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		<title><![CDATA[SoliForum - 3D Printing Community — Hysteresis & Backlash Testing]]></title>
		<link>https://www.soliforum.com/topic/11162/hysteresis-backlash-testing/</link>
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		<description><![CDATA[The most recent posts in Hysteresis & Backlash Testing.]]></description>
		<lastBuildDate>Sun, 17 May 2015 22:10:26 +0000</lastBuildDate>
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			<title><![CDATA[Re: Hysteresis & Backlash Testing]]></title>
			<link>https://www.soliforum.com/post/96092/#p96092</link>
			<description><![CDATA[<p>That&#039;s a nice setup indeed. I have a dial indicator but it did not come with a stand/base, so I&#039;ll have to figure something out. Thanks for the info!</p>]]></description>
			<author><![CDATA[null@example.com (oscahie)]]></author>
			<pubDate>Sun, 17 May 2015 22:10:26 +0000</pubDate>
			<guid>https://www.soliforum.com/post/96092/#p96092</guid>
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			<title><![CDATA[Re: Hysteresis & Backlash Testing]]></title>
			<link>https://www.soliforum.com/post/96035/#p96035</link>
			<description><![CDATA[<p>It&#039;s on it&#039;s own stand/base that has a heavy magnet (with switch) - just set it on metal and rotate switch and you&#039;ll need a horse to move it.&nbsp; Thus, it&#039;s not going anywhere.&nbsp; Two photo&#039;s of it...<br />Note: There are different way&#039;s to measure the hysteresis/backlash, I briefly presented one.</p><p>You could print something (something to hold a small dial gauge) but, the results would also include the bed&#039;s side-to-side play and may mask the X/Y you&#039;re measuring...</p><p><span class="postimg"><img src="http://soliforum.com/i/?mz2Zs68.jpg" alt="http://soliforum.com/i/?mz2Zs68.jpg" /></span><br /><span class="postimg"><img src="http://soliforum.com/i/?qlIbllD.jpg" alt="http://soliforum.com/i/?qlIbllD.jpg" /></span></p>]]></description>
			<author><![CDATA[null@example.com (galaxy99)]]></author>
			<pubDate>Sat, 16 May 2015 22:01:43 +0000</pubDate>
			<guid>https://www.soliforum.com/post/96035/#p96035</guid>
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			<title><![CDATA[Re: Hysteresis & Backlash Testing]]></title>
			<link>https://www.soliforum.com/post/96032/#p96032</link>
			<description><![CDATA[<p>This is an interesting test. Can you elaborate on what you use to hold the dial indicator in place for both X and Y axis? I see it in the pictures but I can&#039;t quite get what it is exactly. Maybe I should try to model something printable for this task... also, can you guarantee that this thing holding the indicator does not have any play, which would throw off the measurements?</p>]]></description>
			<author><![CDATA[null@example.com (oscahie)]]></author>
			<pubDate>Sat, 16 May 2015 21:48:56 +0000</pubDate>
			<guid>https://www.soliforum.com/post/96032/#p96032</guid>
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			<title><![CDATA[Hysteresis & Backlash Testing]]></title>
			<link>https://www.soliforum.com/post/96014/#p96014</link>
			<description><![CDATA[<p>After calibration, I figured I’d do some general maintenance and included a Hysteresis test.</p><p>I wrote a small G-code routine to position the extruder where I wanted it and looped it back and forth (same way I do it on my CNC mill) - this tests for hysteresis primarily due to backlash in gears, belts, rod slop…etc.</p><p><em>Note:</em>&nbsp; I do not have print issues such as layers not being uniform and/ hanging off to the side like some folks have posted.&nbsp; If I did, the hysteresis would show that so, those having those issues may want to try this to verify the problem is in the machine/belt/gears and not the printing gcode or software (or bed slop).</p><p>The down side to the G-code approach is that XYZ’s firmware has hard-code to pre-heat (bed and nozzle) and does not implement the necessary M-codes to pause position, hold and turn off the temps.&nbsp; (I believe Repeater does implement them, per published info).</p><p>So, I tried testing by Jogging (thus eliminating wait time for temps and this approach has the bonus of positioning and pausing where I want.&nbsp; </p><p>Positioning was repeatable and without significant hysteresis (in both approaches).&nbsp; Photo’s attached from one of the Jog approach tests. Pay no attention to the numbers - they&#039;re not metric...<br />Commanded jog = 20mm, it went 19.43mm<br />Commanded jog (from previous point in opposite direction) = 10mm, it went 9.68mm<br />Repeated the above including back to Zero several times.&nbsp; At zero, the average delta max was 0.254mm (0.01&quot;) - that is the amount of hysteresis over a 20mm repeated sweep.</p><p>There is no ability to set motion speed when using the jog approach but, I don’t expect it to be much different at higher speeds (because the mass and acceleration/deccelleration are small and I set the speed to 5000 in the g-code).</p><p><strong>The Jog routine for testing hysteresis is as follows:</strong></p><p>Position a dial guage as far to left as possible<br />Jog the bed to a position that works for your clearance needs<br />Position X and Y so you can set the dial to Zero (or your preferred ref point<span style="color: red"><strong>*</strong></span>)<br />Jog the axis you’re testing using each of the distance settings (1mm, 10mm, 20mm)&nbsp; go back and forth and see if the dial returns to the set-point or if it’s off.</p><p><span style="color: red">*</span>Depending upon your dial guage, you may be able to set zero in mid-stroke of the dial&#039;s pusher.</p><p>Do the same for the other axis.&nbsp; No need to do the Z-axis as the bed position is constant during a layer build (ie, it doesn’t go up/down like a CNC mill).</p><p><strong>This might help identify areas to tweak and improve printing…</strong></p><p><span class="postimg"><img src="http://soliforum.com/i/?hMsSMf3.jpg" alt="http://soliforum.com/i/?hMsSMf3.jpg" /></span></p><p><span class="postimg"><img src="http://soliforum.com/i/?9HQsHjE.jpg" alt="http://soliforum.com/i/?9HQsHjE.jpg" /></span></p><p><span class="postimg"><img src="http://soliforum.com/i/?0FLby7U.jpg" alt="http://soliforum.com/i/?0FLby7U.jpg" /></span></p>]]></description>
			<author><![CDATA[null@example.com (galaxy99)]]></author>
			<pubDate>Sat, 16 May 2015 19:54:03 +0000</pubDate>
			<guid>https://www.soliforum.com/post/96014/#p96014</guid>
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