Making Sigma closing loops

[freestyleleigh 0]

Hi,

I would like to make my own Sigma closing loops. We have the correct line (1000lb spectra) and are using the same washers that were used on our old loops.

They are a simple unit but my question is;

How do you get the spectra through the tiny holes?

I was told by one rigger to use some hand tacking wax thread and pull it through that way but this seems impossible.

There is nowhere to buy these in our country (as far as I know) and the postage on them from the US is much more than the worth of the loop. we have the equiment to make them just this process is inhibiting us from doing so.

Any riggers out there with the gift of the gab?

[koppel 4]

Its one of the Rigger Black Arts. Its possible to get 1250 lb Spectra through them little holes too

I like my canopy...


...it lets me down.

[irishrigger 32]

Hiya,
the easiest way in my opinion is to cut the spectre line with a hot knife.and when you cut the spectra piece cut it at an angle of about 60 degrees. That way you can thread it nice and easy through the holes in the washer.
Rodger

[riggerrob 615]

Another method is to use a piece of E-Thread as a pull-up cord.

[RIGGER 0]

FYI the Sigma main closing loop MUST came from UPT even it's a main container item which is not TSO'd.

Please see the attachment from the manual - I boxed the "WARNING" statement.

The loop spec. are critical & they must be accurate.

*** The only way to mfg. the loop is to have the Approval from UPT & the drawing.

The loop have very specific measurements, finger trap method & a special sewing method.

Do not play with "I can do it - no issues"

They does not cost too much & Air Mail should be low - check with UPT if there are any in your side.

Tandem operation makes money & if you calculate the loop cost per no. of jumps on a loop + shipping you still have a huge profit same for other parts which must be originals from UPT.

Be Safe !!!

[ronny2 0]

Hi shlomo, I know what you mean, but what about this?

http://www.cpsworld.com/tech_pdfs/RWS/WI-038_Rev.0-Sigma1290.pdf

[jerolim 7]

thanks for the post - buahahahaha (evil laugh) .

[pchapman 278]

Quote

http://www.cpsworld.com/tech_pdfs/RWS/WI-038_Rev.0-Sigma1290.pdf

So that demonstrates that 'build your own' instructions for loops exist, invalidating the argument that only the factory is able to produce such things. (...Whether or not any particular person can build any particular item to the required degree of accuracy.)

However, in this case the pdf instructions are for a military Sigma-style container, that uses a 'pulley closing loop' different from our civvy Sigmas ( 7.5" not 8.5").

Their loop system:
http://www.cpsworld.com/tech_pdfs/RWS/Closing_instructions_TS14pulley%20closing_loop.pdf

So, where are the civilian Sigma loop instructions?

[RIGGER 0]

CPS deal with the Military only & the Military has a system that is very different from the civil world including tests, rigging & so on.

The instructions you point on are NOT VALID for the civil sigma & should NOT be followed at all.

We use for the Sigma V13 with Sigma 370 main a loop which is 8.5" long.

Sport market/world & the Military world are two different planets with different specifications.

Be Safe !!!

[ronny2 0]

Sport market/world & the Military world are two different planets with different specifications

We are also from the planet "world" and we jumping the same "Sigma" system

Sigma MM 14
Main: Silhouette 330
Reserve: Silhouette 335
Main loop: 8.5" long

[RIGGER 0]

I like that we are in the same "world" planet - I was pointing on 2 different training/thechnical systems = Civilian & Military even the parachuting systems might be the same or close to that.

The military gets approvals from CPS (PD, UPT, SPP) which the civil market might not get & it could be from technical & liability reasons.

The military have a more organized rigging system which is very clear for yes & no.

Cheers

[jerolim 7]

I have done some reverse engineering. I have marked and disassembled old Sigma closing loop (civil). I have found that it is made in same fashion as in posted document. So you can use steps 1-10 from this document http://www.cpsworld.com/tech_pdfs/RWS/WI-038_Rev.0-Sigma1290.pdf

Regarding length my closing loop (before disassembly) was 22 cm long. This is 8,75 " = 8 3/4 long ! So it looks like this markings from step 1 ( 0–7” – 7 ¾” - 15”–15 ¾”–23” ) are correct.
Because final loop size will be 8 3/4". This is the math : From marks 15 3/4" to mark 7" (15 3/4" - 7" = 8 3/4") equals 8 3/4".

At last picture lenght says 7 1/2" this can be true only if spectra schrinks because it wider after finger trapping !!!

Any way I'll check what are my markings on old disassembled loop and I'll let you know.

Stitch pattern looks like one from step 10 and I have tried to break picked thread with fish scale - it broke at 4 kilos. So, it is definitely thread is E type. Stitch pattern has to be done neatly and one has to pay attention to thread tension if you want to have smooth (less friction) loop at the end.

I don't know if silicon based lubricant (from cypres kit) needs to be applied or not ?

[jerolim 7]

Hi, spectra schrinks after finger trapping.

This are measures in centimeters (for first picture) :
0-21-22-45-47-68

So it is something like
0- 8 1/4" - 8 2/3" - 17 3/4" - 18 2/4" - 26 3/4 "
in inches.

You can play with this numbers maybe everything needs to be shorter a few milimeters. Anyway result will be around 22 cm = 8,5 "