OldGuy Posted July 7, 2004 Share Posted July 7, 2004 Plastic tubing would also help center the load. Quote Link to comment Share on other sites More sharing options...
EricMilfeld Posted July 8, 2004 Author Share Posted July 8, 2004 That's a good idea. Here's a thought - a thick leather strip to support the nail along its entire length. I think a 15-16oz (slightly thicker than 1/4", probably the same stuff in your powerlifting belt) piece of vegetable tanned leather about 2" wide and 9" long would work. Here is how I think I would make it work:Cut leather strap Punch a hole in the middle of the strap on each end Set a heavy duty grommet in the hole Fasten your chain to the hole in the leather via a quicklink on each side Position nail in the middle of the leather, attach your carabiner with weight and lift away. As the nail bends under the weight, the leather should also bend and continue to support the nail along its entirety throughout the whole bend. What do you think? My brain is half fuzzy today so I apologize if it's not clear. It would take a tremendous load to make the leather rip. This seems doable, Clay. The only concern I can think of at the moment would be the bar's sharp ends possibly cutting into the leather. Also, wouldn't bolt and nail heads skew the results a bit by "leaning" a bit, if they are centered in the leather strip? But all these "problems" could probably be fixed pretty easily. Quote Link to comment Share on other sites More sharing options...
Clay Edgin Posted July 8, 2004 Share Posted July 8, 2004 I am pretty sure that anything less than a bullet will not tear through 1/4" leather As for the bolt head being a concern, you could either (a) cut it off entire head and just make a note that the bolt is 5 7/8" and not 6", or shave down the head of the bolt flat on the side that will be resting against the leather, which is probably the easier option Quote Link to comment Share on other sites More sharing options...
EricMilfeld Posted July 13, 2004 Author Share Posted July 13, 2004 I did some more calibrating today: 1) 5/16x6 1/2" FBB: 615 lbs. 2) 5/16x6" FBB: 675 lbs. 3) 3/8x7" Metal Supermarket HRS: 505 lbs. (this stuff made more of a semi-circle bend as opposed to a "U", which would have made for a very tough crushdown) 4) 5/16x7" (actual total length 7 3/16") grd 5 bolt: 615 pounds I'm wondering if a 5/16" grd 5 bolt is within reach of anybody. I was hoping it might be the next standard for which world class benders could aspire. Right now a 6 1/2" Fat Bastard Barbell bar is keeping me busy. What a difference that 1/2" makes! Quote Link to comment Share on other sites More sharing options...
Clay Edgin Posted July 13, 2004 Share Posted July 13, 2004 Eric, it seems that with all the talk of a "black" nail of 3/8" thickness that being able to quantify its strength in pounds and comparing it to the reds would be useful. Interesting to note that a 5/16" x 7" CRS red tested at 490 while a 3/8" x 7" HRS bar tested at 505. The same bar in CRS might test over 600lbs! I personally would be interested in seeing the results for a cut red in 1/4" increments down to 5" I think Pat may be the only person right now who is capable of taking down a 5/16" G5 but I think there are several others here on the board who are certainly capable of reaching that level if they train for it. Quote Link to comment Share on other sites More sharing options...
DAN PETERSON Posted July 14, 2004 Share Posted July 14, 2004 Eric I was recently at Warren Tetting's house and he has a real mad scientist type calibrating system and if I remember right his numbers were quite similar to alot of yours it is great to have see some consistency between the to methods. Quote Link to comment Share on other sites More sharing options...
EricMilfeld Posted July 14, 2004 Author Share Posted July 14, 2004 Eric I was recently at Warren Tetting's house and he has a real mad scientist type calibrating system and if I remember right his numbers were quite similar to alot of yours it is great to have see some consistency between the to methods. Does Warren bend to a 45 degree angle (each end of the bar bending upwards by 22.5 degrees from its straight position) also? But that is great if his results are atleast somewhat proportionte to mine. Quote Link to comment Share on other sites More sharing options...
DAN PETERSON Posted July 18, 2004 Share Posted July 18, 2004 The final bend was about 90 degrees. Thats all the farther his machine would bend them. Quote Link to comment Share on other sites More sharing options...
Drassk Posted July 24, 2004 Share Posted July 24, 2004 For a bending/testing apparatus, I've had a design "in thought" for some time. I think it should handle many of the issues we've had with consistency and other things, especially with different lengths of bolts. Feel free to critique and try to improve on this design, I'll put the main points that I'm not quite happy with at the end. First, the bolt is attached at the halfway point in a vice (so half of the bolt is out). I might suggest going a fixed difference from the halfway point so that the bend happens in the 'natural' point in the bolt. This means that slightly over 50% of the bolt is out of the vice. Now, find one of the big torque wrenches that they use to put the nuts on transport tires. The main reason being that the sockets attach to a nice, thick receptacle. You should be able to get a custom bit fabbed at just about any good fab shop. It would be cylindrical piece of CRS with a cube milled on one end (to fit into the wrench as a socket) and holes 3/4" deep of various widths (1/4", 5/16") drilled around its radius to accept bolt/nail ends. The ends would have to be cut flat, but that shouldn't be a big deal. Then all you have to do is lock the bolt in the vice and bend it to a certain degree with the 'custom socket' by gradually upping the torque cutoff on the wrench. The main problems, as I see it, are the custom socket (although, if you know a good fab guy, then stuff like that isn't expensive) and exactly which point the bolt should come out of the vice. In general, though, it should tell us exactly how hard you need to be pulling down on one end of the bolt to get it to a certain bend. This doesn't account for how many fingers you can use or anything else, but that's not a factor we can ever really consider. If this explanation doesn't work for many, I can make up a technical rendering of the setup. It'll take some work, though, so I'd prefer not to if it's clear. Quote Link to comment Share on other sites More sharing options...
EricMilfeld Posted July 25, 2004 Author Share Posted July 25, 2004 Bob, that sounds like a really good idea. I wonder how long of a bar would be needed to apply the necessary torque to bend some of the tougher stock? Quote Link to comment Share on other sites More sharing options...
Drassk Posted July 26, 2004 Share Posted July 26, 2004 If you can borrow one of the wrenches they use to put the nuts on tractor trailers, I guarantee it's enough. I remember having to jump up and down to get the thing to crack (the wrench) and it was about a meter long. That's 500ft/lbs, and no bolt is taking that at the end and not bending. Not any bolt a human or lesser Greek god could bend, anyways. Quote Link to comment Share on other sites More sharing options...
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