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Watchmaker's vertical slide

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Roderick Jenkins07/03/2019 21:58:59
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HI,

I have one of these Lorch type vertical slides, without the milling spindle.

**LINK**

Can anyone hazard a guess as to why (or even actually knows!) the circular scale is engraved 0-90 rather than 0-360 (or 0-36)?

Cheers,

Rod

Michael Gilligan07/03/2019 22:41:43
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Goldilocks probably could:

360 divisions would be too many

36 divisions would be too few

90 divisions is 'just right'

MichaelG.

Roderick Jenkins08/03/2019 08:01:12
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The most likely rotation for me is from horizontal to vertical which is 22 1/2 divisions which seems "just wrong" but then I'm not a watchmaker 😐

Whatever, I'm trying to design a spindle for it to go on my 1750 Pu!tra.

Rod

JasonB08/03/2019 08:10:15
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Bit like a 90:1 rotary table where 90deg is 22 and a half turns, maybe they did not have a very precise dividing plate when they made itwink

I'm sure you could knock up a vernier scale for it or just mark direct onto the spindle body

Michael Gilligan08/03/2019 08:50:55
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Posted by Roderick Jenkins on 08/03/2019 08:01:12:

The most likely rotation for me is from horizontal to vertical which is 22 1/2 divisions which seems "just wrong" but then I'm not a watchmaker 😐

Whatever, I'm trying to design a spindle for it to go on my 1750 Pu!tra.

.

Pehaps you could put more than one fiducial mark on the spindle body.

... and/or make a pin to locate it at that 'most likely' position.

MichaelG.

Edited By Michael Gilligan on 08/03/2019 08:54:28

Michael Gilligan08/03/2019 09:15:19
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Rod,

The item on Neil's Machines appears to have its fiducial mark positioned appropriately for the most common use-cases:

lorchverticalslide.jpg

MichaelG.

Howard Lewis08/03/2019 21:38:39
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Maybe Herr Lorch did not feel a need for increments of less than 4 degrees?

Could you add another fiducial point to provide a vernier effect, giving a 1 degree increment? At first and not deep thought, this would seem to be 5 degrees from the first.

Anyone want to comment on that instant thought?

Howard

duncan webster08/03/2019 23:51:32
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Posted by Howard Lewis on 08/03/2019 21:38:39:

Maybe Herr Lorch did not feel a need for increments of less than 4 degrees?

Could you add another fiducial point to provide a vernier effect, giving a 1 degree increment? At first and not deep thought, this would seem to be 5 degrees from the first.

Anyone want to comment on that instant thought?

Howard

you'd need more than one extra mark, but I'd need to put my thinking cap on to work out how many and their spacing

JasonB09/03/2019 07:02:08
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Posted by Howard Lewis on 08/03/2019 21:38:39:

 

Anyone want to comment on that instant thought?

Howard

Was that an instant thought as soon as you read my reply or instantly after reading Michael's wink 2

Yes a series of 4 marks additional spaced at 3deg would give the vernier ( Scale is usually shorter than the main scale) or you could simply put two marks at common angles for easy setting at 90deg etc as Rod wanted.

Still does not cure the "odd" numbering system as you would have to set the vernier to 22 divs plus 2 rather than 88deg plus 2 if it were numbered 0-360 ( 0-40, 80, 120, etc) rather than 0-90.

 

 

Edited By JasonB on 09/03/2019 08:03:07

SillyOldDuffer09/03/2019 09:25:37
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Just a thought, but isn't this kind of limited scale only intended to position the slide roughly at the desired angle? This fits well with Michael's '90 degrees is just right'.

The Lorch scale would get you to within about 2 degrees on its own, but I suggest when more accuracy is needed the final angle should be found using a better method. This is how I angle the top-slide on my lathe: optimistically the top-slide scale is good to about a degree, realistically it's not that good. When better than approx 1 degree is needed I ignore the scale and use a template, protractor, Wixey, or trigonometry (angle derived by measuring two distances) to make the fine adjustment. Not had occasion to play with a Sine Bar yet.

