20V drill to hoist dinghy?

[mvweebles]

I'm installing a pipe davit to hoist my dinghy onto boat deck of my trawler (see Pic below of something similar). Typically, an electric winch is wired to provide the muscle - similar to what is used on boat trailers. These tend to rust out after a few years, and getting adequate power to them is a challenge. My dink is similar to what many cruisers carry - 11-foot RIB with 15hp outboard. Probably 250-300 lbs.

Was thinking a simpler and more reliable choice might be a self tailing winch and use a DeWalt 20v cordless drill since I have one aboard.

Thoughts?

[joelhemington]

Sounds like a good plan. If the Dewalt isn't powerfull enough for you, then the Milwaukee 28v lithium rigth angle drill would do it - a lot of older guys use these to raise the main sail. Cheaper than an electric windlass and a right angle drill can be very handy sometimes in tight spaces.

[mvweebles]

I'm really interested to see if the newer 20v LiOn drills are strong enough - I'm looking at an Anderson 12ST which gives a 10:1 mechanical advantage. Compared to my old Milwaukee 18v NiCad, newer Dewalt is a powerhouse. I'm pretty sure it will be plenty, but won't know for a few months. Will probably need a right angle drill.

[Topspin]

Did you consider a pulley system at your davits? Will do it without electrical gear.....


-Richard

[darylat8750]

I have a similar dinghy and use a pulley system and davits. Two disadvantages are that the lines tend to get twisted and require occasional untwisting because with enough mechanical advantage you wind up with a lot of line to keep neat. The other is that it still takes enough effort that my wife has a very difficult time dealing with it by herself. I would be very interested to see set ups that use a drill .....

[cat34shamrock]

When using a drill to drive a winch there is a problem with RPMs, the drill doesn't get up to speed and doesn't cool well running at high loads and low RPMs. You won't know if you have a problem till you try it, I only wanted you to be aware and not damage your drill.

[roverhi]

18v-20v are pretty much the same power, it's the battery capacity that will make the difference if it takes a long run time to hoist the dinghy. Assume Dewalt has different battery capacities as Milwaukee does other than the minimal 2,000mAh battery the drills ship with up to 9,000mAh. Continuous use of these battery powered tools eats up battery charges quickly.

[CassidyNZ]

What a timely discussion for me.

I’m busy designing davits for my boat (not a single arm hoist like the OP proposes) and have same concerns that a multi-run pulley system leaves a lot of rope on the deck. So I’m looking at small hand winches (found on fizz boat trailers) and mechanising one with a reversible 12v electric motor.

I have found that window winder motors (fully reversible) from luxury cars with heavy windows are surprisingly powerful and when geared at 10:1 can pull a substantial load. I’m presently busy with such a motor from an E38 BMW 750iL which came standard with double glazed door glass (heavier than normal). The motor is small but seems really strong.

But it will be a while before I can engineer it onto a suitable winch - too many other projects running right now When I get around to it, I’ll be back.

[captlloyd]

Not scientific at all but I have seen guys going down a street on bicycles powered by battery powered drills. They have a lot of power and Harbor Freight has a lot of high powered battery tools with reasonably priced batteries. With the right reduction should work great.

[Dave22q]

Seems to me that a cheap mechanical winch similar to what you find on many boat trailers would do the job

[Billnpr]

I use a Milawukee 1/2 inch drill which I bought on clearance at Home Depot to raise the mast on my Macgregor 26S. I use a 4 to 1 block and tackle from the bow to the top of the jen pole which has the furler attached. So I am raising the mast and furler as one, I bring the pull line back to the cabin top single speed wench. I have to assist the drill with some pull on the line after it leaves the wench Raising the mast is alot easier with the drill assist thancranking it up by hand..

[EqPierre]

The winch-bit idea has been commercialized long time, even seen one on BOOT-2020 in Dusseldorf last week, a few stands away from the E-Winch

[a64pilot]

I’ve been hoisting my dinghy with my Milwaukee for years using my sheet winches, however I have a 4 to 1 one on the light end and a 5 to 1 on the stern, that way the Milwaukee doesn’t work hard at all, and you can run it at high speed to cool it and the dinghy is lifted at a safe speed, without the pulley system the drill would be working hard and the dinghy would come up too fast, and if the drill broke or fell overboard, you’d never get the thing up by hand if you had to for whatever reason.
Ref line twisting, yes it will if you flake the lines, do not flake them and they won’t twist up. You’ll just have your lines form a figure 8 as opposed to an O.
This is true for any lines that run through multiple blocks, when flaking the line you put a half twist in the line at each fold, this twist is what causes the problem.

[wrwakefield]

Originally Posted by CassidyNZ

What a timely discussion for me.

I’m busy designing davits for my boat (not a single arm hoist like the OP proposes) and have same concerns that a multi-run pulley system leaves a lot of rope on the deck. So I’m looking at small hand winches (found on fizz boat trailers) and mechanising one with a reversible 12v electric motor.

I have found that window winder motors (fully reversible) from luxury cars with heavy windows are surprisingly powerful and when geared at 10:1 can pull a substantial load. I’m presently busy with such a motor from an E38 BMW 750iL which came standard with double glazed door glass (heavier than normal). The motor is small but seems really strong.

But it will be a while before I can engineer it onto a suitable winch - too many other projects running right now When I get around to it, I’ll be back.

Similar to what you describe, I used a 12V DC winch for an ATV on our davit set-up. It works well now for 3 years and counting [full time cruisers...] [10ft RIB w/ 6 gallon fuel tank and 15HP 2 stroke engine; ~275lbs?]

If interested, there are more details on our blog post about that project.

Regarding other questions about hoisting the dinghy with a drill motor, I haven't tried our DeWalt 20V motor, but can testify the Milwaukee 28V doesn't even breathe hard when we used to manually winch it up...

In case any of this is useful.

Cheers! Bill

[aclmck]

Originally Posted by mvweebles

I'm installing a pipe davit to hoist my dinghy onto boat deck of my trawler (see Pic below of something similar). Typically, an electric winch is wired to provide the muscle - similar to what is used on boat trailers. These tend to rust out after a few years, and getting adequate power to them is a challenge. My dink is similar to what many cruisers carry - 11-foot RIB with 15hp outboard. Probably 250-300 lbs.

Was thinking a simpler and more reliable choice might be a self tailing winch and use a DeWalt 20v cordless drill since I have one aboard.

Thoughts?
Attachment 207861

Try using a 20 volt rattle gun instead of a drill it’s designed to take off nuts so it has the torque needed . Personally I’d use a 12 volt rattle gun with a long cord/ lead to a battery (there area lot now made that plug into a car lighter socket and have the the power to remove car wheel nutsso this should do the job easily)

Like others have said though have you explored the use of small blocks to see how easy/difficult it might be by hand?and then a hand winch similar to a boat trailer