How Do Auto Body Frame Machines Work
An auto body frame machine is used to repair damage to the inner frame of your vehicle from collisions, to restore it to its original shape. This damage occurs in about half of all vehicle accidents, so frame machines are a common piece of equipment in body shops. They do the work that humans simply don't have the strength for through the use of hydraulics, leverage, and sheer torque.
Frame machine sizes are usually 15 to 24 feet for standard vehicle bodies, and full-size or larger trucks or SUVS may need a frame that runs up to 24 feet. They can come with two or three rotating (360 degree) towers that allow you to apply stress to the vehicle’s frame, and stretch or pull it to straighten it back to its original shape. Frame repair is usually achieved either by pushing or pulling a section of the frame, depending on the damage and the type of frame. For example, with the unibody frame, which is what most automobiles have, there is no way to get to the other side of the damaged area to be able to push out to straighten a bent section, so pulling is required. The towers accomplish this by acting from outside the zone of the damage and pulling away from the area with increasing torque until the section is straightened. Obviously, the more towers the body frame machine has, the more accurately it can restore the frame's shape back to normal.
Frame machines strap your vehicle’s frame into a static position so that repairs can be made. They typically will have loading ramps so you can drive the vehicle up onto the platform of the machine, where the vehicle is bolted down. Chains are attached to pull the frame, and hydraulics adjust the tension. The more modern and sophisticated machines will include measurement equipment, and even computerized measurement equipment, so you can make more accurate adjustments. It can put in the original dimensions for the frame, and push and/or pull the frame until it reaches that dimension, and then stop. The measurement system will provide height, weight, and length measurements.
In machines for unibody frames or single unit frames, the body and the frame come as one piece. The machine for body-over frames is for vehicles where the body is separate, but then secured to the frame. Some auto body shops may have portable frame machines due to space constraints or because they need to be moved to other locations.
If your vehicle is brought in after an accident, your insurance company will often pay a standard two hours worth of labor hours for your vehicle to be put up on the auto body frame machine and diagnosed. It will report whether the frame is damaged beyond repair, or can be fixed. It will also estimate how many hours worth of frame machine time will be required (i.e., the cost) to make the repairs. Another consideration as to whether the vehicle is worth repairing.