Rat Island, Manchester, Elk River, Shaw and Great Cross Sound Races
Wow - here it is, September 1st, and my last update was back in June!
A lot has happened since then. Here is a synopsis:
Rat Island Regatta: Things were going fairly well for the new gearbox and drive system for the first half of the race heading out to the island, though there was a bit of vibration due to the not-quite-right angle of the coupler relative to the prop shaft. The course itself was rather foggy, and presented some rather interesting photo opportunities.
Anyway, after rounding the island and on the return leg the pin (a stainless steel bolt and nut) holding the sewer rod coupling to the gearbox output shaft fell out and landed on the 3.5 inch wide deck. How lucky was that?!? Unfortunately, as I reached for it the bolt rolled off the deck and into the drink. I ended up getting towed back to the start. Regardless, I definitely like the beachability of the side mounted drive.
Manchester Race: With a completely new aluminum coupling between the gearbox and the prop shaft the vibration was reduced considerably. I had to tighten the setscrews a couple of times as I apparently didn't quite locate the flats on the shafts when they were assembled. Otherwise, the rest of the race was mostly uneventful, with a couple of stops for weed removal. I like being able to pull up the shaft and inspect it for weeds, and removing any that happen to be there. The Inflata-Rest seat cushion seemed to work at least as well as the foam cushion, but was much thinner and a bit lighter. The larger small sprocket was too large (too easy), so I ordered a smaller sprocket.
Top speed is not much higher than before. Could it be due to the gearbox not being stiffly mounted to the boat? Probably - so I added two small aluminum struts to triangulate the gearbox mount with the T-nuts on the hull. This appeared to work quite well - on the bench, anyway.
Elk River Challenge: With the new stiffeners the boat exhibited much better acceleration, though the shaft seemed to be knocking against the hull at lower speeds. The coupler also slipped about half a dozen times before I finally located the shaft flats and torqued the setscrews. There were many areas of weeds on the course, so between the weeds and the coupler slipping I didn't set any records - but I did finish the race and set a new top speed record for the boat: 9.9 mph! This was traveling with a current of about 1 mph, so actual speed was probably closer to 9 mph. The new sprocket is just about perfect.
Shaw Island: Nothing new with the boat this time, but this time Matt was racing with his skin-on-frame V15. He was staying at San Juan Island and pedaled over to Shaw an hour before the race. He impressed everyone by pedaling up to the beach and carrying his boat onto the shore. His boat is maybe half the weight of my plywood beast!
Anyway, Matt kept up with the surf ski racers for the first quarter of the 14 mile race, but after having to clear his prop several times and having a sprocket combination that was too easy he decided to wait for me to catch up. We traveled together for most of the rest of the course - at least until my legs started cramping and my bottom could no longer tolerate sitting. Luckily for me the end was about half a mile away, so I didn't finish too far behind Matt.
So, the prop shaft vibration is still an issue, and the seat back angle needs to be adjusted to place more weight on my back rather than my bottom.
Great Cross Sound Race: Nothing new, except for adding a 1/2 inch thick closed cell foam pad on top of the Inflata-Rest seat cushion. Everything worked reasonably well, though I had to stop multiple times to clear weeds from the strut and propeller. Sometimes just bringing the shaft out of the water was enough to remove them, but other times it required fingers on weeds.
Matt was at this race, too, and was doing quite well - up until his chain fell off and dropped into the drink. He ended up paddling back to shore.
The wind and waves at the Great Cross Sound Race built up during the event, creating a lot of beam waves. The dipping rudders also created a bit of weather cocking, so I ended up applying a lot of rudder to compensate. Even so, I managed to finish the race ahead of a number of single and double rowing shells, though the fastest boats in the race were double sculls.
Photos and stats are at the Sound Rowers web site.
3 Comments:
Mike
Looks like you're getting all the bugs out of your boat. I agree about the beachability advantage of the side drive, since I modified my boat it has made life a lot easier. In the Great Cross Sound race you mentioned waves on the beam, how big were the waves and how much did the outriggers dig in?
Ian
Hi Ian,
The waves ranged up to about 2 feet, nothing too worrisome except right along the shoreline. The outriggers stayed mostly at the surface, and the front planes worked well to keep them from submerging for any length of time.
I forgot to mention that with the position of the propeller mid-hull it aerated only two or three times. If it was at the stern it would have been quite a bit worse.
Hi
Energy transmission from solid (ship) to
fluid (water) effectively, How about to utilize the "Leaf Spring Propulsion Flap"
which is simplified Fish body, Elastic
Spring Plate, fixed to Rigid but Slender Swing Rod(Pipe).
www.youtube.com/watch?v=NalXfnxjkzE
so on
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