Open Source Anchor Project

[Shrew]

Originally Posted by Delancey

For what it's worth I thought I would mention that I did get a price a while back from a local guy with a high-def plasma cutter to cut parts.

He quoted me about $1k including materials to cut a 4' x 8' sheet from which you could get parts for ten anchors so $100 per unit base cost. Have to add in labor to dress edges and assemble as well as finishing costs but still a very reasonable price.

I thought the original intention was to be able to put this together in a pinch. (A guy with a stick welder on the beach.....hurricane bearing down).

Now you're at $1,00 to pre-fabricate 10 of them. It would seem the scope of this Open Source project has crept.

Is anyone going to actually set sail without adequate ground tackle? Will I be able to reasonably find someone to fabricate these parts for me in an emergency?

How has this not completely re-invented the wheel. This reads like trying to build a car or a motorcycle. Possible and practical are mutually exclusive.

At your price-point there is little incentive to not buy something fabricated professionally.

[Delancey]

The need for welding was eliminated with the introduction of the locking through-tenon shank connection. Now the OSA could in theory be made with a cutting torch, a hand drill, a file, and a lot of patience.

High-def plasma cutting is more precise and produces a much better quality edge when compared to a cutting torch which minimizes the amount of grinding labor required. Providing bulk cut parts as an option to facilitate fabrication does not expand the scope or diminish the intent but rather makes it more accessible.

At a $100 base cost for pre-cut parts per unit the OSA is still on the order of 1/4 to 1/6 the cost of a commercially available 20kg/45lbs anchor. Of course you could still make you own using scrap for a fraction of that price.

If you read the thread you will see one of the goals is to capitalize on unlicensed prior art the same way all anchor manufacturers do. If you think this is reinventing the wheel, that's fine. I fail to see anything not possible or practical about the project but if you do, that is also fine.

[Cu Mor Glas]

Exactly! You could take the pdf and scratch it onto whatever piece of plate you have available cut it out with oxy acetylene or oxy mapp. Or whatever is available to cut with. An angle grinder or a file. And a drill (or maybe a careful hole with the oxy whatever) and you have an anchor. But if you weren't out in the wild you could take it to the friendly local cnc shop and get it cut out. Or if you have friends in an off-road club there's always one of those folks with a plasma table. It's about having options.

Ultimately the same thing open source in general is about.

[RobertLeask]

I'm a welder by trade, as well as a sailor. One thing I've found no mention of, with regard to the ease of fabricating your own anchor, is cutting with "zip" disks. Those are the usually 1/8 inch disks used in angle grinders which can cut thin metal very quickly, and just about any thickness given enough time and a sufficient supply of disks. They can be bought from online suppliers for about a buck each and I estimate for cutting 1/2" plate you would need one 6" disk for each 6" of cut. All you need is a fairly good quality angle grinder and a source of AC power. And time, and patience. A one foot cut in 1/2 inch plate could take probably half an hour.

The main disadvantage of this method of cutting is that curves, other than very gradual ones, are not possible. If the design consisted of all straight lines with no curves, it would be quite feasible. Don't forget good eye and hearing protection if you decide to try. It is slow, noisy and not without risk to eyes and hands etc.

As for the welding, I welded all the steel parts for my boat 25 years ago, including highly stressed items like engine beds and exhaust piping, as well as anchors, without any training or experience, with a worn out old AC machine that could only burn tiny 1/16 rods, and nothing has ever failed. I'm not recommending that sort of thing, just making the point that on mild steel even the worst welds seldom fail. Given adequate weld length, a machine with high enough amp rating, and 7018 rods, I believe anyone could make welds that would be more than strong enough.

[evm1024]

Or, You could buy a shank from mantus and bolt it onto your new design anchor fluke....

[RobertLeask]

Originally Posted by evm1024

Or, You could buy a shank from mantus and bolt it onto your new design anchor fluke....

Excellent idea, you could then experiment with sharp, fat, convex or concave flukes, and different angles of attack, without unshackling from your rode. Maybe every sailors dream of an anchor that works everywhere could be realized.http://www.cruisersforum.com/forums/...lies/smile.gif

[noelex 77]

I found this site for a Noah's Ark anchor. I have never seen one, but it is a bit like a Northill anchor.

The interesting thing is that they provide cutting files, PDF and .dxf at no charge so you can make your own. I thought this might be of use to metalworking anchorholics .

