thoughts of clear tubing ...

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thoughts of clear tubing ...

greg lewin-2
... made me think of the tubing used in peristaltic pumps, clear so you can see all that juicy red blood, which is available with ID large enough:

peristaltic pump tubing:

http://www.silex.co.uk/silicone_tubing.html

http://www.longerpump.com/ArticleShow.asp?ArticleID=387

http://www.tygon.com/silicone-tygon-3350-tubing.aspx

- it may be a bit pricey, being made to high spec, though maybe not prohibitively so.  It does of course offer very smooth internal walls, but being squishy by definition it may be too prone to kinking and pinching.

Greg


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Re: thoughts of clear tubing ...

Al Bennett
Here's the tubing I found in a quick google last night:

http://uk.farnell.com/legris/1025v26-00-19/pvc-tubing-25m-d26/dp/4251696

It's 19mm ID, 25M reel for £57.62 (a bit steep as we'd probably need a few of these).

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Re: thoughts of clear tubing ...

tom hardiment
just found that turntable motor...  its only 4w- i'm guessing thats not going to be enough

another option i have is a wiper motor, which would be grunty enough- do we have a 12v supply? it's geared down already, and has 2 speeds- draws either 1.9A or 3A



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Re: thoughts of clear tubing ...

Antonia Mayer-2
what are you building, if i may ask?
may have missed something; got lost somewhere there.


On Wed, May 12, 2010 at 10:31 PM, tom hardiment <[hidden email]> wrote:
> just found that turntable motor...  its only 4w- i'm guessing thats not
> going to be enough
>
> another option i have is a wiper motor, which would be grunty enough- do we
> have a 12v supply? it's geared down already, and has 2 speeds- draws either
> 1.9A or 3A
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Re: thoughts of clear tubing ...

Martin Ling
On Thu, May 13, 2010 at 01:13:32AM +0200, Antonia Mayer wrote:
>
> what are you building, if i may ask?
> may have missed something; got lost somewhere there.

Marble run. The messages don't make much sense without the context of
the conversation at the meeting!

The tubing would be for marbles to run down, the motor would be to drive
the lift pulling them up.

Here's what I wrote to Tom earlier about the idea I presented on Tues:

---------------

Here's what I've settled on, I think:

Balls will be chrome plated steel, 13mm (1/2") diameter (marble size).
The advantage of metal ones is they can close circuits and be picked up
by magnets.

I'm thinking of ordering these here:
http://simplybearings.co.uk/shop/p35271/13mm+Diameter+Hardened+Chrome+Steel+Ball+Bearings+%28Pack+of+50%29+Grade+100/product_info.html

The lift will be magnetic. There'll be a loop of cord going round two
pulleys, one at the top and one at the bottom. The top one will be
driven by a motor. The cord will have small ring magnets tied/glued on
at intervals, perhaps these ones:

http://cgi.ebay.co.uk/50-Neodymium-Ring-Magnets-8-x-4-2-x-4-mm-craft-/130328161822?cmd=ViewItem&pt=UK_Collectables_WeirdStuff_RL&hash=item1e5829ee1e

Balls will accumulate at the bottom of the lift and be picked up by a
passing magnet. At the top of the lift the cord will pass through a hole
which is big enough for the magnet but too small for the ball, so they
get knocked off into a funnel and go down to the start of the run.

Initially we'll set this up with just a bit of plastic hose to take the
balls back to the bottom. Then, anyone who wants to build a bit of
marble run can just cut the hose and splice in their creation. If enough
people build enough bits, it will become a continuous contraption all
the way down.
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Re: thoughts of clear tubing ...

Martin Ling
In reply to this post by tom hardiment
On Wed, May 12, 2010 at 09:31:42PM +0100, tom hardiment wrote:
>
>    just found that turntable motor...A  its only 4w- i'm guessing thats not
>    going to be enough
>
>    another option i have is a wiper motor, which would be grunty enough- do
>    we have a 12v supply? it's geared down already, and has 2 speeds- draws
>    either 1.9A or 3A

I think we have plenty of high-current 12V supplies. I have a 12V 4A one
I could spare for now.


Martin
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Re: thoughts of clear tubing ...

Martin Ling
In reply to this post by Al Bennett
On Wed, May 12, 2010 at 09:17:52PM +0100, Al Bennett wrote:
>
>    Here's the tubing I found in a quick google last night:
>
>    http://uk.farnell.com/legris/1025v26-00-19/pvc-tubing-25m-d26/dp/4251696
>
>    It's 19mm ID, 25M reel for -L-57.62 (a bit steep as we'd probably need a
>    few of these).

