I want to make an adjustable height table, one with a single central
leg. To be more specific I want a 'two heights' table, 34cm to bottom
of table top and 68cm to bottom of table top.

Does anyone know if there is standard hardware available for this sort
of thing or do I need to make it myself?

Since it's (almost exactly) a 2:1 step down it can't be done with a
single pair of concentric tubes. I'm thinking maybe one constructs
the table with a 34cm tubular leg that fits over a foot and then one
makes a 34cm extension which is inserted to make the 68cm version.

Or simply two legs, one 34cm and the other 68cm and you use one or the
other. All this then needs is a thing like a giant wardrobe tube
holder on the underside of the table and on the floor (It can be fixed
permanently to the floor).

That's probably the bit I need to find/make, a short piece of tube
with a flange that will fit snugly over an easily obtained size of
tubing. My guess would be that it needs to be 10cm or so diameter.

Any ideas for suppliers and/or what such a thing is called?

--
Chris Green

On 14/12/2012 16:55, wrote:
I want to make an adjustable height table, one with a single central
leg. To be more specific I want a 'two heights' table, 34cm to bottom
of table top and 68cm to bottom of table top.

Does anyone know if there is standard hardware available for this sort
of thing or do I need to make it myself?

Since it's (almost exactly) a 2:1 step down it can't be done with a
single pair of concentric tubes. I'm thinking maybe one constructs
the table with a 34cm tubular leg that fits over a foot and then one
makes a 34cm extension which is inserted to make the 68cm version.

Or simply two legs, one 34cm and the other 68cm and you use one or the
other. All this then needs is a thing like a giant wardrobe tube
holder on the underside of the table and on the floor (It can be fixed
permanently to the floor).

That's probably the bit I need to find/make, a short piece of tube
with a flange that will fit snugly over an easily obtained size of
tubing. My guess would be that it needs to be 10cm or so diameter.

Any ideas for suppliers and/or what such a thing is called?


One of your issues is going to be the bending moment. In other words,
how wide is the table, what load will it see, and what is the maximum
offset of the load? That will determine the strength required in your
"giant wardrobe tube holder".

Presumably there is a very good reason for needing a single central leg?
One of the standard ways to construct a variable height table is with a
scissors mechanism: think ironing table or industrial scissors lifting
platform.

If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

I'm assuming it is free-standing; you don't have an adjacent wall you
can use to improve stability?

Much more information needed!

Owain wrote:
On Dec 14, 4:55Â*pm, wrote:
I want to make an adjustable height table, one with a single central
leg. Â*To be more specific I want a 'two heights' table, 34cm to bottom
of table top and 68cm to bottom of table top.

If the leg doesn't have to be too thin, i.e. a column would suffice,
you could use a XXXXX concertina support similar to that used on old
washing dryers.
http://www.lakeland.co.uk/4655/Woode...-Clothes-Airer

I think that would be too bulky (and probably wobbly)


Boat chandlers or caravan suppliers probably have table-leg-to-floor
interface plates. Oh yes:

http://www.miriad-products.com/secti...ec=232&xPage=1

Aha, that's the sort of thing I'm after. In particular the "Conical
table leg base" and the "Island Table Leg", no prices though which is
a bit worrying!


http://www.leisureshopdirect.com/car...ess_steel.aspx

Excellent, thank you, and the prices are far from silly.


And bingo, here's a telescopic leg

http://www.leisureshopdirect.com/car...able_pole.aspx

Hmm, a bit expensive that one!

--
Chris Green

newshound wrote:
On 14/12/2012 16:55, wrote:
[snip]
That's probably the bit I need to find/make, a short piece of tube
with a flange that will fit snugly over an easily obtained size of
tubing. My guess would be that it needs to be 10cm or so diameter.

Any ideas for suppliers and/or what such a thing is called?


One of your issues is going to be the bending moment. In other words,
how wide is the table, what load will it see, and what is the maximum
offset of the load? That will determine the strength required in your
"giant wardrobe tube holder".

Yes, stability is an issue.

Presumably there is a very good reason for needing a single central leg?
One of the standard ways to construct a variable height table is with a
scissors mechanism: think ironing table or industrial scissors lifting
platform.

It's a small boat galley table. Seating on three sides and the fourth
side faces the galley itself. Thus there can't really be legs at the
corners. A central leg is pretty standard on these tables.


If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

Yes, adjusting the height is to enable the table top to drop down to
seat height so the whole thing becomes a bed. Doesn't actually need
support in the middle when lowered as the table top rests on an inset
in the edge of the seats.


I'm assuming it is free-standing; you don't have an adjacent wall you
can use to improve stability?

Not for this one (another we have does use the wall plus a slim leg).

The existing table works OK except that removing the table top to
convert to a bed involves undoing eight screws which is somewhat
laborious (especially at bed time).

--
Chris Green

wrote:
Owain wrote:
On Dec 14, 4:55 pm,
And bingo, here's a telescopic leg

http://www.leisureshopdirect.com/car...able_pole.aspx

Hmm, a bit expensive that one!

You have a boat and you think that's expensive? ;-)

Tim

On Dec 15, 12:25*pm, wrote:
newshound wrote:
On 14/12/2012 16:55, wrote:
[snip]
That's probably the bit I need to find/make, a short piece of tube
with a flange that will fit snugly over an easily obtained size of
tubing. *My guess would be that it needs to be 10cm or so diameter.

Any ideas for suppliers and/or what such a thing is called?

One of your issues is going to be the bending moment. In other words,
how wide is the table, what load will it see, and what is the maximum
offset of the load? That will determine the strength required in your
"giant wardrobe tube holder".

