Some questions about engines

Thread Starter

Klaus.emh

Joined May 9, 2019
1
Hi guys. New here, know barely something.
Now, I have an electric engine I got from a string trimmer. It's 350w and worked with standard grid 220v input.
I want to know if it is possible to attach it somehow to work with a portable power source, like a car battery. Do I need a transformator? How can I regulate the speed? I want this engine to push a 60kg trolley. Is it possible? How would you do it?
 

ArakelTheDragon

Joined Nov 18, 2016
1,353
Please post a circuit, your experience a bit more detailed and are you aware of the forum rulles and that anything that is connected to connected to the mains is dangerous, if something happens we will NOT be responsible in any way!
 

MaxHeadRoom

Joined Jul 18, 2013
23,599
60Kg is a fair load, especially if an incline is approached, if you don't want a very high speed, a geared DC motor would be the way to go.
The trimmer motor is probably Universal (AC/DC) but not suitable for portable 12vdc use.
Max.
 

MisterBill2

Joined Jan 23, 2018
9,237
This set of responses is really wandering!
A string trimmer motor is supposed to spin very rapidly, and so the application does require a bit of power. Max thinks that you are hoping to drive a vehicle with the motor, I am guessing that you want to run it without a mains power cord, and have a portable string trimmer. If that is the case then you need a different trimmer, since none of the 220 volt AC mains powered parts will be suitable for portable DC power. And if you want to use the motor for some other application it will need to be mains powered. And all of the safety concerns apply to mains powered systems.
So a clarification of your intentions will lead to much better advice, instead of guesses.
 

danadak

Joined Mar 10, 2018
4,057
Auto stores have some pretty cheap inverters here in US, 12 VDC to 110 VAC.
Various power ratings. I assume other countries using 220 also have those
inverters.


Regards, Dana.
 

MisterBill2

Joined Jan 23, 2018
9,237
OK, the 220V motor is wanted to push a 60Kg trolley, presumably at a reasonable speed. In the UK, or other areas with 220 volt mains the synchronous speed for that motor will be 3000 RPM, and so the needed reduction gearing will be about will be 100:1. That will probably need at least 2 stages, even with a worm-gear reducer, and then there will still be the problem of the power cord limiting the distance traveled. That may be a problem, or not, depending on the application of the trolley. For a desert trolley in a large home it may be fine, for bringing goods home from the market, probably not.
The cost of a reliable inverter suitable to power such a motor, plus the cost of a suitable gearbox, will exceed the price of an adequate DC gearmotor suitable for the application, especially if you can find such a motor on the used stuff market
 

Janis59

Joined Aug 21, 2017
1,348
At my surroundings Engine- its crankshaft+pistons+valves+gears; Motor - its anything rotating and why not electric. So, if Your motor is electric, You ought to buy cheap DC converter 12V-->220V and voila. However, 350W plus some 80% effectiveness factor gives about 400W what turns out the explicit 400/12=36 Amps!. If one hour work is OK, I`m glad. But N=F*v thus 60kg=600N turns out some 350/600= less than 0,5 m/sec speed. Hope it is enough? Where to get inverter? I think You have low hope to build it DIY, better buy it from ebay. One of thousands of options there is like this https://www.ebay.com/itm/600W-Pure-...197361&hash=item3640bf58d9:g:eTUAAOSwFu1b9Pl0
 

MisterBill2

Joined Jan 23, 2018
9,237
There is also a question of how to do speed control if an inverter is used, and battery + inverter is going to take up a fair amount of space. And every bit of energy wasted as heat is that much less available to do driving with. In addition, the motor for a mains powered string trimmer is probably not a very easy to use package for any other application.
 

MaxHeadRoom

Joined Jul 18, 2013
23,599
OK, the 220V motor is wanted to push a 60Kg trolley, presumably at a reasonable speed. In the UK, or other areas with 220 volt mains the synchronous speed for that motor will be 3000 RPM,
For a mains string trimmer, it is more than likely it is a Universal motor so the RPM is generally way above 3krpm (non-synchronous).
Max.
 

Tonyr1084

Joined Sep 24, 2015
6,245
I've been known to reuse something from one thing and turn it into something else. Took an old kids toy reel to reel tape recorder and turned it into an air boat. But despite all the changes I made (at age 7 or 8) the motor I used was powered originally from two D cell batteries and so was the air boat.

A motor designed to run at high RPM on high voltages IF IT CAN BE run on 12 volts it will have next to no more power than the ability to barely spin itself. If even that.

Since you are wanting to make something out of a motor, such as possibly a ride on toy for a child or for some other purpose but you want to power it from a 12 volt battery then you would be better served starting with a motor built to run on 12 volts DC.

I've seen skateboards driven with an 18 volt cordless drills. Here's just one:

[edit] Just to follow up - I have a DeWalt cordless drill too. Mine, when you release the trigger the drill chuck stops suddenly and completely. That feature would have to be disabled, otherwise suddenly stopping the board will throw the rider end over end.
[end edit]

 

MisterBill2

Joined Jan 23, 2018
9,237
I doubt very much that an inverter rated at 500 watts that sells new for $22 will run a 350 watt motor for very long before failing. And there is the issue of speed control to be considered. Not all cheap products are so very wonderful.
 

BobaMosfet

Joined Jul 1, 2009
1,848
Hi guys. New here, know barely something.
Now, I have an electric engine I got from a string trimmer. It's 350w and worked with standard grid 220v input.
I want to know if it is possible to attach it somehow to work with a portable power source, like a car battery. Do I need a transformator? How can I regulate the speed? I want this engine to push a 60kg trolley. Is it possible? How would you do it?
It's original input (220V) is AC. A car battery is DC. You'd have to have an inverter and additional filtering/etc electronics in between the battery to change it from DC to AC, plus you'd have to then have a transformer step from probably 10VAC to 220VAC, and hope there's enough current in the translation to power the motor. Possible? Yes? Should you? Probably not.
 

ian field

Joined Oct 27, 2012
6,539
Hi guys. New here, know barely something.
Now, I have an electric engine I got from a string trimmer. It's 350w and worked with standard grid 220v input.
I want to know if it is possible to attach it somehow to work with a portable power source, like a car battery. Do I need a transformator? How can I regulate the speed? I want this engine to push a 60kg trolley. Is it possible? How would you do it?
You'd have to step up the voltage, and how you do that might depend on the type of motor - but its going to have a heavy current draw. I'd start looking for a scrap electric bicycle and pinch the traction gear off that. ready made speed control & everything...……...
 
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