Rpm Definition and 249 Threads

Why are usually more wasteful fuel engine at low RPM, as the example image below, 900 RPM more wasteful fuel consumption than 1600 RPM.

Let's say I have a magnet inside a coil of wire. If I spin the magnet for a 10 second period, twice, the second time spinning it significantly faster, will more current be induced during the second period? And would this apply to generators in wind turbines, etc.? Thanks.

RPM to Pulley Question Please Help Thanks! I have a log splitter that uses a gas engine 3600 RPM the drive pulley is 1.5"OD diameter and the driven pulley is 18.25" diameter (Super Splitter is the brand name) So from what i calculated was the driven pulley weighs in at 75lbs and spins at about...

I need some help coming up with a formula.. This involves a Vehicles Engine I know how fast the rate of change is (example being 3000 rpm over 3 seconds-an increase from 3000rpm to 6000 rpm in that 3 second period) I know how much weight this RPM has moved (3700 lbs) and I know the Gear...

Hi, I have a lawn mower engine and I need to read and adjust its rpm precisely. I am totally lost. I would like to ask how some of you would approach this problem. What I have right now is I am going to buy an Arduino circuit board controller. Then I am going to attach a tachometer onto...

hi .i am new here i like to know if this motor can't reversed using a switch from turning right to left . i am a knifes maker [was] and my motor have to turn clock wise and counter clock . thank you . yvesj

Homework Statement A weather vane sits quietly on the roof of a barn on a calm winter's day. It has a length of x, is pole-shaped with mass M, and rotates frictionlessly about its center. But just now it is still. Suddenly Justin throws a snowball of mass m at speed v that hits it a...

I have a dc motor geared to a diaphragm pump, and all hardware are unchanged. As i increase the supplied voltage, rpm increases, but so does the current (torque). I thought rpm increase would lead to higher back emf, and thus lowers the current. So would the only reason for my increased...

I am working on a simple motor and I would love input or tips to increase the rpm on it. The motor is built by having a 1.5 v D battery connected to 2 bobby pins for and a coil of wire that one side is fully stripped and the other side is on the other side is only stripped on the bottom. Then...

I require for a project a rotating stand, much like these... http://www.cokerexpo.co.uk/rotating-display-stand.htm ... Which are used in shops However as you can see they have some preset rotation speeds which have nothing like the accuracy that I will require. I need to control the speed of...

I've got a shaft that rotates at about 1 rpm and handles a radial load of approximately 25 lbs, a thrust load of 17 lbs, and a bending moment of about 150 lb-in. The shaft and joint will be submerged in lakewater. A shaft diameter of 1.5 in would be nice, but in general a larger shaft would be...

Hi Shaft A has variable RPM, getting input from some rotating element (say X), ranging from 0 to 2000. The RPM of X cannot be adjusted or controlled. A has to transfer the rotation with limiting RPM of upto 400 to Shaft B. Is there a way to limit the RPM using a mechanism such that at...

I know power = Torque x angular velocity (rad/s) AND I am wondering if angular velocity can be calculated through strokes per minute? The product is a reciprocating saw (not orbital). In this case are RPM's the same as SPM'S? Thanks

As part of a much larger project I am doing for fun, is it possible to calculate the RPM of a combustino engine from the Torque and Interia. Reason I am asking is i have a dyno torque result and an engine torque result and i am trying to calcualte the speed. If anyone wants to know why or...

Im trying to get the Hp or W for the O.S 61FX RC airplane motor that has a propeller size 13x6 that give 10400rpm. The reason for this is to know the max speed that it can obtain discarding the weight and everything.

Hello everybody, I'm working on a project and I want to verify a few theories I have. I'm unfamiliar with equipment for taking these types of measurements, so I wanted a little bit of help on this. Basically a bb is fired from an airsoft gun (350-550 fps), and I want to find the...

How can I calculate the amount of energy I would get if I spun a wheel at a certain about of RPM? I know this is a general question, but I am looking for any kind of calculation I can use.

I want to design a lure course system for my dogs to chase after. The systems I have seen use a 12v car starter motor, solenoid and car battery. It is a closed loop system with nylon type string around the drive pulley of the motor and then the string stretches out over 700+' along the ground...

