Still Confused

[Lyle]

I read all the spring info in th FAQ section and I'm still confused about what gripper on the BB line is approximately halfway between an IM#3 and #4

PLease, those of you with experiance in this give me some advice?

[Matt76]

http://www.gripboard.com/index.php?showtopic=8084

did you get lazy

[Clay Edgin]

I would rate the BBE at about 3.3 and the BBSE (the newer ones) at about 3.7.

[Lyle]

no I didn't get lazy, I saw that page but it gives spring sizes and the poundage listed by the company's doesn't seem to jive ie: the IM#3 is listed as 280lbs and the spring is .281, while the BB Grand Master is listed as 220lbs with the same .281 spring??????

[Anuwbius]

Dont go by the advertisers claimed poundage. It is definitly one of the worst way of judging how hard a gripper is. Spring size is the best way, go by that alone for now.

[Bill Piche]

Forget about poundages. Use spring size.

[EmEx]

How can you compare the resistance with spring size?

If you look at CoC T with .225 and CoC#1 with .235 its less

then 5% but it is surly more then 5% increase in resistance isnt it?

If you compare spring size of the Trainer with the #2 theres only

a small difference in spring size but from what ive heard and read

theres a huge difference in resistance.

My point is that even if the poundage is only aproximate

and inaccurate its still easier to compare and easier to

judge the strenght of the gripper.

Edited May 1, 2004 by EmEx

[gerryg]

Compare grippers by the wire size!

[Rick Browne]

no I didn't get lazy, I saw that page but it gives spring sizes and the poundage listed by the company's doesn't seem to jive ie: the IM#3 is listed as 280lbs and the spring is .281, while the BB Grand Master is listed as 220lbs with the same .281 spring??????

Where the test load on the handle is placed, will give you different

LB ratings. Place a load in the middle of the handle which you want

closed and compare it to a load placed on the end of the same handle,

you will get different readings. More LBs for the middle of the handle test

and less LBs for the load at the end of the handle test. It is all predicated

in where the leverage factor is used.

To make your life simple, just ask the board here what gripper to get

and you will receive the best advice for your needs... Quit sweatin`

the details

[mooinabc1]

I would say BB supermaster is the one

to try. It is about 225 pounds.

Then if you can reps with and then strap holds

on it. You can use the bathroom scale that about 1.5 ratio.

To you #3 for example if it 160 x1.5=240 pounds

[daniel_lidstrom]

How can you compare the resistance with spring size?

If you look at CoC T with .225 and CoC#1 with .235 its less

then 5% but it is surly more then 5% increase in resistance isnt it?

If you compare spring size of the Trainer with the #2 theres only

a small difference in spring size but from what ive heard and read

theres a huge difference in resistance.

My point is that even if the poundage is only aproximate

and inaccurate its still easier to compare and easier to

judge the strenght of the gripper.

When you compare resistance by spring diameter you need to remember that resistance increases squared relative to the diameter. For example: if you double the diameter of a spring you will get a 4x harder resistance. This is because the doubling is two-dimensional. So a 5% increase in spring diameter (1.05) is actually a 10% increase in resistance (1.05*1.05=1.10...).

Another way to see this is to think about what happens if you double the size of a `blob'. Then you would get a blob weighing 8x the first one, since in this case doubling occurs in 3 dimensions (2*2*2=8).

[Bill Piche]

Forget about poundages. Use spring size.

I meant wire size. Not spring size.

[Matt76]

I was just joking about the lazy comment I didn't know you found the site sorry

[3djim]

Force-to-close is approximately proportional to the 4th power of wire diameter, according to well-published mechanical engineering data (see ref below). FTC is also sensitive to handle angle, moment arm (i.e. dist on handle to where FTC is measured from coil center; this is related to what is called "set" or "depth"), "tightness" of coil winding, material properties of wire, etc. However, FTC is most sensitive to wire diameter by orders of magnitude. That is why some of the gripsters advise first to compare wire diameters between grippers, if you must get a preliminary heads up re FTC for possible gripperpurchases. It is also an easy measurement to make. After that you should look at coil diam, "set", etc to get a deeper understanding of FTC for comparison if you are so inclined.

Probably the best advice is to listen to those who already own a variety of grippers and get their opinions as to "betweeners".

From my calculations, using the grippers I own and using info I have gleaned from the board re gripper parameters, I believe the following grippers could meet your need:

BBSM .... ~240 lbs FTC at handle center (I do not own one of these and had to est some of the param's)

BBGM ... ~260 Lbs FTC at handle center (I do not own one of these and had to est some of the param's)

RB 210 ... ~230 lbs FTC at handle center

PDA 262 ... ~227 lbs FTC at handle center

If you are interested, see the following ref for "Torque eqn" showing 4th power of wire diam:

http://www.allmetalssupply.com/torsion_springs.htm

(In that reference, they define "Torque". FTC equals Torque/(moment arm).)

There are a gillion posts about the effects of gripper parameters on FTC, and no formula can capture much more than a theoretical estimate. As to whether analytics interest and are valuable data for you is a personal taste.

[EmEx]

How can you compare the resistance with spring size?

If you look at CoC T with .225 and CoC#1 with .235 its less

then 5% but it is surly more then 5% increase in resistance isnt it?

If you compare spring size of the Trainer with the #2 theres only

a small difference in spring size but from what ive heard and read

theres a huge difference in resistance.

My point is that even if the poundage is only aproximate

and inaccurate its still easier to compare and easier to

judge the strenght of the gripper.

When you compare resistance by spring diameter you need to remember that resistance increases squared relative to the diameter. For example: if you double the diameter of a spring you will get a 4x harder resistance. This is because the doubling is two-dimensional. So a 5% increase in spring diameter (1.05) is actually a 10% increase in resistance (1.05*1.05=1.10...).

Another way to see this is to think about what happens if you double the size of a `blob'. Then you would get a blob weighing 8x the first one, since in this case doubling occurs in 3 dimensions (2*2*2=8).

Thanks makes sense now didnt think of it that way.

[daniel_lidstrom]

How can you compare the resistance with spring size?

If you look at CoC T with .225 and CoC#1 with .235 its less

then 5% but it is surly more then 5% increase in resistance isnt it?

If you compare spring size of the Trainer with the #2 theres only

a small difference in spring size but from what ive heard and read

theres a huge difference in resistance.

My point is that even if the poundage is only aproximate

and inaccurate its still easier to compare and easier to

judge the strenght of the gripper.

When you compare resistance by spring diameter you need to remember that resistance increases squared relative to the diameter. For example: if you double the diameter of a spring you will get a 4x harder resistance. This is because the doubling is two-dimensional. So a 5% increase in spring diameter (1.05) is actually a 10% increase in resistance (1.05*1.05=1.10...).

Another way to see this is to think about what happens if you double the size of a `blob'. Then you would get a blob weighing 8x the first one, since in this case doubling occurs in 3 dimensions (2*2*2=8).

Thanks makes sense now didnt think of it that way.

Actually, according to the page 3djim found, resistance increases ^4 with increased wire diameter. So a 5% increase in wire diameter would be: 1.05^4 = 1.2155 = 22% increase in resistance.

Edited May 2, 2004 by daniel_lidstrom