Rotary Jig

TR7 Restoration Project, Feb-2013

The TR7 chassis rails extend to the extreme front and rear of the car and have end plates to mount the bumpers. The end plates are strong enough to take the weight of the stripped-down car and therefore provide a convenient mount for the rotary jig.

I aleady had the stands for a rotisserie from the Mini project, so the main task here was to fabricate ‘T’ bars to connect to the bumper mountings. I used square section (4mm thickness x 40mm) with 5mm adapter plates welded-on and drilled (rear t-bar):

The front is a bit more complicated as the bumper mounts are angled, so I needed to make up a bracket to suit. A piece of 48mm (4mm thickness) tube is welded on at the centre. This is a single point failure, so if you attempt this type of jig, make sure the weld that joins the tube to the bar has good penetration through both parts and that you build up a thick web around the join.

Here’s the car mounted on the jig. It lifts the car 900mm off the ground and although this looks a bit too high, the car is almost 1700mm wide, so you need to lift it a minimum of 850mm to get 360 degrees of rotation.

I used 3 bolts on each side of the chassis mounts and also found that a bolt through the tube was needed to avoid the stands creeping out as you rotate the car:

This is by far the best way to restore the underside of a car. I can rotate the car to almost any angle and perform any work on the underside in comfort and safety.