Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and
a rubber band: Wrap the band around both, then slide them apart to meet
the target, then let the rubber band hold them in position as the whole
thing is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution
for this.

The idea of two canes is great, it's a similar idea to the way to make a
template with overlapping hardboard panels. But the ends need to be pointed
so there's only one point of contact.

Not sure about the rubber band though, which could move out of position.
Why not simply make a pencil mark across both canes, so you can measure from
the end on each one and then add the dimensions together?


"GMM" GlMiMa-AT-yahoo.co.uk wrote in message
...
Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an angle
(so a small deviation will provide a significant error), so it's important
to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and a
rubber band: Wrap the band around both, then slide them apart to meet the
target, then let the rubber band hold them in position as the whole thing
is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution for
this.

"GMM" wrote in message ...

Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so it's
not possible to read the scale of a tape) and one end is at an angle (so a
small deviation will provide a significant error), so it's important to
measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and a
rubber band: Wrap the band around both, then slide them apart to meet the
target, then let the rubber band hold them in position as the whole thing
is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution for
this.

What you are describing is a crude form of Gunter Rule - which is two lath
shaped pieces of (usually) boxwood, each with a longitudinal slot through
which passes a bolt and thumb screw. The Royal Navy uses a large version
when making emergency shoring up repairs to war damage on board. The Gunter
Rule is used in the holed compartment (usually dark and pretty full of
water!) to measure the length of shoring timbers. The rule can be passed
though a small hole to other compartments where the timber is cut to size.

Andrew

GMM wrote:
Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and
a rubber band: Wrap the band around both, then slide them apart to meet
the target, then let the rubber band hold them in position as the whole
thing is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution
for this.

I'm not sure about exactly what it is you're measuring, but you could
use two tape measures (one from each end), read them at any convenient
point where they cross, and add the readings. Or it might be more
convenient to make one of them a rigid rule.

--
Mike Barnes
Cheshire, England

On 14/06/2014 09:22, Andrew Mawson wrote:
"GMM" wrote in message ...

Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes
and a rubber band: Wrap the band around both, then slide them apart
to meet the target, then let the rubber band hold them in position as
the whole thing is withdrawn and measure the overall length (if that
makes sense!).
It occurred to me though that someone here may have a better solution
for this.

What you are describing is a crude form of Gunter Rule - which is two
lath shaped pieces of (usually) boxwood, each with a longitudinal slot
through which passes a bolt and thumb screw. The Royal Navy uses a large
version when making emergency shoring up repairs to war damage on board.
The Gunter Rule is used in the holed compartment (usually dark and
pretty full of water!) to measure the length of shoring timbers. The
rule can be passed though a small hole to other compartments where the
timber is cut to size.

Andrew


I don't know if I've seen one of those or it was just the product of a
fevered imagination but that is pretty much what I had in mind. It's
particularly good to be able to put a name to it: That way it sounds
like I've built a pro tool rather than a bodge from a few scraps of wood
and some nuts and bolts

Since the range of measurements I need to make will range from ~20cm to
around 65cm, I'll probably have to knock up more than one (or an
extension piece to make the mid section).

On 13/06/2014 23:57, GMM wrote:
Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and
a rubber band: Wrap the band around both, then slide them apart to meet
the target, then let the rubber band hold them in position as the whole
thing is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution
for this.


seen window companies using a telescopic version to do same thing when
measuring for windows.



--
UK SelfBuild: http://uk.groups.yahoo.com/group/UK_Selfbuild/

On 13/06/14 23:57, GMM wrote:
Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and
a rubber band: Wrap the band around both, then slide them apart to meet
the target, then let the rubber band hold them in position as the whole
thing is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution
for this.

Laser measure?
http://www.leica-geosystems.co.uk/en...O-D2_69656.htm





--
djc

On 13/06/2014 23:57, GMM wrote:
Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and
a rubber band: Wrap the band around both, then slide them apart to meet
the target, then let the rubber band hold them in position as the whole
thing is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution
for this.

Advent 2in1 Gap Tape


http://www.tlc-direct.co.uk/Products/FXGT5.html

Bloody brilliant!


--
Dave - The Medway Handyman www.medwayhandyman.co.uk

On 14/06/2014 09:41, Mike Barnes wrote:
GMM wrote:
Normally a little bit of error on an internal dimension doesn't really
matter but it'll be important on this job. Both 'ends' are buried (so
it's not possible to read the scale of a tape) and one end is at an
angle (so a small deviation will provide a significant error), so it's
important to measure just the right spot.
One trick I've used before (and may use here) is two gardening canes and
a rubber band: Wrap the band around both, then slide them apart to meet
the target, then let the rubber band hold them in position as the whole
thing is withdrawn and measure the overall length (if that makes sense!).
It occurred to me though that someone here may have a better solution
for this.

I'm not sure about exactly what it is you're measuring, but you could
use two tape measures (one from each end), read them at any convenient
point where they cross, and add the readings. Or it might be more
convenient to make one of them a rigid rule.

How clever is that!


--
Dave - The Medway Handyman www.medwayhandyman.co.uk

djc is correct in suggesting that a laser measure should be utilised.

Laser to measure
A laser measure, measures uses a laser to take a measurement so removing the requirement for a physical contact between the two measuring points. If you can see the place you would like to measure too, then you can measure to it.

Accuracy
Accuracy is improved over a tape measure and especially a cane. Leica Geosystems have developed instruments with accuracies of 1mm over distances of 200 meters.

Time Saving
Forget using a tape measure anyway, you need two people to take a measurement, one to hold the tape and the other to place the end. As shown in previous conversations, where you cannot actually get to a point you have to improvise so reducing the accuracy of the measurement.

So with a laser measure, one person can measure a house, office, warehouse and even a construction site in a fraction of the time. Commonly a quarter of the time with a vastly improved accuracy.

Leica Geosystems manufacturer a range called Leica Disto starting at just £99. So checkout their range at Leica DISTO laser measures | Survey Express Services | Surveying & Safety Equipment Specialists

A good source of measuring and testing equipment is Survey Express Services
Survey Express Services | Surveying & Safety Equipment Specialists, they have over 40 years experience and office throughout the UK. Plus a little arm twisting and you can get a discount!!!

Hope this helps
Ian Guest

http://www.leevalley.com/en/Wood/pag...513,43553&ap=1

Make your own.

Unfortunately I've found them to be very fragile