Electro-Mechanical Trim Indicators

[tpenfield]

Top quality work. Watching for the next update.

Thanks for your kind words . . . I am looking forward to putting this 'new' system to work. It has been a couple of years in the making with various ideas that have been considered.

I am thinking that I may leave the electronics as is, and change the face of the gauge to include a "yellow range" in the 3rd quater of its movement . . . so 2 green ranges (trim range) and 1 yellow range (nearing the end of the trim range) . . . and then 1 red range (which would be the tilt/trailer range).
Not sure if I will do that, kind of depends how things go based on real life usage this season.

 

[64osby]

Couldn't you install an adjustment between the cylinder and LU mount to work the gauge readings in your favor.

 

[tpenfield]

Couldn't you install an adjustment between the cylinder and LU mount to work the gauge readings in your favor.

No, the mechanical part is pretty much an exact match to the trim cylinder, so the adjustment would need to be in the electronics. I designed in a 'trim potentiometer' into the square white 'modules' that I installed up at the gauges, but I could not get much adjustment out of them when I tried. Maybe 1/8 of the gauge movement, where I really needed almost 3/8 . . .

So, I missed on the electrical circuit calculations somewhere, just need to figure it out.

 

[dozerII]

Very cool project, nice job on the design and fabrication.:thumb:

 

[tpenfield]

Very cool project, nice job on the design and fabrication.:thumb:

Thanks for you compliments. I had a mechanical indicator on my last boat and sort of got used to it. I wanted to have them on this boat, but wanted to do better in terms of tracking the outdrive through the full range of travel and not have the extra gauges at the helm. Also the actuator on my previous boat would often get 'stuck' in the down position rendering it useless until I could fix it.

I've been conferring with another forum member along the way about the design. It started out as a purely mechanical system in concept, but then I came up with the combo of electrical and mechanical.

I just realized that I cannot seem to find my notes from the circuit design, so I cannot remember what values I used for resistors, etc. so that I can make some adjustments to the design. :facepalm:

 

[tpenfield]

UPDATE:

I launched the boat for the season today an got a chance to use the trim indicators for real. . . TOTALLY AWESOME . . . I can get both drives set at the exact same trim and can see the smallest adjustment of trim on the gauge. . . no more 'guessing' where the outdrives are.

I tried trimming up and went from a mid-range setting to a trim near the limit and the boat slowed down about 1/2 mph . . . so I was able to trim back to the initial setting (per the gauges) and the boat speed went back up. I could never do that before; at least not easily.

So, I am looking forward to this season's boating with these more accurate trim indicators. :thumb:

 

[alldodge]

Sure great to hear all your work paid off and now its time to enjoy the season.

Hope I make it sometime this season

 

[tpenfield]

A quick update:

I have used the boat about 5-6 times this year and the trim indicators are really helping out. No more guessing due to inaccurate readings, etc.

One thing I have noticed, which seems to be counter intiutive, is that the boat likes to be trimmed IN a bit more, rather than OUT. If I start out trimmed down a bit (call it 30% trim), get the boat up to criusing speed ( 34 mph 3000 RPM for example) and then trim out a bit (maybe up to 60% trim), the boat slows down by about 3 mph. (I call 100% being at the trim stop, which is 2.75" of trim ram extension of the total 8" that they extend).

Then if I trim back down (IN) the boat speeds back up again. These movements are only about 3/4" of travel on the trim rams, so it kind of shows how sensitive the trim angle is.

Based on my new trim indicator system, the boat seems to like the trim in the 30-50% range. I did try doing a hole shot with the trim at the 60-70% range, and the props ventilated.

My only problem with the system is that the tilt range (being only the last 1/4 of the gauge movement) is tougher to judge. My mooring location is pretty shallow at low tide (about 30" deep) so I tilt the outdrives up. . . but I do not like to tilt them full up. So, it is a bit tough to get them more exact in the TILT range. I have a re-design of the electronics module in the works, which should make the TRIM and TILT ranges more evenly distributed over the gauge needle's movement range. Probably later this summer, I'll swap the electronic module out, if I get them made soon enough.

 

[tpenfield]

Mid-season Update:

I have been using the electro-mechanical indicators for a month or so now and have found the trim range where the outdrives like to be, based on various sea and loading conditions. Essentially, it is the middle 1/3 of the trim range, as pictured below and indicated by the arrows:



The full trim limit is actually 3/4 of the gauge movement as shown by the 2 green ranges and the yellow range on the gauge. (that's just how the electrical part of the system worked out, and I am still trying to decide if I like it that way . . . ) The tilt range is the red area.

