|
Lazlo
Jan 12, 2010, 7:45 PM
Post #1 of 31
(17085 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
Does anyone know what kind of forces you can expect from a funkness device?
Also, What can a 1/16'' copperhead hold?
|
|
|
|
|
coolcat83
Jan 12, 2010, 8:12 PM
Post #2 of 31
(17066 views)
Shortcut
Registered: Jan 27, 2007
Posts: 1007
|
Lazlo wrote: Does anyone know what kind of forces you can expect from a funkness device? Also, What can a 1/16'' copperhead hold?
how heavy is the device? what's it attached by?
also, i don't have experience with copperheads, but i'm going to make an educated guess and say it depends. are you talking about how much force before the head pulls off the wire? or a placement...which could be anything from 0 pounds to the point where the head deforms enough to fail, come off the wire, or the wire breaking.
(This post was edited by coolcat83 on Jan 12, 2010, 8:14 PM)
|
|
|
|
|
adatesman
Jan 12, 2010, 8:24 PM
Post #3 of 31
(17051 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
Lazlo
Jan 12, 2010, 8:27 PM
Post #4 of 31
(17044 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
adatesman wrote: No idea on the copperhead, but a couple swings on my BD hammer and OP funkness cable just came out ~155 pound-force on the load cell.
Wow. I'm shocked it's so low! Hypothesis on the interweb has been around 600 lbs!
|
|
|
|
|
Lazlo
Jan 12, 2010, 8:31 PM
Post #5 of 31
(17037 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
The general consensus is that funking causes more force than bounce testing. Seems quite the opposite though.
|
|
|
|
|
adatesman
Jan 12, 2010, 8:32 PM
Post #6 of 31
(17035 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
Lazlo
Jan 12, 2010, 8:39 PM
Post #7 of 31
(17022 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
adatesman wrote: Surprised me too. I had expected a couple kN, but that's what it came out at. Could be that I'm using a 10,000 pound load cell and a small instantaneous load like that doesn't register so well. But the strain gage indicator is supposed to be able to handle impacts well due to having analog sampling, so perhaps it is correct.
Hmm. Curious.
|
|
|
|
|
sungam
Jan 12, 2010, 9:02 PM
Post #8 of 31
(16990 views)
Shortcut
Registered: Jun 24, 2004
Posts: 26804
|
What type of funker are you using? I would have expected way higher then that from a firm swing.
|
|
|
|
|
adatesman
Jan 12, 2010, 9:25 PM
Post #9 of 31
(16969 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
sungam
Jan 12, 2010, 9:34 PM
Post #10 of 31
(16957 views)
Shortcut
Registered: Jun 24, 2004
Posts: 26804
|
Heh, my bad. Should have read better. I was hoping you were using a claw hammer and some twine, I guess.
|
|
|
|
|
Lazlo
Jan 12, 2010, 9:37 PM
Post #11 of 31
(16953 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
sungam wrote: Heh, my bad. Should have read better. I was hoping you were using a claw hammer and some twine, I guess.
|
|
|
|
|
adatesman
Jan 12, 2010, 9:41 PM
Post #12 of 31
(16946 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
hafilax
Jan 12, 2010, 9:45 PM
Post #13 of 31
(16940 views)
Shortcut
Registered: Dec 12, 2007
Posts: 3025
|
adatesman wrote: No worries Magnus.  And FWIW, I've done that as well and it didn't work at all. IIRC, in order to snap a tied loop of rated 3mm cord I had to funk with an 8lb sledge. Speaking of which, I'm going to go give funking a strand of 3mm a try as a way to check the results of the strain gage. By my calculations a piece of that with fig8 loops on the ends should fail ~400lb-force, so if I can break that by funking then I suspect that the results from the strain gage are off. BRB. 
|
|
|
|
|
Lazlo
Jan 12, 2010, 9:48 PM
Post #14 of 31
(16934 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
adatesman wrote: No worries Magnus. And FWIW, I've done that as well and it didn't work at all. IIRC, in order to snap a tied loop of rated 3mm cord I had to funk with an 8lb sledge. Speaking of which, I'm going to go give funking a strand of 3mm a try as a way to check the results of the strain gage. By my calculations a piece of that with fig8 loops on the ends should fail ~400lb-force, so if I can break that by funking then I suspect that the results from the strain gage are off. BRB.
