Open Source Anchor Project

[roland stockham]

An interesting anecdote for you. Many years ago when new to cruising I picked up a little 26ft folkboat. She was on legs on a beach and I have worked all my tide calculations so I would be there at high tide. strong SW wind blew past the creak and the tide never came! It was 1/2m low... So I ran all the cable out, 50m of 5/16 chain plus 50m 12mm line from the dingy and dropped the anchor. Went back to the boat and put set up a whip and tackle of about 8:1 on the 16:1 winches. I cranked it till the line was bar taught and playing about middle 'C' hoping to slide her down the beach (well I was new to sailing). Didn't work! The tide went out and the creek dried and there sat my anchor - I had managed to drop it on a parge sheet of mud coverd plywood and it hadn't move an inch. The moral of the tale is that most anything works as an anchor if you have enough chain and I have now seen enough people drag to reckon that almost any anchor will drag if you don't.
The easiest one to make is the fisherman's as far as I know the design is public domain.
But I think your idea is exellent and am a big fan of open-source so can I plug LibreCAD as the design platform

[Cotemar]

Originally Posted by roland stockham

The easiest one to make is the fisherman's as far as I know the design is public domain.
But I think your idea is exellent and am a big fan of open-source so can I plug LibreCAD as the design platform

Sure plug away. LibreCAD has to be as good, or better than my Etch-A-Sketch. My kids keep re-booting (shaking it) it anyway.

Come join in the fun as there are no wrong answers here. We use fiberglass, stitch & glue plywood and sheetrock hangers here. It’s all good.

Actually, the more off the wall the idea the better.

Hay, if you do not like to anchor, no worries as we will add a bottle opener to the OS anchor to keep you in the game with us.

[Delancey]

Originally Posted by roland stockham

An interesting anecdote for you. Many years ago when new to cruising I picked up a little 26ft folkboat. She was on legs on a beach and I have worked all my tide calculations so I would be there at high tide. strong SW wind blew past the creak and the tide never came! It was 1/2m low... So I ran all the cable out, 50m of 5/16 chain plus 50m 12mm line from the dingy and dropped the anchor. Went back to the boat and put set up a whip and tackle of about 8:1 on the 16:1 winches. I cranked it till the line was bar taught and playing about middle 'C' hoping to slide her down the beach (well I was new to sailing). Didn't work! The tide went out and the creek dried and there sat my anchor - I had managed to drop it on a parge sheet of mud coverd plywood and it hadn't move an inch. The moral of the tale is that most anything works as an anchor if you have enough chain and I have now seen enough people drag to reckon that almost any anchor will drag if you don't.
The easiest one to make is the fisherman's as far as I know the design is public domain.
But I think your idea is exellent and am a big fan of open-source so can I plug LibreCAD as the design platform

Hey LibreCAD looks pretty neat, does it have good curves/splines? I looked it up on Wikipedia and found a link to this one that looks pretty cool too, QCad, it's also free. It's about time for this stuff to be available.

QCAD - What is QCAD?

[Richard_W]

Here is my idea based on compilation of the bits and pieces I've read in this interesting topic. It also might answer the following question ...

Originally Posted by Delancey

Hello? A anyone? Are you out there? We need some material thicknesses for 20kg/44lb anchors and a no-tech way to bend plate. A little help here?

... by overlaying two flukes to create double thickness center. The shank slides in from the bottom up, and is locked in place by simple shackle.

Introducing the HOE anchor which is as KISS as I could think of ...



...

[Cotemar]

Originally Posted by Richard_W

Here is my idea based on compilation of the bits and pieces I've read in this interesting topic. It also might answer the following question ...



... by overlaying two flukes to create double thickness center. The shunk slides in from the bottom up, and is lock in place by simple shackle.

Introducing the HOE anchor which is as KISS as I could think of ...

Just brilliant. I love it. Great job

[Delancey]

Originally Posted by roland stockham

An interesting anecdote for you. Many years ago when new to cruising I picked up a little 26ft folkboat. She was on legs on a beach and I have worked all my tide calculations so I would be there at high tide. strong SW wind blew past the creak and the tide never came! It was 1/2m low... So I ran all the cable out, 50m of 5/16 chain plus 50m 12mm line from the dingy and dropped the anchor. Went back to the boat and put set up a whip and tackle of about 8:1 on the 16:1 winches. I cranked it till the line was bar taught and playing about middle 'C' hoping to slide her down the beach (well I was new to sailing). Didn't work! The tide went out and the creek dried and there sat my anchor - I had managed to drop it on a parge sheet of mud coverd plywood and it hadn't move an inch. The moral of the tale is that most anything works as an anchor if you have enough chain and I have now seen enough people drag to reckon that almost any anchor will drag if you don't.
The easiest one to make is the fisherman's as far as I know the design is public domain.
But I think your idea is exellent and am a big fan of open-source so can I plug LibreCAD as the design platform

Great input. Never thought of open source CAD for the project. Never said I wasn't a dope sometimes.

