Overcomplicated Variable Torque Wrench Ratchet

prusaprinters

<p>REMEMBER: do not leave torque wrench in preload state. Always unscrew cap to 0 position or below when not in use. It is usual practice using torque wrenches.</p> <p>UPDATE 2020-04-19 added more constant and variable thicknes springs.</p> <p> <figure class="media"> <oembed url="https://www.youtube.com/watch?v=NHQN-asuM1A"></oembed> </figure> </p> <p>As most of my printed parts use M3 hex screws, I got tired of using hex L-key. So decided to make torque wrench for light use.<br/> With default 1.8mm thick spring it works in range of 0.39 - 1.06Nm (depending on PETG manufacturer spring stiffness will vary). You can switch springs if needed to change Nm range. Now I only included 1.8mm and 2.05mm springs. Will upload more springs. Designed variable thickness springs across its length which gives wider range like example 0.5-2.5Nm.<br/> I tested torque wrench mechanism, it can withstand 3Nm load, but since I added ratchet mechanism later and didn't had a chance to test it. So it probably is a weaker point and might break at that point. I doubt anyone needs so much torque, with 3.5Nm I squished 3D printed part and M4 screw itself.</p> <p>Wrench uses 3x 6000ZZ 10x26x8mm bearings, 2x M3 50mm buttonhead bolts and 2x M3 nuts, everything else is 3D printed.<br/> This is probably useless tool for most of the makers as it is pretty bulky, but I hope someone will make some use of it.<br/> This is second gen of wrench, first gen was 2 times shorter, without wide front but lacked ratchet function.</p> <p>Designed to avoid using supports as much as possible.</p> <p>Feel free to ask.</p> <h3>Print instructions</h3><p>Parts BOM below. It's noted which parts has to be printed with PETG.<br/> As I printed all parts from PETG. I included 3 gcode files, each of them has different parts set, Set1 parts with supports, Set2 parts with brim, Set3 parts without supports and brim. I used textured bed sheet.</p> <p>Assembly video: <a href="https://www.youtube.com/watch?v=opOk2o8NLI0">https://www.youtube.com/watch?v=opOk2o8NLI0</a></p> <p>BOM link: <a href="https://docs.google.com/spreadsheets/d/1kFQk56aX42L3CyWq5Kztgkbw85gURGIeB6PzmdoBpio/edit?usp=sharing">https://docs.google.com/spreadsheets/d/1kFQk56aX42L3CyWq5Kztgkbw85gURGIeB6PzmdoBpio/edit?usp=sharing</a></p> <p>Filament Quantity Name<br/> ¯_(ツ)<em>/¯ 1 Filament Top Pin<br/> BUY 3 6000ZZ 10x26x8<br/> ¯\</em>(ツ)<em>/¯ 1 Bit Base V2<br/> P E T G 1 Cap<br/> ¯\</em>(ツ)<em>/¯ 1 Fastener Top<br/> P E T G 1 Insert<br/> ¯\</em>(ツ)<em>/¯ 6 Pusher V3<br/> ¯\</em>(ツ)<em>/¯ 6 Teeth V2<br/> ¯\</em>(ツ)<em>/¯ 1 Spring Preloader<br/> ¯\</em>(ツ)<em>/¯ 1 Tube<br/> P E T G 6 Clip<br/> ¯\</em>(ツ)<em>/¯ 1 Clip Bottom Holder<br/> ¯\</em>(ツ)<em>/¯ 1 Clip Middle Holder<br/> ¯\</em>(ツ)<em>/¯ 1 Clip Top Holder<br/> ¯\</em>(ツ)<em>/¯ 1 Fastener Bottom<br/> ¯\</em>(ツ)<em>/¯ 1 Filament Botom Pin<br/> ¯\</em>(ツ)<em>/¯ 1 Hex Shank Holder<br/> BUY 2 M3 Nut<br/> BUY 2 M3x50mm<br/> ¯\</em>(ツ)<em>/¯ 1 Spacer<br/> ¯\</em>(ツ)<em>/¯ 1 Switch Inner<br/> ¯\</em>(ツ)<em>/¯ 1 Switch Outer<br/> ¯\</em>(ツ)<em>/¯ 1 Switch Ring<br/> ¯\</em>(ツ)_/¯ 3 Switch Ring Holder<br/> P E T G 6 Parametric Spring</p>