Sorry but it's actually on-topic...

A few years ago or so we were talking about bearing material. Someone
pointed out that different materials are used to rub against each other.
I was told that simply adding springs to my trek polls would create a
mess since it was aluminum rubbing against aluminum. Actually it worked
okay. But I did take the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never wear
out.

Now I need to work on a bicycle. Planning to use the same
ultra-efficient method to hang the bike from the crosswise 2 x 4.

If you've never seen it before, you really need to think about it.

On 01/08/2015 10:51 AM, John Doe wrote:
....

... the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never wear
out.
....

Pretty common albeit good to think of it... same idea as the screen door
stop rod/collar.

--

dpb wrote:

John Doe wrote:

... I did take the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never wear
out.
...

Pretty common albeit good to think of it... same idea as the screen
door stop rod/collar.

Thanks for the reference.

It is similar enough, but in reverse. You are pushing on the stop collar
instead of pulling on the rod. The door is not hung. There is a basic
difference between supporting stuff and hanging stuff, like with
bridges.

I just threw together a hanger for my bike. It's a rough draft and would
take one of you about 60 seconds to make. It will never wear out. It is
vertically and horizontally infinitely adjustable on the 2 x 4.

https://flic.kr/p/pMDKev

Using a tube (like for the monitor hang) instead of a rod provides
better rigidity, and it could probably be morphed into something even
sturdier with little additional hardware.

On 01/08/2015 2:14 PM, John Doe wrote:
wrote:

John Doe wrote:

... I did take the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never wear
out.
...

Pretty common albeit good to think of it... same idea as the screen
door stop rod/collar.

Thanks for the reference.

It is similar enough, but in reverse. You are pushing on the stop collar
instead of pulling on the rod. The door is not hung. There is a basic
difference between supporting stuff and hanging stuff, like with
bridges.
....

The only difference is the orientation of the rod; horizontal vs
vertical. The spring tension on the door rod serves precisely the same
function in operation as does gravity in the hanger. The stop is fixed;
so's your hook; both rely on a rotation to close the size of the opening
and let the edges "bite" the rod.

--


--

dpb wrote in :

John Doe wrote:
wrote:
John Doe wrote:

... I did take the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never
wear out.
...

Pretty common albeit good to think of it... same idea as the screen
door stop rod/collar.

Thanks for the reference.

It is similar enough, but in reverse. You are pushing on the stop
collar instead of pulling on the rod. The door is not hung. There is
a basic difference between supporting stuff and hanging stuff, like
with bridges.
...

The only difference is the orientation of the rod; horizontal vs
vertical. The spring tension on the door rod serves precisely the
same function in operation as does gravity in the hanger. The stop is
fixed; so's your hook; both rely on a rotation to close the size of
the opening and let the edges "bite" the rod.

I'm not trying to patent leverage...

dpb wrote in :

On 01/08/2015 2:14 PM, John Doe wrote:
wrote:

John Doe wrote:

... I did take the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never
wear out.
...

Pretty common albeit good to think of it... same idea as the screen
door stop rod/collar.

Thanks for the reference.

It is similar enough, but in reverse. You are pushing on the stop
collar instead of pulling on the rod. The door is not hung. There is
a basic difference between supporting stuff and hanging stuff, like
with bridges.
...

The only difference is the orientation of the rod; horizontal vs
vertical. The spring tension on the door rod serves precisely the
same function in operation as does gravity in the hanger. The stop is
fixed; so's your hook; both rely on a rotation to close the size of
the opening and let the edges "bite" the rod.

In this case, it isn't just the edge biting the rod or tube. Again, as
mentioned in the original post, it takes advantage of the fact that
aluminum sticks to aluminum. The edge is not sharp. I believe there is a
similar mechanism in IRWIN Quick Grips. But I'm not sure if it will last
forever like mine will. If it bites into the rod, it might eventually
loose its edge and fail.

On 01/08/2015 6:23 PM, John Doe wrote:
....

In this case, it isn't just the edge biting the rod or tube. Again, as
mentioned in the original post, it takes advantage of the fact that
aluminum sticks to aluminum. The edge is not sharp. I believe there is a
similar mechanism in IRWIN Quick Grips. But I'm not sure if it will last
forever like mine will. If it bites into the rod, it might eventually
loose its edge and fail.

I don't believe there's much of the force that is "sticking" as compared
to that of the normal friction force from the rotation induced by the
applied force.

--

On 01/08/2015 8:20 PM, dpb wrote:
....

