Open Source Anchor Project

[Cotemar]

Originally Posted by Delancey

We need to get over the weld quickly

Who said anything about a weld?

[Delancey]

Originally Posted by Cotemar

Who said anything about a weld?

I got it. You were adding chamfers. I'm with you there, we will definitely be doing that. I just left them out cuz was focused on the joint. Looks like you found a couple anchors on SketchUp, a great tool. I use it everyday. For sure we will put the OSA in the warehouse. For anyone who wants to tinker SketchUp is available as a free version, hours of fun!


SketchUp | 3D for Everyone

[Cotemar]

Originally Posted by Delancey

Looks like you found a couple anchors on SketchUp, a great tool. I use it everyday. For sure we will put the OSA in the warehouse. For anyone who wants to tinker SketchUp is available as a free version, hours of fun!
SketchUp | 3D for Everyone

This Etch-A-Sketch was given to me yesterday at a yard sale as no one wanted it. I made these anchors myself on this great new device.

Who needs SketchUp when you have one of these babies.

It's just like one of those things my kids call an iPad.

The Etch-A-Sketch needs no batteries and the memory on it last forever, well it should until your kids pick it up and shake it. Kids call that a re-boot.

[Delancey]

Help! I can only be so creative in a day.

I think by incorporating the through-hole cantilever connection we have assured ourselves the high probability of success in our project. A Bügel anchor that doesn't need to be welded, great. Different flukes for different conditions, even better! Done. Pitcairn Island. Anywhere. By anyone.

But we're a salty lot. I know we can do better. We need a low/no-tech way to bend half inch plate. Drive a car over it, drop a piano on it, attach levers, whatever. Find a way to make it work. If if can bend plate without a torch we're golden.

To produce a basic concave fluke we need to bend a single fold of about thirty degrees into a flat sheet. Even better would be if we could do two fifteen degree bends that are convergent. Think like a Mantus.

I might be off base about the thickness but better to have an easy way to bend half inch than a hard way to bend quarter if you catch my drift. I've got some other stuff to work on so if you guys could cover the bending part of it that would be great!

[Jimbo485]

Originally Posted by Delancey

Help! I can only be so creative in a day. I think by incorporating the through-hole cantilever connection we have assured ourselves the high probability of success in our project. A Bügel anchor that doesn't need to be welded, great. Different flukes for different conditions, even better! Done. Pitcairn Island. Anywhere. By anyone.

Stop right there with Mark I. This is great, Delancey!

Mark II can have bends, but Mark I is fine with everything flat. KISS.

[Delancey]

Originally Posted by Jimbo485

Stop right there with Mark I. This is great, Delancey!

Mark II can have bends, but Mark I is fine with everything flat. KISS.

Let's not sell ourselves short. I know we can do better!

That's a tough one though, bending plate that thick cold. You guys better get creative.

[Delancey]

Yeah, two folds like the Mantus would be ideal. Every fold you add imparts shape strength to the material and reduces the unsupported panel area. The stiffer we make it the thinner and lighter it can be which makes a roll-bar free design more of an option.

[noelex 77]

I don't want to sound negative but I do not see how you are going to get enough lateral support with a simple slot cut in the fluke.
An anchor has to resist a force at right angle to the fluke. The spade does this with a welded box construction.
The Kobra does it with this (complicated) system. (See photo) Perhaps I misunderstanding what you are proposing, but the shank has to resist more than a straight pull. I cannot see a simple slot cut into the fluke doing that.

[Delancey]

One more thing. We need data on material thickness of shanks and flukes in the 20kg/44lb class. There are only CQRs and Deltas around here, the Deltas are the wrong size.

In 1944 the US emergency landed a bunch of B-29 bombers in Russia. They didn't all come home and as a result the Russians reverse engineered the TU-4. Owing to the fact of descrepency in standards between metric and imperial measure and the resultant variance in the materials used the plane was never a success. The point here is it flew just fine.

