A multiturn servo will typically go through 4 or 5 revolutions. That's probably not enough to drive a 40cm rack back and forth.<div><br></div><div>Perhaps you can find a rack and pinion assembly and add a servo to it? Again, for linear motion you might be better with a threaded rod, or a toothed belt clamped to a ball-bearing slide.</div><div><br></div><div>Best wishes,</div><div><br></div><div>Andrew<br><br>On Tuesday, 21 April 2015, Brahm Boelee <<a href="mailto:brahmboelee84@hotmail.co.uk">brahmboelee84@hotmail.co.uk</a>> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div dir="ltr">That's good but I need a longer extension than 10cms and pardon my pickiness but it's a bit pricy. Multi-turn servos sound good but it's just finding the pinion on the drive shaft to match the teeth. <br><br>Is this a multi-turn servo:<br><a href="http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=22528&aff=757677" target="_blank">http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=22528&aff=757677</a><br><br>?<br><br>> Date: Tue, 21 Apr 2015 19:47:20 +1200<br>> From: <a href="javascript:_e(%7B%7D,'cvml','hamster@snap.net.nz');" target="_blank">hamster@snap.net.nz</a><br>> To: <a href="javascript:_e(%7B%7D,'cvml','chchrobotics@lists.linuxnut.co.nz');" target="_blank">chchrobotics@lists.linuxnut.co.nz</a><br>> Subject: Re: [chbot] Cheap Rack and pinion servos?<br>> <br>> <a href="https://nicegear.co.nz/robotics/stepper-motor-29-ozin-200-stepsrev-threaded-shaft/" target="_blank">https://nicegear.co.nz/robotics/stepper-motor-29-ozin-200-stepsrev-threaded-shaft/</a><br>> <br>> <br>> Maybe?<br>> <br>> Brahm Boelee <<a href="javascript:_e(%7B%7D,'cvml','brahmboelee84@hotmail.co.uk');" target="_blank">brahmboelee84@hotmail.co.uk</a>> wrote:<br>> <br>> >I really want an extension of 40cm. <br>> ><br>> >On 21/04/2015, at 7:33 pm, Mark Beckett <<a href="javascript:_e(%7B%7D,'cvml','m.beckett@amuri.net');" target="_blank">m.beckett@amuri.net</a>> wrote:<br>> >> <br>> >> Brahm might have been after one of these.<br>> >> <a href="https://www.google.co.nz/search?q=central+locking+actuator&tbm=isch&tbo=u&source=univ&sa=X&ei=Jf01VcbDH8jFmQXj7IHAAQ&ved=0CBwQsAQ&biw=1680&bih=913" target="_blank">https://www.google.co.nz/search?q=central+locking+actuator&tbm=isch&tbo=u&source=univ&sa=X&ei=Jf01VcbDH8jFmQXj7IHAAQ&ved=0CBwQsAQ&biw=1680&bih=913</a><br>> >> <br>> >> <br>> >> Andrew Errington wrote:<br>> >>> Does such a thing even exist? You might have to make your own. Maybe using a multi-turn servo such as a sail winder with a pinion on the driveshaft.<br>> >>> <br>> >>> Presumably you are looking for linear motion. Have you considered a threaded rod?<br>> >>> <br>> >>> Best wishes,<br>> >>> <br>> >>> Andrew<br>> >>> <br>> >>> On 21 April 2015 at 16:17, Brahm Boelee <<a href="javascript:_e(%7B%7D,'cvml','brahmboelee84@hotmail.co.uk');" target="_blank">brahmboelee84@hotmail.co.uk</a> <mailto:<a href="javascript:_e(%7B%7D,'cvml','brahmboelee84@hotmail.co.uk');" target="_blank">brahmboelee84@hotmail.co.uk</a>>> wrote:<br>> >>> <br>> >>> Hi.<br>> >>> Does anyone know where to get cheap rack and pinion servos?<br>> >>> Preferably with a longer rack.<br>> >>> Thanks for your help<br>> >>> _______________________________________________<br>> >>> Chchrobotics mailing list <a href="javascript:_e(%7B%7D,'cvml','Chchrobotics@lists.linuxnut.co.nz');" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>> >>> <mailto:<a href="javascript:_e(%7B%7D,'cvml','Chchrobotics@lists.linuxnut.co.nz');" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a>><br>> >>> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>> >>> Mail Archives: <a href="http://lists.ourshack.com/pipermail/chchrobotics/" target="_blank">http://lists.ourshack.com/pipermail/chchrobotics/</a><br>> >>> Meetings usually 3rd Monday each month. See <a href="http://kiwibots.org" target="_blank">http://kiwibots.org</a><br>> >>> for venue, directions and dates.<br>> >>> When replying, please edit your Subject line to reflect new subjects.<br>> >>> <br>> >>> <br>> >>> ------------------------------------------------------------------------<br>> >>> <br>> >>> _______________________________________________<br>> >>> Chchrobotics mailing list <a href="javascript:_e(%7B%7D,'cvml','Chchrobotics@lists.linuxnut.co.nz');" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>> >>> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>> >>> Mail Archives: <a href="http://lists.ourshack.com/pipermail/chchrobotics/" target="_blank">http://lists.ourshack.com/pipermail/chchrobotics/</a><br>> >>> Meetings usually 3rd Monday each month. See <a href="http://kiwibots.org" target="_blank">http://kiwibots.org</a> for venue, directions and dates.<br>> >>> When replying, please edit your Subject line to reflect new subjects.<br>> >> <br>> >> _______________________________________________<br>> >> Chchrobotics mailing list <a href="javascript:_e(%7B%7D,'cvml','Chchrobotics@lists.linuxnut.co.nz');" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>> >> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>> >> Mail Archives: <a href="http://lists.ourshack.com/pipermail/chchrobotics/" target="_blank">http://lists.ourshack.com/pipermail/chchrobotics/</a><br>> >> Meetings usually 3rd Monday each month. See <a href="http://kiwibots.org" target="_blank">http://kiwibots.org</a> for venue, directions and dates.<br>> >> When replying, please edit your Subject line to reflect new subjects.<br>> ><br>> >_______________________________________________<br>> >Chchrobotics mailing list <a href="javascript:_e(%7B%7D,'cvml','Chchrobotics@lists.linuxnut.co.nz');" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>> ><a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>> >Mail Archives: <a href="http://lists.ourshack.com/pipermail/chchrobotics/" target="_blank">http://lists.ourshack.com/pipermail/chchrobotics/</a><br>> >Meetings usually 3rd Monday each month. See <a href="http://kiwibots.org" target="_blank">http://kiwibots.org</a> for venue, directions and dates.<br>> >When replying, please edit your Subject line to reflect new subjects.<br>> _______________________________________________<br>> Chchrobotics mailing list <a href="javascript:_e(%7B%7D,'cvml','Chchrobotics@lists.linuxnut.co.nz');" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>> Mail Archives: <a href="http://lists.ourshack.com/pipermail/chchrobotics/" target="_blank">http://lists.ourshack.com/pipermail/chchrobotics/</a><br>> Meetings usually 3rd Monday each month. See <a href="http://kiwibots.org" target="_blank">http://kiwibots.org</a> for venue, directions and dates.<br>> When replying, please edit your Subject line to reflect new subjects.<br> </div></div>
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