Yes, stability is an issue.

Presumably there is a very good reason for needing a single central leg?
One of the standard ways to construct a variable height table is with a
scissors mechanism: think ironing table or industrial scissors lifting
platform.

It's a small boat galley table. *Seating on three sides and the fourth
side faces the galley itself. *Thus there can't really be legs at the
corners. A central leg is pretty standard on these tables.

If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

Yes, adjusting the height is to enable the table top to drop down to
seat height so the whole thing becomes a bed. *Doesn't actually need
support in the middle when lowered as the table top rests on an inset
in the edge of the seats.

I'm assuming it is free-standing; you don't have an adjacent wall you
can use to improve stability?

Not for this one (another we have does use the wall plus a slim leg).

The existing table works OK except that removing the table top to
convert to a bed involves undoing eight screws which is somewhat
laborious (especially at bed time).

--
Chris Green

Ikea has a couple of tele-legs not sure if would be rigid enough
though

http://www.ikea.com/gb/en/catalog/ca...kspaces/11845/

Cheers
Adam

On 15/12/2012 12:25, wrote:
newshound wrote:
On 14/12/2012 16:55, wrote:
[snip]
That's probably the bit I need to find/make, a short piece of tube
with a flange that will fit snugly over an easily obtained size of
tubing. My guess would be that it needs to be 10cm or so diameter.

Any ideas for suppliers and/or what such a thing is called?


One of your issues is going to be the bending moment. In other words,
how wide is the table, what load will it see, and what is the maximum
offset of the load? That will determine the strength required in your
"giant wardrobe tube holder".

Yes, stability is an issue.

Presumably there is a very good reason for needing a single central leg?
One of the standard ways to construct a variable height table is with a
scissors mechanism: think ironing table or industrial scissors lifting
platform.

It's a small boat galley table. Seating on three sides and the fourth
side faces the galley itself. Thus there can't really be legs at the
corners. A central leg is pretty standard on these tables.


If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

Yes, adjusting the height is to enable the table top to drop down to
seat height so the whole thing becomes a bed. Doesn't actually need
support in the middle when lowered as the table top rests on an inset
in the edge of the seats.


I'm assuming it is free-standing; you don't have an adjacent wall you
can use to improve stability?

Not for this one (another we have does use the wall plus a slim leg).

The existing table works OK except that removing the table top to
convert to a bed involves undoing eight screws which is somewhat
laborious (especially at bed time).


OK. In that case Owain's linked item looks good; not cheap, but there is
quite a lot of engineering in it. Note that when dropped, it protrudes
below the "floor". It's good that you don't need the same stability in
the lowered position. If I were DIY-ing I think I would look at a single
removable leg. Perhaps you could get stability for the leg by having the
mounting boss on the hull, with the leg supported in a (small) clearance
hole in the deck. Your only problem then would be making the leg - table
fitting sufficiently rigid.

wrote:
newshound wrote:


If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

Yes, adjusting the height is to enable the table top to drop down to
seat height so the whole thing becomes a bed. Doesn't actually need
support in the middle when lowered as the table top rests on an inset
in the edge of the seats.

If it's not needed in the lowered position, what's wrong with a simple
removable leg that you stow somewhere?

Tim

Tim+ wrote:
wrote:
newshound wrote:


If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

Yes, adjusting the height is to enable the table top to drop down to
seat height so the whole thing becomes a bed. Doesn't actually need
support in the middle when lowered as the table top rests on an inset
in the edge of the seats.

If it's not needed in the lowered position, what's wrong with a simple
removable leg that you stow somewhere?

Absolutely fine, but I still need the hardware to make a rigid
connection between the removable leg and both the floor and the table
top.

--
Chris Green

wrote:
Tim+ wrote:
wrote:
newshound wrote:


If you can remove the table when you change the height, the arrangement
you describe doesn't sound too difficult. But you need to know the loads
before you can specify the tube. If the loads and bending moments are
not too high, you might think about using plastic waste fittings, for
example. How steady does the table need to be?

Yes, adjusting the height is to enable the table top to drop down to
seat height so the whole thing becomes a bed. Doesn't actually need
support in the middle when lowered as the table top rests on an inset
in the edge of the seats.

If it's not needed in the lowered position, what's wrong with a simple
removable leg that you stow somewhere?

Absolutely fine, but I still need the hardware to make a rigid
connection between the removable leg and both the floor and the table
top.


Caravan tables just have a tapered socket top and bottom (IIRC) for the
table leg to fit into.

What's wrong with something like this?
http://www.ebay.co.uk/itm/Island-Tab...item2326312acb

Tim

Tim+ wrote:
wrote:
Absolutely fine, but I still need the hardware to make a rigid
connection between the removable leg and both the floor and the table
top.


Caravan tables just have a tapered socket top and bottom (IIRC) for the
table leg to fit into.

What's wrong with something like this?
http://www.ebay.co.uk/itm/Island-Tab...item2326312acb

That's exactly the same as a previous reply took me to (from a
different supplier). Are the two end pieces actually tapered sockets?

--
Chris Green

wrote:
Tim+ wrote:
wrote:
Absolutely fine, but I still need the hardware to make a rigid
connection between the removable leg and both the floor and the
table top.


Caravan tables just have a tapered socket top and bottom (IIRC) for
the table leg to fit into.

What's wrong with something like this?
http://www.ebay.co.uk/itm/Island-Tab...item2326312acb

That's exactly the same as a previous reply took me to (from a
different supplier). Are the two end pieces actually tapered sockets?

IIRC, the top when mounted on the leg doesn't swivel so I think there must
be a slight taper.

Tim