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  1. BalorNG

    Sanity check on 3d-printed/composite frame

    It does decrease your chances of survival, but even by withholding from cycling altogether your ultimate chances are still zero ;) Ok, maybe if your name is Elon Musc or Vladimir Putin, there is a remote possibility of living 'technically forever' now, but I do not find prospect particularly...
  2. BalorNG

    Sanity check on 3d-printed/composite frame

    Yea, I'll certainly be fixing interrupts in the interior reinforcement in my next design, but this one seems to work pretty well so far. The 'stiffer is better' applies to torsional and lateral rigidity though - vertical is fine or full suspension bikes will be unrideable :) Also, there is an...
  3. BalorNG

    Sanity check on 3d-printed/composite frame

    Good idea, didn't think about it! Makes a lot sense. But I'll add a sort a sort of sacrficial cap that will double as support of cantilevered load - there are actualy 3 nuts epoxied into the 'wing' to provide attachment points. By the way, I've experimented with forged composite technique using...
  4. BalorNG

    Sanity check on 3d-printed/composite frame

    https://youtu.be/sVGFOTxVhlc Well, at least I would test it this way... It does feel 'funny', especially because it turns out my front triangle is also a bit off (not by design but happenstance) and in the SAME direction, make the bike even less balanced, but the feeling quickly disappears...
  5. BalorNG

    Sanity check on 3d-printed/composite frame

    Well, I've decided to add another experimental feature - seat support "wings" doubling as frame sliders. Seat mockup: Mocking up the 'wings': I'll have them 'trimmed' once glued of course. Will take a few days I presume...
  6. BalorNG

    Sanity check on 3d-printed/composite frame

    The flex seems to be under control after additional wrap, so I did a test build: Jumped on frame a bit, seems to hold just fine. Now I need to think about seat fittings and actually try and ride the damn thing...
  7. BalorNG

    Sanity check on 3d-printed/composite frame

    Parental advisory: explicit content: https://youtu.be/Cjh8YpO-9Fc Ok, it would likely be already ok for someone of less, ahem, bulky stature, but definitely an other wrap of the lower half needed! No creaks and pops detected, frame seems to be quite rigid laterally, but 2 inches of vertical...
  8. BalorNG

    Sanity check on 3d-printed/composite frame

    I still need to fab seat mounts. I want it to be aero and maybe add a bit MORE passive suspension along the way... considering my options now. I'll be able to 'jump a bit' on the frame to ascertain it's stiffness sometime tomorrow :) This is how it looks like with my cantilevered wheel:
  9. BalorNG

    Sanity check on 3d-printed/composite frame

    Do I deserve a prize in a 'Strangest jig' contest? :) To be frank the frame is pretty damn straight, but I also want to be pretty damn sure :)
  10. BalorNG

    Sanity check on 3d-printed/composite frame

    Ok, I've tested my first wrap and it seems that 'tail' is pretty much exactly right on the flexibility according to '3 point bending' test with my entire body weight, flexes about half an inch. I still need to reinforce transition from tail to main tube with one short layer of carbon sleeve and...
  11. BalorNG

    Sanity check on 3d-printed/composite frame

    Oh, the aptly name 'annealing'* phenomenon. Carbon/GF parts are less susceptible but still not immune to it... I thought it actually makes parts a bit stronger? (*Has nothing to do with actual annealing from metallurgy) Yea, I should have printed the tubes at 45 deg or whereabouts perhaps, but...
  12. BalorNG

    Sanity check on 3d-printed/composite frame

    Yea, due to 90deg steering angle and more or less conventional trail there is not much *moment* on the head tube except what braking/pushing hard (and due to now 20" wheel - not that much either). I understand that interior tube should be 'whole' and interrupts create weak spots - it is quite...
  13. BalorNG

    Sanity check on 3d-printed/composite frame

    Exactly the same. The VERY same in fact :) I do not weld, so suspended bits will be an other project...
  14. BalorNG

    Sanity check on 3d-printed/composite frame

    Oh, sorry, I should have included the picture of my current bike, this frame is an sort of 'sidegrade' - I don't like downsizing the wheel, but it should improve aerodynamics and make bracing for pedal strokes better in comparison. This is a moving bottom bracket (MBB) recumbent: Angle is to...
  15. BalorNG

    Sanity check on 3d-printed/composite frame

    I'm mostly a software engineer by trade, but I have a cycling hobby and been learning CAD and composites on my free time lately. Her is the result of my latest efforts: Gyroid infill: Actual 3d printed parts: Basically, my idea is that by 3d printing (carbon-filled petg, pretty tough...

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