Team Seacats

As I get some time here and there, I’ve begun construction on a couple of US1M hulls. I’m still perfecting my vacuum bagging technique but have settled on a laminate schedule. This hull had a layer of 3.5oz S-glass (the strong fiberglass) and one layer of 5.7oz carbon fiber cloth. Concerned about the oil-canning tendency of the large flat bow, I placed two strips of balsa triangle stock in the bow section for stiffness – they work well, but I’m not completely certain they’re necessary. Certainly both aren’t and only one will be required. The good news is that I’m right at the weight target for the hull and I think I can still get a little lighter with using a 2oz fiberglass cloth on the exterior. This hull half weighed in a 5.39oz (.34 lb) but hadn’t had any of the flashing or PVA washed off yet. I’m trying to get an assembled and reinforced hull and deck down to around 2/3 lb. This includes the primary bulkhead and radio tray. I did still have some void issues in with the vacuum bag but I used a stretchy vacuum film called “Stretchelon” for the second hull half and suffered NO void issues. Good stuff!

The second hull half that I laminated came in at 4.8oz (0.3 lb)after the flashing was removed – that’s right on target! I laminated up a 16″ x 18″ piece of 1/8″ balsa with carbon on both sides to fashion three pairs of bulkheads and radio trays that came in at 5oz ….some rough calcs for cut-away waste and the material for the bulkhead and radio tray should come in at 1.25 oz (.07lb). That puts me at .695lb with the 3.5oz glass…so a switch to 2oz glass on the exterior may just knock it do .66lb and I think that’s as light as I can go and have it be reasonably durable.

We had a family gathering in Folly Beach, SC this past weekend so I looked up the local r/c sailing club and found out that they have club race events every Wednesday and Sunday. I sent an email to the webmaster at their website and was quickly invited to join in with the understanding that most of the club sails Soling One Meters. I packed up Bonnie, G’ma, the dog, and the boat and headed to the coast on Friday evening. After surfing with my brother, playing horseshoes, a low country boil, and a whole lot of relaxing on Saturday, I found the park and the beautiful pond easily on Sunday morning. We drove up a little late and there were already several boats on the water. Bonnie helped me carry some of the gear from the parking area across the street to pond side and I was immediately and enthusiastically greeted by the club’s Commodore, “Crazy Erv”. While setting up my boat, I inquired about radio channel and told Erv I was on 68. I was informed that there was already a club member on 68 and I felt myself on the verge of disappointment when Erv quickly said “no problem” and returned with a crystal set that I could use for the afternoon on 65. Elated, I quickly swapped out the crystals in the receiver and radio and finalized assembly of the boat.

At the beach house, the wind had been howling all weekend with gusts in excess of 22knots. At the pond, the breeze was a bit more gentle but there were some lulls, some crazy shifts, and some monster puffs still finding their way down the pond. The rest of my family eventually joined us and hung out at the park watching the racing as Erv creatively announced the races providing entertainment for all. Immediately Erv began referring to my boat as “Gray Ghost” and I think I like it. (NOTE: he later said that he always thought primer was fast for it’s hydroscopic properties….if ONE MORE person asks me “what color are you going to paint the boat”…..:-) )

I started my first ever r/c race with approximately 10 Soling One Meters and I was cautious to stay out of their way as I was the odd ball and didn’t want to mess with any club series or anything they had going on. I started in a big pack on the start line and struggled to get clear around the course. As I was near several other boats I steered wide letting them duke it out for their racing and I think I finished in 3rd. Several races later, I felt more comfortable mixing it up with these guys and when I started elbowing for starting room and getting clear, I would quickly jump out to a several boat length lead by the first mark as the US1M is a bit more powered up than the Solings. I won several races and didn’t win some more because of poor tactics or boat handling on my part. I did learn several new things about the boat and seeing it compete with other boats was very helpful (even though it wasn’t a fair fight). I’m ecstatic about the speed the boat displayed and several club members who were familiar with US1M boats expressed opinions that the boat has great potential and really had great speed when I wasn’t “dumb thumbing” it (my wording).

I also had my first ever collision with the boat as I tried to roll under a couple of starboard boats toward the finish line. I was also on starboard and close-hauled as one of the boats in this group peeled away reaching under the two other boats I was trying to pass (I believe he was trying to get somewhere he could do a penalty turn or get back to the mark he missed). I couldn’t see him through the other boats until it was too late and I t-boned him at full speed. Neither of us received any damage (although I am amazed he came out of it unscathed) but I was surprised at his reaction that seemed to imply that I was on port and at fault. I let it go since I really don’t know these personalities and I didn’t want to start a fuss.