So, for travelling into the chop, I tend to trim down just a pinch from the dial reading shown to stick the bow into the waves. When running with the chop, I tried trimming up a bit from where the dial is (so top of the green range), but the props wanted to ventilate a bit on the down side of the wave, since the boat was slightly nose down at that point. So, I usually have to bring the outdrives down a pinch to the middle of the second green, as shown in the picture.

In flat sea conditions, if I trim up closer to the trim limit (yellow range on the dial) the boat slows down a couple of mph. And if I trim way down it puts the bow down too much. Top of the green range is about right for flat sea conditions.

Overall . . . So, far so, good, because I can get he trim dialed in really quickly and it is very consistent. The interesting thing is that the trim cylinder movement for these adjustments is only +/- 0.5" (half an inch) . The standard trim senders would barely pick up that small amount of movement, since they have a few degrees of play in them, which equates to about 0.5" of trim cylinder movement. This system seems to be sensitive to the slightest movement of the trim cylinders, which is great.

I think I am liking the way the system is set up now with the tilt range being 3/4 of the gauge movement (2 greens + the yellow range), as it is more sensitive to small adjustments of the outdrive. The tilt range being only 1/4 of the gauge movement is not all that important.

 

[roadslug]

Nice work! I have a 330 as well and crap merc gauges. If I wanted to recreate this, what do I need?

 

[64osby]

Nice update TP. Looks great and it sounds like you have worked most of the kinks out of the system.

So when are you going to market?

 

[tpenfield]

Nice work! I have a 330 as well and crap merc gauges. If I wanted to recreate this, what do I need?

Thank you for the compliment. An engineering background in both mechanical and electrical would be good.

Nice update TP. Looks great and it sounds like you have worked most of the kinks out of the system.

So when are you going to market?

I should go to market . . . looks like roadslug, based on his post above, could be one of my first customers

It is interesting though, now that I can trim with such accuracy and repeatability, I am discovering how sensitive the boat performance is to slight adjustments in trim. My 330 seems to like to be trimmed down a bit at RPM's under 3K (if I trim up much the boat slows down about 1-2 mph). . . at higher RPM's it seems to be OK with trimming up a bit.

 

[Fed]

Now all you need is a level meter to see what the hull's attitude is, Mercury suggest 3-5 degrees is best.
Something out of a 4WD calibrated to the keel?

 

[tpenfield]

Now all you need is a level meter to see what the hull's attitude is, Mercury suggest 3-5 degrees is best.
Something out of a 4WD calibrated to the keel?

That is an interesting concept and would probably be useful in calm waters. I find that with ocean and bay travel, the attitude of the boat is always changing on a second by second basis as it goes through the seas, yet you wouldn't/couldn't change the trim angle that quickly. So, you sort of find a trim position that works best and go with it.

 

[roadslug]

Actually I do have an engineering background. Just need to know some of the part numbers so I can put it together.

Is the factory sensor 0-5v or just a resistor?

 

[tpenfield]

It is all scratch built, no component assemblies purchased. I'll send you a PM.

 

[Mischief Managed]

Now all you need is a level meter to see what the hull's attitude is, Mercury suggest 3-5 degrees is best.
Something out of a 4WD calibrated to the keel?

I trim my boat based on MPG. I tweak the trim until my MPG maxes out for given speed.

 

[tpenfield]

I trim my boat based on MPG. I tweak the trim until my MPG maxes out for given speed.

I think I got to get me one of those fuel flow meters . . . is Floscan what you use? I have been getting some ridiculously low fuel usage numbers over the course of the season, but I am not sure if the fuel usage is better than expected during cruising, or if it is just that I idle around the harbor more than most folks.

On calm/flat ocean days, I can trim by boat speed . . . it tends to vary about 1 mph going in and out of optimum trim. We only get those kinds of days a couple of times a year. Otherwise, I just rely on what the gauges are telling me (now that they are very accurate) and if I am getting any ventilation with the props.

 

[Mischief Managed]

I have a Lowrance LMF-200 with a fuel flow probe and speed sensor. It reads MPG real-time and the fuel flow function is very accurate.

 

[tpenfield]

UPDATE:

I have been using the trim indicators for a couple of years and have made a few design improvements, yet to be tested. Overall, they work great as is.

I have decided to file for a Utility Patent on the system. It probably will take about 1 year to get one, if it gets granted, etc. We shall see how it goes. :noidea: