Foot Stomping Experiment

[j.scribner]

A grip gathering, a few really strong guys, and an experiment. I was there (not as one of the particularly strong guys, BTW), and I witnessed the experiment. There was no real abuse of the gripper initially, just Doc stepping on the thing while it was supported by the piece of steel rod. Therefor, "foot stomping" might be somewhat misleading. Perhaps a different term to describe the action on the gripper (i.e. pumping) would sound better?? At any rate, the experiment was performed exactly as Doc described. And the results were plain to see when the gripper was placed in Chris' Redneck gripper calibrator. There was a statistically significant change in the amount of weight needed to close the gripper. And later, when the piece of steel rod used was big enough to slightly bind the coil, the gripper was markedly reduced in its spread, and I was able to close it pretty effortlessly. (and I can't close a #2 CoC after 2 years of work). I asked Doc if the gripper spring was hot (immediately after he finished his foot pumping), and he let me touch it, and it was slightly warm, but not hot. My conclusion: I wouldn't put any gripper through a "seasoning" process other than just picking it up and closing it, and yes, if someone was starved for recognition enough, they could manipulate a gripper to make it look like they were stronger than they are. That's pretty much the summary as I see it.

John Scribner

[Sean Dockery]

Received my 2.5 yesterday and put it in the device I made to hold it and did 50 closes with my foot in groups of 5, so YES I like to season a new gripper. Lost NO spread and didn't feel any easier.

Few questions after reading your test/results:

Why 200 reps as that seems pretty excessive? Like several YEARS worth of FULL closes on a tough gripper.

Don't understand your discrepancy between "foot CLOSING" and "chest crushing"? Or doing 200 closes 1 at a time over 6 months or however long it takes. All "should" have the same effect on the gripper. If NOT then the REAL value of your test would be to determine WHY foot closing has a negative effect and figure out a way around it.

With that being said I'l offer something else to ponder about foot stomping and weakening a gripper. Could it be the friction of it rubbing against the pipe placed through the spring? 100-200 quick reps WILL create a lot of friction/binding and some heat I'm assuming, and also WILL distort how the gripper closes. I tried the pipe version once and quit after 2 reps.

That's why I made a device to hold them perfectly still, aligned, and NO metal contact against the spring. Give it 50 slow and full closes and it's NO different than a chest crush or whatever....Well other than a chest crush is "acceptable" and a foot close is not

Personally, I don't understnad the discrepancy between chest closing and foot stomping either. I've always just trained with them and not worried about the seasoning efffect.

We did 200 reps cause that seemed to be about average for what I've seen folks talking about with this method. Also, I went thru my training journal and I had done over 200 cycles with my #2 in a 3 month period when I was just barely closing it.

There was no binding of the spring on the bar in the first 2 stomp sessions. There may have been some friction, but I doubt it was enough heat to significantly change the springs characteristics since it never warmed to the touch.

The real value for me was understanding what was happening when someone foot stomped a gripper. I will learn why from an engineer or a torsion spring book. I wanted to see for myself what was happening. I'd never done it before. I tried to replicate what I understood the process to be. I think it's a silly practice, but as always you are free to do what seems best to you.

[mwinsl01]

Received my 2.5 yesterday and put it in the device I made to hold it and did 50 closes with my foot in groups of 5, so YES I like to season a new gripper. Lost NO spread and didn't feel any easier.

Few questions after reading your test/results:

Why 200 reps as that seems pretty excessive? Like several YEARS worth of FULL closes on a tough gripper.

Don't understand your discrepancy between "foot CLOSING" and "chest crushing"?

