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Old February 22, 2015, 12:38 AM   #8
JohnKSa
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Join Date: February 12, 2001
Location: DFW Area
Posts: 21,061
Ok, I've revisited my initial design after using the tester for awhile.

The initial design can be improved in the following ways:

1. Drill a hole in a wood block and clamp the wood block in a vise. The wood block becomes the reference point and replaces one set of washers and the brass collar. The spring guide goes through the hole in the block, then through the spring and then through the compression washer. It makes things a little easier to deal with.

2. Add a small nut on the spring end of the compression washer(s) to stabilize the compression washer(s). Otherwise the compression washer(s) will tend to tilt to one side or the other resulting in inconsistent measurements.

Those two changes, especially the last one will improve the design enough to make it very workable for someone who wants to do a spring measurement once in awhile.

BUT, I decided to run another magazine spring test after posting the results of the first one here. The new test will involve 4 magazines. The prospect of trying to use the original design to repeatedly measure the 4 springs was unappealing so I came up with a new design.

This one uses a rigid frame with a sliding block enclosed in aluminum rails. This design prevents the spring or the compression block from torqueing to one side and allows very accurate and repeatable compression distance. The result is more consistent/accurate results.

I'll try to get some pictures posted in the next few days. Unfortunately this one isn't as simple to put together as the old one was.
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