News and Events

Keep up to date with the latest news and events of Modular Bikes.

Monday, March 25, 2019

Helmet Finished

Old front light mount bolt could be forehead-impaling

New front light mount using cloth covered elastic bands might be a bit safer.
Similar elastic used to hold the lid of my tailbox down.

Mirror in action

Side View.  The original visor has been removed from this Scott helmet, and the blind holes used to secure it drilled through for the cable ties at the side. 

View from below

Wearing it.



Hi

As mentioned last time, I’ve been working on a helmet visor project.  I’ve made 3 different 3d printed samples and have come up with something I’m happy with.  Coincidentally, my friend and neighbour, Stu has been recovering from a bad bike crash which forced him to be helicoptered to hospital from north-western Victoria.  Quite a few people advocate helmet-free-cycling in Australia, but Stu would vote for wearing helmets always, as it’s quite probable that his has saved his life.

Anyway, Stu’s crash and injuries made me think about the safety aspects of my own helmet design, and forced me to make a few changes.  Helmets are …….”protective head coverings especially made of a hard material to resist impact” (Penguin Pocket English Dictionary 1986), and this defines their primary purpose as preventing head injuries during accidents.  But on bikes they can have a range of secondary purposes, and these can include

* preventing accidents themselves by improving cyclist visibility by being brightly coloured, and including front and rear lights and reflectors.
* improving rider comfort by preventing sun glare and sun burn through use of a visor
* improving rider awareness of traffic and comfort by providing a rear view mirror.

These secondary purposes of the helmet are often used, but the primary purpose of the helmet is rarely used. However, as Stu’s accident showed, when used for the primary purpose, the design of the helmet is really important, and the secondary bits on the helmet shouldn’t compromise the original purpose of the design.

So advertently and inadvertently, my new printed-side helmet design takes a few positive steps in this direction. The flutes in the corflute part of the visor now run in the fold direction of instead of perpendicular to the folds as in the earlier version.  This means that on impact the corflute should crush more easily avoiding injury.

The corflute is only held in the side plates by the tight fit of the corflute, and there is no glue, and no pins or other fasteners. (At one stage I was contemplating adding map pins to the design to hold it together, but sofar it hasn’t needed them) So on impact the corflute should slip out of the side plates and not cause injury.

The front light is held on to the visor by this sort  of elastic band which I discovered on a shopping trip with my wife Christine.  This makes for a sort of resilient mount which should break apart on impact. Previously I had drilled the base of the blinky light and the centre of the mirror to hold it in place.  This needed work but also left a large bolt-end protrusion ready to pierce the forehead!
So that’s it for now.  I will put the design on thingiverse soon.  Hardest to obtain might be the 3mm x 20mm x 180mm plastic mirror sheet.

Steps to make helmet mirror thing:

Find a suitable helmet, my conversion is of a Scott Supra-Pak 10 from Anaconda.
You will need 6 cable ties approx 200 x 2.5mm wide,
3mm coreflute,
3 x 180 x 20 plastic mirror.

Navigate your way to Thingiverse.

Print the coreflute plan, cut out and fold the coreflute.
3d print the parts for the sides of the visor.
Remove the original visor from the helmet.
Drill approx 2.8mm through the holes used to hold the visor.  This small diameter means the black visor hole surrounds are not disturbed.
Assemble and test.

Good Luck!


Regards

Steve Nurse

2 comments:

  1. Hi Steve, I like your latest design for your helmet visor. I like how it is safe to allow the helmet to work correctly if needed. Can you let me know its name and when it goes on thingiverse? Cheers Brad

    ReplyDelete
  2. Hi Brad. I'm almost ready to upload to thingiverse. I thought of Ruckvisor (sort of like german ruckweise) for a name but there is already a Tuckvisor! Still thinking! Regards

    Steve nurse

    ReplyDelete