MiniMax
While constrained from doing very much while my old shoulder slowly rehabilitates my mind has wandered off a time or two. This is one of the results.
Thinking about Nomad, the boat I really want to build, some thought was given to the the difference in a boat you sail in (Nomad) and a boat you sail on (MiniMax). Both are suitable for expedition style sailing, which iswhat I’m interested in. Texas 200 style to the Everglades Challenge. Minimax came about in considering the most boat that I’d be able to cartop given that it would be a boat to sail on rather than in. I’ve hauled a 24’ tandem racing canoe around a lot of miles so that’ll be the maximum length. Keeping weight to a minimum, I’m pretty sure the main hull could come in at around 40# and an all up weight less than 100#. Roughly 72 s.f. cambered panel sails on stayed windsurfer masts. Most of construction probably 3 & 4 mm ply, a touch of carbon maybe in the beams that would be tapered. Planks probably 3mm ply sandwiched over foam core. one panel to act as a backrest sailing, dropped down to cover foot rest position at rest to make room for a 2 person tent at night.
Not likely to ever be built by yours truly, I really have gotten to a point where sailing “in” appeals far more than sailing “on”, but it was an interesting diversion.
I’m sure some will say “It’s really a stretched Broomstick” and that’s true (that’s where the rough 3D drawings came from), but the original thinking did come from minimizing Nomad.
Cheers,
Skip
The other image
Always excited to see a post from you Skip, as an On-ie rather an In-ie and schooner rig fan I like MiniMax, the lower CE, shorter masts and the control options are all appealing. Hope the shoulder is on the mend, they are frustrating things that seam to take for ever, really feeling for you.
Keep thing and sending the idea
Tink
Hi Tink,
I agree that schooners make a lot of sense once you get beyond a minimal solo boat. It took long time for me to realize same even though two local proanauts that I admire greatly had boats that evolved from single rigs to schooners over time.
Minimax should also have some maximum performance for minimal effort. Bruce # from about 1.35 to 1.7 depending on load and a B/l ratio of 32/1 on hull should make for a quick boat. Not so sure about ghosting, SA/WS ratio varies from about 2.5/1 to 3.4/1. We’ll see how the Broomstick does once it hits the water.
Afraid it’s going to be a while, rehab on a humongous tear on a 70 year old shoulder just takes some time.
Skip
Very cool, Skip. I really like it. I’ve been thinking the same thing about cartopping—it opens up a lot of launch sites. It also solves some storage issues as well for city dwellers like me.
I’m very excited to see how your rudder-bows and dagger-ama work in practice.
One thought is that maybe you need to do something to keep those windsurfer masts in column. Lowers? Triangular diamond wires? More fiber and glue? Lowers might not be too hard to implement.
Keep em coming,
chris
Very cool, Skip. I really like it. I’ve been thinking the same thing about cartopping—it opens up a lot of launch sites. It also solves some storage issues as well for city dwellers like me.
I’m very excited to see how your rudder-bows and dagger-ama work in practice.
One thought is that maybe you need to do something to keep those windsurfer masts in column. Lowers? Triangular diamond wires? More fiber and glue? Lowers might not be too hard to implement.
Keep em coming,
chris
Still ambivalent about cartopping, lots of pieces to a proa. Still have an internal debate going on regarding the Broomstick. On the one hand, it’s a little awkward to cartop, on the other a trailer is another hassle/expense. Gripping hand, the reasonably inexpensive trailer license could go on Nomad’s custom trailer when the time comes. I suspect there’s a trip to Harbor Freight in my future.
Me too.
If it turns out that windsurfer mast won’t cut it I’d just make some larger diameter birdmouth pieces. In this case I was mainly cogitating on the easiest, simplest way to get the most cartoppable proa possible. The great probability is this isn’t a boat I’d ever build, prefer sailing as an “innie”. Minimax has been an interesting design exercise while I can’t do too much else. It has sharpened up some detailing on the next generation of rudder bows if the Broomstick works out.
Cheers,
Skip
Skip,
How are you supporting the end of the booms??.....without adequate support such as permanent topping lifts, the rig is unstable when the sails backwind (or are being reefed or taken down) and will try to pivot to windward until the sail luff and the bobstay are both in line.
