Sepktrum DX6i, HiTec HSR-5990

Spektrum recently introduced an updated version of the DX6: the DX6i. Horizon Hobby also has an article on the new radio.

This one uses 'DSM2' technology which is described as giving 'full range'. Not sure what that means, but range should be better than with the first generation of 2.4 GHz radios, which at times was problematic (if you did something specific that cut down on the range).

I think the original DX6 was more or less a carbon copy of an existing JR transmitter, but the DX6i seems to be a new ergonomic design. Instead of buttons for navigating the menu it has a roller-device, and there's a new bigger LCD for programming.

The antenna still sticks out at the top even though nobody has had a mobile phone with an external antenna in years. I've mounted the antenna on my own DX6 inside the plastic case and it seems to work fine. I predict and hope that the next version in 1-2 years from spektrum will have the antenna mounted inside the Tx (no fear of breaking it, no problems with leaking rain-covers).

It's going to be in stores in December, for around $180 without servos, which is similar to what the 6-channel 2.4 GHz Futaba sells for.

HiTec has replaced their previous robot servo (HSR-5995, now discontinued) with a new version called HSR-5990. The specifications are roughly the same as for the old model: torque is 24.0 or 30.0 kg.cm depending on if you use a 6 V or 7.4 V battery, but speed is down a bit from 0.15s/60deg to 0.17s/60deg (6 V). The gears are Titanium alloy, and as is visible from the picture the new servo adds a heat-sink to the casing.

Maybe this is the winch for my next boat? At a cost around $110, weight of 68 grams, and 'ludicrous speed', it looks like a strong alternative to a drum-winch. Anyone have good or bad experiences with the 5995 or the new 5990?

Wireless Mast Camera

Jari got a small wireless camera operating on 2.4 GHz and mounted it at the top of the mast on his no2 rig. With the bulky power connector removed and a longer wire for the 9V battery which is under the deck the camera weighs about 20g. Now we used a preliminary aluminium angle to hold the camera, but a better carbon arm should be made for next summer.

This camera is the variant where you can plug the receiver straight into a laptop via the USB port. The receiver even gets its power via USB, so no extra power supplies needed in the field. Range seemed good, and image quality was OK - probably now limited more by the compression used in the PC than by the camera.

The idea is to look at how the sails, mast, and whole rig behaves from on-board images. It's probably hard to say something from a single video or frame, but if some parameters (say shroud height) is systematically varied on the same boat in the same conditions then we're hoping this could provide some insight into what's going on.

MicroMagic's in Vuosaari

There's a new area around Vuosaari in Helsinki being developed and they've built a number of channels/ponds close to a park and the golf course. Google map view here.

8 boats, possibly the largest gathering of MicroMagic's so far in Finland, showed up for some friendly racing today. I tried it too for two races. The boat is very light and responsive, and you really have to react to the gusts of wind. At low speed on a beat I found the boat drifting to leeward quite heavily.

The sailing site with buildings, bridges, etc. around meant that the wind was of variable strength and coming from variable directions.

Two boats heeling over while the others wait for wind.

No rescue boat was used, the marks were just pushed out from the bank/bridge with a long pole.

It looks like we will have a number of these boats for next season, and the action probably starts at Model Expo 2008 (like this year), with hopefully a number of regattas through the summer.

Results will probably appear on the Finnish MicroMagic site.

wp-cache

To make the site a bit faster I've downloaded and installed wp-cache. It's supposed to cache frequently accessed pages (like the front page) and potentially speed up the site a lot. Hope it works, you can comment below if you think the site is slower or faster than before.

This seems like something so central to wordpress that it should come with the default install?

More Marseilles pics

Here's David Potter's GBR20 Lintel. Note how high the gooseneck is. The boat is not so fast in light weather, so this is an attempt to get the rig higher up and gain some speed in the light stuff. Home-made gooseneck with laser-cut stainless steel bearing holders at the top and bottom (note adjustable holder at the bottom), and a carbon swivelling part. David also has the auto-adjusting cunningham arrangement with the line threaded around the mast. It's not very visible from this picture, but the mast-ram is attached to the mast - so there are three mast rams that stay with each rig, and the correct adjustment stays with the rig. Gelcoat on foredeck has been left out to save weight.

laser-cut ss spreaders. They look nice and work well but are not detachable for transport like the normal ones. They rotate to be parallel to the sail, but still stick out a bit more than normal spreaders do.

laser cut hooks for jib and toppinglift, and below that a separate hook for the shrouds. Note how low the jib attaches compared to the middle measurement band - that's because the mast and mainsail are higher up due to the high gooseneck. Rake adjustment with multiple holes in the mast.

Laser cut ss mast crane.

A box full of laser-cut parts.

Pierre gonnet had some fittings on display.

Gooseneck fittings.

some black bottlescrews for shroud tensioning.

Finally a few pictures of Brad's boat.

no1 rig jib attached to the deck with a piece of string through the deck eye. An alternative to the through-deck tube which is more elaborate to build.

A view of the rig. Shrouds attached to the same kind of hook (covered with tape) on the front side of the mast as on GBR20, but much lower on this boat.

IOM details from Marseilles

Here are some detail pictures from last week that I thought were interesting.


