Flexibility of the free end of the spring

[Guest StrongerthanArne]

Interesting observation by Heath about the very deeply set spring on the 295 #3. The Super Duty first set of SOS grippers had also a deeply set spring. I had access to a 330. Adjusted for handle length it would have been about 345 with the new SOS standard. The problem is that it felt much harder than that (whatever that is). Maybe there is a hidden factor here, i.e grippers in which the handle length is short (spring deeply set into the handles) are more difficult to close than what can be attributed to simply a shorter leverage arm. They certainly have a different, kind of rigid feel to them than grippers in which the spring is not so deeply set. I suspect that the free ends of the spring have a fair degree of flexibility in them in an average IM gripper for example. If so there would be a dramatic difference in closing difficulty by pushing a spring say 5 mm more deeply into the handles. Far more than accounted for by the shorter leverage arm.

[Bearcat 74]

Actually, I think this was a Super Duty.  Terminator??

[terminator]

Yup.

[Bill Piche]

If it was one of the first ones, it was a known fact the handles are shorter and therefore make the gripper harder.  No different than filing down the handles like Tom was doing.

[Bearcat 74]

Very true, but i thought that when John measured for handle length that was taken into consideration??

[terminator]

Wanna, true they were shorter.  But, for the numbering system to be valid, it should take into account all variables right?  No real way to correlate one gripper with another via IP.  FYI, a 352 from the same lot with the same short handles is easier.  Go figure.

[terminator]

Still good training tools mind you, just casts doubt as to the acccuracy of the IP numbering, that's all.

[Tom Black]

There was a point that mathematically I was concerned that the way PDA multiplied by 2.375 did not apply to my shorter #2 grippers.  It troubled me that if the gripper was shorter then the half way point would be a shorter and smaller.  Thus when multiplied by the end of the handle point measurement the result would be a smaller number.  And yet, the one short gripper that was tested did seem to bear out the rather obvious observation that they get harder when shorted.  Of course, the measurement off the end must increase and this probably accounts for all of the torque increase, or at least this is what I concluded.

[terminator]

Tom, I guess with all the material removed, the spring would have to compress much more for the handles to touch.  This would also contribute to the different torque reading I imagine.  I don't know if this is what you were trying to say but I think it is a major contributor.

Back to those hard 60d's I have.  I made some preliminary measurements last night.  With 365 lbs on the loading pin, it barely tweaked the nail, discernible only if you roll it.  I have to get creative, I have mostly bumper plates and was at the top of the loading pin.  I was also a bit lazy, I had some lighter bumper plates on the pin already, and just stacked the heavier ones on top.  I will start heaviest on the bottom next go around and see if I can get more weight (hopefully enough to bend it) on the pin.  Stay tuned

[Tom Black]

It's not really the extra compression of the spring that makes my modified grippers harder to close.  With -3/8" cut off the bottom of the handles they do not even move another 1/16" closer.  What makes it harder is that having a shorter distance to the spring affords the hand less leverage to close the gripper.  This can be simply experienced by gripping up on a gripper, and it will feel harder.  Of course, when doing this, the handles touch at the same point so there is no extra compression of the spring, but the gripper feels harder because you have less leverage on the handle.

Wow, that's some 60-penny nail.  Are you bending those nails completely into a U-shape?  I'd like the brand name as well, it would be alot cheaper than the bolts to bend these.