Not sure we'd need that much. I wasn't planning on us making an
interesting marble run out of tubing alone - it would just complete the
circuit to get the thing running initially, and fill the gaps when other
bits are spliced in.

I'm concerned about the PVC stuff though, I think it will tend to
kink/flatten and stop the marbles. What you want is suction hose, which
is reinforced to stop it flattening.

Can anyone find some cheaper than this?

http://www.qvsdirect.com/Clarke-1-Inch-Diameter-Suction-Hose-1-Metre-Length-pr-16846.html

Also, how about some of this stuff to enclose the lift in where it
passes within easy reach of drunkards on the stairs:

http://cgi.ebay.co.uk/20mm-x-2mm-Clear-Acrylic-Tube-Plastic-Plexiglas-Pipe-1m-/300371236716?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45ef85576c

The same seller offers lots of different sizes and lengths. The 15mm
size would be good for cutting in half to get double the length of
straight gutter-type sections.


Martin
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Re: thoughts of clear tubing ...

Ruan Suess
Hi everyone.

I have been thinking about the discussion last Tuesday about the marble run and have come up with some ideas.
I have had some experience building cord based lifting systems before so i know some of its shortcomings such as sagging, snapping and slipping on drive pulleys.

I don't know if pictures can be attached to the mailing list so I made a google document, here is the link:

http://docs.google.com/View?id=df9td5n3_42g6tgf3fs


Ruan.





On 13 May 2010 09:12, Martin Ling <[hidden email]> wrote:
On Wed, May 12, 2010 at 09:17:52PM +0100, Al Bennett wrote:
>
>    Here's the tubing I found in a quick google last night:
>
>    http://uk.farnell.com/legris/1025v26-00-19/pvc-tubing-25m-d26/dp/4251696
>
>    It's 19mm ID, 25M reel for -L-57.62 (a bit steep as we'd probably need a
>    few of these).

Not sure we'd need that much. I wasn't planning on us making an
interesting marble run out of tubing alone - it would just complete the
circuit to get the thing running initially, and fill the gaps when other
bits are spliced in.

I'm concerned about the PVC stuff though, I think it will tend to
kink/flatten and stop the marbles. What you want is suction hose, which
is reinforced to stop it flattening.

Can anyone find some cheaper than this?

http://www.qvsdirect.com/Clarke-1-Inch-Diameter-Suction-Hose-1-Metre-Length-pr-16846.html

Also, how about some of this stuff to enclose the lift in where it
passes within easy reach of drunkards on the stairs:

http://cgi.ebay.co.uk/20mm-x-2mm-Clear-Acrylic-Tube-Plastic-Plexiglas-Pipe-1m-/300371236716?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45ef85576c

The same seller offers lots of different sizes and lengths. The 15mm
size would be good for cutting in half to get double the length of
straight gutter-type sections.


Martin
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Re: thoughts of clear tubing ...

Martin Ling
Ruan,

Brilliant work! I'm sure you're right that webbing would work better
with pulleys.

Also having magnets flat on the webbing means we can use any sort of
magnets, they don't have to be donuts and we have more flexibility on
which type to use - we could probably find some which will only support
a single ball anyway, eliminating the need for a synchronised supply of
single balls at the bottom end. Keep everything simple!


Martin

PS - you can attach pictures but the doc works well too.

On Thu, May 13, 2010 at 11:53:07AM +0100, Ruan Suess wrote:

