bigdaddyort

Hi All,

Im new to setting up the rigging for an RC sailboat. I was wondering if anyone has a northwind 28 that they could show me how they have rigged the sails? I have a small catamaran that I see has some elastic tied to the rigging and did not understand the purpose of it until I rigged up the arm winch and now see that when the arm is rotated the rigging comes loose and sloppy in the control area.

Bottom line is I want to make sure I have run the rigging correctly as it doens look like the previous owner had any elastic rigging and Im not sure how or where to tie the main and jib sail rigging together.

Thanks in advance for any assistance!

mfr02

The requirements for any Bermuda rig model yacht are the same.
The string coming off the arm needs to pass through the deck, usually toward the stern, go as far sternward as possible, turn and split into a line for the main and another for the fore. This is usually where the elastic line connects. Each of the sail lines then passes through either a deck fitting or adjustable bridle ring, then to a point on its sail boom.
A sail arm usually involves having the line pass through its end and back to a fixed point near the entry point through the deck to give more travel. There needs to be enough straight run between the stern turning point and the main sail deck ring to accommodate the travel needed and not have the join foul ether the stern turning tackle (some use pulleys, some have figured out that anything with a radius will do the job) or the bridle ring.
The layout details often vary because kit manufacturers have the habit of planting deck furniture in the way, some like to hide as much string as possible under the deck.
As described, it is possible to arrange the string/boom geometry so that both sails require the same string travel.
An alternative is to use both ends of a double ended arm, one for the main, the other going to the fore, but yours doesn't sound like one of them.

bigdaddyort

Thanks Mfr02

I think I got it ( had to look up a few terms!) - Ill send some pics to lsee if you agree with the setup Ive put together based on your reply.

Thanks again - looking forward to moving from air and land to sea!

Retiredat38

Just in case you don't have the instructions, here's a link where you can download them in pdf format.

Northwind 28 Instructions

bigdaddyort

DefaultThanks for the Manual!

I tried to attach picture of the final product but it says I cant post URLs until after 10 posts - have to figure that one out as I tried to upload pictures not a URL.

It originally had an old Cox radio and servos - switched them out for a couple newer ones 25g ones although Im still using the 4xAA battery pack it came with. However, Im seeing some dropouts when operating both servos simutaneously - thinking of throwing in a 2S as I changed the radio out with a 2.4GHz Spectrum AR400 I had sitting around. Still havent decided where or how to mount the reciever to give it hte best chance of picking up the signal.

If you have any suggestions or comments once I get the pictures loaded, please let me know and thanks again I appreciate all your help!

mfr02

Siting the radio aerial is just a case of ensuring that it is as high as you can easily get it without hiding it behind anything metal. My Victorias just have the business end poked into a straw glued to the underside of the plastic deck. Ok for 200 yards, beyond that it might be working, but I can't see what it is doing.

bigdaddyort

Good to know. Ill do the same. WIll post some more so I can post the pictures. Not sure why you have to post 10 times before being able to post pics of your RC!

mfr02

In theory, to help keep spammers at bay.

thomas.armstrong

Thanks for this manual! I've added it here for future reference: http://www.allradiosailboats.com/design/northWind28

Retiredat38

Spektrum radios have known issues with low voltages. It's called brown outs. Your battery pack is a nominal 4.8 volts. And while the radio will run at this voltage, as the load increases the voltage decreases and eventually it drops below the threshold and "Brown Out". As you may have guessed a higher voltage batt pack is the answer.

Now before someone gets on a high horse, all radios are subject to this situation. It's just that Spektrum seems to be a bit more susceptible than the others. IOW it has a slightly higher threshold.

Now on to 2.4. Simply put 2.4 does not work well around water. If used in a Submarine the 2.4 radio quits once the antenna gets an inch below the surface. While the old 75MHz systems can get 8-12 foot deep without a problem. In surface boats a wave can momentarily block the little antenna. The only solution short of a different radio is to get the antenna as high as you can. Fortunately with 2.4 this is not as difficult as it may sound. While there are limits to how far you can extend the antenna, adding 6-9 inches seems quite practical. But it has to be done right and may involve some precise soldering. Here's a web site that tells you how to extend the Rx antenna. They do this for subs since 75MHz is no longer available. But it will work as well if not better for the surface fleet.
Click on this link and it should open as a pdf file. converting 2.4GHz radio gear
If not, you can find the link on this page: Radios for Subs
In the pdf there's a bit of extra stuff pertaining to subs. Interesting if nothing else. But most centers around the antenna.

Hydro Junkie

Several years back, the forum had a rash of people that would start a thread about a model that was nothing more than free advertising. The powers that be decided to require 10 posts before allowing pictures to be posted to stop the practice and deleted a bunch of single post threads. Since then, we haven't seen any more of the advertising threads since the person starting a thread doesn't have the access to post pictures.

mfr02

Lower frequency signals (who would have thought a few years ago that 75MHz was "lower") can cope with underwater situations as long as it is fresh water. 2G4, as long as the end inch of the receiver aerial is above water, is fine for all practical purposes. Most of the Laser racers around here use the HK radio (cheap and effective), usually with the aerial taped under the centre of the plastic deck without problems. Having it below the water surface level does give problems. The long aerial wire of older systems was difficult to mask - there was always some of it "visible". The tiny 1" bit of 2G4 aerial is much easier to accidentally hide behind, say, a metal mast.
I avoid anything that says "park flyer" because that translates to short range. I just don't like the idea of "antenna free" because that implies that the antenna in inside the box, making good siting difficult. Any radio that has 4-6" of wire poking out of its box should give very adequate siting choices.

