2strong Posted April 22, 2003 Share Posted April 22, 2003 After I came home from work, I decided to modify one of my #3's and here is the result : http://home.nktv.no/~dagroye/modified3/modified31.jpg http://home.nktv.no/~dagroye/modified3/modified32.jpg This will become a useful training tool ! ( Thanks to Tom Black for giving me the idea ! ). Quote Link to comment Share on other sites More sharing options...
underdawg Posted April 22, 2003 Share Posted April 22, 2003 i have a feeling you'll be slamming the 3 shut very shortly. by the way, how the hell did you get that grapefruit to fit in your forearms? Quote Link to comment Share on other sites More sharing options...
2strong Posted April 22, 2003 Author Share Posted April 22, 2003 by the way, how the hell did you get that grapefruit to fit in your forearms? LOL... this is how the text should go : by the way, how the hell did you get that pea to fit in your forearms? You must be really close to the #3 you also ( by looking at your training results ) Train hard ! Quote Link to comment Share on other sites More sharing options...
underdawg Posted April 23, 2003 Share Posted April 23, 2003 getting there, slowly but surely. i'm not nearly as close as you though Quote Link to comment Share on other sites More sharing options...
Tom Black Posted April 23, 2003 Share Posted April 23, 2003 Judging by the length of the extension it is half the length of the distance from the ring to the end of the handle. I'm estimating, but it appears to be around 7/16" long. One of the applications for my new force calculation formula is the prediction of the force need to close an extended or shorted gripper. Eventually, I will make a spreadsheet that makes it very easy to see what will happen when a modification is made, but for now, here's an example with your gripper. First, I'm going to have to assume that the unmodified gripper was "typical," that is, the force needed to close it from the end is 166.5 pounds. It may be lower, it may be higher. If you check it on a scale I can redo my calculations and give you a feel where you are at with your extended close. Also, I will assume the grippers unmodified moment arm is 4.625", many are. Thus, extending this 7/16" gripper will give a moment arm of 5.063" from the center of the spring to the handle end. The force required to close the gripper at this new end will be 152.1-pounds. The extended gripper would be "rated" at #2.55. Restating this in another way, if the unmodified gripper is a "typical" #3.0 gripper then your modified one is #2.55. As you shorten the extension the rating will go up, eventually equal to #3.0 when the extension is gone. Also, if you happened to have a dynamometer and the gripper was a “typical #3” then your reading would be around 208-pounds. That’s assuming that the center of your hand is 1 3/8” from the end of the gripper. Quote Link to comment Share on other sites More sharing options...
Bearcat 74 Posted April 23, 2003 Share Posted April 23, 2003 One thing I would reccommend would be to be sure the original handles are touching. When a gripper is extended, I had to file the inside of the extensions to get the knurled handles to touch. Quote Link to comment Share on other sites More sharing options...
Tom Black Posted April 23, 2003 Share Posted April 23, 2003 Oops, I meant to say your extension was 15/16". It wouldn't be a #2.55 then. I haven't recalculated what it would be, obviously easier. On Bearcat's idea, that would make the extended gripper beyond the range, which is a great training tool. It would also increase the difficulty of the close. Quote Link to comment Share on other sites More sharing options...
2strong Posted April 23, 2003 Author Share Posted April 23, 2003 Thanks for the information guys The extension is 2.3 cm long ( the total length of the handle is 11.9 cm including the extension ). When it comes to strength I would say it's a 2.3 ---> 2.5 ( it's "much" harder than the #2's I have... but I have not seasoned the gripper yet, so i guess it will get weaker ? ). BTW. The picture is "lying"... it looks as if the extension is one piece, but it's actually 8 washers , so I have the opportunity to choose between eight different lengths. Quote Link to comment Share on other sites More sharing options...
2strong Posted April 23, 2003 Author Share Posted April 23, 2003 PS. I tried to check the grippers on a scale ( digital ) and here are the results ( give or take 5 pounds ) : Modified #3 : 116.8 pounds Seasoned #3 ( the one I try to close ) : 135 pounds New #3 : 138.8 New #3 : 138 I didn't come close to 166.5 pounds ?!? Quote Link to comment Share on other sites More sharing options...
