Assembly and Operation of Torsion Testing Device

Owned by Areeb Mohammed
Last updated: Apr 21, 2022 by Sean Rose
3 min read

Note: This page has not been updated to reflect the changes made during Winter 2022.

Assembly

The different parts of the torsion testing device are fastened in place using 1/4”-20 grade 5 steel hex head screws and nuts. Although the torsion testing device has a simple design, the order in which the pieces are put together can affect how difficult it is to assemble. The following procedure will allow ease of assembly.

 

 

 

  1. Assemble the base of the device.

    1. Align the top layer (orange) and the L-shaped piece to the correct position on the base plate (grey). Insert the bolts from the top layer’s side and fasten the pieces together by attaching and tightening a nut from the other end.

    2. Attach the non-adjustable guide piece that runs along the length of the rod to the base by firmly fastening it using a bolt and nut.

    3. Attach the adjustable guide piece to the base using a nut and bolt but do not fully tighten the nut so that the piece is still movable.

    4. Place the rod in between the two guide pieces and position the adjustable guide piece so that it is pressing against the rod. When the adjustable guide piece is in this position, tighten the nuts that are holding the guide piece so that it is firmly held in place. Once this is done, the rod can be removed from in between the guide rails.

    5. Insert the support pieces that hold up the base into the correct slots.

  2. Attach the pulley to one end of the rod.

    1. Slide the discs, starting from the front (orange) disc, onto the rod. Align the slot in the second disc so that the bent part of the rod fits into it. Fasten the discs together by lining up the four symmetric holes and inserting bolts into them. Fasten them using nuts. The discs can also be fastened using barrel nuts. This will allow more ease of assembly.

    2. Attach the L-shaped piece (pink) to the pulley by inserting bolts through the slots on the piece and the two holes near the center of the pulley. Now push the L-shaped piece towards the center of the disc so that the specimen is centered in the pulley. Now add a nut to fasten the piece in this position so that the specimen is held in place.

  3. Put both parts of the device together.

    1. Slide the rod into place on the base of the device. Fit it in between the guide rails and against the L-shaped piece on the base.

    2. Slide the rectangular piece in between the top piece and the base. Push it against the specimen to firmly press it against the L-shaped piece. Now slide bolts through the two holes and tighten it to hold the piece in place.

 

Exploded view of the device assembly

Operating Procedure

Always wear safety glasses when operating the device.

  1. Place the device at the edge of a table so that the pulley is hanging off.

  2. Tie the end of a piece of rope to the hole located at the edge of the pulley.

  3. Start winding the string onto the pulley in a counter-clockwise direction (when facing the device from the side of the pulley). Tie a loop knot at the end of the string so that the masses can be hung on it.

  4. Using a C-clamp, clamp the base of the device to the table so that it doesn’t lift off of the table when the the mass is added to the pulley.

  5. When performing the test, incrementally add weight to the end of the rope and record how much angular deflection is observed for each amount of weight. Use the protractor design on the front disc of the pulley to see how much angular deflection there is using the surface of the base as a reference.

 

A video demonstration of the Torsion Testing Device being used can be found on the Ideas Clinic Torsion Testing Device page in MS Teams, in the Materials Channel.

(https://drive.google.com/file/d/1n7GW7LY39KZJLUs5b6KtrgyxQE5hBeFy/view?usp=sharing)