I enjoyed reading this post. I think someone that seasons a gripper with excessive foot stomping is foolish and a fraud also. For my hg 350, i seasoned it by chest crushing it 7 times total. It went from a 3 in spread to a 2.75 spread. The main reason i did this is because 3 in spread is too big for my hand unless i set it good. I would think this would be the way to season a gripper is by chest crushing it a few times and that's it.

mike

[deaner]

Man do we take this stuff too seriously or what? Sorry but I think grippers are a pretty bad test for hand strength anyway. I remember that seasoning the grippers was generally the accepted thing on here not too long ago. Is this foot stomping stuff really happening on a large scale? I'd like to give guys the benefit of the doubt I guess, at least until they prove otherwise, and if a guy says he can close a #3 and he really can't, who cares? He's only fooling himself, the only way to really compare is in contests or the MM ladder, if a guy does it at home alone, it doesn't really matter what he claims anyway, just say adda boy, good job dude. No ones really getting anything from these claims anyway, unless I'm missing something. I don't think the MM0 cert really carried a lot of weight anyway, just gives you the chance to climb the ladder.

[StalwartSentinel]

Received my 2.5 yesterday and put it in the device I made to hold it and did 50 closes with my foot in groups of 5, so YES I like to season a new gripper. Lost NO spread and didn't feel any easier.

Few questions after reading your test/results:

Why 200 reps as that seems pretty excessive? Like several YEARS worth of FULL closes on a tough gripper.

Don't understand your discrepancy between "foot CLOSING" and "chest crushing"?

I enjoyed reading this post. I think someone that seasons a gripper with excessive foot stomping is foolish and a fraud also. For my hg 350, i seasoned it by chest crushing it 7 times total. It went from a 3 in spread to a 2.75 spread. The main reason i did this is because 3 in spread is too big for my hand unless i set it good. I would think this would be the way to season a gripper is by chest crushing it a few times and that's it.

mike

Losing 1/4 inch in 7 reps is quite a bit and usual for HG grippers. Don't worry, it will lose more.

[Chrisx9118]

This is a mess lol

[Mlstrass]

Personally, I don't understnad the discrepancy between chest closing and foot stomping either. I've always just trained with them and not worried about the seasoning efffect.

We did 200 reps cause that seemed to be about average for what I've seen folks talking about with this method. Also, I went thru my training journal and I had done over 200 cycles with my #2 in a 3 month period when I was just barely closing it.

There was no binding of the spring on the bar in the first 2 stomp sessions. There may have been some friction, but I doubt it was enough heat to significantly change the springs characteristics since it never warmed to the touch.

The real value for me was understanding what was happening when someone foot stomped a gripper. I will learn why from an engineer or a torsion spring book. I wanted to see for myself what was happening. I'd never done it before. I tried to replicate what I understood the process to be. I think it's a silly practice, but as always you are free to do what seems best to you.

Sean,

I appreciate your response as I'm trying to learn from your experiment. I've seasoned all of my "hard" grippers #2, #2.5, #3, BBSM, and BBE and have seen NO change in spread and ONLY on the BBSM I was able to close it about 1/8" farther.

I chose to season as coming from a drag racing background I know how a valve spring will take a "set" after so many initial cycles, so I "assumed" a gripper spring would do the same. I've seen NO negative effects on the few that I own as I only set out to "break" them in faster than through normal use, NOT crush them until they're weakened and useless.

But the REAL question is, just what is happening to affect a gripper so negatively compared to chest crushing or normal use???? Do you feel that with normal use a gripper would eventually weaken to the same level as an excessively foot stomped gripper?

Do you feel that your "foot stomping" was "normal" or excessive to see just how negatively you could affect the gripper? Again just trying to learn, so please take no offense as I'm just trying to pick your brain.

[Mlstrass]

O NO.

I wish that 2.5 would have gone to a non abusive home, I guess we cant save them all.

YOU USE WAY MORE FORCE TO CLOSE THE GRIPPER W/ YOUR FREAKIN FOOT THAN YOU WOULD IF YOU USED YOUR HAND. IT'S NOT THAT HARD TO SEE WHATS GOIN TO HAPPEN.

And 200 reps is nothing.

You can not tell me that gripper will be the same as if you would have never "SEASONED" it.

LABLED.

