Large Centerboard Dilemma

[Cap Erict3]

Look at using proximity switches and LED's. Low power consumption, no moving parts, sealed against corrosion, simple, reliable and inexpensive.

[Formosa Scott]

Originally Posted by rrayfield

Anyone know how to hook that up to a 2 way momentary switch?

Take a look at wiring diagrams for bow thrusters. Here is the style contactor I have Amazon.com : Albright SW182 Style Reversing Contactor 36V : Sports & Outdoors You can get them for different voltage and amp ratings. Mine has a 4 wire motor and obviously a momentary 2 way switch.

[rrayfield]

Originally Posted by GILow

Now I have thought about it some more... I think there's a problem with my suggestion.

There's just going to be way too many revolutions of the spindle if it is driven by the sproket on the worm drive. It is going to haul in many meters of line, no matter how small the drum. So either you then have to add some small blocks to "gear down" the travel of the counter weight, or you are going to need the sight tube for the counter weight to be about 5 meters tall. (That's 15 feet for our non metric cousins.)

A block arrangement is just going to be a pain sooner or later..

So, after all that I am favouring the revolution counter suggest by Barnakiel, I'd prefer a mechanical one, to avoid the electronics problems. But, I am having problems finding one that rewinds. Plenty that reset, but that's just a pain, having to reset at the end of each action.

Hmmm... maybe an electronic counter after all, with a timer reset is not so silly. i.e. it always starts off at zero, you push the down button and it counts the revolutions till you know the board is fully down, you let go of the power button and the unit resets the counter to zero again, after say... 10 or 15 seconds. Then when you hit the up button, again you just watch the counter...?

Matt

ok, I get it and I also saw the problem with the mechanical counter reversing. I don't like the electric route either, so I am going to do it manually.

how about 2 spools and one continuous line that run up to the blocks system.. tube.. with a little yarn marker for up and down... Or something on the line to represent stop. you could add some sort of magnetic electric sensor to the string that would sound a buzzer momentarily?

the only problem with the mechanical counter is its location is going to have to be right on the sprocket or shaft I assume. I can't see that location from the helm. I did however think of mounting a camera watching it that I could plug into my mfd at the helm...

[Zach]

Where is the pivot shaft on the board and where does the cable come through?

Does the board trunk extend above the waterline such that maintenance can be done?

If it does... Add a tag line to the board. A lot less distance traveled to count. Run a turning block high enough to account for the drop, hang a weight or a few pieces of elastic shock cord to keep the rope from jamming up.

[rrayfield]

Originally Posted by Zach

Where is the pivot shaft on the board and where does the cable come through?

Does the board trunk extend above the waterline such that maintenance can be done?

If it does... Add a tag line to the board. A lot less distance traveled to count. Run a turning block high enough to account for the drop, hang a weight or a few pieces of elastic shock cord to keep the rope from jamming up.

The pivot is 3 feet below water line, the trunk is under water all the way up to the worm gear drive. the unit is sealed with gaskets and 50 plus bolts. accessing the cable from the top would be near impossible without major modifications to the worm drive.

if you did take it apart in the water, at some point the board would have to be extended down to take the pressure off the worm gear.

[jimbunyard]

Maybe my suggestion was unclear, so attached is a quick drawing;

1 5/8" bore sprocket 15.00
2 5/8" pillow blocks 20.00
1 5/8" SS threaded rod 10.00
1 5/8" SS nut 1.00
1 30' Morse cable 35.00
1 6x12x1/4" al plate 15.00
Assorted bolts 10.00

Total 106.00 plus your labor.

You'd have to take the amount of chain that passes to raise or lower the board into account to make sure the cable is not moved too much; travel could be adjusted by the size of the sprocket or the thread of the rod. The direction of indication can be changed by which side you anchor the cable on . The actuating stud is just a 1/4" x 1" bolt welded to the nut. If you're worried about the big nut rotating, a piece of uhmw cutting board can be mounted on the aluminum plate, just contacting a flat of the nut to keep it from turning.