>
>    Hi everyone.
>
>    I have been thinking about the discussion last Tuesday about the marble
>    run and have come up with some ideas.
>    I have had some experience building cord based lifting systems before so i
>    know some of its shortcomings such as sagging, snapping and slipping on
>    drive pulleys.
>
>    I don't know if pictures can be attached to the mailing list so I made a
>    google document, here is the link:
>
>    http://docs.google.com/View?id=df9td5n3_42g6tgf3fs
>
>    Ruan.
>
>    On 13 May 2010 09:12, Martin Ling <[hidden email]> wrote:
>
>      On Wed, May 12, 2010 at 09:17:52PM +0100, Al Bennett wrote:
>      >
>      >    Here's the tubing I found in a quick google last night:
>      >
>      >  
>       http://uk.farnell.com/legris/1025v26-00-19/pvc-tubing-25m-d26/dp/4251696
>      >
>      >    It's 19mm ID, 25M reel for -L-57.62 (a bit steep as we'd probably
>      need a
>      >    few of these).
>
>      Not sure we'd need that much. I wasn't planning on us making an
>      interesting marble run out of tubing alone - it would just complete the
>      circuit to get the thing running initially, and fill the gaps when other
>      bits are spliced in.
>
>      I'm concerned about the PVC stuff though, I think it will tend to
>      kink/flatten and stop the marbles. What you want is suction hose, which
>      is reinforced to stop it flattening.
>
>      Can anyone find some cheaper than this?
>
>      http://www.qvsdirect.com/Clarke-1-Inch-Diameter-Suction-Hose-1-Metre-Length-pr-16846.html
>
>      Also, how about some of this stuff to enclose the lift in where it
>      passes within easy reach of drunkards on the stairs:
>
>      http://cgi.ebay.co.uk/20mm-x-2mm-Clear-Acrylic-Tube-Plastic-Plexiglas-Pipe-1m-/300371236716?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45ef85576c
>
>      The same seller offers lots of different sizes and lengths. The 15mm
>      size would be good for cutting in half to get double the length of
>      straight gutter-type sections.
>
>      Martin
>      ........................................................................
>      .........dorkbot: people doing strange things with electricity..........
>      ..........................http://dorkbot.org............................
>      ........................................................................

> ........................................................................
> .........dorkbot: people doing strange things with electricity..........
> ..........................http://dorkbot.org............................
> ........................................................................



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Re: thoughts of clear tubing ...

Anne Suess
Thu, May 13 Martin Ling wrote:
>Also, how about some of this stuff to enclose the lift in where it
>passes within easy reach of drunkards on the stairs:

http://cgi.ebay.co.uk/20mm-x-2mm-Clear-Acrylic-Tube-Plastic-Plexiglas-Pipe-1m-/300371236716?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45ef85576c

This stuff looks brilliant, a bit expensive, though I think a bit cheaper than tubing. Would be perfect though.  I notice they have discounted lines and auction/off-cuts, so perhaps cheaper bits can be found depending on our requirements?? Would it be worth writing to them?

As a less than ideal alternative, in the past for projects I have acquired and used cardboard tubing from the inner of carpet rolls, which was free and could be used in vulnerable places if it proves too expensive to have clear tubing of any sort or if the amount required proves prohibitive!  Since they are substantial we could cut large windows in it and cover with acetate and light them up in cool ways (reference Ruan's post), although I'm not sure of the price of acetate!  Clear plastic tubing would be better, if we can find it at reasonable cost as the alternative might look great, but could also end up looking tacky. 

I'm thinking that the hose taking the marble back down connecting to run bits would also be best to be clear if at all possible, as we have no idea how much run will be built and would at least let us see the marbles drop!  In fact given the various, but odd viewing points provided by the stairs, as much transparency in the build as possible including the run might be best.

Did also think it might be worth asking the other group involved, One Mans Junk, who I presume are experienced in finding recycled stuff to make things, if they have any ideas for sourcing clear tubing cheaply.

Unfortunately because of the location, the accessibility of the balls and possibility of them coming adrift from the run is a consideration not just from drunks, but everyone especially children, as I am assuming it is not going to be supervised.  It is as well to consider this a bit from the outset and not put work and money into it only to be told for Health and Safety reasons it isn't allowed!!!

Sorry I feel old saying this, but have had disappointments in the past due to Health and Safety madness!!  I'm actually really excited by the project and looking forward to it getting underway, so definitely don't want to put a dampener on it or have the disappointment of it being rejected for safety reasons.

Anne

On Thu, May 13, 2010 at 12:46 PM, Martin Ling <[hidden email]> wrote:
Ruan,

Brilliant work! I'm sure you're right that webbing would work better
with pulleys.

Also having magnets flat on the webbing means we can use any sort of
magnets, they don't have to be donuts and we have more flexibility on
which type to use - we could probably find some which will only support
a single ball anyway, eliminating the need for a synchronised supply of
single balls at the bottom end. Keep everything simple!


Martin

PS - you can attach pictures but the doc works well too.