I don't believe there's much of the force that is "sticking" as compared
to that of the normal friction force from the rotation induced by the
applied force.

BTW, "normal" here is in the geometric sense of the component
perpendicular to the tubing; static friction forces to a first
approximation are proportional to same.

The Al-Al advantage for the purpose is that it does have a fairly high
static friction coefficient as compared to steel-on-steel, roughly
1.05-1.35 for Al-Al vs 0.5-0.8 for steel-steel. If it's your innate
knowledge of this fact that you're referring to as "sticking" then
you're correct that Al holds far better than steel for the purpose.

Again, your device is neatly made and certainly useful; only discussing
the "how" of how the physics of it works...

--

dpb wrote:

dpb wrote:
...

I don't believe there's much of the force that is "sticking" as compared
to that of the normal friction force from the rotation induced by the
applied force.

BTW, "normal" here is in the geometric sense of the component
perpendicular to the tubing; static friction forces to a first
approximation are proportional to same.

The Al-Al advantage for the purpose is that it does have a fairly high
static friction coefficient as compared to steel-on-steel, roughly
1.05-1.35 for Al-Al vs 0.5-0.8 for steel-steel. If it's your innate
knowledge of this fact that you're referring to as "sticking" then
you're correct that Al holds far better than steel for the purpose.

Again, your device is neatly made and certainly useful; only discussing
the "how" of how the physics of it works...

Thanks. Yeah, the hole drilled through the aluminum flatbar was slightly
angled in a direction contrary to concern about slippage, but it still
grips. It's been working well for a bike holder. I'm not much for
engineering details, I got the notion from someone else here in a prior
discussion about adding springs to trekking poles.

On 01/09/2015 5:58 PM, John Doe wrote:
....

dpb wrote:
...

....

BTW, "normal" here is in the geometric sense of the component
perpendicular to the tubing; static friction forces to a first
approximation are proportional to same.

The Al-Al advantage for the purpose is that it does have a fairly high
static friction coefficient as compared to steel-on-steel, roughly
1.05-1.35 for Al-Al vs 0.5-0.8 for steel-steel. If it's your innate
knowledge of this fact that you're referring to as "sticking" then
you're correct that Al holds far better than steel for the purpose.
....

Thanks. Yeah, the hole drilled through the aluminum flatbar was slightly
angled in a direction contrary to concern about slippage, but it still
grips. It's been working well for a bike holder. I'm not much for
engineering details, I got the notion from someone else here in a prior
discussion about adding springs to trekking poles.

The interesting thing is that for Al on Al, the coefficient of friction
is unity or perhaps even greater; this is in sharp contrast to steel.
The net result is that the holding force thus turns out to be as much as
or even slightly greater than that applied by the hanger to the rod
whereas it may be only half or two-thirds of that for the steel case.

--

Am Donnerstag, 8. Januar 2015 17:52:11 UTC+1 schrieb John Doe:
Sorry but it's actually on-topic...

A few years ago or so we were talking about bearing material. Someone
pointed out that different materials are used to rub against each other.
I was told that simply adding springs to my trek polls would create a
mess since it was aluminum rubbing against aluminum. Actually it worked
okay. But I did take the idea and make something that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never wear
out.

That's like a sealant gun mechanism.

Chris

Christopher Tidy wrote:

John Doe:

Sorry but it's actually on-topic...

A few years ago or so we were talking about bearing material. Someone
pointed out that different materials are used to rub against each
other. I was told that simply adding springs to my trek polls would
create a mess since it was aluminum rubbing against aluminum.
Actually it worked okay. But I did take the idea and make something
that is IMO very cool.

"monitor hang"

https://www.youtube.com/watch?v=mjVYt_fQ5n0

Still loving the monitor hang. That very useful piece will never wear
out.

That's like a sealant gun mechanism.

In a way, Yes, using leverage is common. It's also like an old-fashioned
doorstop. The more fundamental the mechanism, the more devices it will
be applied to.

This device is aided by the fact that aluminum sticks to aluminum. That
configuration might not work well for a screen door stop rod/collar, a
sealant gun mechanism, or IRWIN Quick Grips.

Given a crosswise 2 x 4 or some other appropriate platform, nothing
could be more efficient. It doesn't get any cheaper, simpler, or more
durable. And it functions like a complex device. You can easily and
infinitely adjust the hangar vertically and horizontally without stops.
It's so easy to make, even I can do it.

"bike hanger"

https://flic.kr/p/pMDKev

FWIW... That's the alias I have for Astraweb, it's not meant to be used.