Rob
Skip,
How are you supporting the end of the booms??.....without adequate support such as permanent topping lifts, the rig is unstable when the sails backwind (or are being reefed or taken down) and will try to pivot to windward until the sail luff and the bobstay are both in line.
Rob
The boom is supported by a topping lift at each end of the boom. Boom is to rotate around its longitudinal axis to reef the sail. Topping lifts and stays from boom to pivot point attach to bearing plate that boom pivots on.
Twin topping lifts are essential, I’ve had a jib club get away and flail around twice that I remember and that was two too many. I spent quite a bit of time noodling about the details of reefing, there not being a rigid connection at the boom bothered me until I finally realized I could just tie off the rigid battens at the boom when rolled up to that point.
The topping lift at the luff may interfere with the set of the sail a bit but my thought is the actual sail setup will put the setup under enough extra tension that the lift will be slack enough that it won’t be a problem. Time will tell.
Second edit, re-looking at your diagram the mast is actually stepped to windward on the beam (2’ +/-) and the mast is held in place by the drift in the fore and aft stays.
Thanks for the question, the older I get the more I appreciate peer review.
Cheers,
Skip
Presumably you need 3 topping lifts per sail??
One to act as a forestay and the other two to hold up the leech boom end, with the leeward one slacked off so that it does not affect sail (leech) set??
You could hank your sails battens and all to the “forestay” topping lift, which will give greater control reefing and dropping sail??
without adequate support such as permanent topping lifts, the rig is unstable when the sails backwind (or are being reefed or taken down) and will try to pivot to windward until the sail luff and the bobstay are both in line.
Note that the fore stays are attached leeward of the mast bases. The fore stays are serving double duty as leeward stays (albeit poorly) in the same way as they do on Russell Brown’s boats. You wouldn’t want to find yourself backwinded in any but the most mild conditions, but the masts themselves should stay up just fine on their own.
Presumably you need 3 topping lifts per sail??
One to act as a forestay and the other two to hold up the boom end, with the leeward one slacked off so that it does not affect sail (leech) set??
You could hank your sails battens and all to the “forestay” topping lift, which will give greater control reefing and dropping sail??
We’ve cross posted a bit, which is anew experience for me.
First, I hadn’t considered using two lifts for the aft end of the sail but it occurs to me that some rigging involving the sheets might make that work remarkably well.
Second, hadn’t thought of that one either, first thought is there’d need to be some geometry changes so that the rotation axis of boom is perpendicular to the forestay. But maybe not, a slightly slack bridle could greatly enhance handling the sail.
Many thanks,
Skip
Second, hadn’t thought of that one either, first thought is there’d need to be some geometry changes so that the rotation axis of boom is perpendicular to the forestay. But maybe not, a slightly slack bridle could greatly enhance handling the sail.
I would have thought that as long as the battens are parallel with the boom, which they appear to be, then the boom doesn’t have to be perpendicular to the forestay???
The other thought I had was regarding the open bridle triangle under the booms, presumably for visibility, but if they were filled with sail as well, you will get more sail area and also make the sail area above the boom more efficient (end plate effect).
If you double the infills, one each side of the boom, like the 49ers do around the boom and vang, you always get a good lee side and then you could also fold them up above the boom to possibly form a lazy jack / sail holding arrangement??
I would have thought that as long as the battens are parallel with the boom, which they appear to be, then the boom doesn’t have to be perpendicular to the forestay???
The battens are parallel to the boom, as the sail rolls up the end of the battens get further and further from the forestay.
The other thought I had was regarding the open rigging triangle under the booms, presumably for visibility, but if they were filled with sail as well, you will get more sail area and also make the sail area above the boom more efficient (end plate effect).
If you double the infills, one each side of the boom, like the 49ers do around the boom and vang, you always get a good lee side and then you could also fold them up above the boom to possibly form a lazy jack / sail holding arrangement??
Perhaps, this one I’ll wait on for a while, like to see where I’m going and will leave the last few percentage points of performance to those more competitive than me.
Cheers,
Skip.