As far as the boat performance goes, the mast and rig are not quite right yet. Under heavy close hauled pressure, the mast inverts and bends rearward in the middle even though I had a ton of backstay on. This is undoubtedly a result of having straight spreaders and I think installing a set of raked spreaders will prevent this reverse bending. The second issue I had was with the sheeting post in the middle of the boat being too high. The boom is not clearing it when the vang is really tight so I couldn’t crank on the vang and get the mainsail to gybe properly. Additionally, I was losing a lot of leech tension between setting it up on the beach and sailing – but I believe that is a result of not being able to maintain the mast prebend while under sailing loads. The last issue I had was with the Futaba servo. After about 1.5 hours of sailing, I lost the ability to sheet in under load. I would have to tack immediately after rounding C to give the servo a chance to reel in the sails. Once there, it would hold them fine. I had full rudder control so I doubted I was having a battery problem but I changed out the battery pack anyway to find that it didn’t solve the issue. I kept racing but will need to remove and test the servo later this week. I suspect something has gone awry inside the servo guts….I was impatient when I mounted that servo and radio board – removal of the servo is going to be difficult.

I want to take a moment to give a “shout-out” to the Charleston Model Yacht Club for being so inviting and accommodating to me and my one meter. I had a blast and can’t wait to go racing again! Next time, I hope to get some one design racing in for a fair challenge.

For the first two hulls out of the mold, joining the two halves has been tricky because I hadn’t quite worked out how best to make that work. I was satisfied with a little extra time to join the two halves and fair them – but that won’t do from a future production standpoint. After some research, I set out to create a “joggle”. I doubt this is an official term but it’s one that I picked up from some detailed online documentation about a full scale glider build project…I’ll blog about that site later this week.

The joggle is a separate piece that will bolt into the starboard hull mold and will create a small offset on the lip of one half of the hull so that it will fit inside the opposing side.  This will (hopefully) leave a perfect surface for a glue joint and the capability to join the halves inside the molds with a high degree of repeatability and consistency. The joggle mold piece must be removable because it is opposite to the draft of the mold and creates a mechanical lock in the part being molded.

I created the joggle by waxing the mold and the original plug and then building up a fiberglass strip along the edge. Before I removed the newly created part, I drilled 16 holes through both the joggle and the mold, applied nuts to the back of screws inserted through the holes, and, after applying release agent to the exposed threads, and globbing resin and microballoons on the back to seal them so they won’t leak vacuum when vacuum bagging the next hull. This way the piece can be very accurately located each time it is removed and installed.

Then, with the joggle removed, I was able to clean up the flat edge, mask off the mating surface, and begin laminating glass to the side that will touch the hull.  This lamination will be slightly thicker than the hull thickness so it will create the appropriate offset of the fiberglass part.

Next, once everything is cured, I’ll sand the newly laminated fiberglass flush with the mating surface, trim up the raised edge for a consistent lip width, and apply some finish to the joggle so there are no sharp points that might puncture the vacuum bag.

Earlier this morning, Neville came over to get some key measurements and some small pieces parts to continue his build of hull #2.  We got most of his rigging points made, mounted, and glued into the hull.

Hull #2 of The Bogy is nearing completion as fellow designer, Neville Cork, is finishing up the body work on his ideas of the deck layout. The rear sugar scoop extends much further forward than mine and his hatch opening is longer but narrower too – I’m looking forward to seeing his final thoughts with regards to control lines and he’s apparently got some trick for sealing the hatch that I can’t quite make out in this photo.

Neville had previously designed a skiff-style US1M that he brought out and we did some sailing against on Saturday.  These two boats were very different in design philosophy so it wasn’t a refined “test” but the Bogy clearly had a performance advantage.  I look forward to getting it up against some other US1M boats.  In an unusual departure from standard, I didn’t take my camera along and only had a camera phone.  Here’s the only sailing photo for the day, which inconsequently, also shows a dragon fly on my head.

There wasn’t much to speak of with regards to the wind, but it was a good afternoon to shake out the boat. We’ll get some higher wind footage and some on-board video soon.

Launch

Click HERE to view / download the larger version of this video (15Mb).