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Printable caterpillar track

by carlosgs, published

Printable caterpillar track by carlosgs Dec 8, 2012

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Description

Testing a caterpillar track that is printable in one piece :)

UPDATE: Here is a video! http://www.youtube.com/watch?v=nigrV9n9658

UPDATE 2: New version 1.2 of the tracks and wheels: more curve to avoid slipping

Recent Comments

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nevermind I figured it out
How can I change the radius of the indentation for the servo mount? I'm new to openscad and im not sure what to change
i see, thank you! Awesome!

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Instructions

Scad code is messy, but i wanted to publish the promising results ASAP :)

Notes:

  • [DONE] An idler is required to reduce lateral force in the servo axis
  • [DONE] The chain needs to be even more curve to prevent it from slipping out
  • Still need to figure out a nice chassis

In order to print the tracks, I use Cura (https://github.com/daid/Cura) and a 0.5mm nozzle. Settings in Cura: Bottom/Top thickness = 0mm Wall thickness = 0.5mm Fill density = 0% Solid infill top = OFF Joris the outer edge = ON

These settings will print the track as a continuous, single-walled spiral, which makes them very flexible and resistant :)

How can I change the radius of the indentation for the servo mount? I'm new to openscad and im not sure what to change

nevermind I figured it out

<p>What plastic is this printed with?</p>

<p>The tracks were printed with green PLA from http://RepRapWorld.com. I have found it is more flexible than PLA from http://faberdashery.co.uk (first design, printed in yellow), which makes it better for this purpose.</p>

<p>i see, thank you! Awesome!</p>

<p>Is nobody building this on the Replicator 2 using MakerWare?  I've tried everything and it always fills the first layer.</p>

<p>I made a more cleaner scad code for the track, the wheel will come soon. I add the possibility to have mores wheels for larger track, snow blade each x teeth:</p>

<p>r=45 ; // outter radius of track<br>h=6; //heigth of track teeth</p>

<p>n=50;// nb of teeth of the track keep 9/10 ratio radius/nb of teeth</p>

<p>t=1;//perimeters width</p>

<p>w=15; //track width</p>

<p>ri=7.5;//radius of the internal wheel at least 1/2 of the width of the track</p>

<p>pi=3.14159;</p>

<p>j=1;//nb of internal wheel for large track</p>

<p>tw=pi*r/n;//perimetral size of tooth</p>

<p>b=0;//blade each teeth -for snow track, keep integer ratio with the number of teeth set to 0 for none</p>

<p>sb=3;//size of the snow blades</p>

<p>union(){</p>

<p> linear_extrude(height = w)teeth();</p>

<p> linear_extrude(height = w)jante();</p>

<p> for(i=[1:j])</p>

<p> translate([0,0,i*w/(j+1)])scale([1,1,1])rotate_extrude()innershape();</p>

<p>}</p>

<p>module teeth(){</p>

<p>for(i=[1:n])rotate([0,0,i*360/n])</p>

<p> polygon(points=[[r-t,2tw/3],[r-h-t,tw/3],[r-t,-2tw/3],[r-h-t,-tw/3]],paths=[[0,1,3,2]]);</p>

<p>if (b > 0)</p>

<p> {</p>

<p> for(i=[1:n/b])rotate([0,0,ib360/n])</p>

<p> polygon(points=[[r-t,2tw/3],[r-h-t,tw/3],[r-t,-2tw/3],[r-h-t,-tw/3],[r-t+b,0]],paths=[[0,1,3,2,4]]);</p>

<p> }</p>

<p>}</p>

<p>module jante(){</p>

<p>circle(r-h);</p>

<p>}</p>

<p>module innershape(){</p>

<p>translate([r-h/2-ri,0,0])circle(ri);</p>

<p> </p>

<p>}</p>

<p>hope this help</p>

<p>because the derivative code from the bracelet is a bit messy !<br> </p>

<p>Can anyone provide guidance on printing this on a R2?  Using MakerWare?</p>

<p>I see the option to print without infill, but it still tries to print what looks like a bottom layer (before I stop the print).  I don't see any options to not draw a top/bottom layer.</p>

<p>Thanks!</p>

<p>(FYI I'm working on cura/replicatorG but it has it's own list of problems I'm trying to work through just to get it to print anything at all)</p>

<p>What type of servo did you use? Brand and size? </p>

<p>Those are Futaba 3003 modified for continuous rotation removing the electronics.<br>But it was just for the first test, I am planning to use SpringRC S4303R (360⁰ continuous servo).</p>

<p> I was thinking making that remote controlled would be too hard for me since I have a receiver and I would mainly just have to buy a transmitter and servos.(I'm not sure if I will since I don't have much money right now) Could you upload the stl for the track that isn't solid (the one that is in the picture).</p>

<p>It would be cheaper using an Arduino with a bluetooth module :)<br>The track is solid because Cura has an option to allow printing only the perimeter as a continuous single-walled spiral.</p>

<p> Ok, thanks</p>

<p>What am I doing wrong - the track is a solid disk?</p>

<p>Print it without infill/up/downskin. This garantees a good solid single line. Same trick is used with some bracelets and most models from "Joris"</p>

<p>That's it.<br>I strongly recommend Cura https://github.com/daid/Cura&Acirc;&nbsp;which is an optimized and simplified version of Skeinforge :)</p>

<p>LOL I hadn't realised you were Daid the developer of Cura, thanks! haha :P</p>

<p>I made a little modification in the caterpilar track scad file:<br>to make wider track I made the number of circular bump in the base parametric.</p>

<p>m=50;// number of bendy parts around the circle<br>nb=3;// number of circular bump on base</p>

<p>internal_radius = 3; //9<br> <br>and made the other modification :</p>

<p>for(i=[1:nb]){</p>

<p>in the module base1 and module base2</p>

<p>so you can increase the width of the track ans add the number of circular bump you need.</p>

<p>I plan to make a ski doo so it is better to have larger track</p>

<p>by the way if a open scad wizard coul explain how to make a transversal fin each 5  zig zag (to increase traction on snow) ....</p>

<p>it coul add some versability to the design</p>

<p></p>

<p>This is why I love open-hardware :)</p>

<p>I will try those parameters in a moment, thanks for the feedback! :PMore iterations are required to get the perfect chain pattern!</p>

<p>Awesome, I'm glad someone finally made a real tank out of these. People kept suggesting it, but I don't have any motors lying around. Well done.</p>

<p>Thanks Emmett, I love all your designs!! they are very inspirational :)</p>

<p>You took arround 2 hours to make it into the Featured list! Congratulations!!!</p>

<p>By the way, its awesome!</p>

<p>Your design is amazing!!! Congratulations!  </p>

<p>Looking good. I like the one piece tracks. Way less hardware required.</p>

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