This device will allow you to set a chair at one height and lock it there.

Step 1: Measure Your Chair

The design should be anchored to a chair with a piston rising/lowering mechanism. The chair should also have a seat anchored to the leg. The lock will anchor onto the screws or bolts.

Step 2: Create Parts

Drag out these parts onto the workplane. Assemble and scale the top section (3 peices). All rectangular prisms are based off a 5x5 square. You will have a generic layout for your hook arm. Lay out all other pieces in general layout, but do not group anything yet.

Step 3: Create the Arm

To create the arm, you will first measure between the begining of the slope from plane on the bottom half of the chair that has the screws or bolts on it to the well or lump surronding the bolt or screw (If there is none, stop a few millimeters away anyway). This measurement is the length of the peice shown in purple. Then, you will raise the peice shown in blue to the height of the top of the bolt or screw and extend it to halfway over the bolt or screw. Another peice may be required to connect the blue and purple peices. The peg can be done two ways. If you are anchoring onto a protruding screw, you will make a hollow tube to affix to the blue piece. Make sure not to group the hole in until you have positioned the tube halfway overlapping with the blue piece. Make sure the hole goes all the way through because you will have to use support to print. Alternatively, you can use a peg that fits in the hole in a bolt or screw head. Or, if you need a cap over a dome, you will have to flip the final product over.

Step 4: Create the Boom

To Create the boom, you will need to drag over the red piece and align it to the angle of the plane connecting the plane with the screws to the plane of the seat. Then, use the workplane tool set against the angled plane of the red piece to adjust length and position. It should be overlapping the purple piece. Finally, drag the pink piece to overlap the red. The bottom of the pink piece is on the chair, so drag a hole to under the pink piece to cut off and of the boom that is sticking down too far.

Step 5: Add the Wedge and Bar

The bar (pink) should be the distance from the bottom of the boom to the hole in the chair that the lever fills when used, plus 5 inches. It shoud be set at the necessary angle. Then, measure the hole above. Set these dimensions as the base of the wedge (green). Then, set the wedge at the proper angle to fit the hole with the arm being on the bolt. Make sure to set the wedge at the proper angle for your chair, noting that the design is upside down to print better, but will attach the other way to the chair.

Step 6: Print!

Group all shapes and print. Make sure to use support and print at an angle where the supports can be removed and do not interfere with the arm.

Step 7: Why Should I Want to Do This Print?

This print solves the problem of childern or clumsy house guests from moving chairs to different heights. It can also reduce distraction among students.