Technical and engineering drawing.

[Martin WParticipant @martinw]

Hi Steve

 

While I like your solution it is only stable if the right angle corner of the supporting block is aligned with the gravitational field and the centre line of the cylinder, excludes magnetic or other supporting forces, and as such is only conditionally stable .

 

I believe that, and I am expecting to be shot down on this point, if the system is to be stable then the cylinder must be attached to the concave surface and this would result in at least one hidden construction line being required on the other views. All that waffle over I think your solution is the best so far.

 

 

Cheers

 

 

Martin

[Steve GarnettParticipant @stevegarnett62550]

Okay, perhaps I should have indicated which direction gravity was working in on the drawing…

 

But regardless of that, I think that original views supporting multiple possibilities in the side views deserve a technically correct but unstable solution, don’t they? And anyway, a perfect sphere meeting a perfect curve has an almost infinitesimally small contact plane – to the extent that you might determine that they weren’t in contact anyway, therefore no hidden line is necessary, it could be argued.

 

And if you think that one’s bad I have an even more unlikely solution which has the curved surface as convex, not concave!

Edited By Steve Garnett on 28/04/2011 11:00:18

[Martin WParticipant @martinw]

Steve

 

I totally agree with what you say that any solution stable or not is worth consideration. The one you suggest with a convex surface I like as well and would make a great balancing act !!

 

I had thought of, but not attempted to draw, of a solution with a slightly corrugated surface where you have got the concave one.

 

Great fun to play with the possibilities and helps keep the grey matter ticking over after retirement.

 

Best regards

 

Martin

[NJHParticipant @njh]

Hi Steve & Martin

 

……but say this was the output from the design office of the velcro factory.?

 

Regards

 

Norman

[Martin WParticipant @martinw]

Hi Norman

 

 

That of course would have been designed using ‘fuzzy logic’ or something similar .

I find it fascinating that once one solution has been submitted then the offshoots from this get even more involved while staying within the limits of the original submission.

 

Great stuff all the same.

 

Regards

 

Martin

[Steve GarnettParticipant @stevegarnett62550]

Posted by Martin W on 28/04/2011 11:22:12:

Great fun to play with the possibilities and helps keep the grey matter ticking over after retirement.

 

I think I ought to confess… I woke up in a cold sweat in the middle of the night a couple of nights ago, and there it was, fully formed, in my mind. This probably explains the slightly left-field nature of it; it certainly wasn’t quite what I was expecting, and it was definitely sub-conscious. Whilst having this happen occasionally has its uses, I wouldn’t want it to occur too often! And no, I haven’t retired either. In fact I have no intention of doing so – can’t see the point.

 

As for what makes either the concave or convex version stay together (if that’s what they are really intended to do) – well, it might be possible by carefully magnetising the objects, although clearly that wouldn’t be very stable either.

 

As far as being objects for testing Velcro (is that what you were hinting at?) – Norman, have you been at the sherry again?

 

Regards, Steve

Edited By Steve Garnett on 28/04/2011 21:54:09

[NJHParticipant @njh]

Hi Steve

 

No not testing velcro – I was thinking made entirely of velcro! Curved velcro plane and velcro cylinder one with hooks the other with eyes . I really like the idea that this is fuzzy logic – but then, as my wife often tells me, my mind works in mysterious ways ( that is when it works at all!)

Now then to more important things:- sherry – no no ! only useful for trifle BUT, by a mysterious coincidence, a connection ( rather tenuous of course) has just sprung into my mind between your sherry and Old Hooky Ale – now we’re talking and, since you mention it I recall that I have a couple of bottles in the cupboard. It would be really nice to share them with you but I guess that’s not possible so I must just make the best of it and despatch them myself!

 

Best Regards

 

Norman

P.S If your are into the sherry I’m not surprised that you wake up in a sweat in the night!

Edited By NJH on 28/04/2011 23:15:30

[Sam StonesParticipant @samstones42903]

Gentlemen,

It has been suggested that ideas and challenges can often be resolved by our subconscious overnight. But don’t let it become a habit.

Like Steve, I woke one night (without the help or otherwise of sherry), only to realise a potential problem at work. I had missed some important parts (ejector push-back pins) from a mould I was designing.

Immediately, I fell asleep again.

Sure enough, the following morning when I removed the cover from my drawing board, it was clear that the pins were indeed missing. I decided however, that since I was only being payed for daytime work, my overnight problem-solving practice should cease.

The year was c.1960.

To pick up the thread again, shouldn’t what has now become known as `Sam’s test’ require at least some semblance of Velcro loops and hooks, or an indication of magnetic polarity and lines of force?

 

Or is the logic becoming too fuzzy.

 

Regards to all,

 

Sam

 

PS Would lines of force be in 1st or 3rd angle?

[Steve GarnettParticipant @stevegarnett62550]

I do like the occasional glass of sherry, but I don’t go overboard on the stuff. But there again, I wouldn’t dream of drinking cooking sherry either – only decent brands. And I don’t think sherry was what caused the cold sweat – I’d have had to have drunk rather a lot for that to happen!

 

As for the lines of force, I think the most fun would be to only include them in the isometric view. And at least there’s a sort-of convention for drawing those – how are you supposed to indicate a gravitational field?

[John OlsenParticipant @johnolsen79199]

I think a solution must be regarded as legitimate, even if it might be difficult or impossible to actually build it. The point after all is that the original two views are actually ambiguous, in that there is more than one way in which they may be interpreted.

 

 

hmmm…I think that means that there would be solutions with two parts that don’t actually touch each other.

 

regards

John

[John Stevenson 1Participant @johnstevenson1]

Shouldn’t post on Sherry, likes, dislikes, brands etc be listed under the coolant thread where it’s more relevant or even the cutting oil thread given that the damn stuff is more like ATF than a drink ?

 

 

John S.

[Steve GarnettParticipant @stevegarnett62550]

Hmm.. a few moments additional thought reveal a conceptual problem with the convex design… I’m not sure that one of those will work at all. So unless something else spectacular happens, I’m sticking with the above.

 

Using sherry (or anything else alcoholic) as cutting fluid might be quite efficient – assuming, that is, you want to flame-harden your work whilst you are cutting it!

 

It is potentially a slightly worrying line of experimentation though – similar to Edison’s early attempts to create electric lamp filaments using the basic food groups…

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