not more information in the bigger 'A'. Now, if you calculate the SQRT of 7 on an HP-67 and on a -97, the result is the same, on both calculators. So the advantage of the bigger display is _not_ in the accurancy of the result. D'accord?

And the same holds true for reading a slide rule with or without a magnifier lense, using it the reading may be more comfortable, alas there is no gain in accuracy.

(Corrected a typo/M.)

Edited: 18 Sept 2013, 3:46 a.m.

[aurelio]

Quote:

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[OMISSIS]Now, if you calculate the SQRT of 7 on an HP-67 and on a -97, the result is the same on both calculators. So the advantage of the bigger display is _not_ in the accurancy of the result.[OMISSIS]

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Hi Mike and thank-you for your replay, the meaning of accuracy was and is for me quite clear and what you wrote in your replay sounds now clear and let me say obvious.
I only apologize to have not well understood your sentence below at first:

Quote:

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It is like HP-67 and HP-97, the one with the bigger display is not more acurate.

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Maybe it could have been clearer (at least for me) if it have been ended with "than the other ".
Thanks again

I placed my question without to take the right time to think and to read one more time your first post: I just came back from a cruise and I'm still suffering for the jet-lag, better to say for the "ship-lag"

(edited for a best quoting job)

Edited: 18 Sept 2013, 10:44 a.m.

[Mike (Stgt)]

Sorry, but you remarked that English is not my first language. And there are some things I remember, like in a diner I can not simply order 'a Coce', I have to say 'a Coce _to drink_'. And here I forgot this 'not more accurate _than the other_'.

[aurelio]

Please, Mike, don't be ashamed for that, it was not absolutely my intention to remark anything (both we don't speak English as the mother-tongue, and unfortunately both we don't use the electronic translator which could be sometime a quite useful help, at least to check what we wrote and avoid so typos).
I'm not an expert in HP calculators I only used and still use and I like them.
So that I could have missed something about the difference between HP97 and HP67: I use both them but I took not yet the time to perform a benchmark.
For this reason I was interested in your comparation and, as I told previously, I misunderstood your sentence.
All the best

[Mike (Stgt)]

<LOL> You are not a native speeker?!? Oops! I did not remark that. No need for you to apologise. Only one question: imagine you are at a party and would like to smoke a cigarette. How do you ask? i) do you mind my smoking, or ii) do you mind me smoking? Which question is correct in grammar?

Fankly, it is now too far off-topic, we should stop now.

Ciao.....Mike

[aurelio]

Quote:

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Only one question: imagine you are at a party and would like to smoke a cigarette. How do you ask? i) do you mind my smoking, or ii) do you mind me smoking? Which question is correct in grammar?

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Hi Mike, there are many people here, who can teach us the right approach and the standard english expression for this situation, but if you like (I appreciate it) to know my personal opinion, I just notice that maybe the first (i) is more correct (but I'm not sure).
Believe me I'm not so prepared in matter of smoke: I stopped to do it several years ago and I forgot all, even the good manners., but I'm sure that it has been the best choice.

Ciao e buonanotte (and thank-you for your time)
Cheers from Italy

Edited: 19 Sept 2013, 5:33 p.m.

[Kimberly Thompson]

AL

The following may help:

Link to Mark's Slide Rule Magnifiers

Link to Slide Rule Trading Company

BEST!

SlideRule

[Al]

Thanks to all who replied, especially Kimberly.

[aurelio]

Many thanks