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Bb Grippers


3djim

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First, I am very satisfied with this line of grippers re quality and reported "force to close" info I obtained from the manufacturer. That info was in a form that I could use to compare with the CoC gripper forces. For example, they said the SA was between the CoC#1 and CoC#2, which is what I was looking for.

Another source of data came from this great GripBoard... many statements that indeed the SA was a betweener.

However, both of the above sources did not venture to say, as far as I could determine, what the actual force might be.

To get an estimate of that number, I have a final source: the "gripper equation" which I now use to estimate "force to close at handle mid pt" for my gripper purchases.

When I received the SA I measured it and obtained the following:

wire diam = .25"

handle "depth" = 2.625" (measured from coil center to handle center)

handle length = 3 3/4"

handle diam = .75"

handle angle (takes gripper from open to parallel position) = 29.5 degrees

crunch angle (takes gripper from parallel to closure) = 7 degrees

coil inside diam = 29/32"

I ran my equation and obtained a "force to close" = 160 lbs. And indeed it did feel like 160lbs relative to my strength level and experience with the lower force grippers.

I have run many of my other grippers through this equation and have obtained numbers close to manufacturers suggested values, when these values are advertised. So I trust the number I calculated, especially when reinforced by other information avenues (e.g. GripBoard comments) of estimation.

However, I still do not understand the BB advertised "force related numbers" like 115 lbs for the SA. The BB people, as I best interpret, said it related to "force to close" at handle end. But this did not make much sense, especially when I translated that number to handle center, i.e. 2.625" along the handle leg. The calculation: multiply 115 by (4 7/16" / 2.625") to get 194 lbs. Certainly way off of 160 lbs!

Other numbers I have obtained from the gripper equation for grippers I own:

CoC T, 102 lbs

CoC#1, 142lbs

CoC#2, 202lbs

old CoC#1, very wide sweep, 150lbs

old CoC#3, very wide sweep, 302lbs

CoC#4, 375lbs

BB "A", 137 lbs

BB "M", 192lbs

PDA "243", 148 lbs

PDA "262", 217lbs

Without knowing manufacturer design targets or owning the following grippers, I estimate:

BB "WC", 480lbs

BB "GG", 765 lbs

RB "WT", 813 lbs

Note: gripper "force to close" can be off 10% - 15% due to manufacturing variations in the various geometric parameters. This applies to the above estimates as well.

If someone could give me values for the 7 geometric dimensions, then I could get more accurate estimates.

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3Djim, this is very interesting to me. I have the line of IM grippers and the 11 BB grippers from the WLW site, the numbers have always kind of bugged me! I go by wire size to guage the difficulty in closing them. Since you seem to be VERY good with the math (no sarcasm, seriously I never would have figured out that formula), assume all but the one parameter(wire size) were equal, what would the closing force be for the BB line. Beg. (.225), Adv. (.235), SA(.250), M(.260), SM(.273),GM(.281), E(.293), SE(.306), GE(.312) , I cant remember the wire size for the PRO or the WC, somebody help me out here! I think it is pretty pathetic, I knew the rest of these from memory! Anyway, I am just curious as to what you would come up with . Mike

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Ok, I checked the FAQ section the PRO(.331),WC(.345),CON.(.362) GAL.(.375). I realize these are just ballpark figures , but still very interesting. Mike

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By the way do you guys know when the new grippers are coming out, the galaxy and others harder than the WC :mosher

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Here are the results, Mike (calculated force-to-close in parentheses):

.225 (114), .235(134), .25(170), .26(197), .273(237), .281(264), .293(309), .306(364), .312(391),

.331(488), .345(569), .362(681), .375(776)

Assumptions:

1) handle sweep (takes gripper from open to parallel) = 30.5 degrees

2) crunch angle (takes gripper from parallel to closed) = 7.5 degrees

3) coil inside diam = .875"

4) handle depth (dist from coil center to handle center) = 2.625"

5) handle length = 3.75"

6) handle diam = .75"

7) force to close is calculated at assumed handle center

As I best understand, you can expect mass produced gripper tolerances about:

+- .002 for wire size

+- 2 degrees for handle sweep

5% for coil ID

+- 1/16" for handle depth

I imagine, for fixed wire sizes, manufacturers play with handle sweep, coil ID and handle depth to target their"force to close" goals. My grippers see variations like these.

If you want more accurate estimates, then I will need to know more clues re the geometric param's on your grippers. All the above param's are fairly easy to measure, except wire size (to within .001) and crunch angle (need to use something like a hose clamp to hold gripper inclosed position ... be careful though for the stronger ones, since the clamp might have limitations to hold high poundages).

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Do you know when the galaxy is coming out

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Thanks 3Djim, I have been wondering for some time what the approx. gripper poundages were for the BBs. I know its not perfect, but it is MUCH better than saying between a #3 and #4 ect. (especially to the non-gripping public-ok so I really mean my family and friends ;) . Your numbers seem to be right where one would expect them (i.e. I had been est. my BBSM at about 240 pounds). I have been wanting to get the 2-3 grippers above the WC just so that I have the entire line (after running those numbers I do not believe anything above the PRO will ever be closed , I mean the Gal. requires TWICE the force to close as a #4!!!!!) Anyway thanks a lot for running those numbers, and good luck with your training. :rock Mike

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3djim, My mistake the BBE is .295. Just want to be accurate in what I am saying. That would maybe bring it up to the 320-325 pounds to close range. Not sure where I got the first number, they say the memory is the 1st thing to go :dry . Mike

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3djim, thanks for clearing that up! I am not positive , but if Kyle called Warren Tetting, I think he has the next 2 paperweights (er, I mean grippers :dry )at his shop for sale. I need to give him a call also so I can add those to the growing list of grippers I own , but cant close. I can only close 9 out of the 16 I own now, so whats a couple more! :D Mike

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I can only close 9 out of the 16 I own now, so whats a couple more!

Mike.... how can you LIVE with yourself?? Only 9 out of 16... how sad. :(

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Syber , its tough, but I take it day by day! ;) I must admit I do like handing a SE or #4 to some of the " bench specialists" I know, and watching their faces when I tell them there are people who can close them! Of course It would have just a little more impact if I could actually close one of those :dry (or an BBE or anyhting else above that!). Mike

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