Trim tabs for Merry Fisher 795

[paulmcc]

I am looking at putting trim tabs on my 795, for both lateral control and getting the nose down into a head sea. 
Does anyone have experience with this or on similar models such as 695 or 755/855.
Looking at Bennett, Lenco or Volvo.
Thanks, 
Paul 

[paulmcc]

Anyone had experience with the Volvo QL tabs on this style of boat??

[Capt’n Ron]

Hey Paul, any luck on the trim tabs?  I've put about 20 hours on the boat an although not terribly bad, the port side does have a bit of dip which I believe is from prop torque and even more so when I had 5 people aboard so I'm thinking of adding tabs as well. 

Cheers,
Ron

[tomati]

In my opinion the trim tabs are a must have. almost mandatory. I have a marlin 755 and the boat suffers a lot with the movement of the crew. It was solved with the installation of a lenco trim tabs.

[hoppy]

Have you guys see this www.zipwake.com/

It looks like a pretty impressive product.

[paulmcc]

Jul 18, 2016 22:07:17 GMT Capt’n Ron said:

Hey Paul, any luck on the trim tabs?  I've put about 20 hours on the boat an although not terribly bad, the port side does have a bit of dip which I believe is from prop torque and even more so when I had 5 people aboard so I'm thinking of adding tabs as well. 

Cheers,
Ron

Thanks Ron,  thinking of Bennett Bolt electric or Lencos at the moment.  Gone off Volvo QL interceptors,  transom access is not great and they need a fair sized hole through it below the waterline.  Only reservation with electric is that I keep the boat on the water,  but lots of Lencos have been put on bigger boats and they seem to go alright.  I'm surprised they don't come as factory option for 795.  I know the 855 has Lencos as factory option. 
I have put a hydrofoil on the outboard and that helps keep the nose down in the chop pretty well, but doesn't help side to side lean.  Inefficient to use prop this way too, a lot of thrust directed downwards to lift transom. 
Hope you're enjoying the boat.  I've got 200hrs on now and am very happy with it, great boat.  A few teething problems but the basics are sound. 
Cheers, 
Paul

[paulmcc]

Aug 7, 2016 21:54:32 GMT tomati said:

In my opinion the trim tabs are a must have. almost mandatory. I have a marlin 755 and the boat suffers a lot with the movement of the crew. It was solved with the installation of a lenco trim tabs.

Thanks Tomati.  Happy with result?   Do you keep boat on water or dry? 

[tomati]

Hi Paul,

Yes very happy, sudenly the boat became more..... confortable.

I keep the boat on the water.

regards

[paulmcc]

Thanks Tomati that's encouraging.  I think I'll go with either Lenco or Bennett Bolt electric.  Haven't heard of anyone putting the Volvo QLs on these boats yet. 

[Capt’n Ron]

I've been emailing with the Bennett folks, which have been very responsive to my questions and it looks like the Bolt 12x12 tabs with the new AutoTrim Pro controller (not available till January 2017) is the way to go. The main reason the Electric over the Hydraulic has to do with limited access on the MF795 inside transom wall.  The Hydraulic requires a connector installed right at the inside transom wall whereas the electric has a 6' wire that I can feed through and snatch up.  This will be my winter project.

Here is the information Bennett supplied via email:

"Our Electro-Hydraulic has proven itself to be the MOST reliable trim tab system on the market today, since we have been manufacturing our hydraulic system since 1972 (Bennett Marine was the first to introduce trim tabs to the marine industry in 1960 and it was an electro-mechanical type from the start, which we still get phone calls & emails on from time to time). Our current style V-351 Hydraulic Power Unit 12 Volt (V351HPU1) has been in production since 1974 with very few modifications over the years, so we manufactured a Pre-1974 Hydraulic Power Unit from 1972 to 1974 (still get some phone calls and emails on this one too). Our current Standard Classic Hydraulic Actuator (A1101A) has been in production since 1972 with only one (1) modification in 1978 that increased the diameter of the Piston Shaft from ¾” to 7/8”, which was to improve the overall robustness of the Actuators and to provide room inside of the Piston for our trim tab indication systems. The hydraulic system also provides us with quite a bit of flexibility concerning mounting limitations, since we can modify the actuators in overall length and stroke to fit different/specific applications. These capabilities allow us to install hydraulic trim tabs in locations and positions that other trim tab companies would not be able to do so.