On Thu, May 13, 2010 at 11:53:07AM +0100, Ruan Suess wrote:
>
>    Hi everyone.
>
>    I have been thinking about the discussion last Tuesday about the marble
>    run and have come up with some ideas.
>    I have had some experience building cord based lifting systems before so i
>    know some of its shortcomings such as sagging, snapping and slipping on
>    drive pulleys.
>
>    I don't know if pictures can be attached to the mailing list so I made a
>    google document, here is the link:
>
>    http://docs.google.com/View?id=df9td5n3_42g6tgf3fs
>
>    Ruan.
>
>    On 13 May 2010 09:12, Martin Ling <[hidden email]> wrote:
>
>      On Wed, May 12, 2010 at 09:17:52PM +0100, Al Bennett wrote:
>      >
>      >    Here's the tubing I found in a quick google last night:
>      >
>      >
>       http://uk.farnell.com/legris/1025v26-00-19/pvc-tubing-25m-d26/dp/4251696
>      >
>      >    It's 19mm ID, 25M reel for -L-57.62 (a bit steep as we'd probably
>      need a
>      >    few of these).
>
>      Not sure we'd need that much. I wasn't planning on us making an
>      interesting marble run out of tubing alone - it would just complete the
>      circuit to get the thing running initially, and fill the gaps when other
>      bits are spliced in.
>
>      I'm concerned about the PVC stuff though, I think it will tend to
>      kink/flatten and stop the marbles. What you want is suction hose, which
>      is reinforced to stop it flattening.
>
>      Can anyone find some cheaper than this?
>
>      http://www.qvsdirect.com/Clarke-1-Inch-Diameter-Suction-Hose-1-Metre-Length-pr-16846.html
>
>      Also, how about some of this stuff to enclose the lift in where it
>      passes within easy reach of drunkards on the stairs:
>
>      http://cgi.ebay.co.uk/20mm-x-2mm-Clear-Acrylic-Tube-Plastic-Plexiglas-Pipe-1m-/300371236716?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45ef85576c
>
>      The same seller offers lots of different sizes and lengths. The 15mm
>      size would be good for cutting in half to get double the length of
>      straight gutter-type sections.
>
>      Martin
>      ........................................................................
>      .........dorkbot: people doing strange things with electricity..........
>      ..........................http://dorkbot.org............................
>      ........................................................................

> ........................................................................
> .........dorkbot: people doing strange things with electricity..........
> ..........................http://dorkbot.org............................
> ........................................................................



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Re: thoughts of clear tubing ...

Martin Ling
On Thu, May 13, 2010 at 09:11:00PM +0100, Anne Suess wrote:
>
>    Thu, May 13 Martin Ling wrote:
>    >Also, how about some of this stuff to enclose the lift in where it
>    >passes within easy reach of drunkards on the stairs:
>
>    http://cgi.ebay.co.uk/20mm-x-2mm-Clear-Acrylic-Tube-Plastic-Plexiglas-Pipe-1m-/300371236716?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45ef85576c
>
>    This stuff looks brilliant, a bit expensive, though I think a bit cheaper
>    than tubing. Would be perfect though.

I wasn't thinking of using much of it - just enough to shield the lift
for a metre or two where it passes within grabbing distance of people
leaning off the stairs.

>    As a less than ideal alternative, in the past for projects I have acquired
>    and used cardboard tubing from the inner of carpet rolls, which was free
>    and could be used in vulnerable places if it proves too expensive to have
>    clear tubing of any sort or if the amount required proves prohibitive!
>    Since they are substantial we could cut large windows in it and cover with
>    acetate and light them up in cool ways (reference Ruan's post), although
>    I'm not sure of the price of acetate!  Clear plastic tubing would be
>    better, if we can find it at reasonable cost as the alternative might look
>    great, but could also end up looking tacky.

I think it would definitely be worth collecting cardboard tubes of all
sorts. I had quite a collection at one point after entering Box Wars,
but threw them away eventually. Don't worry about them looking tacky, a
bit of spray paint goes a long way.

I've raised the issue of funding with the forest, and people seem in
favour of a £50 budget to get the lift up and running nicely. I'm happy
to put a bit of money in myself too.


Martin
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Re: thoughts of clear tubing ...

tom hardiment
In reply to this post by Anne Suess


I'm thinking that the hose taking the marble back down connecting to run bits would also be best to be clear if at all possible, as we have no idea how much run will be built and would at least let us see the marbles drop!  In fact given the various, but odd viewing points provided by the stairs, as much transparency in the build as possible including the run might be best.


