<font color='black' size='3' face='Arial, Helvetica, sans-serif'><font class="Apple-style-span" size="3">The voice of experience. I knew about the brush problems, having fought those carbonizing issues with Hymak oil compensated thrusters (Pisces and Aquarius). Perhaps someone will develop this further and generate a white paper for the psubs archives? Air compensation certainly works for Karl S. and could well be a viable and inexpensive alternative for those in the planning/building stages.</font>
<div><font class="Apple-style-span" size="3">Vance<br>
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<div style="font-family: helvetica, arial; font-size: 10pt; color: black; ">-----Original Message-----<br>
From: Alan James via Personal_Submersibles <personal_submersibles@psubs.org><br>
To: psubs.org <personal_submersibles@psubs.org><br>
Sent: Fri, Jul 25, 2014 6:35 pm<br>
Subject: [PSUBS-MAILIST] Air compensating thrusters<br>
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<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839" class="" style="">Hi psubbers,</div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839" class="" style="">in an attempt to get more information on the compensating issue</div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839" class="" style="">I contacted fugu subs, who I remembered used air compensation.</div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839" class="" style=""><u id="yiv9347982726yui_3_16_0_1_1406326496253_3021" class="" style=""><a rel="nofollow" target="_blank" href="http://www.fugusub.com/" id="yiv9347982726yui_3_16_0_1_1406326496253_3024" class="" style="">http://www.fugusub.com/</a></u><br style=""></div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839">They operate small semi dry ambients probably to a max of 100ft. </div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839">One thiught is that they operate in the warm waters of Florida where you would think</div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839">oil compensation would be an advantage in cooling the motors.</div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839" class="" style="">This is their reply.....</div>
<div id="yiv9347982726yui_3_16_0_1_1406326496253_2839" class="" style=""><span style="font-family: monospace;" class="">Hello Alan,</span><br style="font-family: monospace;" class=""><br style="font-family: monospace;" class=""><span style="font-family: monospace;" class="">I seldom respond to technical letters, but I thought it best to save you
some headaches. Over the last thirty years, we have tried several types of oils for filling motors with, as some "authorities" had recommended. Here's what happens: On motors with brushes, the centrifugal force and pressure of the oil passing between brushes and rotors causes the brush to "lift off" of the rotor, causing power loss. The motor slows down dramatically from internal fluid frictions as well. Another issue is that some of these oils can wreck the vinyl insulate on wires and possibly o-rings. On brush motors, </span><br style="font-family: monospace;" class=""><span style="font-family: monospace;" class="">oil is a failed prospect. Stick with an air system. Good luck with your project!</span><br style="font-family: monospace;" class=""><br style="font-family: monospace;" class=""><br style="font-family: monospace;" class=""><span style="font-family: monospace;" class="">Kind
regards,</span><br style="font-family: monospace;" class=""><br style="font-family: monospace;" class=""><span style="font-family: monospace;" class="">Russell J. Canfield</span><br id="yiv9347982726yui_3_16_0_1_1406326496253_2955" class="" style=""></div>
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