<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>I wrote this a couple of years ago . . . and it is simplified to present the major factors:</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal;"><span style="font-size: 12pt;"> </span><br></div><div>Bob Kane<br>getterflash@yahoo.com<br></div> <div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"> <div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span
style="font-weight:bold;">From:</span></b> Patrick Harris <harris7148@gmail.com><br> <b><span style="font-weight: bold;">To:</span></b> Bob Kane <getterflash@yahoo.com>; General pattern discussion <nsrca-discussion@lists.nsrca.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, May 2, 2013 4:25 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [NSRCA-discussion] Himax 6330 rebuild<br> </font> </div> <div class="y_msg_container"><br><div id="yiv1958596322"><div dir="ltr">Which results in more heat? Correct.</div><div class="yiv1958596322gmail_extra"><br><br><div class="yiv1958596322gmail_quote">On Thu, May 2, 2013 at 12:55 PM, Bob Kane <span dir="ltr"><<a rel="nofollow" ymailto="mailto:getterflash@yahoo.com" target="_blank" href="mailto:getterflash@yahoo.com">getterflash@yahoo.com</a>></span> wrote:<br>
<blockquote class="yiv1958596322gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif;"><div><span><font size="3">This knowledge is in the dusty mental archives from my university days, but basic motor theory will show a motor develops a voltage when it spins. We will call this the "back EMF" voltage. It is easy to measure with a brushed DC motor, hook it up to a voltmeter and spin it. You will see the voltage rise as the RPM increases (and drop as it decreases). This voltage is a function of many things, but we will focus on RPM and the </font>strength<font size="3"> of the magnetic field. The current drawn by a motor is the difference between the supplied voltage and the "back EMF" voltage developed by the motor. Since the back EMF voltage is a function of how fast it spins, it will draw little current when
unloaded, and the as we load the motor with a prop the current will go
up.</font></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;"><span><font size="3"><br></font></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;">
<span><font size="3">Weak magnets will cause the motor's back EMF voltage to go down and result in an increase of the current drawn by the motor.</font></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;">
<br></div><div style="font-style:normal;font-size:16px;background-color:transparent;"><span style="font-size:12pt;background-color:transparent;">Bob
Kane</span><br></div><div style="font-size:12pt;"><a rel="nofollow" ymailto="mailto:getterflash@yahoo.com" target="_blank" href="mailto:getterflash@yahoo.com">getterflash@yahoo.com</a><br></div> <div style="font-size:12pt;">
<div style="font-size:12pt;"> <div dir="ltr"> <hr size="1"> <font face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Patrick Harris <<a rel="nofollow" ymailto="mailto:harris7148@gmail.com" target="_blank" href="mailto:harris7148@gmail.com">harris7148@gmail.com</a>><br>
<b><span style="font-weight:bold;">To:</span></b> General pattern discussion <<a rel="nofollow" ymailto="mailto:nsrca-discussion@lists.nsrca.org" target="_blank" href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</a>> <br> <b><span style="font-weight:bold;">Sent:</span></b> Thursday, May 2, 2013 3:31 PM<br>
<b><span style="font-weight:bold;">Subject:</span></b> Re: [NSRCA-discussion] Himax 6330 rebuild<br> </font> </div> <div><br><div><div dir="ltr">Verne,<div><br></div><div>I was thinking that may be the issue. I pulled
it already so no way to do an amp draw. </div></div><div><br><br><div>On Thu, May 2, 2013 at 11:29 AM, Verne Koester <span dir="ltr"><<a rel="nofollow" ymailto="mailto:verne@twmi.rr.com" target="_blank" href="mailto:verne@twmi.rr.com">verne@twmi.rr.com</a>></span> wrote:<br>
<blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div lang="EN-US"><div><div><span style="color:#1f497d;">If the motor is demagnetized (usually caused by overload and/or overheating) the amp draw will increase dramatically. Of course to know that, you have to have a baseline amp draw from when the motor was new to compare it to. What you’re describing sounds like your old motor was demagnetized. You could try comparing the amp draw on your old motor with the amp draw on your new one.<u></u><u></u></span></div>