Unfortunately because of the location, the accessibility of the balls and possibility of them coming adrift from the run is a consideration not just from drunks, but everyone especially children, as I am assuming it is not going to be supervised.  It is as well to consider this a bit from the outset and not put work and money into it only to be told for Health and Safety reasons it isn't allowed!!!


agree with you thoroughly on both these points, anne!


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Re: thoughts of clear tubing ...

tom hardiment
potential problems seem to be-

>danger of marbles falling off
>sabotage, inadvertent or otherwise
>reliable operation w/particular regard to loading/unloading

-and the right solution needs to work aesthetically.

agree with anne that maximum invisibility is gona look best-
tubes are less than ideal, and even webbing wont look as good as a thin line.


i didn't look properly on tues- can the lift operate in a line-of-sight trajectory?
if so, the sag problem could be avoided with vertical tensioning, as ruan suggested.

with sufficiently strong magnets and line (like really thick nylon?) i think problems 1 and 2 above could be solved, saving cost and unsightliness of tubes.. but that would make the unloading much more of a challenge...

hmmmm!

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Re: thoughts of clear tubing ...

Martin Ling
On Thu, May 13, 2010 at 11:47:41PM +0100, tom hardiment wrote:
>
>    agree with anne that maximum invisibility is gona look best-
>    tubes are less than ideal, and even webbing wont look as good as a thin
>    line.

The problem with a thin line is you'd get very little friction on the
pulleys. Webbing sounds much more likely to work.

>    i didn't look properly on tues- can the lift operate in a line-of-sight
>    trajectory?

Yes - between almost straight up or at about 30 degrees from vertical.


Martin
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Re: thoughts of clear tubing ...

tom hardiment



The problem with a thin line is you'd get very little friction on the
pulleys. Webbing sounds much more likely to work.

yup, you're right, all sorts of problems with a line

if strong enough magnets would solve the safety/sabotage probs, i think this might work to release the balls?

http://docs.google.com/View?id=dhgmmmsc_1hdk5pcd7

would depend on a reliable fixing of magnets onto webbing, and one which wouldn't interfere with getting a good ball-magnet contact
 


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Re: thoughts of clear tubing ...

Martin Ling
On Fri, May 14, 2010 at 04:07:29PM +0100, tom hardiment wrote:
>
>    if strong enough magnets would solve the safety/sabotage probs, i think
>    this might work to release the balls?
>
>    http://docs.google.com/View?id=dhgmmmsc_1hdk5pcd7

Mrm, problem with this approach is that I think the webbing will be
wider than the balls. I was thinking of detatching by just having the
webbing run through a slot, wide enough for the magnets to get through
but not to take the balls with them.


Martin
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Re: thoughts of clear tubing ...

aaron-90
I haven't kept up with any of the marble run business. But if you're  
using magnets to move the marbles (i'm assuming you all mean ball  
bearings, not marbles at all, and therefore not a marble run to  
purists) then won't they become magnetised themselves? Won't this  
potentially cause problems?

  --
aaron

On 14 May 2010, at 16:13, Martin Ling <[hidden email]> wrote:

> On Fri, May 14, 2010 at 04:07:29PM +0100, tom hardiment wrote:
>>
>>   if strong enough magnets would solve the safety/sabotage probs, i  
>> think
>>   this might work to release the balls?
>>
>>   http://docs.google.com/View?id=dhgmmmsc_1hdk5pcd7
>
> Mrm, problem with this approach is that I think the webbing will be
> wider than the balls. I was thinking of detatching by just having the
> webbing run through a slot, wide enough for the magnets to get through
> but not to take the balls with them.
>
>
> Martin
> ...
> .....................................................................
> .........dorkbot: people doing strange things with  
> electricity..........
> ..........................http://
> dorkbot.org............................
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Re: thoughts of clear tubing ...

Anne Suess


I asked Stephen about this Aaron and you're right, but he thinks it will only be a little bit
and shouldn't cause a problem.  If there's a cumulative problem we would just have to
remove them at the end of the day and heat them.  He has tried to magnetise things
like screw drivers, but only ever has very weak results, which barely work!  As there
is so little surface contact between the ball bearings he doubts there will be a problem-
hopefully!

Ruan told me that the webbing should help facilitate simplification of the uptake and
off loading of the balls. He has a suggestion for uptake using the magnets and a switch,
which would be simple and look good.  I've put his link below. As the magnets will be
more firmly attached to the webbing without spinning as on a line, it should also be
easier to neatly wedge the balls off with something non ferrous.

