Faria Speedo (again) - 2004 196 Limited

[sgregg]

Anyone know where to source something like a “micro” hydraulic/pneumatic cylinder? I am looking for something that could be inserted in the line between the pitot pickup and the Gateway that would transfer the pressure to the Gateway but prevent water from getting to it.

[Jonny Quest]

Jonny Quest I like your shift knob!

That Hurst shift knob takes me back to the days of my youth -- when my daily driver in High School was a muscle car: 1971 Plymouth Duster 340. Manual transmission. Shark tooth grille. Orange with black stripes. Hooker headers. Holley 4150 carb. That car had the same Hurst shift knob.

Wish I still had her...

JQ

[Bill]

I wonder why a pressure transducer was not used in the original application? They are used to keep liquids out of all kinds of electronics. Just curious.

[sgregg]

Quote removed by Admin for not following the Guidelines for Quoting Previous Posts in a Thread.

We don’t have the Gateway open yet, but my understanding is there is a transducer inside the box (rather than external to it) - if the seal is compromised, the box can flood. You bring up an excellent point - perhaps relocating the transducer is something we can explore.

[sgregg]

Does anyone have tips on how to open the Gateway box without damaging it? gatorgates?

[SilentSeven]

Regarding the transducer - I don't think this is a hydro/pneumatic transducer as suggested above. It's highly likely it's a pneumatic/electric transducer.

I believe the way pitot system speed system works is that the pitot pickup compresses the air in the speedo tubing which is read by the pneumatic/electric transducers in the Faria ebox. Ebox firmware is calibrated to translate transducer voltage into a speed reading displayed on the gauge. The system is effectively "closed loop" with the transducer on one end and water on the other. Running the boat forward allows some small amount of water up the air line but then the intrusion ends as the air / water pressure equalizes. In normal operation, there should never be water to the Faria box. Supporting this....if the system was water based, you would expect to see a bleed value by the box to remove trapped air. Clearly, there isn't a bleed valve.

Continuing...the failure is when the air seal in the transducer fails which prevents pressure equalization and thus allowing pressurized water all the way to the transducer where it leaks past the failed seal and drowns the ebox.

I'll speculate that Faria/Nautique didn't redesign the ebox to eliminate risk of water intrusion...instead they upgraded the design to use a paddle wheel as it's a simpler and more accurate system. Why have a paddlewheel AND pitots when you can just use the paddlewheel only?

Assuming you can locate identical transducers that are embedded in the ebox, I would think the simplest way to prevent failure would be to migrate the transducers to a separate box effectively air-gapping transducers and eliminating the risk of ebox drowning. Feels like a lot of work.

I still think a more viable approach would be to find an off the shelf 3rd GPS based speedo and see if it's possible to migrate the guts into the current Faria speedo housing. This way you keep the Faria face, the factory LCD displays and have a working speedo. TechBeer has obviously had the gauges open and I think is best able to comment how possible this might be. This was also suggestion 1 in his posted above.

[SilentSeven]

Example of small format transducers - https://www.veris.com/126862/categor...ic-transducers

[TechBeer]

As I told sgregg I'm having a heck of a time getting the gateway open. I've removed the screws and started (gently) prying and ended up just chipping off the plastic on the housing. Then I hit it with a heat gun and didn't really have any luck. The plastic warps before the adhesive lets loose. From other threads it doesn't seem like it should be this hard. I think the gateway in my lab is circa ~2004/2005 with the pitot tubes. I wonder if some gateways were just "sealed" and others were glued with some sort of adhesive.

My ultimate goal was to replace the pressure transducer with some sort of circuit that converted the paddlewheel (or potentially GPS) signal into whatever the output of the transducer is. My guess would be a voltage proportional to pressure. BTW, for fun I hooked a bicycle pump to the pitot input and got it up to 40 MPH... :-) However, if I can't gracefully open the gateway then it sort of defeats the purpose. I'd like to hear from others that successfully cracked open the gateway.

[NautiqueJeff]

What about cutting it open with a small circular blade, like on a Dremmel?

[NautiqueJeff]

What about cutting it open with a small circular blade, like on a Dremel?

[jpwhit]

I've tried using a Dremel with circular blade for sealed enclosures like this and it didn't work out too well. You don't have enough control on depth of cut and I had problems with damaging stuff inside. Part of the issue is it tends to jump around. It also tends to get a bunch of debris inside the box which also causes issue. Abrasive cutting wheels often produce dust which has enough resistance to screw up electronics when it gets inside the enclosure. The stainless steel thin saw blades don't have that issue, but are even harder to control and I've cut myself very badly with those as well.

The way I do it now, which has been consistently reliable, is to securely attach the box to the table on my CNC mill. Then I use the mill to make precision cuts that don't fully penetrate the enclosure. That keeps crap from getting inside and contaminating the interior. The goal is to make the cut deep enough, without penetrating the enclosure, such that after all the cuts are made that I can insert a thin but wide flat blade screwdriver into the cut and crack the remaining material without having to use a lot of force.

[SilentSeven]

I'm having a heck of a time getting the gateway open. I've removed the screws and started (gently) prying and ended up just chipping off the plastic on the housing. Then I hit it with a heat gun and didn't really have any luck. The plastic warps before the adhesive lets loose. From other threads it doesn't seem like it should be this hard. I think the gateway in my lab is circa ~2004/2005 with the pitot tubes. I wonder if some gateways were just "sealed" and others were glued with some sort of adhesive.

Yeah...I tried to open spare my eBox with goal to visually inspect and basically ran into the same problem. I bailed on the attempt when it became apparent there was no simple non-destructive way in.

Here's a prior old post with the box opened..if it helps / https://www.planetnautique.com/vb5/f...351#post496351

My ultimate goal was to replace the pressure transducer with some sort of circuit that converted the paddlewheel (or potentially GPS) signal into whatever the output of the transducer is. My guess would be a voltage proportional to pressure. BTW, for fun I hooked a bicycle pump to the pitot input and got it up to 40 MPH... :-)

This would be really elegant...and amazing if you could pull it off. Curious what line PSI was required to generate a 40mph reading.

[sgregg]

Thanks for finding that old post SilentSeven, i pm’d northofnine - maybe he can help us get the box open

[sgregg]

Northofnine got back to me - he used an exacto knife along the edge after taking the screws out and
a small screwdriver to pull it apart.

[sgregg]

Short update as to where we are at:

TechBeer was able to get his Gateway open, disconnect the pitot transducer and inject voltage to drive the speedometer.

He is looking at designing a circuit that would take the paddlewheel (or possibly GPS) signal to drive the speedometer in lieu of the pitot system.

The amazing guys at Perfect Pass (thanks Mark!) are able to make a jumper to split off the speed signal from the paddlewheel so it can be wired back to the Gateway as well as the PP Master Module.

For boats that don’t have a paddlewheel installed, it would be pretty simple to install one of the transom mounted paddlewheel options and route the cable through the hull in one of the pitot tube locations - the pitot tube diameter is slightly larger than the Airmar paddlewheel cable.

It is going to be a few months before we can test the system Mark is working on (boat is in storage) but will update this post if we get any further along before boating season.

Thanks for the input people have provided - if you know of someone with a pre-2005 Gateway laying around, it might be helpful to have access to it for some testing…