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Re: What is this?

Posted: Wed Jul 18, 2018 9:30 pm
by John-B
Do the knobs screw down to lock the angle? Ie it can be set parallel or at an angle, the legs are locked and then one leg is moved to another position with the same angle?

Re: What is this?

Posted: Wed Jul 18, 2018 9:38 pm
by NickDeAth
Errrrr yes. You can set the arms parallel or at an angle to each other. You can lock one or the other to whatever required angle.

Nick.

Re: What is this?

Posted: Wed Jul 18, 2018 10:16 pm
by Vortex O'Plinth
I don't know what the item is or its purpose, but given a machine tool connection and working from the basic design tenet that 'form follows function' it's fascinating to speculate.
The inscription initiandum is the accusative gerund of the Latin verb initio. One meaning of this is to begin or originate. A liberal translation in reference to a machine tool could be to set up or align the machine prior to use?
The three bosses on the arms are presumably locking thumbscrews to permit and then set the two parallels in angular and translational alignment to one another. If these points of articulation are all independent (not linked) then the parallels could be set at any relative angle between 0° and 90°. This would allow the apparatus to function as an adjustable set square and be used to verify perpendicularity or parallelism of a machine tool axis with a work table or workpiece before starting machining. An example could be checking the alignment of a vertical milling machine spindle relative to the worktable. One parallel would be set against the table and the other against the spindle or a datuming mandrel and then the three thumbscrews locked The two parallels are now aligned at the same angle as the machine spindle and table. If the locked apparatus is now moved to the other side of the spindle and again set with one arm on the table and the other against the spindle any deviation from perpendicularity will be apparent. This has the advantage over using a fixed set square for the same purpose, that any error in perpendicularity is doubled making visual verification more accurate. The alignment of the spindle could then be adjusted until no discrepancy between sides is noted on repeating the set up.

It's possible to imagine similar alignment checks for parallelism of machine axes and spindles with the two arms now aligned nominally parallel to one another.

Where this analysis is incomplete or falls down, is that it doesn't explain why the two arms connecting the parallels are curved. To function as I have suggested they only need to be straight.

Oh well, perhaps another theory bites the dust - anyone else any ideas?

Re: What is this?

Posted: Thu Jul 19, 2018 12:50 pm
by grahamemmett
Damn. Another hour lost to the internet.
Fascinating though.

Re: What is this?

Posted: Thu Jul 19, 2018 8:35 pm
by NickDeAth
Mr O'Plinth, I must congratulate you on your very detailed and plausible theory. (Even though I had to read bits of it twice to get my head round it!)

In the absense of any definitive answer I think we are all probably right to one degree or another. It would be nice if someone could say "I used one of those for ........."

Let's see if there are any further contributions and then I will post a picture of where it will live in the future.

Regards Nick

Re: What is this?

Posted: Fri Jul 20, 2018 9:26 am
by JDB
Ask David Richards on YouTube (https://www.youtube.com/channel/UCBdj-v ... e3vnGoJUag); if he doesn't know then nobody does.
JB

Re: What is this?

Posted: Thu Aug 02, 2018 7:27 pm
by NickDeAth
Well this is where the Initiandum will now live. Sorry for the delay in posting the picture but when I went to open the box I found the keys had been lost. I had to get a neighbour who is a locksmith to open the box and make some new keys.

So the curious object will now spend it's time with all the other redundant imperial measuring equipment in the inspectors tool box.
IMG_0676.JPG