kelby Posted November 4, 2005 Share Posted November 4, 2005 how much pinching pressure does it take to pinch two 45's together. Quote Link to comment Share on other sites More sharing options...
Sybersnott Posted November 4, 2005 Share Posted November 4, 2005 how much pinching pressure does it take to pinch two 45's together. ← O.K., I'll bite... um, enough to lift them up?!? Quote Link to comment Share on other sites More sharing options...
Clay Edgin Posted November 4, 2005 Share Posted November 4, 2005 Depends on a lot of things. Amount of chalk used, smoothness/grit of the plates, etc. How would you measure pinch pressure anyways? Quote Link to comment Share on other sites More sharing options...
nickr104 Posted November 4, 2005 Share Posted November 4, 2005 Depends on a lot of things. Amount of chalk used, smoothness/grit of the plates, etc. How would you measure pinch pressure anyways? ← Good question. Pinch has alot of variables As Clay said above chalk, surface of plates, the amount of humidity in the air, how sweaty or not sweaty your hands are on that day. We talked to RS about this at the GGC. I tend to agree with him some what. It is hard to judge one lift from another in less it is on the same day , same conditions,same plates or any other type of pinching you do for that matter. Just got to look at it as a blob lift is a blob lift 45 lift is a 45 lift. It just felt good and went up that day. There are days i go out to the shed to work out and the blob is flying up then others it feels like I can barely move it Same with 45's. I don't think you will really be able to measure that it takes so many pounds of pinch pressure to lift this because it varies soo much. I hope I didn't ramble to much. Sorry if I did. Quote Link to comment Share on other sites More sharing options...
Dave Lemanczyk Posted November 4, 2005 Share Posted November 4, 2005 practice, patience and time. Quote Link to comment Share on other sites More sharing options...
underdawg Posted November 4, 2005 Share Posted November 4, 2005 A lot. Quote Link to comment Share on other sites More sharing options...
mobsterone Posted November 4, 2005 Share Posted November 4, 2005 I'm with Syber.. 90lbs + 1 worth. Quote Link to comment Share on other sites More sharing options...
supermagnamon Posted November 4, 2005 Share Posted November 4, 2005 I'm with Syber.. 90lbs + 1 worth. ← I'm with both of you guys on that as well. Quote Link to comment Share on other sites More sharing options...
climber511 Posted November 4, 2005 Share Posted November 4, 2005 It takes just a little more pressure than I can do! Quote Link to comment Share on other sites More sharing options...
mobsterone Posted November 4, 2005 Share Posted November 4, 2005 Depends on a lot of things. Amount of chalk used, smoothness/grit of the plates, etc. How would you measure pinch pressure anyways? ← With two bathroom scales. Quote Link to comment Share on other sites More sharing options...
rjkd12 Posted November 4, 2005 Share Posted November 4, 2005 You can probably do it with physics. By pinching on the sides you need to create enough normal force which will increase friction (force increases friction) that will overcome the force of gravity pulling them down. All that is missing from the equation is the coefficient of friction btw plates and skin. Chalk, humidity, rust etc.. will all change the coeficcent. The best way would be to use two bathroom scales, but the main problem is using a material between the scales and the plates that will mimmick skin. The rubber on the scale (if it has rubber feet) will grip the plates much better than your own skin. If you can use something more smooth you might get a ball park number. Just pinch the plates with a huge C-clamp until the 45's are lifted off the ground. Loosen the clamps and the last reading on the scale before the plates drop is the number. That number will be similar to the amount of force needed. Looking back maybe it is a lot harder than I thought. How about someone who can pinch 2 45's pinch a bathroom scale and see what they get. Then someone who is close can do it. If a few people state their progress and the number they get maybe we can get a clue on how much force it takes. Quote Link to comment Share on other sites More sharing options...
jimcg Posted November 4, 2005 Share Posted November 4, 2005 (edited) The very first day you succed to do the lift you know you have the strength required, if you then pinch press on a bathroom scale using the same pinch width as two 45's and read what it says. Wouldn't that give a rough indication on what kind of pressure is required? Or we could ask someone who can already do the feat to try this and tell us the result! //Jim Edited November 4, 2005 by jimcg Quote Link to comment Share on other sites More sharing options...
Kurt Lane Posted November 4, 2005 Share Posted November 4, 2005 Im up for everyone trying the bathroom scale idea... im going to try that now. Quote Link to comment Share on other sites More sharing options...
Number Ten Ox Posted November 4, 2005 Share Posted November 4, 2005 What about using block weights made of wood? Is there any way to compare the amount of weight you can lift without having to pinch the weight together as oppsosed to pinching plates? I.E. "I can lift 110 pounds using a 4x4 block of wood but I cannot yet pinch two 45's..." Quote Link to comment Share on other sites More sharing options...
Tyrannosaurus Dave Posted November 4, 2005 Share Posted November 4, 2005 I once calculated that I got 7 pounds friction per hand on my favorite plates. Everything else is grip, no matter how heavy the plates. Friction depends on surface area but your hand size isn't the only variable, as others have pointed out. Old plates are often pitted or have some weird texture that increases the surface area or provides an extra puchase. Also, painting is a mistake. Any plates I have painted over the original factory coat give less friction. My advice: train on the smoothest, test on the crappiest. (and no, I can't do 2-45's: best is 2'35's+3# RH, or 2-15K, painted, L or R) Quote Link to comment Share on other sites More sharing options...
