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</o:shapelayout></xml><![endif]--></head><body lang=FR-CA link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Thank You Spiros for your nice message.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Did you see my last post about the final setup I will use ?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>The small wheel with tire is making a good steady contact<br>with the scrolling paper I want to measure the speed of..<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>So far so good.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=FR style='font-size:11.0pt;font-family:"Calibri",sans-serif'>De :</span></b><span lang=FR style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Spiros Makris <spirosmakris92@gmail.com> <br><b>Envoyé :</b> 6 janvier 2025 07:29<br><b>À :</b> Jean-Pierre Desrochers <jpdesroc@oricom.ca><br><b>Cc :</b> Gerry Murray <synthimuse@gmail.com>; synth-diy@synth-diy.org<br><b>Objet :</b> Re: [sdiy] Looking for a mini rotary encoder with very low torque (servo type)<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Did you have a look at encoders built for motor control (and robotics in general)? They can in many flavors (and prices), and are usually mount on the shaft of the motor; in your case you might need to devise a different mounting method. Using rubber bands is probably going to slip, but if space allows you could use a belt, the way 3D printers do - if properly designed for the application it will not slip.<o:p></o:p></p><div><p class=MsoNormal>In my experience, trying to make your own using hall sensors and magnets will be hard to nail down, unless you have a 3D printer (or other CNC type machine) that will take care of tolerances for you. If your goal is to keep speed constant, or measure amount of rotation, this can have a very big impact on your application.<o:p></o:p></p></div><div><p class=MsoNormal>Finally, you can get rotary encoders aimed for UI/controls that have a smooth rotation. They specify the torque needed to turn them, so you can pick the lowest. If what you measure is actively moved by a motor then it will definitely have no problem turning it, and will be unlikely to slip, as long as it is mated to the rotating axis properly.<o:p></o:p></p></div><div><p class=MsoNormal>You might also consider tensioning your moving paper in a different way, so that the slip will become negligible.<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Thu, 12 Dec 2024 at 18:55, Jean-Pierre Desrochers via Synth-diy <<a href="mailto:synth-diy@synth-diy.org">synth-diy@synth-diy.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><i><span style='color:#558ED5'>> Is it more important to measure the surface of the paper itself due to torque/slippage reasons like on a tape machine, </span></i></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'>Yes.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><i><span style='color:#558ED5'>> or will measuring the speed of the take up spool get you the same info?</span></i></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>No.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><i><span style='color:#558ED5'>> If the latter is an option, what about a magnet and a hall sensor on the take up spool, <br>> disk the same diameter as the take up reel in the drive mechanism with some other sort of sensor on it like cheater mentioned, <br>> or even a small notch in the take up spool (or equivalent disk in the drive mechanism) that has a limit switch with roller against it.</span></i></b><br>Measuring the take up spool rotation speed will hide the actual problem I have<br>which is paper thickness accumulation on the take up spool (with fixed speed)<br><u>that speeds up the overall moving paper speed !</u><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>So far my software only put 25 fixed parameters (by means of a potentiometer) to control<br>the PLAY stepup motor steps and would not check for any speedup in a song.<br>That’s what I discovered some days ago and am trying to fix.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'>The solution is to read the paper moving surface (regardless of the take up spool speed )<br>But in a very small space to do it.<br>So no place for any encoder disc (it would need to be smaller than 18mm in diameter.. see why below), <br>nor any ‘normal’ size Opto-Interrupter..<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Because of the very small and limited space I could mount this thing,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I will use a model car wheel with rubber tire (overall outside diameter 18mm),<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>mounted on a small 1/16in. shaft that will turn a small glued piece of opaque plastic<br>in the slot of a very small SMD opto-interupter like this one :<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><img border=0 width=248 height=336 style='width:2.5833in;height:3.5in' id="m_6341782698702377523Image_x0020_2" src="cid:image001.jpg@01DB6025.61989E50"><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The below picture shows the actual tiny wheel with rubber tire I will use (to put against the moving paper)<br>and part of the setup I used in a past project with a small rotating piece of plastic<br>moving inside a Opto-Interrupter.<br>Mine will be much smaller. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><img border=0 width=1048 height=593 style='width:10.9166in;height:6.177in' id="m_6341782698702377523Image_x0020_1" src="cid:image002.jpg@01DB6025.61989E50"><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I’m now waiting my Digikey order for the Opto-Interrupters + nylon hardware.