This 3D-Printed RC Car Might Redefine What’s Possible

Comments · 2K

• CU

  @CURV-LAB · 11 months ago · pinned

  What do you think caused the differential failure?<br>Heat? Centrifugal force? Plastic deformation? Let me know your theory below — I’ll feature the most insightful comment in the next video.<br><br>Printable files coming soon.<br>Subscribe so you don’t miss the follow-up episode!

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• WA

  @warracer03 · 11 months ago

  Funny to see the differential demo test bench from the 50s instructional video remade with a 3d printer !

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• MI

  @MiyavViyav · 11 months ago

  <a href="https://www.youtube.com/watch?v=pdKnIPH3JQs&amp;t=564">9:24</a> this non employed desingner is the guy that i want to be in the future as an engineer

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• KO

  @kossu.k · 11 months ago

  Came for a 3D-printed RC car, stayed for the best video about automotive differentials since the 50&apos;s!

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• LU

  @LuisHansenNH · 9 months ago

  Magnificent re-creation of the &quot;Around the corner&quot; very old short that explains differentials.

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• EM

  @EmGi_ · 11 months ago

  Those Hand sketches are so beautiful

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• HE

  @henryford1448 · 11 months ago

  If im not mistaken, the side on the diff where the bearing failed is on the drive belt side from the motor. &nbsp;Due to the small amount of play in the custom ball bearing (which is correct) and the way you tension the drivebelt it causes the drive side of the diff to be offset on one side thus causing the balls to &quot;dig&quot; into the slot of the bearing.

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• RO

  @robertmunafo5039 · 11 months ago (edited)

  I&apos;m going to say that it 100% is because you&apos;re using PLA along with ball bearings in little or no grease. Along with the tension that the belt is putting onto that bearing I&apos;m actually surprised it lasted that long. As I mentioned in a prior comment thread, why don&apos;t you find a bearing that is already existing that closely fits the size you need, may not be exact but that&apos;s the beauty of 3D printing, you can size the rest of the differentials to match that bearing as long as it&apos;s close enough to still work. I think that&apos;s the only way you&apos;re going to get any type of real longevity out of these differentials that you&apos;re making. Awesome video, awesome presentation and I look forward to purchasing your files so I can build this with my granddaughters, they&apos;re going to love it!

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• MA

  @MatHojan-f7j · 11 months ago

  Friction and heat are the causes of the failure. I think you are printing PLA which softening temperature is around 50 deg celsius.<br>1. use grease, dont mind the guys which tells the grease attract dirt. the lifetime of your current bearing its too short to be cautious about this. Grease will reduce the wear but also will improve the heat exchange. Plastics are bad heat conductors and accumulates the heat locally instead of dissipate it. Grease also will make assembly easier. the balls wont be rolling around but stay in place.<br>2. use filament with higher softening temp and higher wear resistance. PETG (around 70 deg) &nbsp;or ASA (around 105 deg) can be good starting point. U can also ask IGUS for the iglidur filament sample which is pretty wear resistant and like 120 deg celcius softening temp<br>3. mind the technology you are using. FDM printing is specific. Be aware of the layer lines and small imperfections. Look on the part like on sandwich of the plastic layers. When u print bearing race every layer overlaps another a little. It looks like stairs, and edge of every stair initially will wear insanely fast, the contact surface increases, the process slows down and finally fit together good, but also the clearance increases a lot. Consider making it tighter. Initially it wont move so smooth, but give it a good spin without load (and with lube), to the point when the balls make perfect race for them, then relube to get rid of the plastic particles.<br>4. consider using bearing available on market. i understand your approach, making own integrated bearing is very compact, and also cheap, but plastic is plastic and eventually it will always wear or melt. Looking on the video you are pretty close to the size of the old bicycles head bearings (bearing and races as a separate parts)

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• BU

  @buzatusebastian2735 · 11 months ago

  <a href="https://www.youtube.com/watch?v=pdKnIPH3JQs&amp;t=180">3:00</a> you saw that video about differentials from 1937 dont lie

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• YA

  @yashkhd1100 · 10 months ago

  This video can be repurposed to explain &quot;How &nbsp;differential works&quot;. This reminding me those 50&apos;s-60&apos;s videos with crystal clear explanation. You need to really consider this level of clear cut explanation videos about various commonly used engineering principals..!

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• UZ

  @UzziPA · 11 months ago

  I&apos;m a bike mechanic and also make RC&apos;s. I was confused seeing you assemble the bearings and gears with no grease. That goes against everything I know about mechanisms; always use grease on anything with friction. I would have used a light synthetic grease and maybe added basic labyrinth dust seals over the bearing ends to keep rocks and debris out of them.

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