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Recent content by MightyGNU

  1. MightyGNU

    Tire size vs traction

    I have seen large rear tires on many a (allegedly) high power RWD car, and have always thought they would increase traction. Just now I realized I have no idea why that would be. Given a tire with x cm^3 in contact with the ground and a given vehicle mass, there should be a certain pressure on...
  2. MightyGNU

    High power gear drive

    That may be true of stock cars but I'm thinking of race vehicles. Those cars are driven at maximum load almost constantly and the load applied when launching or downshifting is in excess of twice the maximum output of the engine. Those shocks are what most frequently kills automotive...
  3. MightyGNU

    High power gear drive

    You're right, I was too tired to be doing math last night 😑️.
  4. MightyGNU

    High power gear drive

    Manual transmissions generally have the entire shaft with gears machined as a single piece. I guess I could cut one up though... I would add that most transmissions have a maximum ratio of about 3.5:1, meaning at least 4 stages. (Also it turns out I did a calculation for the rotor wrong and the...
  5. MightyGNU

    High power gear drive

    I think you are optimistic about my budget. The AW95, the cheapest DIY helicopter kit I am aware of, costs over $10,000 USD and is barely functional as a helicopter.
  6. MightyGNU

    High power gear drive

    Yes that is what I meant. I'm aware of this, I will already need to build a test stand for the rotors to make sure they don't come apart under stress so I will be able to test both at once, If they don't show damage after an hour or so at %150 maximum rpm they should be OK for flight. I seem...
  7. MightyGNU

    High power gear drive

    I'd appreciate it if people would stop saying this. If I were willing to let someone else design things for me (and entrust my safety to them), I would not be asking here. I assume people here understand how expensive these components can be 'off the shelf', buying them that way is just not an...
  8. MightyGNU

    High power gear drive

    drawoh, Most gears are rated only to a certain RPM, and more importantly the engine runs at a fixed RPM. I have played with turboshaft engines but they are expensive to build and difficult to make a reasonable amount of power with, especially at this size. My current plan is to get the largest...
  9. MightyGNU

    High power gear drive

    OK, a few more questions. What's the best way to lubricate them? Fill the case with gear oil? Or Grease? Any additional thoughts or things I missed? Also where can I buy nitrided gears in small quantities cheaply?
  10. MightyGNU

    High power gear drive

    Thanks for that information. Does carburizing/nitriding/hardening really make the metal 100 times tougher though? If I were to get them carburized would I be able to use them?
  11. MightyGNU

    High power gear drive

    I appreciate the response but you didn't exactly answer my question. My car (1988 pontiac firebird) had an engine that made 135hp. The transmission (tremec t5), had fairly small helical spur gears (less than 1" face) and easily handled that 135hp, complete with the very large shocks and torque...
  12. MightyGNU

    High power gear drive

    Hi, I'm new to this forum and not technically an engineer (at least professionally) but I hope you all can help me with this. I'm building a helicopter, I have a 125hp engine the produces a maximum of about 130 lb/ft of torque at about 5500rpm. I need a 15:1 drive in order to keep the rotor...

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