<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Rick,</div><div id="AppleMailSignature">I got this one but haven't seen any others for a while!</div><div id="AppleMailSignature">Alan<br><br>Sent from my iPad</div><div><br>On 8/09/2017, at 5:08 AM, Rick Patton via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div>Doesn't look like my posts are coming through. Anybody seeing them?</div><div>Rick </div><div><br><div class="gmail_quote"><div>On Thu, Sep 7, 2017 at 9:32 AM Steve McQueen via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Yes, I have some. I am planning on using them for the light weight stuff. The holes I was contemplating were to help hold a little more weight than those devices might. I was hoping I was done with all the welding but maybe not.<br>
<br>
Thanks,<br>
Steve<br>
<br>
---- Alec Smyth via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<br>
> Steve,<br>
><br>
> If you go to a hardware store you might find some little aluminum security<br>
> devices for locking sliding doors. I'm sure TrueValue has better (wink wink<br>
> for Scott) but at Home Depot I found some that fit the K250 stiffener<br>
> flanges perfectly. They clamp on with a set screw, and give you a tab you<br>
> can drill for attaching things.<br>
><br>
> Best,<br>
><br>
> Alec<br>
><br>
> On Thu, Sep 7, 2017 at 10:24 AM, Steve McQueen via Personal_Submersibles <<br>
> <a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<br>
><br>
> > Sean, thanks. I was hoping you would respond : ) I did have a clamping<br>
> > approach in mind that I will revisit.<br>
> > Thanks,<br>
> > Steve<br>
> ><br>
> > ---- "Sean T. Stevenson via Personal_Submersibles" <<br>
> > <a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<br>
> > > The minimum moment of inertia of the combined section of the stiffener<br>
> > plus an effective length of the pressure boundary shell may be specified by<br>
> > design, but in any case is to be calculated in consideration of the minimum<br>
> > at the locations where any holes exist. Holes in the flange are far more<br>
> > detrimental than holes in the web, with the mininum impact hole being a<br>
> > hole which is coincident with the neutral axis across the combined section.<br>
> > (i.e. holes drilled in the center of the web of an I-beam have the least<br>
> > impact).<br>
> > ><br>
> > > Better than drilling holes would be to simply clamp to stiffener rings,<br>
> > or weld on brackets or studs such that no material is removed from the<br>
> > stiffener section. Otherwise you do have to account for the reduced moment<br>
> > of inertia of the stiffener section at the hole location in your buckling,<br>
> > inter-stiffener strength and stuffener tripping calculations.<br>
> > ><br>
> > > Sean<br>
> > ><br>
> > ><br>
> > > On September 7, 2017 6:51:03 AM PDT, Steve McQueen via<br>
> > Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<br>
> > > >All, as most probably know a K-250 has internal angle stiffeners (L).<br>
> > > ><br>
> > > >In my rebuild I have avoided drilling any holes in the web portion of<br>
> > > >these stiffeners (actually had some existing holes from the original<br>
> > > >build welded up/filled). However, I am finding it would be nice if I<br>
> > > >could drill a few small (1/4") holes to help mount some interior parts.<br>
> > > >I believe I am looking at 1 to 3 of these holes max. in any single<br>
> > > >stiffener web.<br>
> > > ><br>
> > > >Calculating any reduction in functional strength that might result from<br>
> > > >a few small holes isn't straight forward. I guess I am looking for<br>
> > > >some feedback from those who understand the web function of an L<br>
> > > >stiffener better than I.<br>
> > > ><br>
> > > >My guess is this wouldn't be a significant issue and I an being too<br>
> > > >anal.<br>
> > > ><br>
> > > >Thanks,<br>
> > > >Steve<br>
> > > >_______________________________________________<br>
> > > >Personal_Submersibles mailing list<br>
> > > ><a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br>
> > > ><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="noreferrer" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
> > _______________________________________________<br>
> > Personal_Submersibles mailing list<br>
> > <a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br>
> > <a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="noreferrer" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
> ><br>
_______________________________________________<br>
Personal_Submersibles mailing list<br>
<a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="noreferrer" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
</blockquote></div></div>
</div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Personal_Submersibles mailing list</span><br><span><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a></span><br><span><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br></div></blockquote></body></html>