Sybersnott Posted November 4, 2005 Share Posted November 4, 2005 I'm with Syber.. 90lbs + 1 worth. ← Ladies and gentlemen, we have achieved a milestone! Steve ACTUALLY agrees with me on... something! Quote Link to comment Share on other sites More sharing options...
mobsterone Posted November 4, 2005 Share Posted November 4, 2005 It's happened three times that I can recall. Not to be milked though eh... Quote Link to comment Share on other sites More sharing options...
Old Dax Posted November 5, 2005 Share Posted November 5, 2005 Why two bathroom scales? Wouldn't you have to add the readings together? If you use one set of scales and a plate wouldn't you get a direct approximation? Of course the thickness of the scale(s) would affect the dynamics of the lift. Quote Link to comment Share on other sites More sharing options...
mobsterone Posted November 5, 2005 Share Posted November 5, 2005 No, cos of the way scales and pressure plates work (plus we all need to get out more for even thinking about this stuff). Scales etc pressure pressure on one surface rather than two. I can press all day long down onto a plate but it ain't gonna come off the floor. Friction etc etc is all well and good but doesn't in and of itself help otherwise I'd get velcro or sand paper taped to me fingers and lifts 100's of lbs (a la our old mate vince and his skateboard tape and later super smooth chrome washed hands etc). An IM TTK might be useful but would need a longer plate so more of the fingers upto and including the first knuckle or more as opposed to little more than the finger tips. Quote Link to comment Share on other sites More sharing options...
rjkd12 Posted November 5, 2005 Share Posted November 5, 2005 I think the idea of friction is not well understood. The force of friction is equal to the coefficient of friction (which depends on the material, a higher coefficent means they stick together more like rubber, and a lower one means they slip more) multiplied by the force applied to it. Surface area has nothing to do with friction. Changing surface area sometimes can change the coefficient of friction, but for the most part it is not a factor. I will get flamed for this, but talk to any physicist and they will tell you it is true. This is not my opinion and I do not wish to debate it. So, by gripping the plates very hard you are raising the force of friction enough to be able to pick up 90 lbs. You do not gain "friction." Nor does friction assist you somehow. By using chalk or gritty plates you are increasing the coefficient of friction so less force is needed to lift the two 45's. The force of friction will equal 90 lbs since that is all you need to pick them up. The coefficient of friction will change how much force you need to apply to get the 90 lbs of frictional force. Increasing the coefficient (chalk, tacky stuff, gritty plates) you need less force, decreasing it (oil, slick plates, sweaty hands) you will need to use more force. So, using two scales to pick up the plates will make the act easier since most scales have rubber feet. Its like wearing rubber gloves to pick up the plates. What makes it hard it the smoothness. Scales also register different weight if you are standing on the sides or standing in the middle (most scales). Most wrestlers know if you stand on the sides or lean forward or towards a corner your weight will drop. This makes pinching a scale less reputable. I cannot think of any other way though unless someone builds something specifically for this. Quote Link to comment Share on other sites More sharing options...
mobsterone Posted November 5, 2005 Share Posted November 5, 2005 The scales aren't being suggested as a means of picking up 2 x 45 but as a means of measuring the force. From your own (even more time needed out and about ha ha) post it will be 90+ at the least. Friction etc only taking or adding from whatever force over 90+ lbs is used. Quote Link to comment Share on other sites More sharing options...
Preimes Posted November 5, 2005 Share Posted November 5, 2005 The problem being described is an application of a classical physics problem that asks: "How does one hold a box against a wall and prevent it from slipping down by pressing hard horizontally?" The horizontal force applied on the box produces a normal force on the box exerted by the wall, opposite to the force applied. The force of friction is directly proportional to the coefficient of static friction*normal force. The normal force is defined by Newton's 3rd law of motion. When one object exerts a force on a second object, the second object exerts an equal but opposite force on the first. By increasing the normal force of the box on the wall, the downward force of gravity can be balanced by an upward frictional force whose magnitude is proportional to the normal force. The harder you push, the greater the normal force and thus the greater the the friction force will be. If one doesn't push hard enough the force of gravity>(coefficient static friction*normal force) and the box will slide. It would be much easier to describe with a picture. Ugh. -Matt Quote Link to comment Share on other sites More sharing options...
rjkd12 Posted November 5, 2005 Share Posted November 5, 2005 Above is similar as to what I was trying to get across. Pushing a box against the wall is a much better example than my rambling. Quote Link to comment Share on other sites More sharing options...
Eli72 Posted November 6, 2005 Share Posted November 6, 2005 enough to pick them up...duh Quote Link to comment Share on other sites More sharing options...
TheOtherGuy Posted November 8, 2005 Share Posted November 8, 2005 First off, two bathroom scales pinched together would not be needed. One scale and a piece of wood to make up the thickness would be adequate. Since the scales would be applying pressure to each other (the loads would be in series) they will both show the same force. As for the differences at the edges vs. the center, that difference is certainly measurable. You could just balance a plate on the center, then move it to the edges and make a "map" to correct for the errors. (If a 45lb plate reads 45 in the center, and 40 at the edge, you've got to add 12.5% to the reading. So, anyway, if you actually wanted a way to make pinch force measurements, pinching a scale and a block of wood should be perfectly adequate. If you wanted to measure the pinch required to lift a pair of plates, that would be a little more interesting... The easiest would be to take someone who could just barely lift the two 45's, then measure their pinch force, as was mentioned earlier. The actual pinch force does not depend on the coefficient of friction so this should work - friction only affects the conversion from horizontal pinching force to vertical lifting force. I can visualize lots of ways to do this with all my fancy force transducers at work - maybe I'll spend some time thinking about it and see what I can dream up. Of course, if no one really cares I won't bother. Quote Link to comment Share on other sites More sharing options...
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