When to engage Bennett

[billnpat]

Do we engage bennett when we are going on plane?? or when we leave the slip???

I forgot the answer.....Senior moment:smt021

 

[Great lakes pirate]

Bill are you talking about auto trim?

 

[billnpat]

Bill are you talking about auto trim?

Yes the auto trim tabs....

 

[Great lakes pirate]

On plane would be best.

 

[billnpat]

On plane would be best.

OK Thanks.....

 

[Jimmy Buoy]

I usually lower both tabs manually just before going on plane, manually adjust the tabs roughly to the desired attitude once on plane, then engage the system for the precise attitude and continuous re-adjustments. The reason for this is that I can anticipate the more extreme tab adjustments better/faster than the auto system (from off to on plane transitions).

Coming off plane, I once again manually zero out both tabs which disengages the system.

 

[billnpat]

I usually lower both tabs manually just before going on plane, manually adjust the tabs roughly to the desired attitude once on plane, then engage the system for the precise attitude and continuous re-adjustments. The reason for this is that I can anticipate the more extreme tab adjustments better/faster than the auto system (from off to on plane transitions).

Coming off plane, I once again manually zero out both tabs which disengages the system.

Anything wrong with just leaving them engaged through out the trip??

Thanks Jimmy...

 

[Tabman]

I think Jimmy really summed it up well, that's just what I would recommend.

Lowering the Trim Tabs a bit (a little experimentation will let you know what is best) really helps the boat get up on plane faster (less strain on the drive-train) and with less bow rise (you can see where you are going).

Think of it like cruise control on your car, you engage it when you are at cruising speed.

Tom
Bennett Marine

 

[tbirdvet]

I would not leave the tabs always engaged (down) for the whole trip because that will add drag at slow speeds when you do not need them.

 

[billnpat]

I would not leave the tabs always engaged (down) for the whole trip because that will add drag at slow speeds when you do not need them.

From what i understand now....lower the tabs a little just before going on plane, then when your on plane kick in the tab control like Tabman says cruise control and let the tab control take over.. coming into no wake zone leading to your slip then what???

 

[Vince_nj1]

If I remember correctly, you "set" the tabs when you a on plane and level. Once you have stored your proper running attitude the system will remember it and attempt to adjust the boat to that position whenever you turn the system on.

Re: Bennett Automatic Trim Tabs

I feel like I should cover this topic a bit more completely as there seems to be a bit of confusion.

The ATC is designed to maintain a boat’s optimum running attitude when up on plane. Most boat’s optimum attitude is a few degrees bow up compared to its at rest or idle speed attitude. It is usually about 2 – 4 degrees bow up, but can vary a bit on different hull designs.

To set the “zero point” on the ATC you take the boat out and run it at your cruising speed, and you may use the power trim and Trim tabs to get it level side to side and at its best fore to aft attitude. This is best done in smooth water conditions. To determine the best fore to aft attitude you can watch the RPMs and speed as you adjust the Trim tabs and / or power trim.

Once you are happy with the boat’s attitude and the way it is running you set the zero point on the ATC. The system will now remember this attitude and work to adjust the Trim Tabs when the boat lists to one side from weight shifts or wind, or changes fore and aft attitude due to weight shifts or changes in speed.

Since the ATC has that slightly bow up attitude in its memory when the boat is off plane it will try to raise the Trim Tabs because it senses the boat is now in a bow down attitude. So this will happen if you engage the system while idling out of your harbor before getting on plane.

Normally we suggest that the ATC be engaged after you have throttled up and are on plane, much the same way you turn on your cruise control in your car once you are at highway speed.

However in some boats it seems to work fine if you engage it before you get on plane (you may get the flashing up arrows as mentioned above until the boat is on plane).

Personally I like to deflect the Trim Tabs a bit manually before I throttle up to help the boat come on plane faster and lessen bow rise (I can see where I am going!) as the boat climbs on plane. Then as the boat approaches cruising speed I engage the ATC.

Just like using the Trim Tabs manually, using the ATC can be a bit different for a specific boat and owner, and a little experimentation (trial and error) goes a long way.

Tom
Bennett Marine​

 

[Tabman]

Yup, what that Tabman guy said

 

[Jimmy Buoy]

Anything wrong with just leaving them engaged through out the trip??

Thanks Jimmy...

Leaving the ATC on will confuse the unit when you come off plane. Remember, you have set the zero point while cruising (usually with a significant bow-up attitude). Once off plane, the bow comes back down and the boat is relatively level. The ATC will try and get the attitude back to bow-up by retracting the tabs. This of course will not cause the bow to rise at non planing speeds. Once the tabs are fully retracted and the boat attitude is still not able to get to zero point, the system if I recall will start flashing all 4 arrows indicating an error. It may also stop running the trim tab motor further to avoid damage to the tab pump motor too.

I'm not sure if the system starts again once you change the attitude (eg getting back on plane which creates a bow too high attitude) or not. :huh:

It's just easier for me to remember to zero out the tabs manually as I come off plane, deploy them manually before resuming on plane, then retract them a bit before I get bow steer at plane speed. This is the point where I re-engage the ATC which then makes any fine adjustments to get the running attutude dialed in perfectly!:grin:

Tabman may be able to shed more light on any issues with leaving the unit on throughout multiple transitions.

 

[billnpat]

Thanks jimmy
makes sense,
What i will do from now on is drop my tabs slightly to get up on plane, once there i will engage the auto tabs,
when coming off plane, shut off bennett, till i go back on plane again.
sound right???