Hello, I have to find the maximum rpm of the shaft that has ring mounted on the shaft with interference fit of 0.002". I want to know at what rpm the ring will come loose from the shaft? and If I run the shaft at 7000rpm at 400 degree Celsius, is the interference fit of 002" enough...

According to http://www.aveox.com/DC.aspx" The way to calculate the output of a DC motor in kRPMs is the formula RPM of motor: kRPM = (V - RmI) / Kb V= Voltage Rm = Terminal Resistance I = Current Kb = Voltage Constant (V/kRPMs) This insinuates that an increase in amperage...

Hello, I read this article about someone who made a hover bike prototype from a motorbike and two propellers. Best part is, its classified as Ultralight and doesn't require a license to fly! I can totally see myself building something like that in my back garden! How can I calculate the...

Homework Statement A simple model of the core of a tornado is a right circular cylinder that rotates about its axis. If a tornado has a core diameter of 200 feet and maximum wind speed of 240 mi/hr (or 352 ft/sec) at the perimeter of the core, approximate the number of revolutions the core...

Homework Statement the gear ratio between crankshaft and driveshaft calculates to be 13.579 at first gear the diameter of the car wheel is 0.6m the transmission efficiency is 0.85 weight of the car is 1200kg if the engineer is running at 1500rpm how do you calculate the speed in...

I finally figured out what my previous problem was in my last question posted. I have obtained the plots required but I am a little confused about the trends. (1) At low Mach, should my thrust be lower compared to the value at a higher Mach? (2) Should the RPM decrease with an increase in...

Homework Statement A object(have mass M1) is placed at a R1 distance from the center of a horizontal surface that can rotate. The surface rotation is very FAST INCREASE ( tangential acceleration is non-negligible) until the surface reaches a cirtical rotation rate. At that instant, the object...

Homework Statement A conical pendulum is formed by attaching a 0.900 kg ball to a 1.00 m long string, then allowing the mass to move in a horizontal circle of radius 20.0 cm . What is the ball's angular velocity, in rpm? Homework Equations v=\sqrt{}L*g*sin(\vartheta)*tan(\vartheta)...

Homework Statement I have to derive an equation that relates the rpm of an axle that is fixed to a car wheel of radius r, given the velocity of the car subscripts: w is wheel, a is axle Homework Equations angular velocity of the wheel is given by ω_wheel=2π/T=2πf=v/r_w (1)...

Hi, I'm working on an engineering project and I need to get a 30pound base to rotate at speeds between 6 rotations per hour and possibly 1 rotation per hour. Does anyone know where to get such a motor, or if it is even possible? Can anyone think of a better more efficient way of doing this...

Hi all, long time reader first time poster here. I have a DCBL blower motor that has a fixed wattage at each speed level. I noticed that when I increase pressure (say from 0" SP to .1" SP) the RPM increase and the CFM (airflow) decrease. I understand that CFM will decrease with increased...

Hey folks, I have been thinking about doing a little hobby project for while, but didn't have the right knowledge to do it until now. Basically, I need a relatively small Low RPM, high torque DC motor that can be controlled by a microcontroller. I'm using the arduino duemilanove and have...

I am trying to model the RPM at which the turbo I plan to fit to my BMW will develop the desired pressure ratio. I have determined air flow into the engine at the desired pressure ratio and have determined the rpm at which peak power and torque should arrive. I have also determined the size of...

Is there an Optimal RPM for a DC generator?? I would like to ask if there is an optimal rpm for a DC generators? Or the faster it rotates, the more power it generates? The specification of the motor is as follow: http://www.mitsumi.co.jp/latest/Catalog/pdf/motorav_m25e_11.pdf

Hi everybody, This is my first message here and it looks like an awesome forum! :smile: I have a 12V geared DC motor and i am having a hard time figuring out how to maintain it's torque in from speed 0 to 150 RPM.. I know about PWM and figured it's not going to do it.. I am looking...

Hi, I have a elec generating unit. The shaft has a rpm of 15000. Need to reduce to 250-300rpm i.e. bring it down to generating elec at 50Hz. Could somebody suggest which gearbox is suitable for this application to reduce from high to low rpm. Also suggest which type of coupling has to be used...