OK Einstein explain this one to me. If the 2.5 takes "X" amount of force to close, then whether I use my hand, foot, teeth, or whatever then how am I exerting more than "X" amount of force??? Do you assume that I'm jumping off a ladder or something. I apply pressure with my foot slowly until the handles touch, let it open, and do it again.

Trust me I'd prefer to "season" it with ONE hand, but I'm not at that strength level yet...

And YES I can tell you all my grippers are the same. If I handed you one you'd never know the difference, but I'm glad I provided an opportunity for you to be narrow minded.

[sixlitre]

I don't believe the heat generated is the answer. I work with torsion springs everyday made 4 up today and installed them. Torsion springs work on cycles the spring is designed to be under pressure and realease pressure when the spring is comppressed it elonggates this cuts down on friction. The springs are designed to use the heat(what heat there is) to stretch a person cannot move a gripper fast enough to heat it enough to detemper the spring steel. I'm going to go through the spring books and see if I can find anymore concrete answers. The best I have now is the longer a spring is under pressure it loses tension whether it is moving or not because of the stretch. This cuts back on the cycles I'll see if I can find anymore on it.

I'm with you Stew, to heat the metal to the extent where you permanently change its composition you would have to be getting up to the 400degC range, which I seriously doubt no matter how fast you closed it. I think the answer is that the metal is going through a number of loading cycles, which affect the stress vs. strain behaviour. After a number of cycles, the stress vs. strain behaviour settles down, this effect is known as 'shakedown', and is why once a gripper has been 'seasoned' it should stay at a pretty constant difficulty. There is, as far as I can tell, no reason why footstomping should be any different to normal use in this respect, provided the gripper closes in the normal way and free movement of the spring can take place.

I'll start out by saying, I am currently an engineering student, but I am not a professional and this is not in any way a professional opinion or statement. Now that all the ethical obligation crap is out of the way, I agree with the stess vs strain relationship being the cause of the grippers weakening. Most engineering majors require that the students take a mechanics of materials class which explains, mathmatically, what happens to different materials when you place normal and shear stresses on deformable bodies made from said materials. When you crushed the gripper the way you did in the first two parts, you didn't create enough strain (plotted against normal stress) to cause permanent deformation of the body by exceeding the maximum stress/strain level, only a settling type effect (or "shakedown" as referred to above-a term unfamiliar to me) as you "pushed" the steel along the stress/strain curve (slight amount of deformation possibly to elongation?). Once you implemented the third part of your experiment, you exceeded the maximum strain the material could handle and caused permanent deformation on the molecular level. This is why it lost so much of its strength, and deformed/ lost its width. In a nut shell, you bent it, it lost its temper and its original strength. The steel is now garbage, as there is no way that I know of to fix it other than reforging, as I am sure you well know. Once again, this is my just take on it, and it is in no way totally conclusive. Without being there and seeing the gripper I can only speculate from what I have read.

I still don't truely understand the reasoning behind foot stomping or any other type of gripper seasoning. For me it is definatly a respect thing. Respect for my property, respect for my accomplishments, and respect for my peers.

Referring the previous posts, I am on the list for the MM1, and I am waiting anxiously to climb the ladder.

[Mlstrass]

And later, when the piece of steel rod used was big enough to slightly bind the coil, the gripper was markedly reduced in its spread, and I was able to close it pretty effortlessly.

That would make sense as you were bending the arms of the spring, not compressing it. I would ASSUME that no one is seasoning a gripper that way. Might be a big assumption of course

[Mlstrass]

For my hg 350, i seasoned it by chest crushing it 7 times total. It went from a 3 in spread to a 2.75 spread. mike

Tis a good thing you didn't FOOT STOMP it...

