Cruzpro

Shortly after writing about my Paddle Wheel Dilemma, Mark Corke also wrote about the Cruzpro (also mentioned in my blog) and offered up some pro's and con's. Go over to Mark's blog and have a read. He is going to buy one and install it. Keep an eye on his blog site for updates and reports of this interesting device.

Paddle Wheel Transducer Dilemma

A lot of you out there will know of the frustration when your paddle wheel gets clogged, and fails to work. Pulling the thing out (if it is a thru-hull) to clean is not only a chore, but can let in a bit of sea water.
I have an Airmar DST800 (Depth, Speed, Temperature)  which I bought around 2005. It was for Raymarine ST60 instruments and did the job fairly well. When removing the transducer, I get an ingress of water because it does not have a self closing  valve which would close as the transducer is removed. I believe (I have been told, correctly or incorrectly) this is still the case for the Raymarine  DST800; and yet most of the other transducers of this model (post 2005) have the self closing valve. See their brochure here for the DST800. I was told the transducers were changed after 2005  so that they have the self closing valve, BUT not the Raymarine version. A little research was required.

My instuments (ST60 Tridata) work by taking an analog signal input from the transducer. My ST60 will only display seatalk input if changed to a repeater display. It will not display nmea 0183 or 2000 data, UNLESS one can convert that data back to seatalk (1)

My choices after some contemplation were
 1. Stay as I am
 2. Change to a new DST800  with nmea 0183 output,  and get a nmea 0183 to Raymarine
 converter so I can have the self closing valve.
 3. Purchase a new DST900-EM which has no paddle wheel and picks up speed by electromagnetic induction, also with a self closing valve

Considering those choices, here are the problems.

1. There are plenty of multiplexers out there that will convert Seatalk to nmea 0183; but I've yet to find one that converts nmea 0183 to Seatalk. This conversion would not be needed if the new DST800 has BOTH a self closing valve and analog output. The brochure here says it only comes in nmea 0183 & 2000 outputs.
2. After contacting an Airmar dealer through email, the DST900 isn't on the market as yet. Here's what he said.(Oct. 2012) "The DST900 is still not available yet from Airmar. No date or cost on the release." AND (as the brochure reads only nmea 2000) I would then have to change nmea 2000 to nmea 0183 and then to Seatalk or analog signal. Can't be done, I think. More about that later. I made some more enquiries.

Notwithstanding that statement, I'm sure they will be released soon and have included here a little of what Airmar has to say about the product. For those with nmea 2000, a great choice when it is released!

Here's Airmar's blurb. Check their Brochure here.

Airmar’s NEW DST900-EM is the industries first all-in-one depth, speed, and temperature sensor with no moving parts. The NEW innovative speed sensor circuitry creates a magnetic field in the water. Speed is accurately measured by the voltage created through 

conductive properties of water, combined with the forward motion of a vessel. With no moving parts, the DST900-EM is capable of accurate readings at all vessel speeds. What sets the DST900-EM apart from the traditional speed paddlewheel is the excellent 

accuracy at very low-speeds between 0.5 and 5 knots (0.6 and 6 MPH)—an important feature for sailboat racing. The DST900-EM’s accuracy at high-speeds up to 50 knots (57 MPH) makes it an important sensor for powerboats. By eliminating the traditional paddlewheel, there is no fouling, and drag is reduced to a minimum of 6.3 mm (0.25”) below the hull due to the low-profile housing.  

Rated at 100 W power, the 235 kHz depth transducer provides depth readings in as little as 0.45 m (1.4’) of water and can reach depths up to 180 m (600’). The narrow-beam of this transducer will 

deliver accurate depth readings at speeds over 35 knots (40 MPH). 

Additionally, the 235 kHz frequency prevents mutual interference with other echosounders on the vessel. 

The DST900-EM’s fast-response water temperature sensor provides ±0.2°C (±0.1°F) of accuracy to help in finding the optimum conditions for fishing or swimming. Airmar’s patented housing design incorporates the popular self-closing valve. When the transducer is removed for cleaning, the valve minimizes water flow 

into the boat. 

The lightning-fast processor inside the DST900-EM makes calculations every second, so it can respond quickly to changes in speed, depth, and temperature. This data is then sent to the NMEA 2000®network via a single devicenet cable for an easy plug-and-play installation.

Sounds like it will just support nmea 2000,

But recent enquires put a different light on the question of legacy formats. A recent email had this to say...  "The DST900 most likely will have the self closing valve. The DST900 will be capable of outputting Analog, NMEA 0183 and NMEA 2000 so it should cover all your needs including working with the ST60.