Our Electro-Mechanical (BOLT 12-Volt [BEA2000] Electric Actuator Fixed Upper Hinge) system is fairly new to the trim tab market (released end of 2014), but has been well received by the OEM’s and End-users for its ease of installation (electrical connections only, no hydraulic connections) and the instant gratification you can only get using electric components (press a button or pull a trigger and it works). We incorporated the Flat Neck design from our Hydraulic Actuators into the BOLT Electric Actuator, since it has worked so well over the years without any issues and it eases (reduces installation time) the installation too. Of course, we also designed the BOLT 12-Volt (BEA3000) Electric Actuator (Adjustable Upper Hinge) for those special configuration installations that require the Upper Hinge to pivot, which was released in late 2015.

Trim tab deployment/movement speed has been discussed over the years, but truthfully speed of movement doesn’t quite cover the issue. Please understand that our hydraulic and electric actuators STROKE speed is pretty much the same, so if you are moving only ONE (1) tab you should be able stroke 2-1/2” in four (4) to five (5) seconds (deployment and retraction will be close to the same time frame). Now, if you are moving BOTH trim tabs at the same time, then the hydraulic is going to take eight (8) to ten (10) seconds vs. the electric, which will still be the same four (4) to five (5) seconds. The reason for the difference in speed of movement with the hydraulic system is you are using the same SINGLE Hydraulic Power Unit to FILL TWO (2) hydraulic actuators vs. one. The electric actuators have their OWN motor per tab, so their movement speed doesn’t change regardless if you are operating one or both at the same time. Another issue concerning speed that isn’t covered has to do with STROKE LENGTH, which as stated above is 2-1/2” (the standard). Some of our competition stroke length is only 2-1/4”, so you will not get the same amount of deployment from the unit which should be somewhere between 20 to 25 degrees of deflection (more than that and you have a brake vs. a tab).

As to which type is the best choice for your installation, then we would suggest the BOLT1212 & the BCI8000 since our hydraulic system require attaching the hydraulic lines directly to the backside of the actuators using Pipe Nipples and Elbow fittings."

We look forward to your reply.

Regards,
M.J. Thomas
Client Services

[paulmcc]

Hi Ron.  Wondering how you're getting on with the Bennett Bolt tabs?   They look the goods.  Is your boat moored?   My only hesitation is that Bennett themselves are still recommending hydraulic for moored boats.   I imagine this may change in time but at present they're still telling me that.   Plenty of other examples of immersed electric motors so not sure how much of an issue it is.   Any thoughts? 

[Capt’n Ron]

Hi Paul, I'm still waiting for the tabs to ship. There is a delay from Bennett until next week on the Autotrim Pro controller. I trailer my boat and keep it stowed at my house, so I shouldn't have issues with the electric actuators in the water all the time. No real clear answers though if you keep it in the water. You might be able to modify the hydrolic actuator hose so you don't have to secure it at the inside transom wall, but I would probably take a chance on the electric, knowing I might have to replace an actuator sooner than if it were moored on a trailer. 

Ill let let you know how the install goes and performance once I get it on the water. 

Ron

[paulmcc]

Thanks Ron for your feedback.  I've bitten the bullet and ordered some Bennett Bolt 12x12.  I had a further discussion with Bennett who suggested that the advice re. hydraulic for moored boats is already changing so that was good enough for me.  The MF 895 has Lenco electric from factory. As you know transom access is difficult on the 795, so wires are a lot easier.  The Autotrim Pro won't get out here to Australia until mid-year so I've gone for the EIC switch. All arrived promptly from dealer, plan to put them on next week. Already a nice 1" hole drilled in dash for Fusion USB (which I never use) so that's one less job.  Install looks pretty straightforward but I'll let you know how it goes.  Hope yours all arrives soon.  Great boat, 300hrs now.

[Capt’n Ron]

Just got word Bennett has still not shipped the Autotrim Pro to the dealers yet and expect another week or two. I'll be interested in how your install goes. I'm also planning to put my controller where the fusion USB port is currently on the right side of the dash just above the thruster.  Good luck on the install. 

On another topic, I just ordered a wireless shut off teather MOB+. I do a lot of fishing by myself and often think if I went overboard I would watch the boat troll away.  This device will kill the motors (my main and I have a trolling kicker) if I hit the water or get beyond 50 ft of the boat. The waters can change fast in the puget sound and it's pretty cold. 

Also, looking at your boat it looks like you have a cover on the back deck. Did you get that from Jeanneau?