[carusom1]

I don't believe the heat generated is the answer. I work with torsion springs everyday made 4 up today and installed them. Torsion springs work on cycles the spring is designed to be under pressure and realease pressure when the spring is comppressed it elonggates this cuts down on friction. The springs are designed to use the heat(what heat there is) to stretch a person cannot move a gripper fast enough to heat it enough to detemper the spring steel. I'm going to go through the spring books and see if I can find anymore concrete answers. The best I have now is the longer a spring is under pressure it loses tension whether it is moving or not because of the stretch. This cuts back on the cycles I'll see if I can find anymore on it.

I'm with you Stew, to heat the metal to the extent where you permanently change its composition you would have to be getting up to the 400degC range, which I seriously doubt no matter how fast you closed it. I think the answer is that the metal is going through a number of loading cycles, which affect the stress vs. strain behaviour. After a number of cycles, the stress vs. strain behaviour settles down, this effect is known as 'shakedown', and is why once a gripper has been 'seasoned' it should stay at a pretty constant difficulty. There is, as far as I can tell, no reason why footstomping should be any different to normal use in this respect, provided the gripper closes in the normal way and free movement of the spring can take place.

I'll start out by saying, I am currently an engineering student, but I am not a professional and this is not in any way a professional opinion or statement. Now that all the ethical obligation crap is out of the way, I agree with the stess vs strain relationship being the cause of the grippers weakening. Most engineering majors require that the students take a mechanics of materials class which explains, mathmatically, what happens to different materials when you place normal and shear stresses on deformable bodies made from said materials. When you crushed the gripper the way you did in the first two parts, you didn't create enough strain (plotted against normal stress) to cause permanent deformation of the body by exceeding the maximum stress/strain level, only a settling type effect (or "shakedown" as referred to above-a term unfamiliar to me) as you "pushed" the steel along the stress/strain curve (slight amount of deformation possibly to elongation?). Once you implemented the third part of your experiment, you exceeded the maximum strain the material could handle and caused permanent deformation on the molecular level. This is why it lost so much of its strength, and deformed/ lost its width. In a nut shell, you bent it, it lost its temper and its original strength. The steel is now garbage, as there is no way that I know of to fix it other than reforging, as I am sure you well know. Once again, this is my just take on it, and it is in no way totally conclusive. Without being there and seeing the gripper I can only speculate from what I have read.

I still don't truely understand the reasoning behind foot stomping or any other type of gripper seasoning. For me it is definatly a respect thing. Respect for my property, respect for my accomplishments, and respect for my peers.

Referring the previous posts, I am on the list for the MM1, and I am waiting anxiously to climb the ladder.

Dave- quit talking with all ur molecular jargen

I'm just kidding. Dave is a very intellegent meathead and I totally support his point of view (for once). Who would of thought that he had something intelligent to say

I need to get the #3 on film to sign up with you Dave. This topic here just pisses me off and makes me want to go for the MM1!!

[Timmy]

Performed my own experiment.

I don't know if it made it any easier.

Edited December 6, 2006 by Timmy

[twig]

Performed my own experiment.

I don't know if it made it any easier.

Wow. Helpful. It's info like that that really makes it worthwhile being a member here.

[superfeemiman]

Performed my own experiment.

I don't know if it made it any easier.

Wow. Helpful. It's info like that that really makes it worthwhile being a member here.

Haha. Yeah "I don't know if it made it any easier" isn't really saying much.

[sixlitre]

And later, when the piece of steel rod used was big enough to slightly bind the coil, the gripper was markedly reduced in its spread, and I was able to close it pretty effortlessly.

That would make sense as you were bending the arms of the spring, not compressing it. I would ASSUME that no one is seasoning a gripper that way. Might be a big assumption of course

For clarification, you are not placing the steel on a gripper in compression when you close it (other than were the handles touch), you are placing it in tension. You would NEVER be able to budge even the lightest steel spring if you tried to place it in compression, because you don't have the ability to create the forces necessary to flatten the steel by increasing its surface area. It should only bend, as you stated, or shear depending on how brittle the metal is. You can show that the gripper in question was placed in tension by monitoring the elongation of the steel to make the handles closer. From my own personal experience with grippers, a compression bend would make the handles open up. Just for personal enrichment, not to put your post down as you stated before "picking your brain".

