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  1. scianiac

    Looking for help sourcing a motor for my ebike setup

    I'm not really sure what you mean, the 22 tooth on the cassette? That kinda defines pretty low chain speed because you can't make the front drive cog (which from your design is separate from the pedaling chainring?) that much smaller than that so you have a very small amount of reduction so...
  2. scianiac

    Looking for help sourcing a motor for my ebike setup

    Ok first how dangerous it is has nothing to do with what it resembles or what it's built in, the only real factors that effect danger is the rider and how good it is at doing what you are doing with it. Which was part of my point, if you try and make it do everything it's going to be worse at...
  3. scianiac

    Looking for help sourcing a motor for my ebike setup

    Ok I think you need to better define your power and torque goals here, because they seem all over the place. On one hand you don't want to build an electric motorcycle but you are also talking about big motors and torque numbers. Like you said you want 100Nm output of a 10:1 worm gearbox, look...
  4. scianiac

    Looking for help sourcing a motor for my ebike setup

    Wait so you're going to try and build the worm gear from scratch? That is about 10 times harder than all of the more common solutions. Like a two stage belt reduction to BB freewheeling cranks if you want to pedal or a single belt reduction to BB freewheel cranks and then high rear reduction is...
  5. scianiac

    Looking for help sourcing a motor for my ebike setup

    You should do some research on the efficiencies of worm gearboxes before you just dismiss our comments, yes nylon versions can be more efficient but the efficiency is also RPM, torque, and ratio dependent. Like it's highly likely you'll end up in the 60-80% efficient range which will totally...
  6. scianiac

    FLIPSKY new 20s 100A tiny controller (vesc based)

    Few ways you could do it, that VESC doesn't have a power switch as in there is no way to turn the actual controller off although it will go to a low power mode after being not used but will still draw some power. As for a brake lever with the correct wiring you should be able to use it fine...
  7. scianiac

    Fat tire E bike build help

    When you say snow what do you have in mind, because a little bit of snow is no problem but as the snow gets deeper the power requirements start to become exponential. Using fat tires basically makes most performance worse except for snow and sand, well an I guess extreme mud but generally you...
  8. scianiac

    Tongsheng tsdz2 low gear problems

    If you mean the output from pedal assist is acting weird it's possible the torque sensor was thrown out of calibration or damaged, I recall having a pretty serious pedal strike and it caused some weirdness. It zeros out when you turn it on as doc said so don't want your feet on the pedals when...
  9. scianiac

    Why my battery pack lasts only a few months?

    Nope that's not how series capacitors work and yes the marketing for these is deceptive. You have 250F total like I said, which is still a lot of juice, like 10.5kJ depending on starting and ending voltage probably enough to start a smaller engine even in colder conditions. You can look up...
  10. scianiac

    BLDC Outrunner Over-Voltage

    Yeah no issues if your controller is rated for the voltage but I would tend to stay away from LiHV packs since they are known to have poor lifespans. Although maybe that's not as true now, I remember when LiHV packs first gained popularity for drones, many made by GNB of course and they had good...
  11. scianiac

    DIY Pulse Arc welding copper directly to cells

    I'm guessing he means aluminum battery can thickness which while rare do exist and I've seen are quite a pain to connect. Very interesting project, will be following closely.
  12. scianiac

    Motor to Wheel Gear Reduction

    See that's more useful, the LR big block has a KV of 62 if I recall so does that mean you are planning on using a 48V battery? Either way top speed at 80% of unloaded speed (KV times voltage) is a very rough area to start IF you are using a controller without MTPA or Field Weakening. LR motors...
  13. scianiac

    Motor to Wheel Gear Reduction

    46:1 should be perfect, that will give you a top speed of 5mph, any more than that and it could be dangerous and we wouldn't want that. Seriously though this question is missing about 80% of the required information.
  14. scianiac

    How to write on shrink wrap insulation of cell without it rubbing off

    Yeah I've never had them rub off just using a sharpie and it seems the wrap is solvent sensitive so it makes sense a permanent marker should work well.
  15. scianiac

    Why my battery pack lasts only a few months?

    I think you have the same cap bank as me but 3 of them, remember this means you have 250F total (83.33 each) since they are in series. I calculated from 12.8v down to 9v I can get about 3.5kJ out of mine which is enough to start an engine I think sometimes depending on conditions, if it's cold...
  16. scianiac

    Why my battery pack lasts only a few months?

    I mean a resistor is all you need to limit current between the battery and capacitor, the question though is there enough usable energy in the capacitor to start the car? I've done the math on this before with the capacitor bank I have attached to my lead acid starter battery to extend it's life...
  17. scianiac

    Sensorless position control issues

    HFI has no absolute reference so unless the motor is still powered with HFI running the whole time no, what you are looking for is an absolute encoder like an AS5047P that will be able to return the motor to a set position regardless. Various other encoders are supposed by VESC but that is the...
  18. scianiac

    Why my battery pack lasts only a few months?

    I would go with high power LFP (probably some cells from batteryhookup) with a BMS that has low temp charge protection, keep the supercap and wire the starter solenoid to bypass the BMS that way you don't need a several hundred amp BMS but the charging and discharging of everything else goes...
  19. scianiac

    Plan for MTB to E-Dirt Bike 8kW Dual Motor Conversion - looking for advice.

    I feel like I'm very similar to you in that I really enjoy the building and tinkering as much or more than the riding and I build bikes to be hyper optimized for their use case, which sounds like for my V10 is exactly the same use as you are aiming for. I had long planned to start with a large...
  20. scianiac

    What to look for in electric conversion donor vehicle / requirements for conversion power steering/brakes/transmission etc.

    The easiest and cheapest EV conversion will be to start with an EV like a Leaf with a dead battery. The only cost effective conversions I've seen involve lots of clever scrapping and getting good deals on used parts, often used EV parts which are probably more expensive than just starting with...
  21. scianiac

    Plan for MTB to E-Dirt Bike 8kW Dual Motor Conversion - looking for advice.

    I mean that 7kw of that 80100 is peak probably at saturation, it's not going to put out anywhere that much continuously even with quite aggressive forced air cooling. Perfectly reasonable amount of power for an enduro or DH bike that is to say in the 3-6kw range. But I agree 400Nm even assuming...
  22. scianiac

    Why shouldn't i build a Neumotor RC + planetary gear reduction drive?

    Not to protect a gearbox but to protect the freehub I built a chain guide that goes on the driven side and is sprung with some damping to act similar to a cush drive, I called it a cush guide. I still kinda think a belt reduction is a better choice over a gearbox, would be cool if there was a...
  23. scianiac

    Plan for MTB to E-Dirt Bike 8kW Dual Motor Conversion - looking for advice.

    How much power and torque you can put through a belt is highly variable but belt wrap and the size of the smaller pulley are key. With good belt tension and wrap you can put a lot of power through these belts, supposedly more as well if it's an advanced profile and not just a basic HTD profile...
  24. scianiac

    makerbase VESC 75100 problem

    Well based on those numbers the M4 probably has a fair bit lower Kv so would make sense it has more torque at a given phase current. If that explains the entire difference you are seeing I'm not sure.
  25. scianiac

    Plan for MTB to E-Dirt Bike 8kW Dual Motor Conversion - looking for advice.

    That is quite a complicated drivetrain that will probably be quite noisy. I don't really see the advantages here over a 2-3 stage belt/chain setup. You can for instance install a much much larger chainring on the rear which will do a lot of the reduction and put less stress on the chain. From...
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