There're lots of solutions for the indicator end too.

[rrayfield]

Originally Posted by jimbunyard

Maybe my suggestion was unclear, so attached is a quick drawing;

1 5/8" bore sprocket 15.00
2 5/8" pillow blocks 20.00
1 5/8" SS threaded rod 10.00
1 5/8" SS nut 1.00
1 30' Morse cable 35.00
1 6x12x1/4" al plate 15.00
Assorted bolts 10.00

Total 106.00 plus your labor.

You'd have to take the amount of chain that passes to raise or lower the board into account to make sure the cable is not moved too much; travel could be adjusted by the size of the sprocket or the thread of the rod. The direction of indication can be changed by which side you anchor the cable on . The actuating stud is just a 1/4" x 1" bolt welded to the nut. If you're worried about the big nut rotating, a piece of uhmw cutting board can be mounted on the aluminum plate, just contacting a flat of the nut to keep it from turning.

There're lots of solutions for the indicator end too.

WOW! Thanks for the illustration! yes I guess i did misunderstand you in your original post. This makes much more since now. And you are correct, I could do anything at the other end of the cable. Hell I could mount a fuel sending type gauge showing up or down for view at the helm.

That drawing was perfect! thanks. Im pretty sure this is the perfect mechanical solution keeping everything inside the boat...

Ryan

[rrayfield]

Originally Posted by rrayfield

WOW! Thanks for the illustration! yes I guess i did misunderstand you in your original post. This makes much more since now. And you are correct, I could do anything at the other end of the cable. Hell I could mount a fuel sending type gauge showing up or down for view at the helm.

That drawing was perfect! thanks. Im pretty sure this is the perfect mechanical solution keeping everything inside the boat...

Ryan

Just moving along with this new graphic information, I could have trim guage (like for an outboard motor) at the helm. And instead of the morse cable attached I could just use a trim sender like this Sierra Om Trim Sender 7634, Sierra Engine Parts

and a gauge like this

Faria Outboard Competition OMC Cobra Trim Gauge Part GP7307 | eBay

now granted that is mixing a bit of electronic and mechanical together, but I assume trim gauges are pretty reliable since it works similar to a fuel gauge (on resistance).

How about that? any other thoughts?

[jimbunyard]

You're welcome.

As long as the sender and gauge are compatible electrically, looks like they'll work fine, you might have to manipulate either the thread (fine or coarse) or the sprocket size to get the correct throw, same as using a cable. Though I do kinda like the idea of being able to tell where I'm at without juice.

The other thing I was thinking about was a spring loaded limit switch on each end of the nut's travel. That kills the down power when the board reaches all the way down, but leaves the up power on, until you raise the board all the way which then kills the up power. In between, you've both up and down. Probably save wear and tear on the drive system overall.

One other thing, in the sketch, it shows the sprocket as if it is heavily engaging the chain. It should be arranged so there is as little load as possible (without skipping) on the indicator drive sprocket.

Jim

[chris95040]

Another possibility, one that similarly uses an idler sprocket being spun by that chain, is to use the idler to drive a sequence of shafts with ever reducing gear ratios. The goal would be to have the whole range of motion at the input end to result in just a 1/4 or a 1/2 turn of the final output shaft. Stick an arrow on that pointing to calibrated "up" and "down" indicator locations and you're done.

All parts available on mcmaster-carr I'm sure. See attached photo. It'll convince you that Jim's idea is better.

[jimbunyard]

Ryan,

Thought about it some more in the bar last night, revised the idea a little to use your proposed lever action potentiometer. Additional drawing showing the back side is attached.

Should be pretty self-explanatory. The slot through which the fork protrudes also keeps the nut from turning. Drew it with 1/8" sheet just because; you may find it easier to get that than 1/4", although bending the stuff is a little difficult without a brake. Either will work fine.

The other advantage of using your proposed sender is that it makes the sprocket size or thread of the rod less important, because moving the sender vertically alters the length of throw.

Regards,
Jim