Jens for radar

 

Hello Jens.

As discussed, I have a B&G N2K network in which I continue to receive a "no radar" message.   While I was negotiating the purchase of the boat, Serge Duvalier had indicated that he had a tech check it and it was able to be made to function, and I believe he did send me a photo at the time confirming a radar image.    

Installation Particulars

The network is laid out as follows, and all other connected instruments are recognized.  I have not updated any firmware.  The list below shows the age of each instrument, if not 2024, it was installed in 2019 or 2020.   

• Standard Horizon GX1850B and SSM70H RAM4 remote mic  (2024)
• B&G zeus broadband 4G Radar  (includes RI10 radar junction box, located at Nav station.)
• Simrad Radar ethernet bypass cable is aboard
• B&G zeus3-9 worldmap MFD
• B&G zeus3-7 worldmap MFD  (2024)
• B&G NAC-3 Autopilot (2024) and new rudder position sensor.
• B&G NAIS-500 class b AIS transceiver
• B&G GPS-500 GPS antenna
• DST810 through hull sensor (2024)
• WS320 wireless wind sensor  (2024)
• WS200 Bluetooth (2024)
• forward looking sonar

Troubleshooting so far

• The N2K network is otherwise functioning correctly, other instruments are found and operational.  
• I have ensured that there is adequate voltage available (at the internal connection points at the nav station) to allow the radar to start.  
• I have been able to  determine that the RI10 junction box is not the source of this issue by bypassing the RI10 with the appropriate ethernet adaptor cable, which remains aboard.     
• I have attempted to get it working with only the bare minimum of N2K network attached.   Same "no radar" message.   
• I have not updated any firmware.  
• I have not inspected any cabling other than that indicated, and I have not been up the mast at all.   
• As we discussed this suggests that either the radar dome itself, or its cable/connectors is the problem.  

Access to necessary components

The cabling and the RI10 can be accessed behind the two hinged drop down panels at the nav station.     

Below: The new radio/MFD panel is currently open, and should be left that way as I have not yet installed a latch.

Below:  with the switch panel dropped, you can see the N2K splitters clearly, and, to the right of those, less clearly, the RI10 radar junction box.   

The batteries are fully charged but are not connected.  They are accessed in the port side aft cabin and this has been left open as pictured below, so you can simply remove the link connecting the batteries and connect the two house bank cables.  It'll be obvious. 

Gebo Hatch refurbishment

While the 20-year old GEBO hatches were fully operational and leak-free, they were showing signs of age, with crazed plexiglass and UV-degraded hardware. Time for renewal.  

Fortunately GEBO still exists, the style of hatches used are still in production. Their responsiveness and communication was excellent.    Here is the factory literature: https://www.gebo.com/wp-content/uploads/2019/08/Standard-Deckhatches-without-flange.pdf

The plan was to prepare the lenses in my shop in Toronto, order the hardware from The Netherlands, and the DOW 795 glazing silicone from the USA, and ship the lot to the boat for installation.  While visiting the boat I had photographed the hatches, documented the hardware required, and measured the glazing.

Fabricating new Acrylic lenses

When I was at the boat, I had indeed measured the glazing dimensions accurately but I had neglected to note the corner radii.  It appeared at first that the hatches used by Alubat might have been the off-the-shelf items listed below, so I reached out to GEBO to see if they had dimensioned drawings available.  They did not have a drawing, but were able to provide the glazing dimensions and corner radii of the current, standard hatches.  This meant that I could make blanks in the shop at home, but had to drill the holes for the hardware at the boat.  

The overall dimensions are consistent with current production hatches, with the exception of the largest hatches where I measured glazing 7mm wider than the standard item.   

Unfortunately the larger hatches futher differ from standard items with a 40mm corner radius vs the 61mm radius on the current standard hatch.  The 2001 OVNI hatches use the smaller 40mm radius for all hatches hatches   Best to confirm the glazing dimensions, corner radius, and hole placement using the actual hatches installed - assume nothing!  See the table below containing my measured dimensions and their 2023 standard hatch dimensions.

The acrylic is specified by GEBO as 10mm thick for all 8 of the deck hatches supplied on the OVNI 435.  This thickness is not available in North America, where 3/8" is the rough equivalent.   GEBO describes the colour as "Grey tinted" and the colour code for dark grey tint that I've used previously is # 2074.   3/8" acrylic, 2074 tint is stocked here at Plastic World in Toronto, where a 4'X4' half-sheet currently (June 2023) costs C$234.  This is enough to re-glaze all of the GEBO hatches on the 435.