Graham Bantock's Topiko. Note quick-release bottlescrew and deck-fitting far right. Also note how the cunningham is threaded through a plate with holes around the mast. I think this gives a variable cunningham tension (tight on the beat, looser on the run?)



Recessed jib-sheeting hooks. With the new sheeting system and the arm-winch configuration there's no endless-loop or other sheeting lines on the deck. Just the jib sheet very neatly coming out of a PTFE fitting in the foredeck. Many boats do not use a separate sheeting position for the no2 and no3 rigs, so I guess threading the sheet under the metal wires for the no2 and no3 rigs is optional.



Same kind of recessed wire-hooks for no2 and n3 rigs. The no1 rig uses a piece of Dyneema that attaches to the bottom of the boat and comes up on foredeck through a tube. I wonder if the added complexity for building this is worth it? Sheeting angle adjustable with a bowsie.



John McPherson's very serious looking rigbox. My own is similar but this one is deeper so could probably fit two sets of rigs.



A Gearman, breathing version of a rigbox.

Craig Smith sailed the same Obsession prototype that he won with in Mooloolaba, and Simon Kellet's Obsession boat pictured here is the first (and so far the only!) production boat.



The round Decor hatch with all the radio installations neatly in one place. The battery even has connectors on the bottom of the fibreglass casing - just press it down and it connects.



Note how much the rudder tube leans forward. I wonder what this does to the function of the rudder. Any boat designers want to comment below?


Craig Smith's no1 rig jib. Note how the topping lift bowsie is to the left in the picture and the topping lift is threaded inside the boom and comes out at the end. The pink elastic keeps the topping lift tight so it doesn't catch the spreaders. There's only one sheeting eye in the deck that is used with all three rigs. Similar to GBR-95, the cunningham is threaded around the mast to give an auto-adjusting effect. Lester Gilbert has two interesting notes on auto-adjusting cunninghams here and here.



Forward end of Craig Smith's no1 jib. Craig is also using the Dyneema thread idea for the no1 rig jib swivel. Although putting in the tube is one more job when building the boat you do get a useful stiffening of the foredeck at the same time. Craig seems to use the same deck-eye for both the no2 and no3 rigs as there is only one attachment point aft of the no1-rig swivel.



Craig's very neat and minimal top jib attachment. The overall rake of the mast can be adjusted by moving the hook up and down on the mast. Note how the topping lift and the jib attach to the jibstay. There's no shroud attachment point in sight in this picture (compare that to pictures below) - which means Craig uses a much lower attachment point than Graham.

I'd love it if someone took measurements and wrote them up like I did in 2003.


Graham's boat again with another view of the new quick-release bottlescrew. Note that Graham doesn't use adjustable sheeting attachments any more. I think it's because the arm-winch is significantly more precise than a drum winch, so there is not much variability from day to day or month to month in how far the sails come in when you set up the boat.


Graham's top jib attachment with a bowsie for controlling mast rake. Note use of the flat steel tape for the topping lift. The same steel tape is used for the shrouds, which attach just below the jib-attachment point. Compare this to Graham's Mooloolaba boat where the shrouds both attached to the same point on the front side of the mast. (more from Mooloolaba here)



Brad Gibson's no1 rig jib with a nice cnc-laser-cut steel hook for the jibstay and the toppinglift, and a piece of string pulling the topping-lift forward and clear of the spreaders. Again no shroud attachment point in sight - which must mean that Brad uses a similar low-shrouds configuration as Craig.

I have some more of these which I'm hoping to get online soon, in particular some pictures of the Lintel and more cnc-laser-cut fittings from David Potter.

If anyone has some pictures that they think would be a good addition please feel free to comment below or email me directly!

Racing Day 6

Final day of the 2007 IOM Worlds today, two more races completed. Much colder today!

#1 rig wind coming and going from different directions at 0900.

1028 22D finishes. The first two heats use courses with starboard roundings, but later the race committee switches to port roundings.

1048 22C finishes

1132 22B finishes

1147 22A finishes

1240 23D finishes

1340 23A finishes. New world champion Brad Gibson wins the last race!

It takes until around 1530 before the jury resolves about three protests arising from the last A-heat. During the prize giving it starts to rain for the first time during the week.

Final results here.

Racing Day 5

0900 No wind

0929 an attempt to start 17A is made, but there's still not much wind

0951 now there is a bit of wind and 17A has one general recall before starting

1019 18E general recall

1021 18E starts, but the wind dies almost completely. Most boats finish within the time limit, but a few are too late.

1123 18D finishes. Still very little wind, shifty with a lot of wind holes.

We wait for wind. The wind now comes from the north as the previous day. Nowhere near the same strength as yesterday though and we have #1 rigs for the whole of today.

1214 18C has one general recall before starting at 1216 (finishes at 1226)

1230 18B has one general recall before starting at 1233 (finish 1241)

1248 and 1251 18A has two general recalls

1257 18A starts under black flag and three boats are caught over the line so need to retire immediately. Finish at 1304

1313 19E start

1410 19B finishes

1427 19A starts

1504 20D start

1522 20C start, finishes 1531

1550 20B finishes

1614 20A finishes

1639 21E finishes

1652 21D starts

1710 21C starts

1727 21B starts

1805 21A has two general recalls and so again starts under black flag. Three boats are again forced to retire immediately.

Results hopefully to appear here.