[paulmcc]

Ron,
Yes the rear canopy is from Jeanneau.  I have fitted solar panels onto it as well  (see new profile picture) It still folds away when not needed.
Wireless MOB sounds interesting.  I too don't like the idea of treading water while Elsel disappears over the horizon!  Will have a look into it.
Will keep you posted re Bolt install.  After that I might just post on the other 795 thread and let the trim-tabs one wind up.  There are not a lot of these boats out here so its great to hear of other peoples experiences.
Paul

[paulmcc]

Ron,
Tabs are on.  Bennett Bolt 12x12.  Install went surprisingly smoothly, transom access was not such a problem, it was easy enough to feed the wires through.  Drilled 1" hole in port wall of lazarette to bring port wire though.  Stbd wire came though with the sonar transducer.   Needed to flatten transom first, shipwright made a fibreglass mould.  Helm switch fitted into USB port (with a little encouragement!) and I put the control box under the sink.  Boat is still out of water so haven't tried it all yet.  Everything certainly fits well though, the upper actuator hinge lands very neatly between scupper hole and towing ring.
Can't post photos on this forum but if you give me an email address I'd be happy to send some through.
All in all, easier than I thought.  Now we'll see how they work!
Regards,
Paul

[MalcolmP]

Feb 16, 2017 9:53:34 GMT paulmcc said:

Can't post photos on this forum but if you give me an email address I'd be happy to send some through.

Hi Paul you can if you upload them to an external host eg imgur.com/uploadno need to register. more info at:

jeanneau.proboards.com/thread/8029/revised-guidance-photo-uploads-forum

all else fails you can email me the images [e-mail] and I will add them to the thread.

[Capt’n Ron]

Paul, that's great to hear, and congrats! I just got confirmation my tabs shipped with the Autotrim Pro controller, so I should get them installed within the next couple of weeks. I know Malcolm is working with you to get the images uploaded, but if you could send them to my email I would appreciate it. All in all, how long did the job take?

Thanks,
Ron
[e-mail]

[davemf795]

Feb 16, 2017 9:53:34 GMT paulmcc said:

Ron,
Tabs are on.  Bennett Bolt 12x12.  Install went surprisingly smoothly, transom access was not such a problem, it was easy enough to feed the wires through.  Drilled 1" hole in port wall of lazarette to bring port wire though.  Stbd wire came though with the sonar transducer.   Needed to flatten transom first, shipwright made a fibreglass mould.  Helm switch fitted into USB port (with a little encouragement!) and I put the control box under the sink.  Boat is still out of water so haven't tried it all yet.  Everything certainly fits well though, the upper actuator hinge lands very neatly between scupper hole and towing ring.
Can't post photos on this forum but if you give me an email address I'd be happy to send some through.
All in all, easier than I thought.  Now we'll see how they work!
Regards,
Paul

Hi Paul
I've just ordered a MF795 in Perth, arrives mid 2017, and will most likely install trim tabs. I had narrowed it down to the Bennett Bolt 1212's too, and then found this forum - I'd be keen to see your pics of the install, if its not too much trouble. Also keen to see the solar panel pics and set up you've got - apologies, I'm a novice on this forum and can't seem to find the pic you refer to in your post.
Thanks
Dave

[davemf795]

Probably need my email address eh...
[e-mail]
Cheers!

[paulmcc]

No worries can do.   The tabs are working well.  I just use the engine trim now to keep prop aligned at best angle and not to lift to stern.  Install was not difficult but transom is curved and needs flattening.   My shipwright did a permanent f'glass form shaped to the transom.   The rest was pretty straightforward.  Will get some photos to you asap.
Paul

[Capt’n Ron]

Paul's turned out pretty good. I've been waiting to get my boat back from the dealer so I can install mine, which should be this week. I had asked around about options to flatten the transom, other than what Paul had done, and was told to use Staboard and shape it to the transom, so I picked up a small sheet (12"x27") and cut it to the size of the tab mount. I used my workbench belt sander to shape the curve and it looks pretty good. I'll let you know how the install goes, hopefully next weekend. I contacted Bennett and they recommended using washers to shim each side, but I think the Starboard will be a better option. 

Cheers,
Ron

[wndsnd]

Hi Guys,


I would be interested in seeing pictures of these and possible install as well. If someone could post a link I would appreciate it.

 I hope they work as planned and are durable for you.


JB

[Capt’n Ron]

I installed my Bennett Bolt Electric 12x12 trim tabs and AutoTrim Pro controller on my 795 this last weekend. 

