[TG] [TG11] EV-150 zig zag

[Shockedby277v]

Hello,

I have a 1993 Bayliner 2252 Classic Mercury V6 4.3l inboard Alpha One outdrive. It had cable with power assist steering. I changed it out to a Seastar hydraulic steering system. I paired it with the EV-150. I use my boat for trolling Lake Michigan and intend to use the autopilot for the same between 2 to 4 mph and to basically maintain a heading. My fishfinder and gps is a Humminbird and not part of the network.

After start up I took it to the lake for testing. It doesn’t hold a straight coarse at all. It makes sharp zig zags. The thought might be there may be air in the lines so I bled it for a 3rd time. Back to the lake same issue. I found there is a software issue when not using a rudder with the ACU 100. I looked and looked and found no way to update my software. Through a Facebook group I am being told I would need a MultiFunction Display in order to update. There is also search bar that says “detecting magnetics”. Not sure what that means either. I am out of ideas what may be the cause. Please help!

[Tom - Raymarine - Moderator]

Hello Shockedby277v,

There are a number of possible causes for this sort of thing, but don't worry, I'm sure we can get to the bottom of it. To clear up a couple of other points first though:

Quote:There is also search bar that says “detecting magnetics”. Not sure what that means either.

This means that the pilot is working on calibrating (linearising) the compass, to try to remove background magnetic interference from the boat itself. By default the EV pilots always do this in the background, whenever you're under way at between 3 and 15 knots. However, if your pilot doesn't have a GPS or paddle-wheel speed-through-water input, it doesn't know that you're under way and can't start the process. You can either go into Menu > Setup > Autopilot calibration > Commissioning and set Compass Lock to On, or connect a source of GPS data. You can see more detail in sections 7.9 and 7.10 of the p70's manual.

Quote:I found there is a software issue when not using a rudder with the ACU 100.

There is a software issue that affects a small number of ACUs that have the very latest hardware revision, when used without a rudder reference, that can cause over-active and oscillating steering. You can tell whether you have one of the affected pilots by looking (in Menu > Setup > Diagnostics > About System on your p70-series display) at the ACU's current software version. If you have v3.11 then you need to get an update to v3.12: if you have any other version, this issue does not affect your system. If you have v3.11 then your supplying dealer should be able to help get the software updated through warranty. The ACU does not need to be replaced, and with an MFD the update is a 5-minute job.

Quote:I would need a MultiFunction Display in order to update.

Yes, that's correct. We use an MFD as a front-end to get software into a system, because most Raymarine systems contain an MFD now and they have a slot for a memory card or, in modern MFDs, internet access over Wifi. Most Raymarine MFDs from the last 15+ years can update an EV pilot.

Quote:It doesn’t hold a straight coarse at all. It makes sharp zig zags.

Assuming you don't have the v3.11/v3.12 issue, I'd guess that you have one of two common things going on:

1. Your calibrated Hard-over time is wrong. This is the important setting that the pilot uses (when there's no rudder-reference) to work out how long/hard it should drive the motor output in order to achieve a certain helm angle. If the HO time is calbrated wrongly then the pilot doesn't drive hard enough, or as may be the case in your system, drives too hard.
2. Your pump may be too large (pumping too much fluid) for the capacity of the steering cylinder. Sometimes pumps are mis-selected (sometimes people guess the pump capacity required based on the size/type of the boat for example) and if you have a pump that's too large/fast for the cylinder then the steering is too sharp. Our pilot software is designed for a steering HO time of between 8 and 12 seconds, but if the pump in question gives an HO time of say 6 seconds then the pilot can't make fine-enough ram movements to settle the steering in the right place.
   

I would suggest double-checking the ram capacity against our pump specifications to confirm that you definitely have the right pump (e.g. between 80 and 230cc if you have a T1 pump), and then looking at the HO time setting.
The HO time calibration is often misunderstood: this is the length of time it actually takes the pilot to drive the steering lock-to-lock. If your steering's too sharp, try reducing this value.

If you're still having problems after these steps, come back to us.

Regards,
Tom