Member postings for Michael Gilligan

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Thanks for the additional information, Mike

You obviously know your subject much better than I ever will ... but I am still a little bewildered.

Are these threads really produced with a closed-down 5-40 die, or are they perhaps a truncated thread-form ?
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If you have a commercially produced one available, I would be happy to photograph it for our mutual education.

MichaelG.

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Edit: The two lines for 5-40 on this chart make interesting reading

https://www.engineersedge.com/screw_threads_chart.htm

Edited By Michael Gilligan on 29/09/2020 17:41:01

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Very noble of you, Norm

MichaelG.

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Or you could just click the hyperlinked words Code of Conduct ... on this very page

on the line immediately above the (Add Posting) button

MichaelG.

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May I suggest a very simple practical test ?

Take two thick strips of of your Aluminium alloy and clamp or glue them face-to-face

Now drill through the pair at two locations

Separate them, and de-burr if necessary

Turn the top strip over, and try passing a couple of close-fitting rods through the assemblage.

If all is well, you can proceed to doing something similar, but with four holes on a square grid.

The two plates should then match in eight pairings [four positions, and two ways up]

If you find any errors ... investigate.

MichaelG.

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So presumably I am not included in ‘people’

MichaelG.

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No ... but presumably that would not require the high torque that collapsing by a millimetre would.

[ and therefore would not be particularly relevant to the OP’s question ]

MichaelG.

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The numbers look valid ... so the problem is real

That’s one of the reasons why some of us still prefer traditional ‘fixed size’ collets

MichaelG.

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I apologise, Tony ... You were correct in your first assertion.

I have just returned from a good long walk, and some pondering; and it became quite clear that the mis-aligned chuck would simply form part of the “any shape you like, provided it’s stiff enough” trammel beam.

By way of demonstration : here is the scrappy little sketch that I doodled whilst I was out.

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MichaelG.

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Sorry, Tony ...

It’s simple trigonometry : If there is an angular error between the ‘output axis’ of the chuck and the axis of the machine spindle, then your trammel beam will act like a swash plate and the DTI will rise and fall.

MichaelG.

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Edit: Swash Plate animation: https://youtu.be/z-wA9Tx8930

Edited By Michael Gilligan on 28/09/2020 10:23:21

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That should start an interesting discussion

MichaelG.

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Edit: and I see it already has

Edited By Michael Gilligan on 28/09/2020 08:54:08

Chas

I have no idea whether this is a definitive list, but it looks a useful place to start: **LINK**

https://www.rivetsonline.com/drive-screws#1

I remember, when my dad worked for GKN in the early 1960s, there was a wide variety available.

MichaelG.

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This is all rather bewildering, Mike

In trying to ‘catch up’ ... I have just found this page: **LINK**

https://elcoda.com/bow-screw-250938.html?language_code=en

... which seems to present another ‘variation on the theme’

[quote]

Bow Screw with Rolled Inch Thread, Bronze Eyelets, Violin, Viola, Cello
These bow screws are finely-crafted in the style of the great French bow makers.The rolled thread allows the thread portion of the screw to have a larger diameter than the shaft portion.
Violin,Viola - dimensions 74 mm, thread 1,8", shaft diameter 2,7 mm.
Cello - dimensions 80 mm, thread 9,64", shaft diameter 3,0 mm

[/quote]

Can you provide any close-up photos of typical specimens of what you are working with, please ?

MichaelG.

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P.S. There are crucial differences between the BA and Unified thread forms, so I think this merits serious further investigation.

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Presumably told by someone who didn’t appreciate the sophistication of the thread-form

Blessed are the ‘Bean-Counters” ... ?

MichaelG.

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Au contraire ... I see the ‘whinge’ as a direct and relevant response to the opening question.

MichaelG.

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Personally, yes ... especially with German to English

... and I find the interface convenient.

MichaelG.

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For 99p that had to be worth a bash : **LINK**

https://apps.apple.com/gb/app/cuckoo-clock-calibration/id1171487289

... even if the developer does claim/admit :

Turn your iPhone into a precise train count sensor with an unbelievable 0.01 milliseconds accuracy!!

on his website ... and 0.001 milliseconds on the AppStore

MichaelG.

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^^^

MichaelG

Strangely enough ... Espacenet found this patent when I searched for ‘Macrome’ : **LINK**

https://worldwide.espacenet.com/patent/search/family/009819914/publication/GB753221A?q=macrome

... the Macrome process gets a mention in the closing paragraph

MichaelG

Until someone comes up trumps ... try DeepL : **LINK**

https://www.deepl.com/translate

MichaelG.

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Missed that, yesterday, Jason

The opening ‘titles’ are sheer joy ...

I shall watch it with due reverence, later.

MichaelG.