Bearcat 74 Posted April 23, 2003 Share Posted April 23, 2003 Maybe it would make your gripper beyong the range, but when I extended my 4 the handles liked a little bit from touching. I ground the washers so the kurled handles would touch, maybe I set it up wrong..... Quote Link to comment Share on other sites More sharing options...
2strong Posted April 23, 2003 Author Share Posted April 23, 2003 Maybe it would make your gripper beyong the range, but when I extended my 4 the handles liked a little bit from touching. I ground the washers so the kurled handles would touch, maybe I set it up wrong..... The knurled handles are about 3-4 mm from touching when the extension bit is touching... So I have to ground the washers ( like you did ) to make the gripper handles touch . When I said I have eight lengths to choose from, I meant in the vertical direction... not the horizontal direction. Anyway... Thanks for the tip ! Quote Link to comment Share on other sites More sharing options...
Bearcat 74 Posted April 23, 2003 Share Posted April 23, 2003 The knurled handles are about 3-4 mm from touching when the extension bit is touching... So I have to ground the washers ( like you did ) to make the gripper handles touch . When I said I have eight lengths to choose from, I meant in the vertical direction... not the horizontal direction. Anyway... Thanks for the tip ! Glad I could help Quote Link to comment Share on other sites More sharing options...
Tom Black Posted April 23, 2003 Share Posted April 23, 2003 I didn't come close to 166.5 pounds ?!? Yes, that is not surprising. My easiest #3 was only 145 pounds the last time I checked (that was awhile ago, I haven't checked it since writing the article). The PDA gripper I have has a spring the size of a #3 and it measures 139.5-pounds. This is not a very wide gripper, thus the small rating. I call 166.5 "typical" for lack of a better term, but it is not necessarily "average." I decided not to take a guess at what "average" should be, especially since IM grippers seem to change monthly! I have 5 #3 grippers, I would say only two of them are around or above 165-pounds. The oldest one is way over 165-pounds, beyond what I can accurately measure on the scale. I think that if people keep sending me their numbers (and are as accurate as they can be) then we will see an average emerge. Interestingly, there appears to be recent evidence that IM is trying to create a more consistent product, and they seem to be going for the higher end. My feeling is that whoever is making the grippers for them could be very well aware of the known spring formulas and in fact is shooting for the 166.5 at the end, or since they are going with the 280, the force needed to close at the ring. It would be weird in my opinion that someone would go to the trouble to make a gripper as well as they do (they really are a nice product, better made than the old ones) and yet not understand simple principles regarding springs. I'll try to calculate the values tomorrow for you on both your 135 and your extended. I think the extended may only be a "2.3" as you say or a little lower, but your 135 (if standard length) would only be a "2.38" Possible pitfalls with the scale method seem to be pushing down more on the center of the handle and getting too high of a reading. Low readings might be caused by not touching the handles at the end. This can happen because the thing hurts your hand so much you just want to stop! BTW, 116.8 seems somewhat pitifull for even an extended #3. Many guys have tested #2's in that range long before I wrote my article. With the extended leverage of the long handles it would be even easier than a #2, but you may also have an easy #2, maybe from the same batch. Make sure you are touching the handles and stabilizing the reading at the end. Quote Link to comment Share on other sites More sharing options...
Bill Piche Posted April 23, 2003 Share Posted April 23, 2003 Tom, what did the 3 measure that Heath closed for many many reps at the AOBS? He told me it was pretty much the easiest 3 he's ever tried to close. Quote Link to comment Share on other sites More sharing options...
Tom Black Posted April 23, 2003 Share Posted April 23, 2003 Yes, that's the one, 145-pounds. There were three strong guys training on that gripper at that time, I think it had a lot of negatives and near closes on it and hence that's why it is weaker. I've got too much chalk on that gripper now, I've got to take some off because I think it's making it harder. At any rate, at 145-pound is the lowest of my five and clearly "feels" that way too. I purposely picked a harder #3 for my extended one so I would get more use out of it. Quote Link to comment Share on other sites More sharing options...