"OK Einstein explain this one to me. If the 2.5 takes "X" amount of force to close, then whether I use my hand, foot, teeth, or whatever then how am I exerting more than "X" amount of force??? Do you assume that I'm jumping off a ladder or something. I apply pressure with my foot slowly until the handles touch, let it open, and do it again."

In answer to this, the rate at which the force is applied directly relates to the energy given to the system, and since energy can not be created or lost, it has to be absorbed somewhere in the system, whether it is as friction, heat (friction releases energy as heat), or absorbed by the molecules of the steel (deformation). The method you use, described in your post, should have the same effect as closing it with your hand, as long as you are not pushing the handles past one another (when the handles touch, you can't create enough force to deform the steel/alum as stated above, but it might be possible to make them slide past each other, placing the spring in a possition to cause it damage from bending). So your assumption of force would be correct, assuming none of the previous apply.

[mbcx6pmw]

For clarification, you are not placing the steel on a gripper in compression when you close it (other than were the handles touch), you are placing it in tension.

That's not quite true, you are placing the spring in bending, which means the outer surface will be in tension, the inner surface will be in compression. It's likely a very small amount of yielding (i.e. permanent deformation) occurs in normal use, otherwise the 'shakedown' (seasoning) effect I referred to earlier would not occur, although that may be due to residual stresses from manufacturing.

Anyway, enough of this crap, let's just get back to shutting the damn things

[Rick Browne]

The molecular components of a torsion spring gripper move and load up to the points of force. In other words, the molecules in the coil will run to the legs of the spring as the handles are compressed.

[dubthewonderscot]

Ok, quick sanity check.

Are we here on the "Gripboard" talking about the molecular components of a gripper spring as we squeeze it?

Pardon me if I'm out of place here.

Grab em, squeeze em. If the handles touch, get a harder one, grab it, squeeze it.

Rinse, repeat as desired.

Pretty simple stuff for this meat head.

W

[Mlstrass]

For clarification, you are not placing the steel on a gripper in compression when you close it (other than were the handles touch), you are placing it in tension. You would NEVER be able to budge even the lightest steel spring if you tried to place it in compression, because you don't have the ability to create the forces necessary to flatten the steel by increasing its surface area. It should only bend, as you stated, or shear depending on how brittle the metal is. You can show that the gripper in question was placed in tension by monitoring the elongation of the steel to make the handles closer. From my own personal experience with grippers, a compression bend would make the handles open up. Just for personal enrichment, not to put your post down as you stated before "picking your brain".

In answer to this, the rate at which the force is applied directly relates to the energy given to the system, and since energy can not be created or lost, it has to be absorbed somewhere in the system, whether it is as friction, heat (friction releases energy as heat), or absorbed by the molecules of the steel (deformation). The method you use, described in your post, should have the same effect as closing it with your hand, as long as you are not pushing the handles past one another (when the handles touch, you can't create enough force to deform the steel/alum as stated above, but it might be possible to make them slide past each other, placing the spring in a possition to cause it damage from bending). So your assumption of force would be correct, assuming none of the previous apply.

Looks like we're saying the same thing but I used the wrong terminology. Don't have your background as I'm a computer geek by day. Thanks for the informative post and another chance to learn.

So do we have anyone on this board strong enough to do 200 chest crushes with a BBSM? That seems to be what's needed next to do a comparison.

Do you feel it's the speed of the closes, continuous reps, friction from metal pipe, possible misalignment of gripper closing, or ??? that's causing such a negative impact on the gripper he tested?

Personally I enjoy this discussion as there's only two things you can do with a gripper: close it or try to close it, so not a lot to discuss normally

[Darco]

Ok, quick sanity check.

Are we here on the "Gripboard" talking about the molecular components of a gripper spring as we squeeze it?

Pardon me if I'm out of place here.

