Spring Tester

Modeltec dec 1985

Here’s a versatile Spring Tester

by Jack Edwards

Modeltec, December 1985

photo by author

When I needed to know what weight some springs would carry and what deflection there would be, I made a cylinder of 1-1/4 inch OD brass tube having a bore of 1-1/2 inch diameter which equals 0.994 square inches, near enough to 1 square inch. A plunger acting on a fluid in the cylinder will register a direct reading in pounds load on pressure gauge calibrated in psi.

Assemble with light grease on the sliding parts. Stand in a pot of water (the assembly, that is!) and extend the plunger to draw in water. Remove it from the water, turn the assembly on its side with gauge hole up, push the plunger half way in and screw in the gauge. This may have to be repeated until no air is in the system. A gauge with a range of some 100 pounds above the maximum load to be measured will be suitable.

The device can be used under an arbor press, drill press, or in a vise to compress springs, etc. Warning! Make sure the spring is secure under compression.

Since making this gadget I have found other uses for it. For example, checking the deflection of a flat bar that had to carry a certain load, finding the weight carried by an axle, weighing Locomotive, and other such calculations.