[PSUBS-MAILIST] Hull Calc: 78" spheres

[Sean T. Stevenson via Personal_Submersibles]

Yeah, you really need to cross your t's and dot your i's when tendering a bid or ordering a part to specification. Anything not explicitly spelled out is subject to interpretation or disregard.  I always create completely dimensioned and toleranced engineering drawings for this purpose, in addition to material specifications and test performance requirements, and make clear that if the part doesn't pass QC, the supplier is responsible for correcting the problem. I get such an agreement signed. Of course, I have the benefit of having been doing this professionally for years. Strict hobbyists cannot be expected to be as informed.

That said, I would take the required tolerances, roundness, test procedures and so forth right out of the guides, and present this when getting quotes so that I get the true cost for what I need, and discover right away if it is not within a supplier's capabilities.

How did your dome turn out? Were you able to correct it?

Sean


On January 9, 2015 7:29:44 PM MST, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
>Sean,
>EE did my parts and my dome was quite bent when sitting on the bench. 
>They told me too bad, it is within ASME specs.
>Hank--------------------------------------------
>On Fri, 1/9/15, Sean T. Stevenson via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>
> Subject: Re: [PSUBS-MAILIST] Hull Calc:  78" spheres
>To: "Personal Submersibles General Discussion"
><personal_submersibles at psubs.org>
> Received: Friday, January 9, 2015, 9:24 PM
> 
> I never thought to add the functionality to solve
> for diameter. I'll have to look into that.
> I'll run your calc. Stay tuned.
> Sean
> 
> 
> 
> 
> On January 9, 2015 6:16:50
> PM MST, "swaters at waters-ks.com via
> Personal_Submersibles"
> <personal_submersibles at psubs.org> wrote:
> Sean,Can I ask you to do one more calc for
> me? 516 gr 70 sphere, 1" thick, 72"
> diameter. The 78" was not within ABS rules
> at 1000m. I think the 72" might just make it, yet give
> me more boyancy than the
> 60"Thanks,Scott
> Waters
> 
> Sent from my U.S.
> Cellular® Smartphone
> 
> -------- Original message
> --------
> From: "Sean T. Stevenson via
> Personal_Submersibles"  
> Date:01/08/2015  8:28 PM  (GMT-06:00) 
> To: Personal Submersibles General Discussion 
> 
> Subject: Re: [PSUBS-MAILIST] Hull Calc: 
> 78" spheres 
> 
> 
>     On 2015-01-08
> 19:01, via
>       Personal_Submersibles wrote:
> 
>     
>     That's what I got.
>           Only without the format. Sweet. Thanks Sean.
> It's going to
>           take a syntactic buoyancy package to get it right,
> but it
>           looks like a decent alternative. A 6 1/2 foot
> sphere displaces
>           about a thousand pounds more than the pair of 5
> footers.
>           Pretty close, and might be marginally less
> expensive. What
>           would a 39" radius do for depth in the
> thicknesses you have
>           already given?
>         Vance
> 
>         
>       
>     
> 
>     As
>         requested:
> 
>         
> 
>         ASTM A516 Grade 70, 78" sphere, 0.75"
> wall:
> 
>       
> 
>     
> 
>     
> 
>     ASTM A516 Grade 70, 78" sphere, 1" wall:
> 
>     
> 
>     
> 
>     HY-100, 78"
>         sphere, 0.75" wall:
> 
>     
> 
>     
> 
>     HY-100, 78" sphere, 1" wall:
> 
>     
> 
>     
> 
>     Sean
> 
>     
> 
>   
> 
> 
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
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> 
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