This is a simplified spoke tension meter.
This meter uses readily available parts to assist a wheel builder in achieving accurate and even spoke tension when building a bicycle wheel. It can be built with readily available parts. Printing can be done with any rigid filament such as PLA, ABS, Nylon, and even PETG.
STEP and F3D files are included for self-modification if needed. Import them into your favorite 3D CAD Application.
All files updated to match STEP, STL and F3D, fixed minor problem with dial indicator lock screw.
Version 6 clips the bottom corner off Handle #2 and adds a raised standoff for Handle #1. M3 screw now needs to be lengthened to 20 mm.
Two M4 x 20 mm Socket Head Cap Screws
One M4 x 10 mm Socket Head Cap Screw
Three M4 Nylon Insert Lock Nuts
One M3 x 20 mm Socket Head Cap Screw
One M3 Nylon Insert Lock Nut
One M2 x 8 mm Socket Head Cap Screw
One M2 Nut
In addition to the nuts and screws you will need a few other items.
One 0.041" x 0.312" x 1.25" Compression Spring
One 1" Dial Indicator
One M4 Nylon Washer
One 624ZZ Precision Bearing
Starting with Handle #1 push two M4 nuts and one M3 nut into the recesses on the bottom of the handle. In Handle #2 push in the 624zz bearing, one M4 x 20 mm hex head screws through the bearing. Place the M4 x 10 mm hex head screw in the remaining hole and secure it with an M4 nut. Before securing both handles together place the nylon washer between the two handles on the M4 socket head screw. Secure the two handles together. Place the spring in the recess. slightly compress the handles toward one another to reveal the 3 mm hole, placing the M3 socket head screw in the remaining hole. Push the Dial Indicator into the hole in Handle #1 and secure with an M2 screw from the back side of the handle.
In order to properly calibrate your tensiometer for use, look at this model, https://www.thingiverse.com/thing:3322907
Instructions for use
Before you use the tensiometer to perform a measurement, the dial gauge has to be set as follows to rest at the zero position.
Switch on the dial gauge by a short press of the control button usually labeled “On/Off“.
Hold the tensiometer so that the compression spring presses the lever arm all the way to the stop (rest position, fully open).
The reading of the dial gauge has to show the measured value 0.00 mm in the rest position. If another measured value appears, press the control button “Zero/Tare“. Now the tensiometer is ready for use.
Compress the lever arm so that it touches the supporting arm, and clamp the spoke between the studs by lining the spoke up along the spoke line on the tensiometer. Release the lever arm. Hold the tensiometer parallel to the hub axle.
NOTE: With bladed spokes, hold the tensiometer at a right angle to the spoke without twisting it (do not apply any additional torque). Fix the middle stud support at the pivot in the middle of the spoke. With butted spokes, the stud supports must absolutely lie within the butted section and not in a transition.
- The gauge has to be switched off manually when not in use. Press and hold the control button "On/Off" until the unit turns off.
The dial gauge shows the deflection in mm.