The Ghetto Grip Calibration Device
This design is basic and inspired by the Morton Grip Calibration Device. The setup is basically the same, but mine is wood and pipe.
I really like there design, but don't have access to a welder and didn't want to pay someone to do it for me. I'm hoping the results would be the same on either device.
The Pictures above are of an original Ironmind Silver Crush #3 being tested. Below is a close up of the machine.
The part that holds the gripper is a 3/4" X 2" black plumbing pipe. It is held on by two 3/4" galvanized straps. It was necessary to drill the holes in the straps slightly larger. One is on top the other for strength. It's bolted to the 2X4 with 2" 1/4 inch bolts. Washers are used on top and bottom mainly to strengthen the straps. Larger 5/8 inch bolts and a connector are used to prevent any flipping of the gripper. The unit is belted to a 1/2 rack. A small piece of plastic is placed in the pipe, to prevent gripper damage. Overall, it was a lot easier to make and use than I expected.
Weights include loading pin and straps. Weights were calibrated on a digital postal scale. I blind repeated three test and results were within 1 pound. The results were within 5 pounds of my un calibrated tests.
IM Trainer 59.5 pounds
IM "old" Trainer 67.5 pounds
IM 1 79 pounds
IM "old" 1 92 pounds (note 1 below)
IM 1.5 Tweener 95 pounds
Master 115 pounds (note 2 below)
IM "easy" 2 116 pounds
IM 2 118 pounds
IM 2 "double stamped" 122 pounds
IM Original Silver Spring 2 131.5 pounds (note 3 below)
IM 2.5 Tweener 132 pounds
IM 3 "easy" 141 pounds
IM 3 149 pounds
IM 3 "double stamped" 149.5 pounds
IM Original Silver Spring 3 160.5 (note 4 below)
Elite silver spring double stamped 180 pounds
Note 1: The gripper seems harder than the 1.5. This is likely because it is wider and unless you use a parallel set, requires a greater distance to close. This is a factor not taken into account with weight measurements. It could be a big factor in non-parallel set closures.
Note 2: This is also a wide gripper and seems nearly as hard as the double stamped 2. It seems very easy at the start and gets hard towards the end. I call it squishy. It was also hard to test as it seem to react slightly differently to the same weight each time tested. I didn't experience this with other grippers. The handles don't come together clean, which also made it more difficult to test.
Note 3: This gripper seems harder than the 2.5 when closing. This is do to it also being a wide gripper. The handle also has a much weaker kurdling, that adds to it's toughness.
Note 4: This is an original Silver Spring #3. Similar to the one Richard Sorin and several others qualified on. It is also a wide gripper and has a weak kurdling.
I will have a lot more results soon.