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>And thanks Gerry for your nice suggestions !<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=FR>De :</span></b><span lang=FR> Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a>> <b>De la part de</b> Nathan Trites<br><b>Envoyé :</b> 12 décembre 2024 10:17<br><b>À :</b> Gerry Murray <<a href="mailto:synthimuse@gmail.com" target="_blank">synthimuse@gmail.com</a>><br><b>Cc :</b> <a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a><br><b>Objet :</b> Re: [sdiy] Looking for a mini rotary encoder with very low torque (servo type)</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>This is the direction I was just thinking, and was also on the Adafruit site looking at plug and play sensor options. <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Jean-Pierre - I'm assuming this is to make the speed on your piano roll player programmable/repeatable? Is it more important to measure the surface of the paper itself due to torque/slippage reasons like on a tape machine, or will measuring the speed of the take up spool get you the same info? If the latter is an option, what about a magnet and a hall sensor on the take up spool, disk the same diameter as the take up reel in the drive mechanism with some other sort of sensor on it like cheater mentioned, or even a small notch in the take up spool (or equivalent disk in the drive mechanism) that has a limit switch with roller against it.<o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>If it must be against the paper, opto-interruptors and disks are available on their own, and then you could rig something up so that assembly rests lightly against the paper:<o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><a href="https://bc-robotics.com/shop/opto-interrupter-with-mounting-tabs/" target="_blank">https://bc-robotics.com/shop/opto-interrupter-with-mounting-tabs/</a><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><a href="https://bc-robotics.com/shop/encoder-disc/" target="_blank">https://bc-robotics.com/shop/encoder-disc/</a><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Nathan<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On Thu, Dec 12, 2024 at 9:22<span style='font-family:"Arial",sans-serif'> </span>AM Gerry Murray via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'>Hi JP<br><br>You could maybe try a resolver. The resolution of them can be very high <br>: up to 16 bit.<br><a href="https://www.mouser.co.uk/applications/resolver-encoder-motor-control/" target="_blank">https://www.mouser.co.uk/applications/resolver-encoder-motor-control/</a><br><a href="https://www.instructables.com/Arduino-Resolver-Module/" target="_blank">https://www.instructables.com/Arduino-Resolver-Module/</a><br><br>I always like it when you put an inquiry on the list because, usually 6 <br>months later on, a really cool project emerges. :-)<br><br>Best wishes<br><br>Gerry<br><br><br>On 11/12/2024 15:09, Jean-Pierre Desrochers via Synth-diy wrote:<br>> I'm looking for a very small (20mm or less body diameter)<br>> rotary encoder with very low torque (servo type).<br>> The low torque shaft is needed because it will turn by means<br>> of a small wheel with rubber sides that will be put against a moving surface, turn and 'follow'<br>> the moving surface.. no slipping allowed !<br>><br>> The precision of steps/turn is not important.<br>> But the higher will be best..<br>><br>> I was thinking of using a dismantled PC mouse (rubber ball type)<br>> and use one of the two X/Y optical rotary encoders, but these PC mice<br>> nowadays are hard to find.. So.<br>><br>> I checked Digikey and Mouser but they have encoder too big<br>> for my uses..<br>> The smaller I found has 20mm in diameter..<br>> <a href="https://www.digikey.ca/en/products/detail/nidec-components-corporation/RES20D-50-201-1/6469509" target="_blank">https://www.digikey.ca/en/products/detail/nidec-components-corporation/RES20D-50-201-1/6469509</a><br>><br>> Any suggestions ?<br>><br>><br>> ________________________________________________________<br>> This is the Synth-diy mailing list<br>> Submit email to: <a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br>> View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/" target="_blank">https://synth-diy.org/pipermail/synth-diy/</a><br>> Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">https://synth-diy.org/mailman/listinfo/synth-diy</a><br>> Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><br><br><br>________________________________________________________<br>This is the Synth-diy mailing list<br>Submit email to: <a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br>View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/" target="_blank">https://synth-diy.org/pipermail/synth-diy/</a><br>Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">https://synth-diy.org/mailman/listinfo/synth-diy</a><br>Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><o:p></o:p></p></blockquote></div></div></div></div><p class=MsoNormal>________________________________________________________<br>This is the Synth-diy mailing list<br>Submit email to: <a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br>View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/" target="_blank">https://synth-diy.org/pipermail/synth-diy/</a><br>Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">https://synth-diy.org/mailman/listinfo/synth-diy</a><br>Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><o:p></o:p></p></div></blockquote></div></div></div></body></html>