The acrylic was cut to size on the tablesaw.   A template was made for the corner radii per the guidance provided by GEBO,   and the corners traced with a fine pencil, cut on the bandsaw, and sanded to the pencil line.  The plastic scraper’s V-Notch was used to relieve all sharp edges.   This all would have been much more difficult to do at the boat.

The plexiglass dimesions were correct except for the corner-radius issue noted above, and required only light sanding to achieve an adequate perimeter gap for the sealant.   There was sufficient material in the half-sheet to make a spare large hatch replacement.  3 larger deck hatches, two cabin top and 4 cabin side resulted in a 35lb bundle to be shipped. 

Replacing the hardware

 Gebo specifies its hardware based on the glazing thickness, (10mm or 15mm) which is in this case 10mm.  All hardware is available as of 2023. The handles are an equal mix of left and right handed, with the small, cabin side hatches intended to be operated with one's left hand.  Thoughtful.

Required parts and spares:

The GEBO hardware requires two 6mm blind holes (for anti-rotation pins) and a 14mm through hole for the handle.   You will require one of their special wrenches to access the hinge nuts.  (included in the hinge repair kit)  Order extra external handles and hinge caps.  

I took a chance and ordered the very high quality bug screens for the mid-sized cabin top hatches, and they fit perfectly.    I really should get some screens for the small hatches.

Dow 795

Great stuff and the only silicone I would use on a boat.  Ensure the material is fresh - it will not cure if it is past its shelf life!

How to remove and reinstall the glazing

By first slicing the silicone from above, then gently inserting a thin, flexible, putty knife between the frame and the plastic lens from below, and patiently working it around the entire perimeter, the acrylic lens can  be parted, intact, from the frame.   It will then serve as a perfect template for  the replacement.   See blog post here for more specifics.    If you know of a good way to remove cured silicone please share.    

Mark took two full days to refurbish the hatches, and they look new.  Thanks Mark!

Misc photos 

Battery Installation and Victron Lynx Application

OVNI 435 battery boxes can vary in size, but my 2001 435 #6 measures 22.5" X 30.25"X 9.5" deep and is located below the cockpit.  It is made of welded aluminum and is bolted in place. It has an outward turning 2" flange around the top, with a seperate, single-piece plywood lid,     With the lid removed, the batteries are partially accessible from either aft cabin.  The electrical connections are made on the port side.    

The one-piece plywood cover is secured to the flange with machine screws and easily-dropped nuts, and it has a 2"X2"  (approx) cleat around its perimeter.   It is bulky and inconvenient in use, and access is more difficult than it needs to be.  It can easily be improved.

Cables enter the battery compartment through randomly-drilled holes on the port side.   There is no positive bus bar, and no fusing at the batteries,    Over time, accessories with a mishmash of fuse styles (or none) have been stacked on the various battery terminals. none labelled, most with no means of disconnect.  The cables intrude into the middle of the box, interfering with battery installation and removal.   

The house bank's 4 group 31 batteries were connected in parallel with heavy, well-made jumper links.  With the limited clearance to the conductive cockpit sole above, caution is required when working here, especially with top-terminal batteries.  

The starter battery was/is also in this box, furthest aft.  Access is particularly inconvenient.   

The photos below show:

• how access is restricted by the cockpit, 
• how the cabling was installed and intrudes into the box.
• The many live connections that must be made in an awkward, confined space.    

Below left you can see that batteries must be placed in or removed from the box it in a fore and aft orientation.  Below right shows a pair of terminals in the cockpit locker that were connected to the starter battery.    Presumably this was to provide for boosting or charging.  This DIY hack has been removed, and I will eventually relocate the starter battery to a more accessible location, probably in the port side cockpit locker. 

What to do?

  With the upgrade from 4 group 31 to 2 group 4d (ish) lithium batteries, it became a necessary to re-think the stowage of the batteries, and opportune to upgrade the installation with a bus bar, circuit protection, and a safer, more orderly layout.  There's plenty of opportunity for improvement.