Tom Black Posted April 23, 2003 Share Posted April 23, 2003 Yikes! I just convinced myself some more. I really did think that the 116.8 was too low but…when I plugged 116.8 into my formula, added .9” (that’s 2.3cm) to the "typical" handle of 4.625" I found that this gripper should be 139.5 unmodified. This number seems very close to the other two grippers mentioned of 138 and 138.8. If they are all new and from the same batch then that’s what I would expect. Hey, I can close a 139.5 consistently now but I'm not going to buy another #3, they've got too much of my money! Quote Link to comment Share on other sites More sharing options...
OldGuy Posted April 24, 2003 Share Posted April 24, 2003 Tom, I would imagine that the springs are ordered from a manufacturer of torsion springs. They are probably told the wire thickness and the number of turns and the inside diameter formed by the coils and so on. Who knows what the quality of the wire is and how consistent that quality is? The handles probably come from another source and may even be predrilled to accept the spring. Someone else is slapping the pieces together and stamping numbers on the handles. I doubt if the process is a very controlled and sophisticated one. Quote Link to comment Share on other sites More sharing options...
Bill Piche Posted April 24, 2003 Share Posted April 24, 2003 FYI Tom to add some info to what you were working with the formula. More offline input...your AOBS #3 was likened to a "Paper Clip" by another person so if that thing measures anywhere near some of your other 3's it might tend to indicate your formula is flawed. With this data, does the formula still make sense? Quote Link to comment Share on other sites More sharing options...
Tom Black Posted April 24, 2003 Share Posted April 24, 2003 "Paper Clip" is a little harsh As I said there is no inconsistency at all with the formula, it is absolutely the easiest on the scale and in the hand of the 5 that I own. Don't you have some grippers from that same vintage? As far as these other ones being even lower (138-139) that is absolutely possible. Looking at the pictures zoomed in it appears that the modified one is not set into the spring very deep (but this is hard to tell). I thought about giving a range of possibilities for each gripper in the article, I expect the range to be wide, you know that also based on your experience. I would have said 140-180 for the #3’s based on mine, but that's "only" 5 so it may not be enough data points. Most of my #2's have been modified in some way so I have very little to test. Maybe 105-125 off the end. Please don't say "see, you’re wrong, look at those numbers being much lower than 166.5-pounds." I never said that 166.5-pounds was average. The clearest way I can state it is: Ironminds stated 280 if measured at the ring would be 166.5 if measured at the end of a 4.625" moment arm gripper. I can't help it if this gripper is not consistently produced by them. Oldguy, you are somewhat right, I must admit I don’t know how they slap them together, but the newer ones do look nicer than the old. Required force and torque are variables known to a spring manufacturer. To put it another way, if you say “I want a 3-coil torsion spring that will give me F-pounds of force at 2.75” and at 26-degrees of deflection” they can create that spring. Obviously, there is a range of acceptable variation of these springs and this causes the grippers to be inconsistent. I haven’t seen where a spring manufacturer gives this range and it makes me wonder what the range is. I think the gripper variations may be caused more by the total angle of deflection and spring set (total moment arm length) than the variability of steel, but I am not sure. I am getting closer to the answer, and as you have noted I have “great patience and perseverance“ and don’t give up easily. Quote Link to comment Share on other sites More sharing options...
OldGuy Posted April 24, 2003 Share Posted April 24, 2003 Grippers are cheap. Surely if a profit is to be made on them, the components would need to be very cheap. I would imagine that the cost of torsion springs made to exacting, consistent specifications, and in not very large numbers would be somewhat costly. The only way to produce very consistent grippers is to always use identical springs that are always set into the handles at the same depth. Assuming of course that handles are always of the same length which should be the easy part. Quote Link to comment Share on other sites More sharing options...