Retiredat38

Regardless the water conditions 75 remains far superior to 2.4 at maintaining the radio link. One inch above the surface is reliable only on a glass smooth surface. But any wave action can cause momentary drop outs of signal as the rolling waves rise up to block the antenna. The wave action also causes reflections which can confuse the Rx making these momentary drop outs even worse. Ditto for hiding it behind a "metal mast". Metal will create a blind spot due to reflectivity. Keeping the boat close to you, as in 20 yards or less will minimize these effects. But it's really not a solution. Regardless of the frequency, you want your Rx antenna as high and unobstructed as you can manage. It's just that the 2.4 design with the stubby antenna makes this a bit more difficult to do.

Hydro Junkie

It's interesting that you would say that. Several years ago, Spectrum came out with the first 2.4GHz systems. What was sad is someone showed up at a scale hydroplane race, soon after that, with a brand new 1980 Budweiser with a Spectrum system. They did a range check on the beach, found everything to be good, fired up the boat and launched it. A minute later, the boat was in pieces on the bank in the left hand turn. The exact scenario you described is what happened though no one believed it at first. Once we determined the cause(I had to have them do another range test with the receiver being held just above the water by someone in the chase boat to get everyone to believe it was the radio and not a linkage issue), the 2.4 was banned until the problem was fixed. Spectrum had to design new receivers while Futaba held off on releasing their new 2.4s until they were sure it would work in a marine environment. I have been running the Futaba 4PLS 2.4 system in my sport and scale hydroplanes for several years without an issue.

Retiredat38

Well, I never said 2.4 wouldn't work in a marine environment. Just that it has some issues one needs to be aware of. And yes, the radio manufacturers did a double take with their marine/surface radios. But they didn't solve the problem as much as simply minimizing it through software coding. They changed how the receiver reacts when the signal is momentarily blocked or degraded below specs. Receiver sensitivity may have been adjusted and Tx power may have been bumped. But their main "fix" was in the coding and how the Rx responds. Still, the modeler can make a big impact in the simple positioning of the Rx antenna. And in spite of everything the manufacturers have done, a submarine still must have it's 2.4 antenna above the surface to work reliably.

And an outgrowth of this is we now have airplane systems with multiple remote receivers one can place in various places in the model. These receivers literally are little more than a 2.4 tuner and amplifier which then sends the signal to the "Rx" for decoding. But, it gets more antennas in the air in various places so should one be blocked, the others can pick up the slack.

Something to consider too is how far away do your boats get? How far will you let them go? My point is in spite of everything the manufacturers may have done, a marine use of a radio will have far less effective range that the same system in an airplane. Even though one can still see it, i.e. clear line of sight. And that is due to the immediate environment the Rx is in.

Hydro Junkie

Surface radios have always had about half the range of air systems due to ground clutter and such. Just the nature of the beast.
I know the manufacturers didn't bump up power as they are limited by the FCC to .5 watt. They did add a second receiver antenna and added to the programming. As far as range goes, I can cover, safely, 100-150 yards. Futaba says I can go roughly three times that but I've never needed to so I haven't tried to go that far. I also am, normally, between 5 and 10 feet above the water, not counting my height of hand being another 4 feet so, unlike someone that's standing on the bank and just above the water, my signal is going down so it's not affected as much by the water and reflection

mfr02

True regarding range. All of the radios that I have read the spec for give a surface range about half the air range. For full range sets this works out at about 500 meters surface. Beyond 200 I can't really tell which way a yacht is actually pointing, and that includes a 1 meter yacht with a six foot mast, a great deal more visible that a 28" Northwind.. A scale boat is a vanishing dot. A scale warship demonstrates that camo does work.
Most of us sail standing on a bank, very few have a large lake inside a surrounding wall. As a result, most transmitters will be "looking down" on their receiver. Any receiver with a sensible aerial (ie one not enclosed in the case) has the option of siting the business end in a good spot.

Real submariners know about radio not working under water. Thats why they pay out about a mile of wire for doing comms over very low RF. Unless they care to come to the surface, poke a satellite antenna up and use burst communications before going invisible again.

Hydro Junkie

It's not that the radio won't work, it's the frequency being used. I know, back in 1984, I was listening to a Houston Astros game in the Indian Ocean on an HF radio in one of my squadron's aircraft. That is something that couldn't have been accomplished with a standard AM or FM radio. Submarines can and do communicate while underwater using a very low frequency, hence the long antenna wire. What must be remembered is that the lower the frequency, the longer the antenna has to be to match the wavelength of the signal. That is why a 2.4 system we use for R/C models only has about 1cm of exposed receiver antenna, it matches the wavelength of the signal being received

Retiredat38

Quite familiar with the ELF system or whatever the current version is called. Problem there however is at the low frequency the data rate can be counted on one hand. Hence they use prepackaged messages identified by three letter codes the system transmits. The data rate is the draw of the 2.4 systems in RC though I doubt many boaters need that rate. And few flyers.

