Need ideas on electrifying davits

[jimbunyard]

Kiss--no wires, batteries or reduction blocks...

[txg]

Don't overcomplicate things. Either get better line and blocks or a lighter dinghy. Our 8ft aluminium rib with 10hp tohatsu is 70kg including a full tank which is about half the weight of yours.

[Bruce K]

I installed a pot hauler capstan (12V) and a turning block near one arm of my davits; have a 6:1 on outboard end and 4:1 on bow of dinghy (11' alu V nose punt with 15 4st Suzi) I can lift dinghy without pot hauler, if necessary. Usual practice is to pull bow by hand,(easy) and winch stern, (even easier)

[Scotty Kiwi]

Sheet winches - but had five, so for the dink it be the one at the center back of the cockpit. Just needed four more blocks to run the dink lines. 18 Hp Tohatsu, 2.8 meter Aquapro. 15 years, no prob, just one service for all winches.

[sailormed]

On your picture it doesn’t look like you have a good installation for a 6 to 1 purchase. Following the KISS principle zi would start with a complete redo of the installation, new lines, check blocks etc.

[Hesti]

May I guess that not all of your sheaves on the tackle are running on ball or roller bearings? Upgrading all blocks and the two individual sheaves to racing gear with ball or roller bearings should make a difference already.

[Sailorman Ed]

wrwakefield- nice writeup and pic. I especially like how the opposing lines mostly cancel out the force on the mount.

[wrwakefield]

Originally Posted by Sailorman Ed

wrwakefield- nice writeup and pic. I especially like how the opposing lines mostly cancel out the force on the mount.

Thank you, Ed.

This approach does keep the tensile loads isolated to the extreme end of the davits— and athwartships; which has the added benefit of reducing operator risk if lines ever disconnected/released while under tension... [The winch operator stands on the aft deck using either a hard wired up-down momentary toggle switch, or a cabled remote— all positions out of harms way...]

I have added another photo [below] I took after my first response in this topic.

It provides a peek at the home made disk which divides the line spool in half. It also shows the lifting lines [orange Dynema] in a slackened state, with the load on the double-braid safety lines I described in my first response.

[Note to self:] This photo also reveals I am still using the 4 snatch blocks I originally installed during the proof-of-concept stage... That reminds me I need to reclaim them at some point- replacing them with dedicated single blocks.

This will require more steps than appear at first blush since I made permanent eyes with thimbles on each end of the lifting line [orange Dynema] where it attaches to the dinghy... [At least I planned for this (and other eventualities) by spooling as much extra Dynema on the winch as would fit before cutting to length... Hopefully that will be enough...]

Another task [when I re-run the lifting line] is installing a microswitch [low amperage disconnect for winch control relay... wiring already run...] This will serve to stop the winch automatically when the dinghy reaches maximum 'height'. Right now stopping the winch is incumbent on the operator... [A distraction could produce interesting results... Not unlike those which have occured with other electric winches...]

I will also install polyurethane rubber plug [snubber] directly behind the newly spliced thimbles to mitigate damage to the blocks should the line be reeled tightly against them...

[I add all the above because your kind response made me think of details others might find of interest... or not...]

Cheers! Bill

[Ostinato]

wrwakefield that’s very well presented. Until your detail I was having some trouble figuring out how a single winch would work. The comment on the blocks not being up to snuff is also well said. I can’t see how a hand crank system would work with my particular configuration.

I am a little worried about being totally dependent on electric winch even when carrying a backup. I suppose I could keep a six or four part system as part of the setup.or have one ready to clip on.

I was asked for an additional photo showing more of the bimini and arch and I have included one below. Thanks everyone.

[wrwakefield]

Originally Posted by Ostinato

wrwakefield that’s very well presented. Until your detail I was having some trouble figuring out how a single winch would work. The comment on the blocks not being up to snuff is also well said. I can’t see how a hand crank system would work with my particular configuration.

I am a little worried about being totally dependent on electric winch even when carrying a backup. I suppose I could keep a six or four part system as part of the setup.or have one ready to clip on.

I was asked for an additional photo showing more of the bimini and arch and I have included one below. Thanks everyone.

Thanks Ostinato. I'm glad some of it was useful.