Bearcat 74 Posted April 24, 2003 Share Posted April 24, 2003 There were three strong guys training on that gripper at that time, I think it had a lot of negatives and near closes on it and hence that's why it is weaker. How is that? My grippers have thousands of closes and they aren't weaker. Quote Link to comment Share on other sites More sharing options...
OldGuy Posted April 24, 2003 Share Posted April 24, 2003 I do not believe that grippers can be seasoned or somehow get easier with use. If you had huge hands took drugs and had an easy #3 that had been seasoned by an army of guys, the gripper would shut by itself and stay shut! Quote Link to comment Share on other sites More sharing options...
terminator Posted April 24, 2003 Share Posted April 24, 2003 If that gripper got any easier than it was it is now a #2. I wouldn't bother to certify if that was the only 3 I could close. Fortunately that is not a problem. I agree with Oldguy and Heath, seasoning is a figment of someone's imagination. If anything, springs work-harden with use. The only way it could get easier is if someone deliberately bent the spring during seasoning, or if there was mechanical interference in the coil that wore away (unlikely). All the formulas in the world don't add up to a closed #3.......work harder. Quote Link to comment Share on other sites More sharing options...
2strong Posted April 24, 2003 Author Share Posted April 24, 2003 I got 4 #3's ( one of them are modified/extended ) and I got 3 #2's ( one of them are modified/filed ). I'm going to sort the grippers from the strongest to the weakest : New #3 ( not seasoned ) : 138.8 New #3 ( not seasoned ) : 138 Seasoned #3 ( the one I try to close ) : 135 pounds Modified #2 ( filed ) : 129 pounds Modified #3 ( extended ) : 116.8 pounds #2 ( seasoned ) : 116 pounds #2 ( seasoned ) : 112.4 pounds Here are some pics : Here are all the grippers ( the weakest is top left and the strongest are on the bottom ). http://home.nktv.no/~dagroye/grippers/allgrippers.jpg Here are my filed #2... It's a monster ! , and I have only closed it once. I have filed the handles so much, that the gripper is awkward to close ( you have to position the gripper just right to be able to close it ). http://home.nktv.no/~dagroye/grippers/filed21.jpg http://home.nktv.no/~dagroye/grippers/filed22.jpg This is the gripper I am trying to close ( #3 ). http://home.nktv.no/~dagroye/grippers/gripper3.jpg All my grippers have the same measurements when it comes to handle length and width ( length : 9.53 cm width : 7.7 cm ). I have not measured the spring setting on the grippers. http://home.nktv.no/~dagroye/grippers/measure1.jpg http://home.nktv.no/~dagroye/grippers/measure2.jpg Here is how i measure the grippers on my scale : http://home.nktv.no/~dagroye/grippers/scale1.jpg http://home.nktv.no/~dagroye/grippers/scale2.jpg http://home.nktv.no/~dagroye/grippers/scale3.jpg http://home.nktv.no/~dagroye/grippers/scale4.jpg And this is me after realizing all my grippers are sissy grippers http://home.nktv.no/~dagroye/grippers/lol.jpg PS. I think my modified #3 was more difficult for me to close, because my hand was positioned fairly high on the handles ?? Quote Link to comment Share on other sites More sharing options...
Bill Piche Posted April 26, 2003 Share Posted April 26, 2003 If that gripper got any easier than it was it is now a #2. I wouldn't bother to certify if that was the only 3 I could close. Fortunately that is not a problem.I agree with Oldguy and Heath, seasoning is a figment of someone's imagination. If anything, springs work-harden with use. The only way it could get easier is if someone deliberately bent the spring during seasoning, or if there was mechanical interference in the coil that wore away (unlikely). All the formulas in the world don't add up to a closed #3.......work harder. Actually, seasoning is not a figment and I disagree Pat. Ask someone whose expertise is dealing with these springs. I believe that's where the info came from. PDA merely confirmed it. Quote Link to comment Share on other sites More sharing options...
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