Ruan's link:
http://docs.google.com/View?id=df9td5n3_47dhr7pmd3

Anne

On Fri, May 14, 2010 at 4:23 PM, aaron <[hidden email]> wrote:
I haven't kept up with any of the marble run business. But if you're using magnets to move the marbles (i'm assuming you all mean ball bearings, not marbles at all, and therefore not a marble run to purists) then won't they become magnetised themselves? Won't this potentially cause problems?

 --
aaron


On 14 May 2010, at 16:13, Martin Ling <[hidden email]> wrote:

On Fri, May 14, 2010 at 04:07:29PM +0100, tom hardiment wrote:

 if strong enough magnets would solve the safety/sabotage probs, i think
 this might work to release the balls?

 http://docs.google.com/View?id=dhgmmmsc_1hdk5pcd7

Mrm, problem with this approach is that I think the webbing will be
wider than the balls. I was thinking of detatching by just having the
webbing run through a slot, wide enough for the magnets to get through
but not to take the balls with them.


Martin
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Re: thoughts of clear tubing ...

Anne Suess
On Thu, May 13, 2010 at 11:47:41PM +0100, Tom Hardiment wrote:
>
>    agree with anne that maximum invisibility is gona look best-
>    tubes are less than ideal, and even webbing wont look as good as a thin
>    line.


Fri, May 14, 2010 at 12:11 AM Martin Ling wrote:
>
>The problem with a thin line is you'd get very little friction on the
>pulleys. Webbing sounds much more likely to work.

I can see why you thought a thin line would look better Tom, as it would
give maximum visibility to the balls from all directions as they go up,
which would be ideal.  Ruan suggested webbing for practical reasons,
because of potential traction, stretching and snapping problems and to
simplify the on off mechanism, however he also thought it could look good. 

It does have the problem of obscuring the view of the balls going up from
some directions, but I think this could be compensated for with the
advantage of being able to sew wire and LED's onto it for other interesting
effects both on the viewing side of the rising balls and the other viewing
side of the lowering bare magnets, which would perhaps have a clearer
view of the falling balls.  I think it may even be an advantage to be a bit
more substantial, so that it doesn't get lost in all the other activity once,
hopefully, other interesting things happen with the run aspect of the whole
thing, which would definitely benefit from being transparent. I was concerned
with whatever chosen method of rising the balls having to be covered for
protection/safety and not being seen, which is why I am so keen on
the acrylic plastic stuff Martin has found.  I do also like the idea of having
cardboard sections with windows and lights if we can avoid it looking tacky.
I agree with Martin, I think we can.

It would be good to have interesting stuff going on from which ever view point
chosen.  If some aspects can't be seen from one angle as with the balls rising
obscured by the webbing, it will encourage people to move round the thing
which will be good, but only works if we have compensated with something
else interesting to see.  This is why I think there should be as much
transparency as possible in the rest of the build and care taken to consider
how it will look from all angles.

Hope this helps you feel better about possibly using webbing :-)

Anne

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Re: thoughts of clear tubing ...

Anne Suess
Thu, May 13, 2010 at 11:01 PM Martin Ling wrote:
>
>I think it would definitely be worth collecting cardboard tubes of all
>sorts.
>
>I've raised the issue of funding with the forest, and people seem in
>favour of a £50 budget to get the lift up and running nicely. I'm happy
>to put a bit of money in myself too.

It is good to have some budget idea, but it is doubtful it can be done with only
£50 from forest!  Perhaps this needs to be addressed, before a realistic plan can
be made.  We could also perhaps start making a list of prices we already know.

It would also be good to make some measurements by stretching
some string in the space to see which line best fits, (bearing in mind the likely
width between the rising and falling 'belt' once on a pulley), as from experience
I have often found that a plausible line-of-site can sometimes be less than good
once you actually get down to trying to build on that line!  Once we have a
reasonably accurate measurement it will be easier to know how many magnets,
balls and line/webbing etc we need to buy which will help with working out the
budget!

In the meantime I will try and remember where I acquired the cardboard tubes
from carpet rolls, as it is a long time since I remember doing it!  :-)

Is there a case for an extra meeting to plan the whole thing??  Hopefully not at
the weekend as Ruan has to be in Glasgow finishing a job and would like to help
with planning the lift system!

Anne


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