PET Strapping for Megatree

AussiePhil

AussiePhil

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Canberra, ACT, Australia
Been looking at various options to redo one megatree this year and the US guys have long spoken of pallet strapping.


In doing some research i found PET pallet strapping, nice some edges and tough as nails and really doesn't stretch when pulled tight.


First got a sample of 16mm wide but by the time you put a 12mm hole in it there wasn't much left so bit the bullet and ordered a roll (900M) of the 19mm wide stuff.
It has something like a 800Kg breaking strain so even with a bunch of 12mm holes in it it still doesn't stretch.


Now one thing with the PET strapping is it splits lengthwise really easy so normal drills just cause it to split, so you have to use diamond coated hole saws which cut though it cleanly (and quickly).
You get holes like this...


P9220352.jpg




And the pixels go in like this.... these pixels are really tight so I'm looking at some sort of press jig to make it easier on the fingers.
P9220353.jpg



string of 50 rolled up looks like..
P9220354.jpg



Stretched out in the hallway there is no sign of twisting.
P9220357.jpg



P9220361.jpg





I did make a drilled jig up, 3D printed of course, but don't have a photo handy.


What i haven't yet worked out is the top and bottom fixing methods for the strapping.
 
I've purchased the automated machines and pet strapping for a couple of companies I've worked for. You can use the old steel strapping snap on seals on the strap if you have access to them. The only issue there is you wouldn't be able to remove them. You can try some decent size cable ties. Apply a cable tie, fold the strap back over the cable tie and then use another cable tie or two to hold it (cheapest and easiest option for removal). We've used htat method for strapping onto crates. I was surprised how well it worked.
I'm sure you'll be flooded with some great ideas for anchoring from our talented and clever members.
 
where did you get it from phil?

i would be interested to see if i could make it work with my laser cutter.
 
Phil, you could make something with your 3d printer that the strap could thread threw (like a small buckle). On the other side have a place to hook in a bungie cord to secure down.
 
Where to buy:
I bought mine from http://www.hipac.net.au/pet-strapping-seals
For those in other states do a search for a local packaging supply firm


How to precisely space that holes:
I designed and then 3D printed this little jig set up, keeps the strap centred and flat.


P9260362.jpg



The hole cutter is a 12mm diamond tipped hole saw.


They are an absolute pain in the butt to clean the centre cut bit out of but there is no other way to safely drill this stuff.


Cozbert: I reckon the laser cutter would work really really well.




We also made progress today on a top of the tree connector for the strapping.


P9260374.jpg



As i always put my strings up as 100 count pairs it made sense to design a dual strap bracket.
The two holes are for 6mm rod to form the actually hook to the topper on the pole.
The right hand one is deformed a little as i was doing a little stress test by hanging the above in such a way that i could step into the loop of strap with my 100kg weight. Apart from the slight deformation there seemed to be no other issues.
The "F" for front is there as the strap slots do have a 5 degree angle on the slot.
 
One of a million reason for a 3d printer! Looks awesome I cannot wait to see what it turns out like!
 
Would you be able to post theSTL file for the jig?
If not here over on thingverse.
Cheers
 
Well they say 3D designs go through variations......


Designed the bottom bracket for the strapping and made a self locking design.
P9290383.jpg





This resulted in me redoing the top connector to be a similar design, but as a joined pair...
P9290384.jpg



The grey filament is a little thinner hence the gaps in the top layer above,


Klanook: Happy to post the STL, i'll add it into this thread for the time being.
 
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