You want to select a gear such that the rpm is low enough to avoid overheating and you want to choose a gear that gives you enough torque for the application. A car is going up a 20% grade at a speed of 60 km/h. Gear ratios: 1st - 3.143:1 2nd - 1.870:1 3rd - 1.235:1 4th - .949:1 5th -...

Homework Statement A small engine flywheel rotates at 2000rpm and has 4 permanent magnents pressed into the flywheel at a radius of 10cm spaced 90deg apart 1.2cm diameter magnets. A 1.2cm diameter pickup coil with 500 turns is at the edge of the flywheel. Max voltage detected is .76 volts...

1. A cars wheels starts from rest and accelerate to 210 rpm in .73 seconds. a.) Find angular acceleration in radians/sec^2 b.) Find the revolutions completed in the time interval c.) Find the total acceleration when it is 12m from the rotational axis at 180 rpm. 3. 1. a.) 210x2pi= radians/ min...

Hello, I would like to know how to determine the max RPM of a disc. I would think it would be the centrifugal force against the Yeild Strength. Any help would be appreciated. Thanks, Ron

Hi, My setup is a DC motor driven by PWM output. Motor is attached to a wheel in a cart. Can somebody help me to figure out what approach should I take to control the speed of the motor under varying loads? i.e, let's say I need acceleration of 2 m/s when the cart is empty. if I want the...

How do you determine RPM when given your velocity and the radius or diameter of the cirlcle? thanks in advance.

Ok, here's a question I've been worrying about recently: If you were to be rotated about your waist, at what rotational rate would your body begin to tear apart, specifically decapitation? Basically, I've been doing lots of gainers (running back-flips) and I'm concerned that if I get...

I'm trying to figure out how to select a motor for a project. I want to spin an aluminum disk between 400 and 3000 rpm. How would I go about calculating the correct specifications for a motor? Thanks -Kevin

Hi, I am not a mechanical engineer but an aeronautical engineer. Hence I am very poor with Mechanics & request for your help. I am working on design which produces approximately 17,400N-m of Torque at 25RPM. I want to maintain this Torque but increase the RPM to 1500. Is that possible? I...

Hi, new to the forum here I have this bike-engine here and I am thinking whether it would be possible to mount it to an electrical generator. The thing is it easily hits RPM's up to 13000. My question is if I make a magnet spinning at let's say 10k rpm what poweroutput are we talking then...

I have a picture of two gears, but I need some help with mechanical advantage. Let's say the larger gear is providing the work, and if there was no load supplied to the smaller gear, the large gear be spinning at 1,000 rpm, which would make the small gear spin at 3,000 rpm since the gear ratio...

Through our research we discover that an AC induction motor can act as a DC amplifier, as long as there is torque making it turns. Applying the process we are able to build RPM independent grid tie induction generator. Tested with variable US grid at consumer configuration. Similar to PMA...

Hey guys, I'm kinda simulate vehicle dynamics. I got gear ratios, torque and RPM values. I find how to calculate instant accerelation from http://spreadsheets.google.com/ccc?key=pBCH2ClzmrplHUNFgrkT7HA Ok now I got acc. :wink: I can calculate velocity from acc but my problem is how to...

Good Morning All! Is it considered poor engineering to gear up a 100 RPM high torque motor to achieve a 1000 RPM medium torque final drive? What would be the major drawbacks? Thanks! Bill

Hi everyone I am damn confused about torque and rpm variation.Please tell me: 1.> When we shift from lower to higher gear, definitely RPM at wheels increase, but does the torque at drive wheel increases or decreases? 2.> I read yesterday that a car accelerates fastest at an RPM...

1. I need to find out the kinetic energy of a wheel, mass 15kg, diameter 1.2m, radius of gyration 0.4m traveling at 4ms. To do this I need to find RPM 2. Kinetic Energy = 0.5 Iw^2, I = mk^2 3. I = 15 x 0.4^2 = 15 x 0.16 =2.4kgm^2 KE = 0.5 x 2.4 x w^2 W = rpm x 2pi/60 How...