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#11418 - 08/21/06 05:11 PM Compression Springs and #280 s-hook BAD
Hal Offline
Moderator

Registered: 07/17/00
Posts: 9945
Loc: Blue Creek, Ohio, USA
For those of you who are interested, I just built a new contraption for testing BADs on snares. It's crude, but it's fairly accurate within 5 to 10 percent anyway.

The first thing I tested was some cam locks with #280 BADs. A dozen averaged 270 lbs. Then I put one of John Grams 50 pound compression springs between the end stop and the lock. I put a small washer between the spring and the s-hook. Now I am unsure where the compression ratings comes on these springs. I measured them and they reached full compression at 20-25 pounds. But, that's almost a moot point.



The spring equipped snares broke out at exactly the same place -- 270 pound average. I did notice that when the spring becomes fully compressed it is just as if you have a piece of steel tubing on the end of the snare. Once the pulling force exceeds the compression force of the spring the spring bottoms out and the rest of the force is applied to defeating the snare. I would expect to obtain the same results with different weight springs. As long as the spring is less strong than the BAD, it will have no effect on the break away strength.

smile -- Hal
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#11419 - 08/21/06 08:16 PM Re: Compression Springs and #280 s-hook BAD
archer01 Offline
Member

Registered: 03/25/05
Posts: 340
Loc: N.E. Penna.
Hal,
Interesting!
Why do you think the compression spring is bottoming out at half of what it is rated?

Also your last sentence,
< As long as the spring is less strong than the BAD, it will have no effect on the break away strength. >

Wouldn't a stronger spring also have no effect on the break away strength..?

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#11420 - 08/22/06 12:47 PM Re: Compression Springs and #280 s-hook BAD
redsnow Online   content
Moderator

Registered: 06/11/06
Posts: 2050
Loc: WV
I'd like to see a picture of your "contraption." I assume it's basically : an anchor, a snare, scales, and some type winch/come-along? One thing that I don't understand about these BADs is, if the "anchor" is 1 inch pipe/rod, it's(the BAD) going to "fail" before it would on a 3 inch pipe/rod. (resistance) I hope that makes sense. ?? What happens when the snare is on something "fleshy/squishy" like a cow/horse leg? I can see where the postition of the lock, and diameter of the snared "object" could make a lot of difference. Right or wrong?

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#11421 - 08/22/06 05:56 PM Re: Compression Springs and #280 s-hook BAD
Hal Offline
Moderator

Registered: 07/17/00
Posts: 9945
Loc: Blue Creek, Ohio, USA
Archer: Yes, I believe the break away strength would be about the same no matte what strength of compression spring you would put in.

Red: Wrong. The larger the diameter of the anchor, the lower the strength of the BAD. I just put at few 280's on a 7 inch pipe just to confirm this. They broke at 240 lbs. Leverage trumps friction. There is actually very little friction involved here. (You might want to search the Traps & Equipment Archives for previous discussions on this.)

As for fleshy squishy, that is exactly the kind of variable this test avoids. The 3 inch pipe was standardized at the Denver Research Center in 1990.

smile -- Hal
_________________________
Endeavor to persevere.

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#11422 - 08/22/06 09:54 PM Re: Compression Springs and #280 s-hook BAD
redsnow Online   content
Moderator

Registered: 06/11/06
Posts: 2050
Loc: WV
Whew!!!, just finished reading the BAD Test thread. From the pics I see that friction is not a factor. Has anyone state/country came-up with a "standard" test, or is it all still guess work? I'd like to see the "test equipment" they developed for use in the field to test BAD's. smile

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#11423 - 08/23/06 07:31 AM Re: Compression Springs and #280 s-hook BAD
littleguns Offline
Member

Registered: 06/20/05
Posts: 269
Loc: Jay, Maine
Why do you use a compression spring with a cam lock? Is it to inshure a constant tightness on the animal for a quicker kill?
Littleguns

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#11424 - 08/23/06 09:10 AM Re: Compression Springs and #280 s-hook BAD
Hal Offline
Moderator

Registered: 07/17/00
Posts: 9945
Loc: Blue Creek, Ohio, USA
LG: Yes, the purpose of the compression spring is to keep a constant tension on the animal and make the snare more lethal. A lock equipped with a spring like this is not a relaxing lock. This set up would be illegal to use in Ohio and a number of other states.

Red: After than long discussion on BADs, I did find documentation for this test. It was done by Phillips, Blom, and Johnson at the Denver Wildlife Research Center. From a report titled "Evaluation of Breakaway Snares for Use in Coyote Control" published in 1990 (Univ. CA Davis) I quote: "To our knowledge there have been no established techniques for testing the physical strength characteristics of snares…"

"Samples of each type of snare (n=12) were connected to a Southwark-Emery universal testing machine… to determine the tension required to break the locks or release mechanisms. Each snare was attached… by placing the snare loop around a 3-in diameter steel rod… As the machine slowly tightened the snare loop… maximum tension was recorded when the snare lock or release mechanism separated from the snare."

"This testing procedure was not intended to simulate the forces an animal applies when captured by a snare. However, it did allow us to develop a standardized comparison for snare locks when they are subjected to a slow and steady pull…"

This is the documentation I had been looking for all along. Since this is the only scientific documentation I can find, I assume there are no other sanctioned competing tests, and the test as described forms a bench mark for comparison of the sundry devices out there. (I'm still exceedingly curious at to what value a 90 lb BAD would be.)

smile -- Hal
_________________________
Endeavor to persevere.

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#25459 - 10/25/17 01:34 PM Re: Compression Springs and #280 s-hook BAD [Re: Hal]
Archive Offline


Registered: 03/12/03
Posts: 1116
Dated for search.

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