In April 2011, Stephen C. Martin completed an inexpensive test for coiled compression springs to evaluate compliance with specifications. The testing apparatus included a controlled screw jack for applying compressive force, a fish scale for measuring that force, and a digital caliper for measuring compressed length, all totaling under $215. The project demonstrated a cost-effective approach to assess spring performance efficiently.

1. Inexpensive Test of
Compression Spring
Completed in April 2011
By
Stephen C. Martin

2. Situation:
 A factory submitted a batch of coiled
compression springs for approval.
 An inexpensive method was needed to
quickly evaluate potential compliance
with specifications.

3. Actions:
 Assembled apparatus that could create
the specified conditions.
 Selected equipment that could measure
the performance of the spring under the
specified conditions, ie. compressed
length of x inches under a load of y
pounds.

4. Test Stand
 A screw jack provided
controlled compressive
force.

5. Force Measured
 The strain gage in an
electronic fish scale
measured the
compressive force
delivered.
 An eye bolt, washers,
and a metal bracket
secured the spring.

6. Compression
Measured
 A digital caliper
was used to
measure the
length of the
compressed
spring.

7. Results:
 Screw Jack < $100
 Fish Scale < $75
 Digital Caliper < $40
 2” x 6”, brackets, screws, and C-Clamps
were found in my garage.
 Total Cost of Project < $215