Open Source Anchor Project

[Delancey]

Originally Posted by Delancey

We could make the shank more able to resist the side load if we made it thicker, but to be efficient with our materials we might want to make it out of the same stock as the fluke. Currently for our 20kg/44lbs Bugel-style we are expecting to use 1/2" material for the fluke because that looks like about what the Wasi version of the same anchor uses.

One thing I want to add to this that also relates to the Imperial/Metric issue is that whenever the OSA design is at a point where it can be released, it will be released as a RECOMMENDED minimum specification provided for exclusively for academic purposes.

Since we can't provide any measure of control over execution, we can't provide any warranty or guarantee, nor can we assume any liability. Ultimately, the end user will assume total and complete responsibility for the success or failure of the anchor they produce and use.

The upside to this minimum specification is two fold.

First, the guy on the beach far away somewhere, with minimum tools and who is confident of the quality of the materials he is sourcing, can build an anchor to the OSA plans and specifications and be able to sleep well at night knowing the basis for his anchor design has been peer reviewed through the design development process and has satisfied the testing standards applied by the forum.

Second, the guy who is well funded somewhere in the first world, can up-spec materials to his or her satisfaction. You want a shank that isn't quite so bendy as the spec, make it out 5/8" mild steel instead of 1/2". It will weigh a little more but be a lot stronger. You've got even more cash in your pocket, make it out of tool steel instead of mild. You're saving so much money by making it yourself in the first place? Make it out of stainless.

I think Rebelheart early on pointed out that execution was as much or more important than design and I couldn't agree more. I also view this as a good thing, we are free to lavish as much love and attention on our anchors as suits our fancy.

I am excited to see that as the project progresses, we have so many more options open to us than I had imagined. I started out thinking that for this project to be a success we needed to recognize that you can't be all things to all people all the time. Now I am not so sure that the opposite isn't true.

Our mechanical shank/fluke connection and the option of different fluke styles with interchangeable parts coupled with very basic construction and a free design means the same money you would spend on a single Chinese anchor bought online and shipped to your door would buy you several different OSA anchors.

Since you're not going cruising without at least a couple anchors, those interchangeable parts provides your redundancy. Where I come from redundancy is a pretty good thing. When those anchors meet the personal specifications of the end user, all the better.

[Delancey]

Originally Posted by Delancey

Using this as starting point, as we scale up and down I think it would be best to scale cubicly, to maintain the proven shape and proportion, based on commonly available Imperial/Metric sizes, where the finished weight is whatever weird not-round number we end up with. Trying to produce a separate design that weighs exactly 15kg or 25kg or whatever seems like a waste of effort with no real benefit.

What you end up with is anchors that aren't sized by weight but are sized by material thickness. 3/8"-10mm, 1/2"-12mm, 5/8"-15mm, and so forth.

It some ways I think this makes a lot of sense. Its not about matching the weight of the anchor to the length of the boat, it's about matching the material to the size of the load.

Maybe this could be confusing to people who don't know what their load is, but maybe it would be good for them to have to learn what that load is to determine what size they need.

In the end you'll have a Metric or an Imperial version that is a little stronger or a little weaker than it's counterpart. This is okay, it will be strong enough either way.

The important thing is that the overall proportions and shape, and therefor the performance, won't be compromised for the sake of conveniently round numbers.

[Shas Cho]

Re these photos-
a double-ended lanyard
run from the shank
over the lower bow-pulpit rail
and back to the helmsperson's hand
would make this anchor "self-launching".
Just give a tug, and release one (whipped) end of the lanyard
when the anchor has launched.
Easy-peasy, no?

[Delancey]

Originally Posted by Shas Cho

Re these photos-
a double-ended lanyard
run from the shank
over the lower bow-pulpit rail
and back to the helmsperson's hand
would make this anchor "self-launching".
Just give a tug, and release one (whipped) end of the lanyard
when the anchor has launched.
Easy-peasy, no?