Scope

1. determine battery orientation  ensuring:
1. optimal use of space, 
2. minimal wiring
3. tool-less method to install/secure/remove batteries. (small ratchet straps?)
4. must be easy to reconfigure with - at most - basic woodworking tools.    
5. Battteries must be well secured
6. Ideally, either house or start betteries could be removed while leaving the others in place.
2. design/install distribution and circuit protection for current uses and future expansion
1. Likely this means locating the bus bar and fusing outside of and adjacent to the battery box for better access, however it must then be protected from accidental contact.    
2. it should be easy and safe to disconnect each battery while leaving the other(s) in use.
3. a ATO/ATC "blade" fuse block may be required for some low-current accessory connections.   
3. Improve the cover
1. Cut the existing cover in a fore and aft direction. 
2. Incorporate a tool-less means of securing the cover so that either side can be quickly accessed. 
3. Ensure that terminal fuses can be inspected and replaced from the port side.   
4. Incorporate storage into any unused space if possible.
5. Insulate the interior sides of the battery box to reduce the risk of contact with a live conductor.
6. Provide clearly marked storage for spare fuses nearby.

The Physical part - Thinking inside the box.

I cut a thick rubber mat to size and placed it in the bottom of the battery box.  This provides some cushion to the batteries, and prevents them from sliding.  

Due to the size and shape of the batteries and the restricted access to the box, satisfying the above critieria is trickier than it first appears.  Particularly item 1.6, as the batteries must be placed in the box in a fore-and aft orientation  and then rotated atwhartships if that is the intent.  This creates a bit of an assembly puzzle.   See below, the mdf mock-up of the box and batteries.  

I ultimately decided to arrange the batteries as pictured above, with a hold down system made of stout oak rails, with two 2" wide rails at either end of the box, elevated off the bottom by 2".  In the photo mock-ups of these can be seen at the narrow ends of the box. Note that the postive terminals are at what will be the forward end of the box.   The 2" width was chosen to provide a protected space for cables and terminal fuses around the perimeter of the box.      

2"X2"  movable rails, running the full 30" length of the box, are placed in the empty box, and slid under the raised. fixed rails.   The fixed  rails prevent the longitudinal rails from lifting.  The batteries are placed between the longitudinal rails as pictured, and against the forward rail.   Ratchet straps looped around the movable rails are used secure both house and start batteries.   Wooden spacer blocks are be used in the remaining space to further secure the movable rails (and therefore the batteries) laterally.  The lid may be configured as a secondary means of securing the batteries, should the ratchet strap fail.   

No tools required, and the layout can be reconfigured as required in future. 

Parts of Oak  

The mdf protoype worked well, so a more refined version was committed to red oak.     You can see the short end rails with the M8 bolt holes, and the movable rails with the added refinement of a cleat to secure the hold down strap.  The straps were cut and loops sewn as shown.

Below you can see how the movable rails and ratchet straps engage the fixed rails to secure the batteries by pressing them downward into the rubber mat on the bottom of the box.    Filler pieces will be fitted on site to further restrict movement of the rails.   Also visible are some additional refinements to the rails. 

Ready to be packed.the long rails are oriented as they would be in the box.

The Electrical Part - Safe and Simple?

Circuit Protection at Battery box

https://marinehowto.com/battery-banks-over-current-protection/

Based on the info above and the cabling already in place, the following circuit protection should be incorporated. 

1. Battery 1 terminal fuses @150a
2. Battery 2 terminal fuses @150a
3. Inverter charger 1600w/70a (100A)
4. Small inverter.  (40A)
5. 70A Alternator via smart regulator (verify cable, regulator output)
6. House loads (125A per dwg, s/b fused already - where?)
7. Future water maker (100A circuit?)
8. 200W (450W future) PV (50a)
9. 200W Sailgen (50a) 
10. Wind (50a)  **  The wind generator may be retired.

That’s a lot….  Too much in fact.   It will be consolidated.

Bus bars, circuit protection and monitoring

After having purchased the necessary bus bars and breakers to upgrade the DC distribution, I struggled to design a safe and compact electrical layout that would work in the limited space available.  This brought me back to Victron, and their Lynx bus bar range.   I had previously ruled this system out as being too expensive, but, all things considered, it isn't. Relatively few additional components are necessary with this system.