Awesome! Good thinking!
|
|
|
|
|
adatesman
Jan 12, 2010, 10:17 PM
Post #15 of 31
(16910 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
quiteatingmysteak
Jan 13, 2010, 1:43 AM
Post #17 of 31
(16819 views)
Shortcut
Registered: Dec 15, 2004
Posts: 804
|
Lazlo wrote: Does anyone know what kind of forces you can expect from a funkness device? Also, What can a 1/16'' copperhead hold?
Funkness devices have broken biners, you should try to avoid testing fixed heads with them, and I've pulled the wire out on at least one occasion. You can get big forces.
I've never been a fan of using a funkness to test placements, but I also suck mightily.
A friend of mine makes great teeny tiny heads, and also good rivet hangers that are kinda doubled back... real interesting stuff, his name is Donny and I think you can still get them in the Yos mountain shop. I know he's climbed on his smallest heads on grape race, and tested once a quarter the size to body weight. not sure if I would recommend doing either of those ;D
|
|
|
|
|
adatesman
Jan 13, 2010, 4:55 PM
Post #18 of 31
(16756 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
Lazlo
Jan 14, 2010, 3:09 AM
Post #20 of 31
(16692 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
adatesman wrote: Another data point... I was unable to snap a piece of 4mm when set up the way the 3mm was (single strand, fig8 on each end). At least, it didn't snap after half a dozen tries, at which point I got my hand caught in a loop of the funkness. Not recommended whatsoever. Not only did it cut deep (not to the bone, fortunately), it's a really ugly torn cut that'll take forever to heal. Ugh. Needless to say, I'm done playing with this....  
Dude, that sucks!
Pictures?
How much is the 4mm rated for?
|
|
|
|
|
adatesman
Jan 14, 2010, 3:35 AM
Post #21 of 31
(16681 views)
Shortcut
Registered: Jul 13, 2005
Posts: 3479
|
|
|
|
|
|
Lazlo
Jan 14, 2010, 3:41 AM
Post #22 of 31
(16677 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
adatesman wrote: Ah, the sacrifices I'm willing to make in the name of science... Here's a pic of the samples. I seem to have already lost one end of the 3mm Fig 8, and please pardon the goofy knot on the other sample. I don't offhand remember the name of it, but it seemed well suited to impact testing since it supposedly doesn't jam. Turns out that is the case, and it comes out quite easily after loading. Anyway, the 4mm is from BW and rated to 900#, so conservatively figure 630#/2.8kN with the knots. And in case that's not what you were looking for... The chunk missing from the edge of the hand is literally 1/8" thick and about 3 times the size of the the blood blister. You'd think I would have used the excuse to wear the new fingerless aid gloves I got for xmas, but no....
Well, I thank you for your efforts! I highly appreciate it. I also learned the importance of gloves while aiding!
|
|
|
|
|
moose_droppings
Jan 14, 2010, 4:07 AM
Post #23 of 31
(16663 views)
Shortcut
Registered: Jun 7, 2005
Posts: 3371
|
The length of perlon your using for funkness seems a bit short. I'm thinking you could break that 4mm with a good 2' swing.
Feel free to use your other hand and give it another try.
|
|
|
|
|
Lazlo
Jan 14, 2010, 4:24 AM
Post #24 of 31
(15900 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
moose_droppings wrote: The length of perlon your using for funkness seems a bit short. I'm thinking you could break that 4mm with a good 2' swing. Feel free to use your other hand and give it another try.
