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26-12-2013, 23:44
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#346
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Registered User
Join Date: Jan 2008
Location: Hong Kong
Boat: Custom Freya 20m
Posts: 1,020
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Re: Open Source Anchor Project
Forgive me if my suggestion is a duplicate.
Would it be possible to have a variable fixation pin to facilitate different angles of the flukes - something like Fortress do. Can select the angle to suit the bottom substrate.
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27-12-2013, 08:16
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#347
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Registered User
Join Date: Oct 2011
Posts: 3,607
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Re: Open Source Anchor Project
Estar- thanks for pitching in BTW!
I will have to try to remember where I got the number from but have it in my head that we need to proof our 20kg/44lbs anchor to only 5,000lbs. Unless we are really bad anchor designers, we shouldn't be anywhere near breaking out prototype.
Per the FEA simulation provided by Mantus we aren't even quite to breaking at 40,000lbs and then only at the shackle eye, so that should be like an 8:1 safety factor. I link below to the ABS rules as it pertains to anchor proof testing as well as a photo of what looks like an Anchor Right product in a testing frame.
This of course is a straight line pull to prove the anchor design. Any OSA builder would do well to proof test their product in the same manner, as proof coil chain is tested. I was thinking anybody with access to a fork lift could do it, maybe we can come up with some other ways.
As a straight line pull, the test provides us a benchmark but probably doesn't really reflect real world conditions, but it's the standard so it is what it is.
One thing I have noticed that newer anchors tend to have lower aspect flukes when compared to the Bügel as well as a more forward shank attachment. This may be wholly natural or it may be a cheat to have a thinner fluke as the load point for the fluke is called out as 1/3 the distance from the tip of the fluke to the shank attachment point, so shorter lever less leverage.
http://www.uscg.mil/d13/cfvs/docs/ac...t2Chapter2.pdf
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27-12-2013, 08:42
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#348
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Registered User
Join Date: Oct 2011
Posts: 3,607
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Re: Open Source Anchor Project
Quote:
Originally Posted by 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 :-)
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Was sort of thinking we should make and proof test a prototype first , so haven't bothered to upload anything yet. Just to explain a bit, when I say "cut files" what I really should be saying is the scaled vector drawings. These are usually an AutoCAD extension like ".dwg" or ".dxf" or maybe an Adobe Illustrator file like a ".ai" extension. Because of these extensions I can't just post them here on CF.
Typically one would import these files into a software program that will define tool paths and output code to a specific machine like a CNC router table or CNC plasma cutter. These files would be more accurately described as "cut files" but since I send these straight to the machine I never really call them anything but refer to my vector drawings as my cut files because they are the artwork that has my finished dimensions. You really only need these if you are using one of these machines.
For anybody else you have other options such as printing out the PDF version full size as a template or using the x and y dimensions provided in inches as well as the radius and diameter dimensions given and drawing the parts out with chalk on the steel.
You could also use the dimensions to make you own vector art with whatever program you use. The vector art is different from a rasterized image like a .JPG in that it is uses math instead of pixels to describe something, and is therefore infinitely scalable.
Unfortunately, I am out of town for the week but when I get back I will post a PDF of the fluke as well as provide metric dimensions.
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27-12-2013, 08:54
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#349
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Registered User
Join Date: Sep 2011
Posts: 208
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Quote:
Originally Posted by Delancey
Was sort of thinking we should make and proof test a prototype first , so haven't bothered to upload anything yet. Just to explain a bit, when I say "cut files" what I really should be saying is the scaled vector drawings. These are usually an AutoCAD extension like ".dwg" or ".dxf" or maybe an Adobe Illustrator file like a ".ai" extension. Because of these extensions I can't just post them here on CF.
Typically one would import these files into a software program that will define tool paths and output code to a specific machine like a CNC router table or CNC plasma cutter. These files would be more accurately described as "cut files" but since I send these straight to the machine I never really call them anything but refer to my vector drawings as my cut files because they are the artwork that has my finished dimensions. You really only need these if you are using one of these machines.
For anybody else you have other options such as printing out the PDF version full size as a template or using the x and y dimensions provided in inches as well as the radius and diameter dimensions given and drawing the parts out with chalk on the steel. Or it you want, you could use the dimensions to make you own vector art with whatever program you use. The vector art is different from a rasterized image like a .JPG in that it is uses math instead of pixels to describe something, and is therefore infinitely scalable.
Unfortunately, I am out of town for the week but when I get back I will post a PDF of the fluke as well as provide metric dimensions.
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That's sort of why I was checking to see if you had uploaded them somewhere (ideally in different formats) , so that if I do end up chatting with my machine shop buddy, he could pick whatever format that he's able to work with.
