<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1436229892486_2801"><span>Hank,</span></div><div id="yui_3_16_0_1_1436229892486_2803"><span id="yui_3_16_0_1_1436229892486_2802">I was looking at some Deep Worker photos. The dome retaining bands</span></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805"><span id="yui_3_16_0_1_1436229892486_2804">look like they can be wound tight from a central point at the top.</span></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805"><span id="yui_3_16_0_1_1436229892486_2891">I am wondering if they pre stress these significantly so that there is less movement</span></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805"><span id="yui_3_16_0_1_1436229892486_3003">when they are compressed at depth. <br></span></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805"><span id="yui_3_16_0_1_1436229892486_3063">Also I commented on your retaining system when I first saw it, that I thought the</span></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805"><span id="yui_3_16_0_1_1436229892486_3064">vertical floatational force might move it upward, or the dome pivot out from the bottom.</span></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805">Perhaps you could exert more pressure on the dome with your clamping system?<br></div><div dir="ltr" id="yui_3_16_0_1_1436229892486_2805"><span id="yui_3_16_0_1_1436229892486_3341">Alan</span></div><br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1436229892486_2895"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1436229892486_2894"> <div dir="ltr" id="yui_3_16_0_1_1436229892486_2893"> <hr size="1" id="yui_3_16_0_1_1436229892486_2892"> <font size="2" face="Arial" id="yui_3_16_0_1_1436229892486_3201"> <b><span style="font-weight:bold;">From:</span></b> Alec Smyth via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Tuesday, July 7, 2015 12:31 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] calculation<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1436229892486_3369"><br><div id="yiv3221434423"><div id="yui_3_16_0_1_1436229892486_3371"><div dir="ltr" id="yui_3_16_0_1_1436229892486_3370">Does the window seat have some sort of inside diameter edge? I would think if it does not, then its pretty much guaranteed to slip with or without grease - with grease being the quieter less-terrifying option.<div id="yui_3_16_0_1_1436229892486_3372"><br clear="none"></div><div id="yui_3_16_0_1_1436229892486_3373">Best,</div><div id="yui_3_16_0_1_1436229892486_3374"><br clear="none"></div><div id="yui_3_16_0_1_1436229892486_3375">Alec</div></div><div class="qtdSeparateBR"><br><br></div><div class="yiv3221434423yqt7039758066" id="yiv3221434423yqt35711"><div class="yiv3221434423gmail_extra" id="yui_3_16_0_1_1436229892486_3376"><br clear="none"><div class="yiv3221434423gmail_quote" id="yui_3_16_0_1_1436229892486_3377">On Mon, Jul 6, 2015 at 6:50 PM, hank pronk via Personal_Submersibles <span dir="ltr"><<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none"><blockquote class="yiv3221434423gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;" id="yui_3_16_0_1_1436229892486_3378"><br clear="none">
Sean,<br clear="none">
Thank you for the input, I think I will just use weights like Alan says.<br clear="none">
I am making a fixture to simulate the EPDM gasket compressed under my dome. I want to test it with grease and without. I will squeeze the gasket in the fixture then push the top plate sideways with a pusher bolt to see if the gasket allows movement. I want to make sure my dome can expand and contract at depth.<br clear="none">
Hank<br clear="none">
--------------------------------------------<br clear="none">
On Mon, 7/6/15, Sean T. Stevenson via Personal_Submersibles <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none">
<br clear="none">
Subject: Re: [PSUBS-MAILIST] calculation<br clear="none">
To: "Personal Submersibles General Discussion" <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none">
Received: Monday, July 6, 2015, 9:08 AM<br clear="none">
<div><div class="yiv3221434423h5"><br clear="none">
Hank - the force developed is dependent on the<br clear="none">
stiffness of both the bolt material and of the specimen<br clear="none">
you're pushing on. You can't necessarily equate<br clear="none">
this directly to torque because of friction in the bolt<br clear="none">
threads and at the bolt end contact, and of course the<br clear="none">
elasticity of the bolt itself. You can only estimate it. <br clear="none">
There are many online tools for calculating the developed<br clear="none">
tensile force in a bolted connection, for example, but these<br clear="none">
consider only the bolt as the deformable element, and<br clear="none">
require an accurate estimate of coefficients of friction,<br clear="none">
and this will change with lubrication. As you complicate the<br clear="none">
system, it becomes more geometry dependent.<br clear="none">
A 1" - 8 UNC 2A thread is 8 threads per<br clear="none">
inch, so a set number of turns will give you the approximate<br clear="none">
axial displacement (0.125" per revolution - approximate<br clear="none">
because the bolt will change length under load). If you<br clear="none">
assume a rigid fixture, then your strain is equal to the<br clear="none">
overall change in length (calculated from # of bolt turns),<br clear="none">
divided by the gauge length (distance over which the length<br clear="none">
change occurs, which would be the length of your specimen<br clear="none">
measured between the rigid fixture and the end of your jack<br clear="none">
bolt). Compressive or tensile load is then calculated based<br clear="none">
on the modulus of elasticity of the specimen. <br clear="none">
Alternatively, you can measure the load (make the bolt or<br clear="none">
fixture into a load cell or strain gauge the specimen) and<br clear="none">
calculate the material properties.<br clear="none">
Load, axial displacement, modulus. You need any<br clear="none">
two to calculate the third.<br clear="none">
What are you making / testing?<br clear="none">
Sean<br clear="none">
<br clear="none">
<br clear="none">
<br clear="none">
<br clear="none">
On July 6, 2015 6:26:49 AM<br clear="none">
MDT, hank pronk via Personal_Submersibles<br clear="none">
<<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none">
Hi all,<br clear="none">
I<br clear="none">
need help, can anyone tell me how to calculate how much<br clear="none">
force a bolt can push or pull using a torque wrench to turn<br clear="none">
the bolt. So how many foot pounds of torque does it take to<br clear="none">
rotate a bolt to create 250 lbs push with a 1 in coarse<br clear="none">
thread bolt. I need to make a test fixture.<br clear="none">
Hank<br clear="none">
<br clear="none">
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