The frame consists of right and left stands, a lower bracer bar (front), 3 rollers with cloth sleeves (back) and 3 sprockets (on the bracer bar)
The right stand has 3 grooves cut to receive the rollers and the left stand has 3 holes where the rollers are inserted with the sprockets to hold them in place.
First the bracer goes on.
Then the rollers. Two in back one to pin the top onto and one to pin the back onto. The batting is fed between these poles and all 3 layers are pulled to the front pole and pined together on the front leader.
You can see the sprockets (circles with the teeth) and flippers hold the rollers in place and provide the tension on the bars = "Self basting"
Next comes all the pinning to the frame, but I have no batting so I will save that info for another day.