At this point we still do not know when it will be released." 

So if I wait long enough, maybe this will be my solution of choice. Sometimes this is called vapor ware.

So, I'm no closer to solving the paddle wheel "blues". However....

Here's another solution. Don't have a transducer at all!!

This solution by Cruzpro here is great if you don't mind SOG instead of STW .

The CruzPro SOG1 takes NMEA 0183 data from a GPS and creates an analog paddlewheel signal so you can display Speed Over the Ground (SOG) on a standard speed log without a transducer.

SOG1 NMEA 0183 to paddlewheel signal converter

The SOG1 creates an analog paddlewheel output signal from a GPS NMEA 0183 $GPRMC sentence so you can display Speed Over the Ground (SOG) on a standard analog or digital speed log.

The SOG1 replaces a thru-hull or transom mount paddlewheel speed transducer and provides Speed Over the Ground in place of Speed Through the Water.

No more cleaning of paddlewheels to remove marine growth or weeds.

Provides a more accurate estimate of time to get to your destination since it is not affected by water currents and provides a resolution of 0.01 knots from 0.00 to 60.00 knots.

The SOG1 is powered by 12VDC and draws less than 0.020 amps.

NOW,

Back to to Airmar's current selection; Thinking that the new DST800(V) isn't available for Raymarine instruments, I came across the following info in this Newsletter. It appears that perhaps they do have a new DST800 that will do the ST60 instruments AND the self closing valve. Read below their blurb....

The DST800 Retractable TRIDUCER® Multisensor is now available with

a VALVE

The industry’s only depth, speed and temperature retractable transducer is

now available with a valve! The DST800V meets customer demand for our

patented valve assembly that prevents water from rushing into the hull when

the insert is removed. And the addition of a valve lets boaters service the new

DST800V while the vessel is in the water, saving time and money!

Offered in NMEA 2000®, NMEA 0183 or Analog versions, the new DST800V simplifies any

installation by delivering three readings while having only one hole drilled in the bottom of the

boat. These three important readings can then be displayed on instruments, echosounders,

NMEA repeaters or Network navigation systems.

The new DST800V includes:

• Airmar’s patented self-closing valve assembly.

• Two O-rings, one at the top and one at the bottom for a water-tight seal.

• Industry standard 2” thru-hull hole size.

• NMEA 2000®, NMEA 0183 or Analog versions available.

Although the new DST800V contains Airmar's popular TRIDUCER® insert, the original DST800inserts cannot be retrofitted into the new housing with a valve. This is because all DST800 insertsmanufactured prior to November 2005 have ribs and an alignment key. If an older style insert withribs is pushed into the new P617 housing (which contains a valve), the insert will damage thevalve assembly.

However, all DST800s manufactured after November 2005, do not have ribs or an alignment keyon the insert. These can be retrofitted into existing installations that have a plastic P17, bronzeB17 or stainless steel SS577 housing. To insure proper sealing when installing a DST800 in aP17, B17 or SS577 housing, the yellow O-ring at the top must be replaced with a black O-ring.

Sooooo; my choices now are, I can wait for the NO paddle wheel DST900 and change out (choosing the analog version). Change to the upgraded DST800 (with self closing valve) but have to pull it out occasionally to clean the paddle wheel ( but not suffer the ingress of water due to a self closing valve), or go no transducer and loose the depth and water temperature in the process. Hmmmm, I think I will just sit and wait another year!
What would you do?

Home Handyman Aluminium Repair

Have you ever had an aluminum repair or 'thing" you wanted to make, but thought you had to use a TIG welder, which you don't have, and end up taking it to someone who has?
Then try this product; HTS2000


Other products (rods) that do a similar job are Durafix and Alladdin 3 in 1. Shop around with the products to get the best price. I've heard of prices from $5 to $60 per pound for very similar products

All of these rods are aluminum brazing rods and they are made basically from aluminum and zinc
You can use propane, oxy/propane, oxy/ acet. The smaller and thinner the pieces, the better it is to stay away from the O/A and use the mapp (preferred) or propane unless you have the correct size tips as the O/A can get to the melt temp really quickly. Use a very fine tip (00 or 0) when working with 1/8" or thinner material with O/A.

If you can braze then you can use this product.

Don't use this product on high temperature items. Even though it says you can do cylinder heads and exhaust manifolds, I wouldn't. Use a TIG instead.

And then of course there is stainless steel brazing rod, of which there are a few varieties. Most all contain silver as one of the alloys. You can do the search to find out what's out there.