I'll PM you my email address, if you could send the AutoCAD files. It should be the highest fidelity, and I'm guessing he'll be able to send that to his CNC. Should have mentioned, he sometimes does prototyping for the medical device industry, like parts for heart stints, etc, so he's used to getting things digitally.
I, on the other hand would be handcutting using a plasma torch on a chalked out piece of metal...
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27-12-2013, 08:58
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#350
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Open Source Anchor Project
The "streight line pull" should be no problem . . . But does not seem like a very useful test. I doubt anchors ever fail that way. I believe we know that even the known low strength rocnas "passed" the streight line pulls. With the streight line, I was thinking to try to pull it to yield, rather than just "proof", so that you know what/where the yield mode is.
The more difficult question . . . I was thinking about how to clamp the anchor for off axis pulls on both the shank and flukes. Perhaps this will not be so difficult because the off axis yield points may be relatively low. I would think yield points and failure modes would be interesting. You have an "innovative" (for anchors) design and off axis pulls will get people more confident with it (the joint design).
My test bench has a bit more than 40" of pull space (I designed it to test 2 20" back to back dyneema splices) but if needed I also have access to both a bigger bench and an industrial building with steel beam lifts in the ceiling.
That photo is a bit funny . . All the broken junk off to the right edge of the pic, and I have to believe it is not (and is rather some high strength synthetic) but it looks like a leather strap taking the load over the fluke, and the shackle thru the shank looks wrong. The whole picture just has a junk yard feel to it.
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27-12-2013, 09:14
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#351
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Registered User
Join Date: Oct 2011
Posts: 3,607
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Re: Open Source Anchor Project
Quote:
Originally Posted by monstads
That's sort of why I was checking to see if you had uploaded them somewhere (ideally in different formats) , so that if I do end up chatting with my machine shop buddy, he could pick whatever format that he's able to work with.
I'll PM you my email address, if you could send the AutoCAD files. It should be the highest fidelity, and I'm guessing he'll be able to send that to his CNC. Should have mentioned, he sometimes does prototyping for the medical device industry, like parts for heart stints, etc, so he's used to getting things digitally.
I, on the other hand would be handcutting using a plasma torch on a chalked out piece of metal...
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I can get you what ever format he needs, ask him and let me know. Probably ".dxf" will be fine. For quoting purposes show him the PDF of the shank. The fluke width currently is about 20" and the length is given on the PDF.
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27-12-2013, 09:19
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#352
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Registered User
Join Date: Oct 2011
Posts: 3,607
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Re: Open Source Anchor Project
Quote:
Originally Posted by estarzinger
The "streight line pull" should be no problem . . . But does not seem like a very useful test. I doubt anchors ever fail that way. I believe we know that even the known low strength rocnas "passed" the streight line pulls. With the streight line, I was thinking to try to pull it to yield, rather than just "proof", so that you know what/where the yield mode is.
The more difficult question . . . I was thinking about how to clamp the anchor for off axis pulls on both the shank and flukes. Perhaps this will not be so difficult because the off axis yield points may be relatively low. I would think yield points and failure modes would be interesting. You have an "innovative" (for anchors) design and off axis pulls will get people more confident with it (the joint design).
My test bench has a bit more than 40" of pull space (I designed it to test 2 20" back to back dyneema splices) but if needed I also have access to both a bigger bench and an industrial building with steel beam lifts in the ceiling.
That photo is a bit funny . . All the broken junk off to the right edge of the pic, and I have to believe it is not (and is rather some high strength synthetic) but it looks like a leather strap taking the load over the fluke, and the shackle thru the shank looks wrong. The whole picture just has a junk yard feel to it.
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Straight line pull is easy, side load is the killer. Thanks to our mechanical connection we can make a test fluke out of rectangular bar stock that would be very easy to clamp up to evaluate side loading the shank.
I don't think any manufacturer would make public any side load testing as all will fail. I think the "junk" in the photo is just to prevent the sling from slipping down. As far as junk yard feel, no comment other than I believe it's Anxhor Right product so take it for what you will.
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27-12-2013, 10:14
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#353
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Open Source Anchor Project
Quote:
Originally Posted by Delancey
I think the "junk" in the photo is just to prevent the sling from slipping down.
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off topic . . but . . . I get the wooden blocks . . . I was referring to the stuff way further right . . . broken electrical boxes and such
Back on topic, I can read cad files (any of the normal formats) and would be curious to see them.
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27-12-2013, 17:01
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#354
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cruiser
Join Date: Sep 2011
Posts: 267
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Re: Open Source Anchor Project
My test bench has a bit more than 40" of pull space (I designed it to test 2 20" back to back dyneema splices) but if needed I also have access to both a bigger bench and an industrial building with steel beam lifts in the ceiling.