Grab em, squeeze em. If the handles touch, get a harder one, grab it, squeeze it.

Rinse, repeat as desired.

Pretty simple stuff for this meat head.

W

God forbid something would make you think !

If that's all there was to it this board would have 1 thread. "i squeaze gryperz" with 7000 replies saying "me 2"

[crouton_cc]

And later, when the piece of steel rod used was big enough to slightly bind the coil, the gripper was markedly reduced in its spread, and I was able to close it pretty effortlessly.

That would make sense as you were bending the arms of the spring, not compressing it. I would ASSUME that no one is seasoning a gripper that way. Might be a big assumption of course

For clarification, you are not placing the steel on a gripper in compression when you close it (other than were the handles touch), you are placing it in tension. You would NEVER be able to budge even the lightest steel spring if you tried to place it in compression, because you don't have the ability to create the forces necessary to flatten the steel by increasing its surface area. It should only bend, as you stated, or shear depending on how brittle the metal is. You can show that the gripper in question was placed in tension by monitoring the elongation of the steel to make the handles closer. From my own personal experience with grippers, a compression bend would make the handles open up. Just for personal enrichment, not to put your post down as you stated before "picking your brain".

"OK Einstein explain this one to me. If the 2.5 takes "X" amount of force to close, then whether I use my hand, foot, teeth, or whatever then how am I exerting more than "X" amount of force??? Do you assume that I'm jumping off a ladder or something. I apply pressure with my foot slowly until the handles touch, let it open, and do it again."

In answer to this, the rate at which the force is applied directly relates to the energy given to the system, and since energy can not be created or lost, it has to be absorbed somewhere in the system, whether it is as friction, heat (friction releases energy as heat), or absorbed by the molecules of the steel (deformation). The method you use, described in your post, should have the same effect as closing it with your hand, as long as you are not pushing the handles past one another (when the handles touch, you can't create enough force to deform the steel/alum as stated above, but it might be possible to make them slide past each other, placing the spring in a possition to cause it damage from bending). So your assumption of force would be correct, assuming none of the previous apply.

You do compress and stretch the steel wire when it bends. If you take a cross sections of the wire, only the very center row of molecules will remain in a compression/tension free state. The outside of the bend (convex side) will be under tension and the inside (concave) will be under compression. I took this straight out of chapter 7 of my Engineering Materials textbook. Take one of theose bendable drinking straws (the one that has the /\/\/\/\/\ joint on it) and bend it at the /\/\/\/\/\/\. One side will be like |||| the other side will be ------ (sorry for my drawing). The same goes for steel. Its this concept that makes I-beams so strong. They keep the center small, and place alot of steel on top and bottom where all the tension/compression forces are exerted.

[Scott Styles]

If that's all there was to it this board would have 1 thread. "i squeaze gryperz" with 7000 replies saying "me 2"

We'd probably all be stronger for it.

[sixlitre]

Crouty and Noob Siabot, you are both very correct. What I reiterated was from memory, and wasn't aware that I needed to recite my text book. The objective was to add some clarification as to why the gripper lost its strength. To me, the spring seems to be designed to work in tension, true that the bending moment causes compression on the inside and tension on the outside, but had the bar not been placed where it had, the spring would have been able to resist the bending moment by transfering the stress along the spring, agreed? Point of story: force steel to bend destructively, force steel to lose ability to resist future forces.

Anyways good points guys, but I agree that we should get back to squeezing these things and not over analyzing them.

[PowerHouse]

I have read quite a few times several people on this board say that they have lost significant amount of spread/strength through footstomping, so why wouldn't someone assume footstomping is the cause of this? I have closed my grippers hundreds of times yet they haven't lost nearly as much spread/strength as I have heard footstomping does. Maybe this isn't the case for you and your grippers, if not then more power to ya. But when several other members do experiments like this one and it messes up a gripper what should one think?

I myself dont understand WHY footstomping would screw up a gripper and I dont really care. I just use them like they were ment to be used.