Dave

JasonB09/03/2019 10:20:00
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The original question was not really about the size of divisions but why number the divisions rather than number by degrees.

90 divisions fits around the available space quite well but you have to divide every angle you want by 4 to get what division to line up with eg if you wanted to set it at 60degrees you need to line the mark up with 15?

Michael Gilligan09/03/2019 13:53:16
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Posted by JasonB on 09/03/2019 10:20:00:

The original question was not really about the size of divisions but why number the divisions rather than number by degrees.

.

Alternatively, we could ask: Why not ?

Watchmakers are comfortable with counting [perhaps more so than working with angles]

... so why not simply count in increments 4°

MichaelG.

JasonB09/03/2019 16:08:45
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Why not, well it would be no harder to stamp 0, 40, 80, 120, or 0, 4, 8, 12 etc but would make use so much easier and less risk of errors

Michael Gilligan09/03/2019 17:26:12
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[ for what it's worth ... in my personal opinion ]

The Lorch markings are a model of clarity, compared with the Pultra equivalent:

pultra_vertical_slide.jpg

MichaelG.

Edited By Michael Gilligan on 09/03/2019 17:28:49

JasonB09/03/2019 18:13:41
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Can't argue with that. Numbering every 4th or 6th division would have been better but at least they are working with 360 in a full rotation

Michael Gilligan09/03/2019 18:25:06
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Rod,

You might find it useful to grab these images for reference:

**LINK**

MichaelG.

.

http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=291492870854&t=0&tid=310&category=117039&seller=ps692003&excSoj=1&excTrk=1&lsite=3&ittenable=false&domain=ebay.com&descgauge=1&cspheader=1&oneClk=1&secureDesc=0&oversion=4802b4c9

Edited By Michael Gilligan on 09/03/2019 18:25:38

Michael Gilligan09/03/2019 23:37:09
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Further investigation reveals that dials with 90 degrees [sic] to the circle, are used in Astrology

Here is an explanation: **LINK**

http://www.uranian-institute.org/bf90dialexplan.htm

Personally, however, I think my original 'Goldilocks' hypothesis is more logical

... and now it's time for bed.

MichaelG.

JasonB10/03/2019 07:02:54
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Posted by Michael Gilligan on 09/03/2019 23:37:09:

... and now it's time for bed.

Hope nobody else has been sleeping in itwink

SillyOldDuffer10/03/2019 09:17:33
3991 forum posts
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Posted by Michael Gilligan on 09/03/2019 23:37:09:

Further investigation reveals that dials with 90 degrees [sic] to the circle, are used in Astrology

Here is an explanation: **LINK**

http://www.uranian-institute.org/bf90dialexplan.htm

Personally, however, I think my original 'Goldilocks' hypothesis is more logical

... and now it's time for bed.

MichaelG.

I thoroughly enjoyed reading the Uranian explanation and didn't believe a word of it! Odd how humanity likes to clothe daft notions in respectable terminology, misused. Doesn't Mr Finlay come straight off the rails by calling the sub-divisions 'harmonics' rather than 'undertones'? Even odder that so many still trust in astrology despite centuries of strong evidence to the contrary.

We Scorpios are above all that rubbish. Only foolish Virgos believe their own propaganda!smiley

Dave

Neil Wyatt10/03/2019 12:33:34
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"While the most dismally traditional astrologers referred to these angular relationships as "malefic" or "evil" due to the dynamic and challenging quality of the interaction between the 2 planets involved, the Hamburg School astrologers and the later Cosmobiologists and Uranian astrologers have continually verified that these are the most energetic angular relationships and therefore of greater significance for personal growth, and for prognosis of significant change and developmental periods"

It's a relief to find out that Astrologers are open to testing and refining their approach using the scientific method, imaging where we could end up if we still, thought and angular conjunction was malefic rather than energetic!

devil

Neil

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