The only additional component not shown in the mast topper pics is the sleeve bearing, (similar to the crankshaft bearings on a car engine, (the way they work is a film of pressurized oil, instead of oil we are using just regular grease, ( a super simple concept..).
Yea I could have made delrin ball bearings, (like on Hobies mast topper) but at the time I had no idea if the thing was going to work at all, (I designed it all while pushing my cart thru Home depot on the fly, ( the orange sign in the pic of the brass tube is the Home Depot shopping cart, (lol).
The pin bearing is just a 3/8” dia stainless bolt ground to a point, glued on center in the upright, (the whole T and upright is several used drill bits dropped inside the T then filled with west epoxy, (make sure you get the 3/8” bolt on center). I just made it too long, then trimmed the length later.
The sleeve bearing is nothing more than a crest tooth paste tube with the end where the tooth paste squirts out drilled out to 3/8 dia, cut the bottom of the tube to the right length with scissors, then fill with grease and slide over the vertical part of the T. To hold the tube in place I just wrapped a few loops of electrical tape over the 3/8” shaft to hold the tube in place, (I could have used a hose clamp, but home depot was closed at the time).
The pin bearing spins inside a 3/8” thick polyethylene ( walmart cutting board) washer with a 3/8” dia hole drilled threw the center, ( the round washer fits loosly inside the brass tube). I dropped two if those washers into the tube, the washers sit against the 5/16” dia cross bolt inside the tube with a dab of silicone to keep them from falling out. The 3/8” dia pin bearing, (ground to a dull point) rubs against the side of the 5/16” dia cross bolt. The pointed end is the thrust component of the mast topper, (no different than Hobies setup at the base of the mast).
Sure I could have designed everything fancy and used real ball bearings, but why,,, I only planned to use it a couple times to test out the concept, (who the heck would ever know if the thing was even going to work, (nobody had done anything like this before, why spend alot of time and money on something you don’t expect to work at all). This was all on saturday, and I really wanted to go out on Sunday, And I still had to make the motor mount, (made from 1 1/2” pvc dropped in the rod holders, filled with epoxy). And still had to make all the rigging for the sails. For the jib I just used an extra Hobie kayak sail on a pvc roto- furler we had laying around the garage, (we had 3 or 4 extras just layin around the garage). For the spinnaker I used the 40sqft spinnaker I had on our old Oasis, ( they both pretty much sucked, but they worked, who knew). Later on I made a 135sq ft spinnaker, and made the jib bigger, (around 40 sq ft, which ended up being too big, I folded a hull) so I cut the jib down to 30sqft and added a bow sprit and re-enforced the front end of the boat, that was a big oops).
Also with the big sails I kept breaking the 1/4-20 stud at the base of the hull, I broke a bunch of them. Then one day in the front yard I opened the sail all the way, then gave the sail control line a swift tug, the 1/4-20 stud snapped as if it wasn’t there at all, (oops theirs the problem). That’s when I added a small plate behind the mast holder and epoxied it in, ( all easily removed), I put those plates in all the TI’s after that. A few yrs later Hobie went to a stronger ( rolled thread) 1/4-20 stud). The other issue was the bearing plate that the white delrin balls sit in. The plate was just mig welded to the front of the 1/16” thick cross brace, I ripped off several of those plates. Starting in 2012 hobie changed the bearing plate design, (with a thru weld to the back and front of the tube), that cured the problem. The rear stay line is kinda important when adding big sails, (just sayin).
Keep in mind 98% of the TI owners out there are perfectly happy with the stock boat. If your not happy with the stock performance it might be better to get a different boat, (H16’s and Getaways are really nice, the Windrider 17, or the Weta are also nice I hear).
However I feel Hobies optional spinnaker is a really really good sail, just came 7 yrs too late for us, ( hopefully they will soon get the bugs worked out on their mast topper design, ( really none of my business, since I no longer own a boat, and should probably shup up). It’s just too bad they didn’t look at the bearing design at the base of their mast, (with the point bearing), I don’t think the length of the cross member of their current design can be extended much, (wrong bearing type design)
It’s just we really loved our TI’s, and I wouldn’t want to own anything else, (checked all our boxes off with our mods as the perfect boat to fit our lifestyle). We will miss ours, good luck everyone.
Been kind of frustrating to me, took me 15 minutes to design the mast topper while walkin down the Home Depot Isle, and a couple hrs to build, then 8 yrs of explaining over and over again how it works, ( just frustrating that’s all). I kinda regret posting anything now.
FE
Here is a pic of the tooth paste tube:
No need to follow my design in any way, anyone can design a mast topper anyway they like. However understanding how to design something that actually works is another story. Below is the basic concept of how my mast topper worked.
As far as how the sails hook up you would need to scour thru the old ultimate island thread and look at videos and pics, (none of it exists anymore, so I can't provide any more).
Actually page 4 on the ultimate Tandem Island thread shows all the rigging and furlers on all the sails, I installed harkin cleats across the front AKA cross bar to handle all the lines and furlers, (like 5 cleats, all our TI's had all those cleat positions pre-tapped for adding cleats, ( I bought the cleats at West Marine), and used them for pretty much everything. Note: to be able to cleat overhead lines, (like halyard lines), you simply wrap the line around the AKA cross bar before inserting into the cleat.
There is a closeup of the top of the mast, (the old original mast topper), I just used round rings held onto to the mast topper with hose clamps. Note these early versions from (2010-2011) didn't have the dual halyards, (those came later).
Here is a link to the Ultimate Tandem Island thread for your viewing enjoyment, (lol).
https://www.hobie.com/forums/viewtopic. ... 0&start=45