He's attaching the cord to a 24" funkness.
|
|
|
|
|
moose_droppings
Jan 14, 2010, 4:57 AM
Post #25 of 31
(15887 views)
Shortcut
Registered: Jun 7, 2005
Posts: 3371
|
d'oh
Missed that, thanks.
|
|
|
|
|
frodolf
Feb 7, 2010, 3:27 PM
Post #26 of 31
(2310 views)
Shortcut
Registered: Oct 1, 2006
Posts: 81
|
I often funk test heads and other pro (nuts, pitons, the occasional shallow cam placement). I think it is an important skill to have as an aid climber. After a while you learn how hard to funk and what forces are accumulated. I can determine, pretty accurately I think, how hard I should hit to test a piece for body weight, and then for a little bit more than body weight. It can be really good to have this skill when on a traverse or on wildly overhanging stuff where it can be hard to bounce test safely/easily.
I don't use a wire. I use a nylon sling as a funkness device, with tied loops for biners at each end. Works great, is cheaper, and ads just a little bit of stretch, which is good. Me thinks.
One should be careful with the smallest heads, though. They break easily. Don't funk them if it can be avoided! The middle siezes to bigger you can funk pretty darn hard. But don't give them more than, say, 4-5 hits tops as the wire have a tendency for creeping at every stroke. The same rule applies for bounce testing heads, BTW. What will break first, if you've done a decent job placing it, is the wire, leaving a dead head. And eeeverybody hates them – so take it easy!
M
|
|
|
|
|
rightarmbad
Feb 8, 2010, 10:50 AM
Post #28 of 31
(2269 views)
Shortcut
Registered: Mar 22, 2005
Posts: 218
|
Yes, but there may be too much mass in the device to catch a peak at low levels correctly
|
|
|
|
|
skinner
Feb 10, 2010, 5:14 PM
Post #29 of 31
(2182 views)
Shortcut
Registered: Nov 1, 2004
Posts: 1747
|
quiteatingmysteak wrote: Funkness devices have broken biners, you should try to avoid testing fixed heads with them, and I've pulled the wire out on at least one occasion. You can get big forces.
I agree that funking is not a good alternative to bounce testing, but I assumed this was just about testing the holding strength of heads, more for curiosity sake.
Even if that is the case, I can't imagine how accurate this is with so many variables in each placement, not to mention variables in the heads themselves.
The only time I do anything funk-like to a head, is when removing them, and then it's an outward funk anyway.
All that said.. I'm always amazed what heads *will*(thankfully) hold!
|
|
|
|
|
Lazlo
Feb 11, 2010, 1:38 AM
Post #30 of 31
(2149 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
skinner wrote: quiteatingmysteak wrote: Funkness devices have broken biners, you should try to avoid testing fixed heads with them, and I've pulled the wire out on at least one occasion. You can get big forces. I agree that funking is not a good alternative to bounce testing, but I assumed this was just about testing the holding strength of heads, more for curiosity sake. Even if that is the case, I can't imagine how accurate this is with so many variables in each placement, not to mention variables in the heads themselves. The only time I do anything funk-like to a head, is when removing them, and then it's an outward funk anyway. All that said.. I'm always amazed what heads *will* (thankfully) hold!
Correct. I made my own heads and just wanted to see what kind of abuse they could take.
|
|
|
|
|
Lazlo
Feb 11, 2010, 1:40 AM
Post #31 of 31
(2147 views)
Shortcut
Registered: Nov 14, 2007
Posts: 5079
|
Lazlo wrote: skinner wrote: quiteatingmysteak wrote: Funkness devices have broken biners, you should try to avoid testing fixed heads with them, and I've pulled the wire out on at least one occasion. You can get big forces. I agree that funking is not a good alternative to bounce testing, but I assumed this was just about testing the holding strength of heads, more for curiosity sake. Even if that is the case, I can't imagine how accurate this is with so many variables in each placement, not to mention variables in the heads themselves. The only time I do anything funk-like to a head, is when removing them, and then it's an outward funk anyway. All that said.. I'm always amazed what heads *will* (thankfully) hold! Correct. I made my own heads and just wanted to see what kind of abuse they could take.
I haven't had one break yet either. I've been quite amazed.
|
|
|
|
|
|
|
|
|
