I always make my own take down sleeves out of some steel pipes. Formerly I did them with a 90° cut, nowadays I prefer a 45° on the inner pipe (which is for the upper limb). When you make the bow asymmetrical (1″ above and 3″ below geometrical center for the handle) you will end up with two pieces, the upper and the lower limb, nearly same length. This maybe of interest when you storage the limbs in a flightcase or something similar.
We need two matching pipes, I have for the outer a diameter of 38 mm and for the inner 35 mm. Both have walls of 1,5 mm, so the inner pipe fits excat the outer. The outer is cut 90° and 100 mm long. The inner at one end 90° at the other 45° , length is in middle 50 mm. Mark (here red line) the shortest distance, this is facing to the archer or simple it is the belly of the bow. Put it in the outer pipe and fix it with a piece of tape. Now mark also the outer pipe (red line), we neeed this line for orientation. Next step is to get the thing in the vice, red line up and exact in the middle. Some wooden blocks are useful to get the pipes absolut horizontal in the vice, of course they are removed before we ress with the vice. The first round is to get an oval, then clamp asymmetrical (using a thinner block) for an egg shaped cross section. The angle of the inner tube has changed a bit, because of the transformation. A belt sander or a good file will bring that inner sleeve in form again. That’s all – not that difficult!