That photo is a bit funny . . All the broken junk off to the right edge of the pic, and I have to believe it is not (and is rather some high strength synthetic) but it looks like a leather strap taking the load over the fluke, and the shackle thru the shank looks wrong. The whole picture just has a junk yard feel to it.
__________________
www.bethandevans.com
Dang, I will just have to get rid of that photo, doesn't look right" well I suppose it's a new angle, hope this tidies it up a bit.
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28-12-2013, 02:07
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#355
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cruiser
Join Date: Feb 2011
Location: Pittwater, Sydney
Boat: Lightwave, Catamaran, 11.5m (38')
Posts: 1,000
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Re: Open Source Anchor Project
Quote:
Originally Posted by Delancey
Straight line pull is easy, side load is the killer. Thanks to our mechanical connection we can make a test fluke out of rectangular bar stock that would be very easy to clamp up to evaluate side loading the shank.
I don't think any manufacturer would make public any side load testing as all will fail. I think the "junk" in the photo is just to prevent the sling from slipping down. As far as junk yard feel, no comment other than I believe it's Anxhor Right product so take it for what you will.
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I think you are both right and wrong
quote
I don't think any manufacturer would make public any side load testing as all will fail.
unquote
There is no 'standard' so they will all pass, or fail - depends on what standards you want to set.
But be careful when you set your standard as you will want to ensure that Mantus meets them.
As another person who has probably never seen an Anchor Right product and certainly never tested one we can take your comment as being based on ignorance, or something worse - take it for what you will.
Jonathan
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28-12-2013, 09:16
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#356
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Open Source Anchor Project
JonJo, take your AnchorRight defensiveness someplace elsewhere.
Delancey did NOT criticize AnchorRight. he simply told me it thought it was an AnchorRight product in the photo. Which seems to be correct. So your comment about "ignorance, or something worse" can just be pointed right back at YOU.
And I did NOT criticize AnchorRight (in the comment Delancey was responding to). I simply said the facility in the photo looked like a junkyard. I had, and have no idea if it is an AnchorRight facility or not - but it does look like a junk yard in the photo. That's a simple fact, not criticism.
And in the other thread . . . I simply said that I was puzzled by Rex's seeming to be unfamiliar with the equipment number formula - when I posted it he said very plainly that it was not how he thought the survey officers did it. That was not criticism. That was puzzlement, particularly given he had also said his own anchor sizing was based on the survey requirements. He must have taken the survey requirements into his own chart in a different way, and I would have been interested to learned how/what that was. There was no criticism in any of that. Simply a discussion and attempt to learn.
And what is with your dig about Mantus below. Why should Delancey want to 'ensure Mantus meets them"? He is doing an open source project. Mantus offered to help with some calculations, but Delancey certainly did not sell his open source soul to them. He is still producing a product which will compete with theirs, and I given them great credit for offering to help in that circomstance. And if/when I actually do the pulling I don't care what Delancey or Mantus or you think . . .I will just report the results. You again are suggesting bad or hidden motivation where none exists.
You are way way too quick to both feel someone has somehow slighted AnchorRight and also to attribute ignorance or bad motivations.
Is that because YOU have some hidden/bad motivation for so actively protecting/defending Rex in all these threads
(don't respond to that . . .that was just to let you see how it feels to be accused in that unfair way . . . . . I in fact only have great respect for your various attempts to bring some data to anchor testing . . . but you are way over the line in your 'attack dog' mode on these threads. . . . ).
Quote:
Originally Posted by JonJo
But be careful when you set your standard as you will want to ensure that Mantus meets them.
As another person who has probably never seen an Anchor Right product and certainly never tested one we can take your comment as being based on ignorance, or something worse - take it for what you will.
Jonathan
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28-12-2013, 14:10
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#357
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cruiser
Join Date: Feb 2011
Location: Pittwater, Sydney
Boat: Lightwave, Catamaran, 11.5m (38')
Posts: 1,000
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Re: Open Source Anchor Project
Maybe you thing this is complimentary:
Quote from Delancey:
'As far as junk yard feel, no comment other than I believe it's Anxhor Right product so take it for what you will.'
end quote
I'm not sure that you were criticised, if you felt so and feel the need to defend your and Delancey's actions - fine by me
This Forum I have been told is to help and support cruisers, what I see is an unediucated and ignorant barracking of a manufacturer yet when another manufacturer makes and posts a video that is clearly unsafe and makes an anchor whose shank is clearly well under strength I note that the support for cruisers on this Forum was clearly missing. There are many experts who bought that anchor - but not one of them said a word against it.