RE: Back-up: I have 3 matching multi-part tackles with carabiners at each end that are not designated for any particular use. [e.g, MOB recovery, etc.] My plan is to use 2 of them [one per side] if/when the winch fails. And besides, that is what I had before installing the winch. We know how it works... [I also have a back-up winch in spares as well... Too cheap not to... (Both me and the winch...)] For perspective, my wire run cost more than the winch...

Another design detail I'm considering when I replace the snatch blocks I used for the initial setup is: instead of creating loops with thimbles in each end of the Dynema lift line [preventing it from being able to be removed through the non-snatch blocks] I may instead just make a soft eye [no thimble.] That way I can make two short pendants [one per side] with a thimble on one end and soft eye on the other. I would cow-hitch the pendant soft eye to the lift line soft eye to complete the assembly on each side. That would allow me to remove the thimbles [pendants] and pull the remaining soft eye through the blocks for maintenance, block replacement, winch removal, etc.

In addition, one could also use ratcheting blocks as an added safety against accidental dinghy launch...

Food for thought...

Cheers! Bill

[Simi 60]

Found this write up a while ago with a bit more detail



Lifting the dinghy with an electric hoist

[wrwakefield]

Originally Posted by Simi 60

Found this write up a while ago with a bit more detail



Lifting the dinghy with an electric hoist

Perfect! Thanks Simi! That should fill in the any missing details...

Cheers! Bill

[Dave_S]

Sorry didn't read all posts.

I have started doing a similar thing.

I want to be able to lift the tender by remote control while in the tender with all provisions.

Here's my plan...

• Remove the blocks, you need 1:1 ratio for this (if you have 6:1 and need to lift the tender 1.2m that's 7.2m of line you need to keep separated before the winch.
• Splice the two lines at a point so that only the single line feeds onto the winch when the tender is lifted to full height.
• Use an ATV winch rated to 50% greater than your expected maximum weight, get one with a remote control that controls feed in and out
• In my case I need an extra brace to support the increased weight from the lifting point to the rear transom.
• I also will have a support that will swing under the tender so the loads are spread in rough weather and so the tender is captive on passage

[srt]

I installed my electric winch and 2 lifting ropes without a dividing collar and have had no trouble with tangling. I was concerned initially that there might be an issue with tangling so used 2 different colour ropes to aid in potential untangling, but it has never been a problem, has never tangled, ropes happily lay on top of each other going in and feed out going out. I have used small diameter lightweight 2t breaking strain cord that does not take up much space on the winch. Another concern was how much current the 3000lb capacity winch might draw and what size cables would be required, but found that to lift my 70kg dinghy and motor only draws 10-13 amps, so cabling not to beefy.

[Dave_S]

Originally Posted by wrwakefield

Thank you, Ed.

This approach does keep the tensile loads isolated to the extreme end of the davits— and athwartships; which has the added benefit of reducing operator risk if lines ever disconnected/released while under tension... [The winch operator stands on the aft deck using either a hard wired up-down momentary toggle switch, or a cabled remote— all positions out of harms way...]

I have added another photo [below] I took after my first response in this topic.

It provides a peek at the home made disk which divides the line spool in half. It also shows the lifting lines [orange Dynema] in a slackened state, with the load on the double-braid safety lines I described in my first response.

[Note to self:] This photo also reveals I am still using the 4 snatch blocks I originally installed during the proof-of-concept stage... That reminds me I need to reclaim them at some point- replacing them with dedicated single blocks.

This will require more steps than appear at first blush since I made permanent eyes with thimbles on each end of the lifting line [orange Dynema] where it attaches to the dinghy... [At least I planned for this (and other eventualities) by spooling as much extra Dynema on the winch as would fit before cutting to length... Hopefully that will be enough...]

Another task [when I re-run the lifting line] is installing a microswitch [low amperage disconnect for winch control relay... wiring already run...] This will serve to stop the winch automatically when the dinghy reaches maximum 'height'. Right now stopping the winch is incumbent on the operator... [A distraction could produce interesting results... Not unlike those which have occured with other electric winches...]

I will also install polyurethane rubber plug [snubber] directly behind the newly spliced thimbles to mitigate damage to the blocks should the line be reeled tightly against them...

[I add all the above because your kind response made me think of details others might find of interest... or not...]

Cheers! Bill

This is neater than my plan, I had considered running both lines onto the winch (in the same direction with no divider) but thought the lines might not feed in evenly if one line wrapped on top of other line when the other didn't.

Have you experienced this ?