ArkWall
Arkwall is a system for construction of circular walls or sections of circular
walls. This system tells you every courses distance from origin. First course
is RADIUS and each course after that is longer. Fix the swivel at the origin,
use a long steel tape and mark every courses 'Distance from origin' with a fine
tipped white marker and off you go. The higher you go, the more the plumb error
you'll get, if you are off gauge. The spec sheet tells you the plumb error at
every course for difference in gauge. For example, for the first few courses,
if you're 10 mm low or high the 'Plumb error' is negligible. As you get higher,
the Plumb error is greater for any variance in gauge. Check gauge when the
error gets significant ( like over 10 mm) and the spec sheet tells you the
correct distance from origin for each 10 mm difference in gauge. Choose the
Full Circle, if your doing a full circle or
Arc for a section of a circle Enter the inside radius. If it's a section, enter
the inside Arc length, or leave empty for full circle Enter the number of
courses. You must pull your tape right from the swivel at the origin point, so
if your working from a slab, you can't get the swivel right at gage level (
unless you drill a hole? ). If the swivel (origin point ) is higher or lower
than gage, enter the Origin Offset +- to adjust for the difference. Just fix
the swivel at the center on the slab and measure up to the point the tape will
hook to and that's the Offset. Ark will display the Radius and Arc Lengths
inside and outside. Number of blocks in the circle or section, and the
remainder in quarter block increments. Perp joint sizes, inside and out. Block
+ Perp Outside measurement.
This measurement makes it easy to check your bond
as you go around. If you've laid 10 blocks, multiply the Block + Perp
measurement by 10 and run your tape round the outside of the wall to see if
your forward or back. Use the toolbar buttons to open or close the perp joints
a quarter block each time, to get the best results. For tight curves ( short
radius) the outside perps will be large. You generally need the tightest inside
perp size, to give an acceptable outside size. For short length section, if the
perp sizes are to large, click the toolbar button to cut the last block ( not a
quarter, three-quarter or half ) to give comfortable 5mm inside perps. This
option is best for short lengths, where you can't get acceptable perp sizes
with quarter block increments.
The sheet tells you the correct diagonal
measurement for each course at gage, and alternate measurements for variances
in gage, in 10 mm increments. The smaller colored numbers next to the alternate
measurements are the Plumb error for this gage variation.
As you get higher,
check the gage and if your low or high ( usually you'll be low ) and the plumb
error is unacceptable, choose the appropriate alternate measurement, to keep
Plumb.The Plumb error is negligible for the lower courses, but increases as
you get higher For higher walls, it will be easier (and more accurate) to
raise the origin, and start again
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