Make fast the anchor end of the lanyard with a slip knot so that once it falls the weight of the anchor pulls it free?

If you have rope, pay out your rode, flake it down, and cleat if off ahead of time. Then when you sail up to your spot, tug the lanyard from the cockpit and you are good to go?

Have to give it a try.

Getting some parts-cutting prices BTW

[Cheechako]

I was taught to lower the anchor, not just pitch it over.....

[avb3]

Originally Posted by Cheechako

I was taught to lower the anchor, not just pitch it over.....

Yeah, that pitch over thing is soooo Captain Ron, isn't it?

[Delancey]

Just something I have been thinking about lately. About what anchors are really doing when they dive. You might notice the parafoils have bridles across their width and could just as likely be a flat or convex shape for what that's worth.

[Shas Cho]

Originally Posted by Delancey

Getting some parts-cutting prices BTW

And here was me,
thinking you were creating price-cutting parts!

[Shas Cho]

Originally Posted by Cheechako

I was taught to lower the anchor, not just pitch it over.....

True, true.
I've never tossed an anchor off the boat yet
(well, okay, I did throw a dinghy anchor over
the first time I went boating)
but "self launching" is such a popular advertising claim
that I couldn't help considering the potential...
Americans are shy of any purchase
that isn't "automatic".
I saw a battery-operated coffee-stirrer the other day!

[Delancey]

Originally Posted by Delancey

As far as a next step, I want to make another mock-up using the current shank design to try it on my bow roller again. The first one fit about as well or better than my rusty CQR and I think in general the Bugel style should work for most. That said I increased the clearance on the current design because it seemed like the first one could fit better. We shall see.

After that, we need to decide who is going to make and test our prototype. Since I obviously have a dog in the fight, I suggest it not be me. Mantus has offered kindly, they also have a dog in the fight so to speak, but mainly I don't want to be a burden to them any more than we have to.

I am willing to put my money where my mouth is and front some cash, just don't tell my wife, we are trying to save for our cruising kitty. Maine Sail comes to mind as a pretty well regarded individual. Also, sounds like there are a couple folks down in Oz who are anxious to get building.

Any thoughts?

Just a little end-of-year bump for the old Open Source Anchor Project.

Have to say, based on the number of page views, I am a little surprised that apparently I am the only person who thinks building and proof testing a prototype would be fun. I mean, breaking stuff (or not) is fun, right? Surprised, given I offered to front some cash, but not dissuaded.

I'll prolly get around to making one in the next month or so, depends on my work situation. It's winter here now and I am not likely doing any in-water testing until April and so am not in any big hurry. If you have ants in your pants, let me know and I will give you the cut files I have for shank and fluke.

In the meantime, I wish you Happy Holidays and all the best in the New Year!

Cheers

[estarzinger]

I have a 10ton hydraulic puller and load cell, and love breaking stuff. I would be happy to if someone shipped bits to me. But I already have enough on the agenda not to want to get involved in cut files and making parts.

[Delancey]

I'll make it you, can break it. Deal?

[Jimbo485]

Send me the files and we will build it and then test it with the higher windage of a cat. Approx 30 kg version.

[estarzinger]

Originally Posted by Delancey

I'll make it you, can break it. Deal?

I am happy to break. Let me know when you are ready and I will give you shipping address . . . . when you are sizing the parts, I have the capability to pull 10 tons, but my preference comfort level is to be max 5 tons (and my load cell is more accurate there) . . . stuff snapping at 10 tons is scary . . . You probably want to know 'yield points' rather than 'actual breaking point' and yield is safer for me.

I will have to dream up some clamping methods. Should not be too difficult but any ideas welcome.

[monstads]

Did the file share ever get set up? If not, please send the files over.. I might stop by a machine shop buddy of mine tomorrow, and would love to get his input on the cut files, and see if he'd be interested in doing a prototype. How well do you think it would hold in snow and ice :-)