When I borrowed the extra sail for my twin sail project I needed to make it furl without drilling holes or pressing a bearing onto the mast in case I had to return it. The simplified system works well and is easy to fit. In an earlier system I made I had a bearing at the base of the mast which added complexity. This is not needed.
Here are the parts required:
The main parts are the 7/8" Canopy Bow Knuckle readily available from a boat supply shop and the thrust bearing balls and retainer which I ordered from an online bearing supply shop. It has the following specs and fits the Hobie mast perfectly:
Nominal ID (mm) : 22.225
Nominal OD (mm) : 34.925
Nominal Thickness (mm) : 2.362
Material (Retainer / Balls) : Nylon / 440C Stainless
Ball Size : 3.962
The other parts are readily available from a good hardware store.
Here's how it looks assembled on the mast and fitted to the boat:
The system relies on the weight of the mast bearing on the thrust race. To get clearance from the end of the mast in the mast tube assemble the bearing and knuckle on the mast, fit to boat, tighten knuckle with screwdriver, remove mast and then fit the washers. This will allow the mast end to sit above the tube base and spin freely.
The knuckle needs to be notched for the sail downhaul bungee. I drilled it out but it doesn't need to be this deep.
A round file may be better to use to get a knotch just deep enough so the bungee doesn't slip.
The plastic tubing fits over the knuckle bolt to protect the line from the sharp threads. A tube clamp can be used to retain the bearing when not in the mast tube
or the furling line can be tied around the mast end:
The sail is fitted to the boat furled around the mast. The small furling line is wrapped clockwise around the mast a couple of times higher up and then threaded through a small jam cleat located just in front of the hatch.
A small eyebolt allows smooth operation of the furling line:
The mainsheet can now be locked down.
To unfurl the sail undo the furling line from the cleat and pull on the mainsheet. The mast will turn as the sail unrolls and the furling line will wrap around the mast. With a little practise the sail will unwrap easily from around the mast. I find it helps to unfurl the sail a bit, release tension allowing mast to straighten and then pull on the mainsheet again.
To furl loosen the mainsheet and pull on the furling line. The sail wraps easier than it unwraps.
Great for landing or when the wind picks up!
PS- If you cannot get the thrust bearing retainer I think you could try the Hobie teflon disk they sell for their cat mast. Drill a 7/8" hole in the disk for the mast to fit through and fit it between the washers. It should work but I got the bearing for about half the cost of the teflon disk. If you use a hole saw you may even be able to drop the cutout into the mast tube for easier spinning!
It may even work just with the washers -though not as smoothly