In the end the video was pulled and shank upgraded - which suggests the comments were valid. I assume everyone is proud of their reticence at the time - excuse me if I think the support from Cruisers sometimes misses the mark.
I dislike bias, however it is expressed, and I dislike bias based on total ignorance. I think there is an internet term that covers such ignorant barracking - but I do not recall what it is. It does not matter which company is the focus, I'll defend Fortress, Spade etc and have done - if I think the comments are wrong or based on total ignorant.
Jonathan
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28-12-2013, 14:22
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#358
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Registered User
Join Date: Oct 2011
Posts: 3,607
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Re: Open Source Anchor Project
Wood screw, machine screw, sheet metal screw. Drywall screw, lag screw, decking screw, Confirmat screw, carriage screw, masonry screw, hanger screw, set screw, breakaway screw, eye screw. Slotted, Philips, Pozidrive. Torx, hex, Allen, security, square, spanner. Straight, tapered, self-tapping. Bronze, steel, stainless steel, aluminum.
That's a lot of different flavors. I know a drywall screw is the best for hanging drywall, but I am pretty sure any of the others would do the job if I asked them to. What do they all have in common?
Well they all owe their existence to some guys who we're trying kill each other better. Like pretty much all technology, screws started life as a military technology.
While the Archimedes Screw had been in existence since the time of well, Archimedes, the screw as a mechanical fastener didn't come into existence until it was invented in the sixteenth century by European armorers, people making armor so they could kill each better.
If you are in New York and visit the Metropolitan Museum of Art and go to the gallery with the suits of armor you can see the most amazingly beautiful screws of all time. They are thoughtfully and artfully hand crafted with the kind of attention to detail you might expect would accessorize a suit of armor fit for a king with, because well, that's what they are.
What's happened in the past five hundred years of screw design? Not much really. It's still an inclined plane wrapped around a shank with a head that allows you to impart torque so you can drive the thing in.
The design climax pretty much came and went with its initial development. Anything "new" in screw design is little more than finesse in the details, refinement, variations on a theme.
If space aliens visit planet Earth some day, I am pretty sure they are going to recognize a human screw when they see it because if, at any point in their history, they ever wanted a removable fastener, I am sure they have used something we would recognize as screw.
What's my point with all this screwing around?
Bügel, SARCA, Knox, Ronco, Mantus, Manson, OSA. Same difference. From 50 feet away they all pretty much look the same to the unobessed.
I don't have to have ever laid hand on an Anchor Right product to know it's probably as good as any other. I can tell that just by looking at it. Materials, finish, all looks good to me.
Is anyone of the aforementioned anchors the best? Considering the amount of variables involved in the anchoring equation, I really think debating this is about as productive as a bunch of school kids arguing on the playground about who has the best sneakers.
Do I think the aforementioned anchors are all good anchors? I have no doubt, clearly the market supports that notion. Do I think that in a hundred years anchors will look dramatically different? There is no doubt in my mind they will look basically the same.
Do other people really think a subtle massaging of any given details is that important? Do other people really think any of these anchors are really that different? Apparently some of them do based on the amount of time they spend on the playground arguing about it.
Personally, I don't think so and it pains me to see so much effort in my eyes squandered. I think on any given day in any given location any anchor might do better than others, but I also think on any other day in any other location the results will likely be different.
I knew anchor threads were electrified and I had previously never bothered with them. When I finally did read through one though, what I read really bothered me. When things bother me I do something about them.
So, I started this thread. To be productive. To share my expertise as a designer. To educate. To empower. To make a difference, even if only a small way. To have fun. To have something to show for my leisure time spent on the internet. To do something to benefit other people I can feel good about.
Anyone who would assert my motives lie elsewhere can go screw themselves.
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28-12-2013, 14:28
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#359
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Registered User
Join Date: Oct 2011
Posts: 3,607
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Re: Open Source Anchor Project
Junkyard was Estars language, not mine. My comment was "no comment" and besides Rex pointed out it's not even Anchor Rights facility so who cares? Let it go.
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28-12-2013, 14:29
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#360
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Open Source Anchor Project
Quote:
Originally Posted by JonJo
Maybe you thing this is complimentary:
Quote from Delancey:
'As far as junk yard feel, no comment other than I believe it's Anxhor Right product so take it for what you will.'
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If you would read it without your attack dog mindset . . . you would see it's a simple statement of fact and he goes out of his way to word it so that it is neither complementary nor critical nor biased.
'no comment' and 'take it for what you will' is an explicit statement he is making no judgement or conclusion.
And what, you are somehow blaming him for Mantus shank upgrade!?
You are off base. It does not do credit to you and does not help rex. It just reminds us of the bad times with Craig.
And I for one think Delancey is trying to do something interesting here and does not deserve your attack.
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