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    Motor for 18ft Electric boat

    Don't forget to take a look at the belt driven alternator starters ( :es: BAS) from some hybrid vehicles out of a junk yard aka car recycler. You can get battery, power stage, and motor from there. All you have left to do is to connect a Lebowski or vesc brain to the power stage (or hack the...
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    correct controller for 10s lipo? will a 36v/48v ebay one work?

    It is relatively easy to change some resistors in the voltage divider that the controller uses for the low voltage cutout. I just modified a 48-72V controller I had laying around to work with a 10s pack. I have another one that I could modify for you.
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    Air Rivet Gun For Solid Rivets Question

    I am just working on an airplane restoration and bucked a couple hundred rivets last week. The tips that go in the rivet gun are called rivet sets. These go against the factory formed head of the rivet and need to be the right size/shape for domed rivet heads. For flat, countersunk rivets you...
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    2wd hub motor build

    What is the bike/trailer being used for? If you are trying to move a trailer around, an electric version of this may be an option. https://www.youtube.com/watch?v=W7U-X0LlgSE I have two Invacare wheelchair hub motors that would be ideal for this with the appropriate tires.
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    I will be voting for Bernie Sanders

    There was never a chance for a white dude running for the left anyway. The demographic group that is deciding the outcome of the next election are college educated, white women. The rest is going to stand where they stood the last time. I hope that the targets of populist lures thrown in the...
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    DIY Solid State Relay

    Nice work. A lot of things are switched on and off electronically in today's cars. The button you push just sends a signal to some FET somewhere. I am sure that there is some information out there to show how these circuits are made reliable with different type of loads.
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    I will be voting for Bernie Sanders

    If you take a closer look at the biographies of the richest people in the world, you will see overwhelmingly more 'rags to riches' stories than 'born with the silver spoon' upbringings. That is not a coincidence. These folks were not content with their status quo and they did something about it...
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    Standard formula for Calculating Ebike Range

    Please stop using Ah to indicate your battery capacity. This is meaningless without knowing your voltage. Wh ("Watt hour" = Ah * Volt) or kWh ("kilo Watt hour" = 1000 Wh) is the correct unit of measure for battery capacity.
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    Liquid Fuels Made By Sunlight

    This is pretty much what is envisioned by SpaceX to get back from Mars. The reaction of CO2 from Mars' atmosphere with water (also found there) will produce Methane and Oxygen in almost the correct ratio for their rocket engines.
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    I will be voting for Bernie Sanders

    In the following article, they do make a compelling case that Socialism and Democracy are incompatible. Socialism Is Not Democratic The arguments presented in this article are hard to refute in light of the recorded history of Socialism on this planet. How people who complain about over-reach...
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    Dumb question about BLDC motor voltage

    For someone who just dabbled around with MOSFETs, even 104V nominal is "high". As you can see in my previous posts, the currents needed to extract maximum (peak) power from the motor at the rated 55.5V is giving me a bit of a headache. Brammo used this motor in their Enertia motorcycle...
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    Dumb question about BLDC motor voltage

    I played around with the simulator but every result is fundamentally different than what the manufacturer of the motor published. The attached data are for a motor with different ratings and constants but close enough. When pushed to max torque (solid blue line) the inverter is feeding a...
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    Dumb question about BLDC motor voltage

    Axial flux with single rotor between two coil plates. Low resistance, low inductance, and low pole count (4 pairs). PMS-120 from Heinzmann as used in Brammo motocycle. I am not trying to go over 4500 rpm. That's why I was asking what voltage the motor "sees" internally when governed by...
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    Dumb question about BLDC motor voltage

    Heat dissipation is an issue regardless of switch type. See numbers in my previous post. From what I can tell, the IGBT come in modules that are physically more suitable for shedding the heat. Albeit at a steep price.
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    Dumb question about BLDC motor voltage

    18kW into the motor would require at least 330 A on the DC side. Depending on the PWM duty cycle that will be somewhere North of 450 A phase current. Even in a 24 FET inverter each FET in the active switch would have to carry well over 100 A. I think this is feasible but certainly not in the...
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    Steampunk Voltmeter?

    As expected, a fine wire for the Voltmeter. If you already tear this thing apart and get an Arduino involved, you might as well go with a stepper movement. Check out the link in my previous post.
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    Dumb question about BLDC motor voltage

    Supposed I have a motor with the following ratings: Power: 7 kW Torque 14.8 Nm Speed: 4500 rpm Voltage 55.5 V (IP 54) Current: 90 A (Duty S1 -EN 60034) Ke: 11.2 V/1000rpm Assuming that this motor would be driven by a controller that monitors DC bus voltage, phase current, employs FOC, and can...
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    Steampunk Voltmeter?

    The opened gauge is indeed an Ammeter measuring current, as the face indicates. The current flows through the coil of green wire and the resulting magnetic field pulls the curved bar into the coil. The bar rotates around an axle that carries the indicating hand on the face side. The force of the...
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    Lead current limit for different MOSFET packages?

    Thanks for reminding me that we are dealing with a sine wave crated by TWO switches. That makes the whole scenario more promising. Your explanations also make it more understandable why FET manufactures advertise silicon currents that you could not possibly get in and out of the packaging. The...
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    Lead current limit for different MOSFET packages?

    I am trying to put together a power stage for the Lebowski controller that can output a short duration maximum of ~18 kW from a ~60 V nominal 16s high capacity battery pack. The resulting peak (as in occasional, short duration) current is going to be about 70% of the maximum battery discharge...
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    Powerchair Direct Drive Brushless Motor (High-Torque)

    Sorry for the late reply; I was off the sphere for a while as I finished several ICE-driven projects and moved our household and my shop again. I got the hall sensors but did not put them in since I got the motor running with a Lebowski controller on the bench. Then, the project sat idle so I...
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    Heatsink useful for 15s3p Zippy Lipo battery pack?

    I am going to build a 15s3p from 15 pcs 3s 5000mAh 20C Zippy packs. Two stacks of 5 pcs paralleled in 3 rows. Is it beneficial to put aluminum plates between the rows or should I just sandwich the whole pack in an aluminum housing? Attached picture shows arrangement with aluminum plates...
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    Mystery 18-FET controller

    Thanks. That explains why some pictures worked and others not. I only paid attention to the overall file size.
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    Powerchair Direct Drive Brushless Motor (High-Torque)

    Rather than starting a new thread, I'll ad to the valuable info already collected here. I purchased two of these motors recently, took them apart, and got them running yesterday with a cheap Chinese 18 FET controller in the sensorless mode. I calculated the k/V to be around 9.4 (525rpm with...
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    Mystery 18-FET controller

    Here is a picture of the label on the controller. Despite the label saying something about 48V, the controller worked up to 60V (as far as my lab supply could go). It cuts out somewhere around 40 Volt on the low side. BTW: Embedded images are still hit and miss as you can see at this post...
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