Nora3 Fitting Guidance
Nora3 is designed to be helmet mounted. Fitting is fairly intuitive. The standard alloy lamp bracket requires 3
holes drilled in the front of the helmet (4.5mm). When drilling, take care not to damage cradle etc, on inside of
helmet. The lamp bracket can be used as a template. Position of lamp bracket is personal preference, and
helmet type dependant. If possible, position lamp high enough to avoid interference with peripheral vision.
Orientate lamp and mark position of lamp bracket central fixing hole, drill helmet, and attach bracket to helmet.
M4 stainless steel allen screws & lock nuts are provided for this. Mark other 2 bracket holes, twist bracket to
one side (or remove completely) and drill helmet. When fixing bracket to helmet, nuts should be on the
outside. The extending arms of the alloy lamp bracket will need to be adjusted to suit lamp and accommodate
curved helmet profile. They can be bent carefully by hand as required.
Fitting the battery box, with 2 off M3x35mm allen screws, washers and nuts, requires 2 holes (3.5mm-4.5mm)
drilled in rear of helmet 49.5mm apart. Screw heads and washers should be on the inside of the helmet, and
nuts on the outside. Battery box should be orientated so that bottom of box is just above the helmet rim. Some
helmets may benefit from shorter 30mm screws (not supplied). Alternatively, the battery box can be attached
with two cable ties or with suitable shock cord. The battery box has 2 grooves to accommodate this and
requires that 4 suitably positioned holes are drilled in helmet.
The lamp can now be fitted to the lamp bracket. The lamp housing and cable should be threaded under the
rim of the helmet, behind the cradle inside the helmet and back and out at the front of the helmet. Nora has
been designed for cable to run inside the helmet. Nothing pisses us off like a cable draped around the outside
of a helmet.
The lamp is fitted to the bracket with 2 off M5 cap head screws. The M5 stainless spring washers fit between
the screw heads and the bracket, the M5 stainless washers fit between the bracket and the lamp body.
Orientate lamp to desired angle and lock up both screws. The lamp bracket and battery box lid use the same
4mm allen key. This will need to be carried along with any spare batteries if on a very long trip that might
require additional batteries. To maintain good water integrity, high viscosity silicone grease can be used on
battery box O ring and front window O ring.
Battery and lamp connectors are polarized so correct polarity is ensured. Battery connections should be made
outside of the box, and battery pack orientated in battery box, with wires and connectors typically orientated
down inside wall of box (opposite side to cable entry). Battery is best inserted with wires from heat shrunk
pack positioned to the bottom of the box. Take reasonable care when fitting battery pack that battery and lamp
wires do not get trapped / damaged, and individual batteries are orientated correctly in Nora battery holders.
The Modification of Helmets for Caving
By necessity helmets have to be modified in order that they can effectively be used for caving or adapted to
suit the requirements of a particular task within the caving environment. Invariably holes will need to be drilled
in the shell so that lamp brackets or reserve lamps can be fitted. Cavers drill helmets; as they principally use
these to mount lamps and protect from light bumps.
If holes are drilled in sensible positions and kept to a minimum they are unlikely to have an adverse effect on
the overall strength or protection offered by the helmet shell, but obviously this can't be guaranteed. Drilling
holes into a helmet shell technically invalidates its certification as Personal Protective Equipment (PPE) and
may have an adverse effect on the amount of protection provided by it, so anyone who modifies or uses a
modified helmet must be aware of, and fully accept, the potential incurred risks of the modification beforehand
and during subsequent use.
Li-ion Battery Packs
Nora3 uses high capacity, quality 2p li-ion battery packs, professionally manufactured with appropriate
protection circuitry. Our cell packs are produced in an industry standard flat pack configuration; no fancy
layouts to tie you into our product. You can also use 2x individual 18650 li-ion batteries (unprotected) and 3x
AA batteries with appropriate Nora holders.
