Petzl Duo Mounting Problem

[flexx]

I am attempting to mount my duo on my elios helmet. And before anyone asks i had the helmet before getting the duo thats the reason i don't have the spelios. The problem is that all three holes on the battery box don't sit flush on the helmet due to the mounting for the rear strap. I have searched all over the internet and the forum and cannot find a solution. Anyone else come across this?
I can mount the battery box above the strap but then it sits too high and i will almost certainly smash it off on the first trip.
Any help appreciated thanks.

http://www.flickr.com/photos/92515387@N05/

 

[PaulW]

i'm about to do one my self.

you will find you will probably need to cut of the offending pieces of plastic the the stap goes through on the read of the battery box

 

[PaulW]

Ah sorry just seen your pics,

i will have to look at a friends spelios to see how it is done if no one else comes up with the answer

 

[Pete K]

The Spelios uses a different strap attachment than the Elios, I think some kind of rivet.
I fancied a black 'Spelios' so fitted a Duo to an Elios a couple of years ago. I took the plastic strap retainer out and trimmed it down slowly with a sharp knife until it presented less of an obstruction. I think it was mainly the plastic either side of the strap that I trimmed. Once I'd done that I had no problem fitting the battery box, I just didn't fully tighten the lower screw in order to not flex the helmet shell. Mine is approaching 5 years old now and still in A1 condition - see avatar.

 

[PaulW]

Cheers for that Pete, hopefully thatwill help us both out, i have a black and blue elios spare, but i think the other half will prefer the blue one

 

[potholer]

Would it be possible to add some kind of standoff (short pillar or 'thick washer') to the lower mounting to allow the box to sit further away from the helmet while still being rigidly mounted?

 

[flexx]

Cheers for that Pete I will have a go at filing the strap down. 
With regards to the washer without filing down the strap mount I think it would have to be a fair few washers to bulk it out.

 

[heinrich]

Standoffs/washers will surely work. 
However, I took a much simpler approach and mounted the battery
container over the plastic strap retainer without any modifications.
The container (and helmet shell) tends to deform slightly if screws
are locked down and you might have troubles to insert the batteries.
Allowing for a 2mm spacing between container and helmet shell
is enough to relax the assembly sufficiently to insert/remove batteries and
to close the the container.
Probably not pretty, but works since 3 years now without problems.
http://www.flickr.com/photos/92541799@N07/

 

[Pete K]

I was worried over time that the movement of the screws through the shell in heinrich's method may wear the holes larger and lead to the screws pulling through, a bit like the screw thread acting like a file against the plastic. I see after his 3 years of use that that was a worry I may not have needed.

 

[potholer]

With regards to the washer without filing down the strap mount I think it would have to be a fair few washers to bulk it out.

'Thick washer' was in quotes.
Lots of things could do the job, such as a suitable block of material glued onto the battery box around the screw pillar - all that's needed is something to increase the spacing to allow
a) the screw to be tightened and the box solidly mounted
with
b) the box not being excessively bent over the lump

Various things might work, depending on the relative curve of the box and helmet - maybe a slab cut from a plastic cork (which might deform nicely to fit the curved box and helmet).