While the Lynx Shunt wasn't absolutely necessary, it provides the opportunity to further consolidate components.   The Lynx Power-In has been "hacked" to incorporate fuses (google it) and now functions as a Lynx distributor .(minus the LED blown fuse indicator)  The fuses (and breakers) are of a type and rating to protect the cabling in the event of a dead short, they are not intended to protect the equipment.     (Fuses are a topic worth investigating.)    Two thermal breakers were added and provision was made for an additional Victron smart shunt to monitor non-GX compatible charge sources.  

The components were arranged on a piece of 3/8” polycarbonate that will be fastened to (or very near) the port side of the battery box.  The polycarbonate was drilled and tapped for M5 allen head cap screws, to secure the Lynx devices, two thermal breakers and a future Victron smart shunt.     Clearance holes were drilled for M5 screws which will would be tapped into the battery box to mount the entire assembly.   These screws will also secure mounts for releasable cable ties to secure the cabling running below the lynx devices.

 Below you can see the space around the perimeter of the batteries and the oval holes at either end of the battery box for the battery cables, which exit the box and  connect to the adjacent bus bars (red and black covers in the photo.)  There is very little cable exposed.  

There is room for a third house battery if required but the removable hold downs might require some minor revision.   

There are fuses on each battery terminal and a very fast fuse in the lynx shunt.  

Load and charge source cabling will enter at the bottom of the Lynx power in, where it connects via a fuse to the bus bar.  The Lynx shunt is located between all grounds and the battery negative. 

Hopefully I can simplify and remove some of the massive amount of cabling and trunking that runs beside the battery box. 

There are two less-than-ideal aspects to this approach:

• one of the house batteries must be removed to remove the start battery.  (I will relocate the start battery at some point)
• There is no means to externally disconnect each house battery.   This means that an unused battery cable would remain live unless first unbolted from the bus.   While this is not unusual, and can be accommodated,  battery disconnects or external fuses might be more convenient than terminal fuses.   

Notes

Fuses required 

CNN350DIN.   Fast fuse for dead short, in lynx shunt.

Mbrf for terminal fuse disconnect battery.  There is a problem here in that either end of the wire will remain live.  For disconnect it should be at the lynx shunt.  

Mega (50.8mm) fuses within the lynx shunt.  

Littelfuse makes mega/AMG fuses as low as 40a

 

435 Centreboard Cylinder Removal

The following is based on my experience with my 2001 OVNI 435 #6.  It may not reflect any changes to the 435 through the years.   Any input to improve this document is welcome.  

Specific tools required 

• Flare (helpful) and 14mm open ended wrenches
• Hammer and drift for 10mm pins
• small 90 degree pry bar to assist with removing covers.  

The centreboard cylinder is situated within the centreboard trunk, positioned horzontally above the  centreboard.   It is not necessary to remove the centreboard to remove the cylinder as there are access covers on top of the trunk for this purpose.   

In order to remove the centreboard cylinder, you will need to first gain access to, then remove the two pins that secure the cylinder.  The forward pin fastens the cylinder's piston rod to the centreboard.   It is the extension and retraction of the piston rod that raises and lowers the centreboard.   The aft pin anchors the cylinder base between reinforced areas on the opposite sides of the centreboard trunk.  Once both pins are removed, and you can disconnect the 2 hydraulic hoses and lift the cylinder through the access cover. 

In preparation, the centreboard must be safely supported in the fully-retracted position. Lower the board slightly to ensure the cylinder is no longer bearing the board's weight, and can be safely removed. 

Gaining Access

To access the hoses, first remove the plywood cover opposite the galley fridge.  This cover fills the triangle between the main bulkhead and the settee corner.   You will see the hoses and the acrylic  cover though which they pass into the trunk, via cable glands.  (which may have become brittle and broken with age)    

1. Remove the cable ties securing the cables to the bulkhead.   
2. Note the fore/aft orientation of the acrylic cover.
3.  Slack off the gland nuts and remove the cover screws.  
4. Gently pry the cover free and slide it up the cables.   It is through this opening that the cylinder will be withdrawn.  

The 10mm forward pin is accessed from the top and sides of the centreboard trunk in the forward cabin.

1. Remove the plywood trim covers from the top and starboard side of the CB trunk and lift the plywood berth board to gain access to the two upper aluminum covers on either side of the trunk, and the acrylic cover on top.  
2. The aluminmum covers are secured by M4 philips screws, and sealed with Sikaflex.  You will likely need to use a small pry bar to break the cover free of the sealant.   
3. With the covers removed, you will see the cylinder's piston rod end where it engages the CB via the 10mm pin, itself secured with two cotter pins.  If you do not have complete access to this, the board is not fully retracted.  