We don't need to nail it, we just need to be in the ballpark so we can start designing the fluke. You can read about the Russian plane here Tupolev Tu-4 - Wikipedia, the free encyclopedia

[Cotemar]

Originally Posted by Delancey

Help! I can only be so creative in a day.

I think by incorporating the through-hole cantilever connection we have assured ourselves the high probability of success in our project. A Bügel anchor that doesn't need to be welded, great. Different flukes for different conditions, even better! Done. Pitcairn Island. Anywhere. By anyone.

But we're a salty lot. I know we can do better. We need a low/no-tech way to bend half inch plate. Drive a car over it, drop a piano on it, attach levers, whatever. Find a way to make it work. If if can bend plate without a torch we're golden.

To produce a basic concave fluke we need to bend a single fold of about thirty degrees into a flat sheet. Even better would be if we could do two fifteen degree bends that are convergent. Think like a Mantus.

I might be off base about the thickness but better to have an easy way to bend half inch than a hard way to bend quarter if you catch my drift. I've got some other stuff to work on so if you guys could cover the bending part of it that would be great!

You’re taking the we out of team here.

I agree with the KISS design.

I think the team is saying we should leave the Fluke flat.

A Mantus formed fluke from a flat pattern is extremely hard for anyone without a large tonnage bender to make.

You say you do not want to use welds, but you would like to use a large tonnage bender? The kiss design just went out the window.

[Delancey]

Originally Posted by noelex 77

I don't want to sound negative but I do not see how you are going to get enough lateral support with a simple slot cut in the fluke.
An anchor has to resist a force at right angle to the fluke. The spade does this with a welded box construction.
The Kobra does it with this (complicated) system. (See photo) Perhaps I misunderstanding what you are proposing, but the shank has to resist more than a straight pull. I cannot see a simple slot cut into the fluke doing that.

I know where you're coming from but I might have a trick or two up my sleeve for this one, drawings to come. The fluke thickness will be key to going all the way on it.

I know that on some it varies, we can do that no problem by stacking plates. Will likely end up doing that anyway as the easiest way to provide stiffness from the shank to the tip.

[Delancey]

Originally Posted by Cotemar

You’re taking the we out of team here.

I agree with the KISS design.

I think the team is saying we should leave the Fluke flat.

A Mantus formed fluke from a flat pattern is extremely hard for anyone without a large tonnage bender to make.

You're right, my bad. But can we at least try first? If it doesn't look doable so be it, but I think we owe it to ourselves to at least explore it.

[noelex 77]

Ok it sounds like you have thought about the problem.

Note you need to keep the fluke as light as possible except in the tip (in front of the shank) Notice how the Kobra has a thin lightweight fluke where the shank attaches with a thicker ballasted area in the shank in front of the fluke.

The Bugel does not have this level of sophistication with a uniform fluke thickness. Even so it not thick enough to support the lateral loads of a simple slot to attach the fluke. Adding weight behind the tip will decrease anchor performance below the level of the Bugel.

If you want to develop a non roll bar anchor like the Boss or Raya the heal of the fluke (and shank) has to be light.

I think the future of anchor design is probably in this area, but the Oceane, Sword and Raya have not worked well. It is too early to predict if the Manson Boss will be a success. The balance and design of this sort of anchor is critical. To try and achieve this with very simple construction and no welding is a tall order.

[Shawn67]

"If you want to develop a non roll bar anchor like the Boss or Raya the heal of the fluke (and shank) has to be light."

Relative to the tip. The heel of the fluke is likely light, the shank is probably pretty heavy though as it is fairly large. Its position near the front of the fluke helps position the weight on the point and the point is also considerably thicker as well.









Shawn

[Shawn67]

Won't this simplified triangle shape fluke resist setting? With a flat side the weight of the anchor will be distributed over the entire length of the side. Seems that will make it more likely to slide across the seabed instead of trying to dig in. Notice how the Bugel ( and most other flukes) rest on two points on their sides.

Shawn