Standing higher above the water is certainly a plus. But boating wide is that the rule or the exception?
Speaking of exceptions, some of us have particularly good vision. Like Chuck Yeager I can see at 100 feet what 20/20 sees at 50. So should I stay close to shore simply because everyone else has too?

I'm not saying don't use 2.4 but I am saying be aware of its limitations and know that there still are some things one can do to improve things. I have a good friend who's pushed 100 milliwatts over 10 miles with a T-1 data rate. The freq was 23 gig and granted the antenna was a large part of that. And a rain drizzle dropped that to half a mile in seconds. Again, knowing the limitations of the system is a big part of it. In this day of cell phones and Wifi most people continue to think a radio is a radio is a radio. And while that is true in part, it's no where near 100% anymore.

Hydro Junkie

You just kind of identified the problem. Generally speaking, most don't understand radios and how RF works. 27, 50, 72 and 75MHz are just numbers to identify the band. They don't understand that the numbers also denote the wavelength and everything that goes along with it, such as antenna length. They don't get that 2.4GHz has 32 times the signal capacity and 1/32nd the wavelength. They also don't get that the first part of the signal has an ID code that is what is actually programmed into the receiver when it is bound to a transmit ter.

bigdaddyort

Thanks for all the inputs. I've done some RF work so I get where you are coming from. From my standpoint, I agree the older/ low freq would be ideal but as Im playing with cars, planes and now boats, Im trying to slowly consolidate and use what I have around. Its interesting what retiredat38 and hydro geek mentioned about the spectrum reciever mods (extra antenna at right angle and the SW fix). I saw Spektrum used to make a marine reciever but wasnt sure if they dropped it in liu of making either the land or air recievers more adept at handling the issues of water control.

As far as range is concerned, Im usually within 100-200 yards as they get small and I hate having to go and rescue items far out in a kayak or blow up boat - thus my current purchase of a used toy tugboat that I want to mod to have a "crane" mounted that I can use to extend and drop a line to catch a wayward sailboat - trying to find a cheap linear actuator and my dx6e to control. I was thinking to tape the antenna to the underside of the deck but now am wondering if I run a hole through the deck and tie it to a non-metallic vertical piece.

I hope I have reached the 10 posts - will try uploading the pics for comments - again, just getting into the boating realm (have a steerix toy catamaran, another older sailboat about half the height of the northwind, as well as a couple modded electric speedboats - and a pretty funky nitro powered air speed boat I picked up at auction. Just dabbblind in the nitro area but its a pretty interesting boat. Will probably post in whatever group would be best for others to see - uses an air prop up top but has the hull of a race boat - similar-ish to a miss bud type of boat versus a swamp boat.

bigdaddyort

fist picture of the final rigging

mfr02

A very pretty boat. Should look good on the water and go well. Just a personal thing, I would be strongly tempted to lose the stanchions and side ropes. Letting sails in and out is always fraught with the certainty that slack lines will grab and tangle on anything available. Also, is there any sort of seal under the edges of the hatch? It can be surprising, with the right weather and everything working well, how much water goes onto the deck, and how much force is behind it when it finds the hatch.

bigdaddyort

Good point on the stanchions. It hurt me to cut off the other wheel that was on the opposite side of the remaining wheel for that very same reason.

As for the hatch, no there is no seal. the hatch is "loosly" held on by the indentations on the cover that lightly snap onto the outer raised edge of the hull opening and the pressure of the (thing) that overhangs the hull and the wire goes through. I assumed that any water that got underneath would go out the back of the underside of the hatch cover as there is no raised edge back there but Im not sure I trust it. Havent figured out a way to easily put a waterproof and hold down mechanisim on it - sees a bit of a design flaw in my view.

Thanks again for the help and insight

mfr02

Using modern materials, one way might be to use bathroom silicone sealant. loosely wrap the lid in cling film, put a bead of sealant round the lip of the deck hole, apply the wrapped lid firmly, come back a day later. Carefully remove the lid, remove the cling film from whatever it is now clinging to, you should now have a custom gasket.
Having a water deflector on the deck in front of the hatch will help. A clubmate had a Seawind - he spent a lot of time re-engineering his hatch. Kit yachts' hatches seem to attract a lot of attention. Maybe designers tend to be over-optimistic?

Looking at the pictures again. It will probably be better if the bowsie under the jib boom is let out about 1/2". This will then cause the boom to lie a few degrees off centre where it needs to be, an let the jib swivel line point at the top fitting on the mast. Also moves the fore sail a little further away from the mast, avoiding fouling and giving the slot between sail and mast that is needed for proper airflow.
The sail arm servo will benefit from better fixing. When it operates, all the force from the sails goes through it and its mount, and a twisting force is applied. At some point, the screw heads have to cope with this. One screw in each hole with a washer, or stainless larger head screws.