So far I've been using the pros version of SketchUp, which is also available free, that has some bells and whistles like square-area computing which is really handy for getting weights on funny shaped parts like our shank.

Totally using LibreCAD or QCAD for this project. Normally I do all my modeling in SketchUp then cut my sections and elevations then export to AutoCAD for outputting to drawings or to the machine. Not no more!

[Delancey]

http://en.m.wikipedia.org/wiki/Hoe_(tool

[avb3]

Originally Posted by Richard_W

Here is my idea based on compilation of the bits and pieces I've read in this interesting topic. It also might answer the following question ...

... by overlaying two flukes to create double thickness center. The shank slides in from the bottom up, and is lock in place by simple shackle.

Introducing the HOE anchor which is as KISS as I could think of ...

...

Pretty hard to get better in concept. Now we need the dimensions/ratios.

[Delancey]

Originally Posted by avb3

Pretty hard to get better in concept. Now we need the dimensions/ratios.

That's right. We need to know what the other guys are using. We are interested in knowing what the thinnest material and the largest unsupported panel area are that we can get away with for the fluke. We also want to know how thick they are from tip to shank.

Once we know that we can figure out what we can and do in terms of forming, when we know what are limits are we can start to design our fluke.

If the fluke has to be 1/2" thick throughout we're looking at a Bügel. If we can get away with something thinner for the larger portion of the fluke area then we're in business for something a little more sophisticated.

Anybody with a car jack and a couple 2 x 4's can bend sheet. Two car jacks and you are getting into realm of thin plate. We only need a couple slight bends to make a nice concave fluke. Could make the difference between a good anchor and a great one.

[Shawn67]

Originally Posted by noelex 77

Non roll bar, non balasted tip anchors are the Formula 1 of the anchor world. They are finicky and sensitive to small changes in weight and balance.

I think that is true with more than just that type of anchor. Look at the performance difference between the two different "danforth" type anchors for example.

Shawn

[Richard_W]

Originally Posted by avb3

Pretty hard to get better in concept. Now we need the dimensions/ratios.

We also need the conceptual specs and/or defined requirements. As I read the topic I took notice of examples of "best outcomes" and desired limitations that lead to the HOE anchor concept.

I think to go forward the agreements on specs/requirements need to be formalized, still fluid but documented. For example, I learned from this topic that flat surface holds better than concave, and convex is useless.



Shouldn't the flat surface be an agreed requirement/spec now? Just asking ...

[Delancey]

Originally Posted by Richard_W

We also need the conceptual specs and/or defined requirements. As I read the topic I took notice of examples of "best outcomes" and desired limitations that lead to the HOE anchor concept.

I think to go forward the agreements on specs/requirements need to be formalized, still fluid but documented. For example, I learned from this topic that flat surface holds better than concave, and convex is useless.



Shouldn't the flat surface be an agreed requirement/spec now? Just asking ...

How bout three shanks? A spike for rock, a scoop for medium sand, and a big flat one for mud. Would that make you happy? We've got the shank/fluke connection that will allow for it.

[Delancey]

Put two 2x4's on the ground with a space between them in a doorway, maybe an exterior doorway. Put a piece of metal down on the 2x4's then another 2x4 on top of the metal. Then put a car-jack on top of the top 2x4 and brace it to the top of the doorway.

Now pump the jack and smile, your forming the flukes for your new anchor. Not strong enough? Get two car-jacks and move outside to your 10' wide garage door.

By manipulating the thickness of the 2x4's and their distance apart we can control the angle of the bend. I can provide the dimensions required.

[Richard_W]

Originally Posted by Delancey

How bout three shanks? A spike for rock, a scoop for medium sand, and a big flat one for mud. Would that make you happy? We've got the shank/fluke connection that will allow for it.

You lost me ... is that a question or a spec?
You want to bend the metal go for it ... just make it clear.

[smaarch]

following this with interest
the assumption of needing lateral stability for the shank is based on the current development of the slotted joint to work in one direction. any force in any direction other than the plane of the shank will introduce a bending force.
this makes it clear the joint between shank and fluke is a critical element, no matter the anchor design.
if this joint were designed in such a way as to rotate 360 degrees, several things become possible
1. the bending moment is eliminated
2, the configuration of the fluke is affected by the possibility of accommodating a reset in all directions.


draftsight is another open sources cad program worth a look