Nora4 Fitting Guidance
Nora4 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 hex 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.
The standard Nora4 / Edna2 battery box can be attached with shock cord (suggested 4mm) or two cable ties.
This will require up to 4 suitably positioned holes drilled in helmet, depending on preferred fixing method
and helmet design. See Little Monkey website for other battery boxes.
The lamp can now be fitted to the lamp bracket. Nora has been designed for cable to run inside the helmet,
though many arrangements are possible. The lamp housing and cable can typically be threaded under the
rim of the helmet, behind the cradle inside the helmet and back and out at the front of the helmet, though
many arrangements are possible
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, using 4mm hex key. To maintain good water
integrity, high viscosity silicone grease can be used on battery box O ring and front window O ring.
The battery box is opened at the opposite end to the cable gland. 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). Take reasonable care when fitting battery in order that wires do not get trapped /
damaged, and individual batteries are orientated correctly in Nora battery holders. The battery holder has li-
ion protection circuitry. Take care not to damage this. The cable gland end of the battery holder can be
opened for service / maintenance purposes.
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.