The 10mm aft pin is accessed by removing  two small aluminum covers located on either side of the centreboard trunk, roughly opposite the fridge.  The starboard side cover is concealed beneath a plywood trim panel, the portside cover is under the  forward end of the settee, most easily accessed by unscrewing the removing the plywood panel that forms the seat.  

1. Remove the plywood trim cover and unscrew and remove the plywood panel that forms the forward dinette seat. 
2. Remove the square aluminum covers. The 10mm pin will be seen seated in its close-fitting hole.  

Once all the covers are removed clean the area as much as possible. Remove any residual sealant.

Removing the Cylinder

Removing the forward pin first allows the piston rod to be fully retracted which is necessary for removal, but also eases the next steps and ensures that the more difficult-to-remove aft pin is not binding in the cylinder. 

1. The forward pin is secured by cotter pins. Remove one or both of the cotter pins and drift the pin out.   
2. The pin should yield to moderate taps with the hammer and punch.  If not, first use the hydraulic pump to ensure that the cylinder is not still loaded with the weight of the centreboard.  If badly corroded or bent it may be difficult to remove.   
3. Once the forwad pin us removed, using the hydraulic pump, select the position used to lower the board, and pump to fully retract the cylinder's piston rod.  
4. Carefully drift the aft pin out with a hammer and drift, from starboard to port.  This pin may be extremely difficult to remove due to corrosion, the amount of contact area, and the pin's the close fit in its holes.   Once this second pin is removed the cylinder will be lying loosely on top of the centreboard, connected only by the hoses. 
5. Disconnect the hoses using an open-end 14mm wrench for the nut and a second flare wrench to prevent the hose from turning while doing so.   Some fluid will be released as the fittings are loosened.   
6. When both hoses are disconected, tape the ends to prevent any debris from entering the system.

The cylinder can now be removed.

Reassembly

(If you are reading this you already know about sealants, and where and how Tefgel/Lanolin must be generously applied.)

Reassembly is generally the reverse of the above, with a few additonal hints.   

1. Before proceeding, ensure that the piston rod is fully retracted and that the holes in the cylinder base and the piston rod are in the same plane, by rotating the rod as required.  It'll probably be stiffer than you expect, and may require some leverage.  
2. Place the cylinder in the trunk in the correct orientation.   (base aft, fittings up)   
3. Switch the hydraulic pump to the "raise" position, and cycle it until it spurts fluid from the aft hose.  This helps ensure the hose is free of debris and excess air.    
4. Connect the aft hose only.   
5. Insert the rear pin to secure the cylinder base to the CB trunk.    
6. Use the hydraulic pump (still in the "raise" position) to slowly extend the piston rod.  Guide the rod end between the centreboard flanges and pin it in place.   Do this slowly and be careful not to overextend the cylinder.  (You will need two people to do this efficiently.)
7. Celebrate the fact that you've mostly purged the cylinder of air.
8. Switch the pump to the "lower" position, and as before cycle the pump to purge the forward hose. 
9. Reconnect the hose, and switch the pump back to the centre "locked" position.
10. The system will now be operational but must be checkd for leaks and fully purged of air.   
11. Once you are certain the system is functioning and connections are leak-free, replace and seal the aluminum covers and acrylic covers.  Do not reinstall the trim, tighten the glands or secure the cable ties.
12. After the boat is launched, fully cycle the hydraulic system.   With the board down, secure the hoses with new zip ties and tighten the cable glands.
13. After ensuring that there are no seawater leaks, replace the trim and cosmetic covers.

Misc photos and notes

The photos below show the flanges on the centreboard, between which the cylinder's piston rod is pinned.  If you are replacing the cylinder, ensure you order the correct part as it changed during the 435's production run.   

The photo below shows the two configurations of cylinder ram.   Note the different length of the flat section.   

The photo below shows the aft pin, and how it engages the cylinder base and the reinforced sides of the centreboard trunk   Note that I cut this access hole myself in order to saw off the pin as it could not be removed otherwise.   

The photo also shows the two nuts used to secure the hose to the 90 deg. male fitting on the cylinder.  The upper (in the photo) nut is held firm while the nut adjacent to the fitting is turned.