How fast do starter motors spin

It would be interesting to hear about the cheapest ebike designs people have come up with. Re: Car starter motor Post by Link » Feb 10 am babydark wrote: This motor turn around rpm at 12v and draw something like 40 amps at no-load. My mind is an enigma. So much so that, sometimes, even I don't know what I was thinking. Re: Car starter motor Post by rkosiorek » Feb 10 am car starter motors are often shunt wound and do not have any magnets.

Goldwasser -. Re: Car starter motor Post by Toorbough ULL-Zeveigh » Feb 10 am About twenty years back there was an old guy, retiree went by the name Metro, who tooled around town on a homebuilt electric delta trike. The trike was FWD with this huge starter motor angled up alongside the front fork as a friction drive. He lugged a 3. Re: Car starter motor Post by Link » Feb 10 am rkosiorek wrote: car starter motors are often shunt wound and do not have any magnets.

Re: Car starter motor Post by rkosiorek » Feb 10 pm oops, uh errr. Re: Car starter motor Post by fechter » Feb 10 pm Many of the newer starter motors have permanent magnets. You need a motor with more turns on the armature to get the current down.

Rewinding is one option, but a real PITA with a motor like that. Turn the key beyond the 'ignition on' position to feed current to the solenoid. The ignition switch has a return spring , so that as soon as you release the key it springs back and turns the starter switch off.

The movement of the rod closes two heavy contacts, completing the circuit from the battery to the starter. The rod also has a return spring -when the ignition switch stops feeding current to the solenoid, the contacts open and the starter motor stops.

The return springs are needed because the starter motor must not turn more than it has to in order to start the engine. The reason is partly that the starter uses a lot of electricity, which quickly runs down the battery. Also, if the engine starts and the starter motor stays engaged, the engine will spin the starter so fast that it may be badly damaged.

The starter motor itself has a device, called a Bendix gear, which engages its pinion with the gear ring on the flywheel only while the starter is turning the engine. It disengages as soon as the engine picks up speed, and there are two ways by which it does so - the inertia system and the pre-engaged system. The inertia starter relies on the inertia of the pinion - that is, its reluctance to begin to turn.

The pinion is not fixed rigidly to the motor shaft - it is threaded on to it, like a freely turning nut on a very coarse-thread bolt. Imagine that you suddenly spin the bolt: the inertia of the nut keeps it from turning at once, so it shifts along the thread of the bolt. When an inertia starter spins, the pinion moves along the thread of the motor shaft and engages with the flywheel gear ring.

It then reaches a stop at the end of the thread, begins to turn with the shaft and so turns the engine. Once the engine starts, it spins the pinion faster than its own starter-motor shaft.

The spinning action screws the pinion back down its thread and out of engagement. The starter motor is responsible for turning the engine over during ignition and allowing everything else to happen.

When you turn the ignition on, the starter motor engages and turns the engine over allowing it to suck in air. On the engine, a flywheel, with a ring gear attached around the edge, is fitted to the end of the crankshaft.

On the starter, the pinion is designed to fit into the grooves of the ring gear. The pinion meets the flywheel and the starter motor turns. This spins the engine over, sucking in air as well as fuel.

As the engine turns over, the starter motor disengages, and the electromagnet stops. The rod retracts into the starter motor once more, taking the pinion out of contact with the flywheel and preventing potential damage.

The armature is an electromagnet, mounted on the drive shaft and bearings for support. It is a laminated soft iron core which is wrapped with numerous conductors loops or windings. The commutator is a section of the shaft at the rear of the housing on which the brushes run to conduct electricity.

The commutator is made up of two plates attached to the axle of the armature. These plates provide the two connections for the coil of the electromagnet. The brushes run on a section of the commutator at the rear of the housing, making contact with the contacts of the commutator and conducting electricity. The solenoid contains of two coils of wire that are wrapped around a moveable core.

The solenoid acts as a switch to close the electrical connection and connects the starter motor to the vehicle's battery. The plunger works by using the connected vehicle battery and the solenoid to push the plunger forward, which engages the pinion.