These items lend themselves to emergency repairs on a boat, or a DIY project that doesn't need the expense of a TIG welder. You would have to make a decision as to whether a TIG is required or brazing will do. Keep in mind that if the brazing doesn't work, and you have to use TIG, all the brazing work will need to be ground out, before you can use the TIG. 

My intention for my next cruising season, is to carry a propane torch that will run off the BBQ gas tank, and some of these rods for emergency repair. Any comments?

New Port Hole Bug Screens

 I have two port holes in the side of the cockpit well (near the floor), which we keep open all the time. We place in the port holes, these snap in bug screens; but as you can see, from the picture to the left, some of the plastic has broken off. It is also broken in a couple of other places not visible in the photo. These bug screens are 1985 vintage and have just deteriorated through use and I suspect UV damage. Also, these sit around shoe level when sitting in the cockpit, and occasionally get popped out by an accidental heel kick.

Wooden Template

In reconstructing these, I first made a wooden template suitable for a router. I used MDF (medium density fibreboard).
Next I procured some PVC board, which when doubling the thickness of the PVC board, was just a few millimeters thicker than my old bug screen.
I used PVC, but could just as easily have worked with Polyethylene plastic board.
Next I cut out of the PVC board, four rough finished frames which were about 5-10mm wider than my template.
You might notice that my template has a wider surface than the original bug screen. This was to give it some added sthrengh and make it easier to place the bug mesh between the two PVC cutouts.

Routering

I used double sided sellotape to secure the template to the rough cutouts and then routed the remainder of the PVC off to the finished template. Each one was done in turn.
Then because my template wasn't exactly symmetrical  I matched two pairs so that all corners lined up perfectly.

Mesh glued and trimmed

 I lay one side of my PVC cutout down and placed a small bead of 3M 4000 deck caulking compound in the centre of the flat surface. Then I placed my bug screen mesh (Nylon I think) over the top off this, then spread the 4000 over the mesh so that it was in the middle and not near the edges, and sat level with the mesh and not proud. Final tension was then applied to the mesh and it was allowed to set up. This was to act as a "glue" so I could the trim the mesh about 1mm in from the outer edge after it had set up.

4000 applied before 2nd side attached

Next application of 4000 was applied in a thin layer over the mesh, but not approaching the inside edge by about 5mm. If the 4000 is squeezed out to the inside and over the mesh, the job looks "ugly" and once set is hard to remove from the mesh without damaging it.

Glass over top for glue to set

Finally the other side was applied, being careful that both PVC cutouts lined up perfectly. The PVC was pressed down from the inside edge to the outside, squeezing out any excess 4000. A plate of glass was applied over the two pieces and allowed to set up.
After it has set up, a sharp craft knife was used to trim the excess off, on the outside edge.

Finished product

 The finished product to the left. It's both flexible and hardy. Should last several years. But, if you need to change the mesh, just slip a  blade between the two sections to break the bond. Clean up and repeat the process for new mesh.
What am I going to secure it with in the port hole? Probably "blue tack"; but one could use a double sided foam tape, like they use to secure mirrors on walls.
Don't try to do the glueing in one step with the mesh. I tried and it was very difficult to have both PVC pieces line up perfectly. Also when trimming the mesh off, you could still see the mesh on the outer edge and it looked "ugly". A much better finish, if you glue the mesh to one piece first; have it set up, and trim the mesh back from the out edge. Then, when trimming the final outer edge of 4000 is done, a nice white finish is all you see.  So, in essence, what you see here is a bug screen that has had the mesh replaced once because I didn't do it right first time. Cost $30 for the PVC 1 square meter sheet; and $7 for the mesh.

An iPad Experience

   I wrote in January 2012 about using iNavX and an iPad as an affordable chart plotter. I have yet to procure mine and install. Till I do check out this other bloggers experience.           
  Andrew from the yacht Arabella has written a blog about his experience of using the iPad as his charting display of choice He starts out by saying........

"The loss of my trusty, semi-retired MacBook Pro, as a result of its impromptu shower on the Round The Island Race, had forced me to consider alternative methods of chartplotting. "

His blog is quite jnformative and is aimed more to those whose boating is in Europe; even so, well worth the read for his comment around 5 charting solutions listed here.

• iChart (Solent)
• Marine Imray Charts: English Channel
• Navionics HD UK & Holland
• Memory Map (Free version)
• iNavX

Andrew covers such topics as which iPad to choose; waterproofing and mounting; tides and wind vectors. Overall, lots of photo's, discussion and practical examples given through out. Hop on over to his blog to read more.