<div><span style="color:#1f497d;"><u></u> <u></u></span></div><div><span style="color:#1f497d;">Hope this helps.<u></u><u></u></span></div>
<div><span style="color:#1f497d;"><u></u> <u></u></span></div><div><span style="color:#1f497d;">Verne Koester<u></u><u></u></span></div>
<div><span style="color:#1f497d;"><u></u> <u></u></span></div><div><b><span style="font-size:10.0pt;">From:</span></b><span style="font-size:10.0pt;"> <a rel="nofollow" ymailto="mailto:nsrca-discussion-bounces@lists.nsrca.org" target="_blank" href="mailto:nsrca-discussion-bounces@lists.nsrca.org">nsrca-discussion-bounces@lists.nsrca.org</a> [mailto:<a rel="nofollow" ymailto="mailto:nsrca-discussion-bounces@lists.nsrca.org" target="_blank" href="mailto:nsrca-discussion-bounces@lists.nsrca.org">nsrca-discussion-bounces@lists.nsrca.org</a>] <b>On Behalf Of </b>Patrick Harris<br>
<b>Sent:</b> Thursday, May 02, 2013 1:57 PM<br><b>To:</b> <a rel="nofollow" ymailto="mailto:jpavlick@idseng.com" target="_blank" href="mailto:jpavlick@idseng.com">jpavlick@idseng.com</a>; General pattern discussion<br><b>Subject:</b> Re: [NSRCA-discussion] Himax 6330 rebuild<u></u><u></u></span></div>
<div><u></u> <u></u></div><div><div>Just last week I had to replace a 210. It was getting so hot you couldn't touch it. It was putting such a load on the Jeti that it shut down in the air. The bearings feel fine, so it may be the magnets. Can magnets cause this to happen?. Oh and a year or so ago I did replace the shaft in mine and it had just a hair of end play.<u></u><u></u></div>
<div><div><u></u> <u></u></div></div><div><div> <u></u><u></u></div></div></div><div><div style="margin-bottom:12.0pt;"><u></u> <u></u></div><div><div>On Thu, May 2, 2013 at 10:13 AM, John Pavlick <<a rel="nofollow" ymailto="mailto:jpavlick26@att.net" target="_blank" href="mailto:jpavlick26@att.net">jpavlick26@att.net</a>> wrote:<u></u><u></u></div>
<div><div><div><span style="font-size:11.0pt;color:#1f497d;">You had to rebuild an electric motor? I thought they never wore out (which is why they’re better than glow engines)… LOL</span><u></u><u></u></div>
<div><span style="font-size:11.0pt;color:#1f497d;"> </span><u></u><u></u></div><div><span style="font-size:11.0pt;color:#1f497d;">Seriously, how long do magnets last in these big motors (if you’re careful about heat + current draw)? Does anyone offer a “magnet-zapping” service?</span><u></u><u></u></div>
<div><span style="font-size:11.0pt;color:#1f497d;"> </span><u></u><u></u></div><div><div><span style="font-size:11.0pt;color:#1f497d;">John Pavlick</span><u></u><u></u></div>
<div><span style="font-size:11.0pt;color:#1f497d;">Cell: <a rel="nofollow" href="">203-417-4971</a></span><u></u><u></u></div><div>
<span style="font-size:11.0pt;color:#1f497d;"> </span><u></u><u></u></div><div><u></u><u></u></div><div><span style="font-size:10.0pt;color:#1f497d;">Integrated Development Services</span><u></u><u></u></div>
</div><div><span style="font-size:11.0pt;color:#1f497d;"> </span><u></u><u></u></div><div><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in;">
<div><b><span style="font-size:10.0pt;">From:</span></b><span style="font-size:10.0pt;"> <a rel="nofollow" ymailto="mailto:nsrca-discussion-bounces@lists.nsrca.org" target="_blank" href="mailto:nsrca-discussion-bounces@lists.nsrca.org">nsrca-discussion-bounces@lists.nsrca.org</a> [mailto:<a rel="nofollow" ymailto="mailto:nsrca-discussion-bounces@lists.nsrca.org" target="_blank" href="mailto:nsrca-discussion-bounces@lists.nsrca.org">nsrca-discussion-bounces@lists.nsrca.org</a>] <b>On Behalf Of </b>Kirk Sutherland<br>
<b>Sent:</b> Saturday, April 27, 2013 11:14 AM<br><b>To:</b> NSRCA<br><b>Subject:</b> [NSRCA-discussion] Himax 6330 rebuild</span><u></u><u></u></div></div></div><div><div> <u></u><u></u></div><div><div>
<span>I have rebuilt a Himax 210 . When I replace the retaining bolt in the back how much end play should the can have in it when moved front to back ?<br> <br>
Thanks Kirk<br> <br> </span><u></u><u></u></div></div></div><div align="center" style="text-align:center;"><span><hr size="1" width="100%" noshade="" style="color:#aca899;" align="center">
</span></div><div><span>No virus found in this message.<br>Checked by AVG - <a rel="nofollow" target="_blank" href="http://www.avg.com/">www.avg.com</a><br>Version: 2013.0.3272 / Virus Database: 3162/6274 - Release Date: 04/26/13</span><u></u><u></u></div>
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