Noahs Ark Anchors, simply the best, safety first, quick setting,

[artic warrior]

I saw this a few years ago and thought what an awesome anchor for getting through the weed but still ok ish in mud and sand ( small flukes)

Originally Posted by noelex 77

I found this site for a Noah's Ark anchor. I have never seen one, but it is a bit like a Northill anchor.

The interesting thing is that they provide cutting files, PDF and .dxf at no charge so you can make your own. I thought this might be of use to metalworking anchorholics .

Noahs Ark Anchors, simply the best, safety first, quick setting,

[Hydra]

This anchor has the same drawbacks as the fisherman's or old-fashioned anchor: there is a risk that the upper fluke catches the rode at the turning of the tide and this fluke is a danger for hulls in shallow water.

Alain

[jongleur]

Originally Posted by noelex 77

Noahs Ark Anchors, simply the best, safety first, quick setting,

How 'bout if the two concave parts are
rotated sideways toward each other 90 degrees
and then a roll bar put on from one to the other?
So then it would look like two mini anchors side
by side. Oh, yeah, take out the bar in the middle.
Would that solve some of the issues
with this anchor?

[artic warrior]

There is an anchor like that but with out roll bar next to right now,,,will take a pic if I can

Originally Posted by jongleur

How 'bout if the two concave parts are
rotated sideways toward each other 90 degrees
and then a roll bar put on from one to the other?
So then it would look like two mini anchors side
by side. Oh, yeah, take out the bar in the middle.
Would that solve some of the issues
with this anchor?

[UNCIVILIZED]

I like the northill'ish anchor, but without a hydraulic press how would you create those concave shapes? Cut multiple pieces of steel & then weld them together in a fashion akin to strip plank hull construction?

As to cutting steel, how about a high pressure water jet? I know a few custom knife makers that do this so that there's no alloy altering heat involved in cutting out blanks from plate stock. Heck, with such a tool it may even be possible to cut bevels & angles in the steel.

Then if you want to get fancy, there are CNC driven laser cutters. Which, various cutting tools get hooked up to CNC in order to cut things like sail panels, or flat pack kits for boats; in metal, or wood, etc.

[Orion Jim]

Has anyone fabricated one of the open source anchors? A photograph of a completed unit would be great.

[oldbilbo]

Originally Posted by Cotemar

Maybe I will add a bottle opener to the Convave anchor I designed for the Convex anchor lovers on the Anchors, Bigger is Better thread. Will get right on that. Those boys need another beer. Those convex anchors have them all over the harbor.

http://www.cruisersforum.com/forums/...ml#post1401266

A friend pointed me to this thread, and I have to say I already HAVE a solution. Here it is....

[Delancey]

Originally Posted by oldbilbo

A friend pointed me to this thread, and I have to say I already HAVE a solution. Here it is....

Oh man! It's a lengthy thread but I think the bottle opener got officially incorporated in the design specifications somewhere on page 11. I was making fun of anchor manufacturers who give-away bottle openers and wondered why they didn't just incorporate them into the design so you could be standing on the dock next to the bow of a boat and open a beer if you wanted. You know, multifunctional?



Anyhell, I'm a designer by trade. I started this project when business was slow and I had some time on my hands.

I thought it was worthwhile and I was hoping to attract some like-minded individuals interested in participating in a cooperative effort to create something useful that would be accessible to all. I put effort into it that I never felt was reciprocated so I put it on the back burner. I installed a new engine, new battery bank, new galley, blah, blah, blah.

I then went cruising with my wife, we spent all of our money, and ended up in Miami to try and build our kitty again to get back out there when Irma blew in and we lost our boat.

It's been good to have some time away from the project. I have some new thoughts about the design but am also always open to suggestion. If anyone wants to dig in I will gladly assist. Or as time permits will likely do more work on it in the future.

Meanwhile, as time rolls on the "digital fabrication" revolution in manufacturing continues to grow and as a result I believe the project only gains relevancy.

I also continue to believe -

Peter Bruce was a genius designer. All "new generation" anchors are essentially derived from his concepts and ground breaking exploration of anchor design.

Using the publicly available concepts that Peter Bruce developed, a viable open source anchor design can perform as well as any other commercially available anchor that exploits these same concepts while being cost effective.

Instead of buying Chinese anchors made from recycled Chinese manufactured products we bought and then threw away into the trash which then got shipped back to China where they were melted down and shaped into anchor-shaped pieces of metal and then shipped back to us, we should be buying anchor shaped pieces of metal from our friends and neighbors in our own towns. Growth in digital fabrication only makes this more possible.

Every anchor should have a beer opener built into it!