Lessons Learned:

• Highly recommend having two people for this job.
• Flattening the Transom for the trim bracket - The transom has a slight curve so when you mount the trim brackets you end up with about 1/16th to 1/8th tapered gap at each end of the bracket.  I purchased 12'x27' starboard and cut two pieces for each bracket. I used a workbench belt sander with 80 grit paper to taper the starboard to a thin layer in the middle out to 1/4" at the ends.  They matched up great on the transom providing a flat surface for the metal trim bracket. 
• Attaching the actuators - This one is pretty straight forward, but I would recommend drilling the top actuator  9/16" hole for the wires first (after you attached the bottom plates) so you can push the mount flat to the transom and then drill the screw holes.
• Routing the wires - this was a bit challenging on the Port side.  It was pretty easy to grab the wires through the transom through the access hole at the back of the boat on the Port side.  I used a fishing tape (wire puller) to feed the stiff fishing cable from the access hole up along the inside shell of the port rail (this was tricky) up to the length where the battery storage area.  I had a 2" hole cut in the port facing wall where I was able to grab the fishing cable and attached the actuator extension cables and pulled it back through to the transom to connect to the cable from the actuator.  I ran that cable across the back side of the battery compartment to the Starboard side where I ran it through a boot to under the sink and to the fuse panel. (note: I had an additional fuse panel mounted next to the fuse panel that came from the factory.  I highly recommend doing this for adding additional electronics.)  The starboard side actuator cable was much easier to pull through and up to the fuse panel.
• AutoTrim Pro controller installation - I mounted the controller flat side down just inside the fuse panel area, then ran the power cables to the fuse box.  Note: The installation manual calls for a 20amp fuse for the controller power wire, but when I took it out for sea trial I kept blowing the fuse while the tabs were under heavy water load.  I worked with the Bennett technical staff and they said the actuators were drawling a higher amp under load, so they were going to send me replacement actuators to put on. This made may jaw drop because the actuators are sealed onto the boat with 3M 5200 Sealant so I was concerned I'd have to rip them off the transom, thus damaging the gel coat.  Instead I put a 25amp fuse in and everything is working as it should now.  After talking to Bennett they said their engineering team spoke and said they are changing the specs to use a 30amp fuse, which should resolve the issue.
• AutoTrim Pro rocker controller. - I chose to mount this just to the right of the Fusion USB port and the bow thruster control.  I was a bit nervous drilling a hole in the dash for the controller with concern of the hole saw teeth grabbing and cracking the black hard coating of the dash.  NOTE: I had a friend who told me to start the guiding drill bit hole of the hole saw, but then put the drill in reverse and cut the hole in reverse.  I thought that was crazy, but I tested it on the Starboard then tried it on the dash.  It was as smooth as butter with a very clean hole, in fact better than some of the holes Jeanneau drilled at the factory.  The rocker switch looks great and is in the perfect position for adjusting the tabs while under way. The manual says to connect the red power cable to the helm power, but I ran the power and the ground wire to the fuse box with a 20 amp fuse, and would recommend this approach.
• Connecting the rocker controller to the ignition wire - This is recommended in the manual so whenever you turn the ignition off it will retract the tabs to full up position.  I traced the yellow ignition wire from the ignition switch to the Yamaha gages and spliced into that wire with the purple wire from the controller.  This worked great and the tabs retract as expected    
• Setting up the AutoTrim functions. - The instructions that came with the controller for calibrating the angles and pitch had left out a few steps to get it working.  The quick guide on the Bennett site has the updated install procedures.
• Last note on the installation.  Do your planning in advance and have everything laid out and organized on a table.  It will take anywhere from 4 to 8 hours for two people depending on your cautious or aggressive approach.  The guy that helped me was an ex-Boeing Airplane Quality Control specialist, so we took our time and double and triple checked angles and clean up of the wires.

Performance of the tabs and auto controller:  I couldn't be more happy with the performance improvements with the tabs, although keeping in mind I've only done a short sea trial at this point.  I noticed a smoother ride in rough water, a leveled ride, and a decrease in fuel consumption of 2GPH at 20 MPH.  The auto controller is really amazing. The tabs auto deploy on hole shots and level out to the favorite setting (there are two FAV1 and FAV2) when on plane at any speed above 15 MPH (the boat doesn't usually plane at that speed).  When there is passenger movement on the boat the tabs auto adjust to level planing angle and when settled back to no wake speed the tabs auto retract.

I hope you find this post useful for those who venture to install trim tabs.  The 795 definitely benefits from trim tabs

Captain Ron

 

[wndsnd]

Great write up Ron with some very good suggestions.  I have never heard of using the hole saw in reverse on fiberglass but it makes perfect sense.

Sounds like a nice clean installation.  Thank you for taking the time to detail it for us.

JB