Results 1 to 9 of 9

Thread: gas/petrol to elecric tool conversion

  1. #1
    Join Date
    Mar 2009
    Location
    ibeeria
    Posts
    3,762

    Default gas/petrol to elecric tool conversion

    I have a small, 25 cc 2 stroke strimmer. not professional class but pretty good around the garden and can take blades or cord.
    ~it gets used hard for two or three hours, maybe ten or twelve times a year.

    But like most garden stuff, chainsaws, hedge cutters, etc. It NEVER starts first time out, aftera lay-up more than a few weeks.....I go throught the routine of fresh gas, clean the plug, and if it wants to, it starts. maybe.

    I'm seriously peed off and thinking about just taking off the power head and substituting an electric motor. any number of old drills, and other various elecctric motors, kicking about in the shed, but i have no idea of comparisons of power delivery or rpm. If I have the right motor I'll worry about the mechanics side of fitting it, but is there an accepted gas engine to electric motor equivalence regards HP RPM etc...?
    Anybody done this ?
    Bilious, choleric, sanguine and phlegmatic

  2. #2
    Join Date
    Jun 2010
    Location
    PNW, an island west of Seattle
    Posts
    2,744

    Default Re: gas/petrol to elecric tool conversion

    I don't have any advice about the electrics but I share your pain re the gas engine frustration. I've taken to using Stihl's proprietary fuel. It's already blended with the oil for their machines and it uses gas that has little additives. When one buys a new machine of theirs along with the fuel, the warranty is automatically extended two years. Since I've taken to using this (expensive) fuel, my frustration level has gone way down.

    Jeff

  3. #3
    Join Date
    Jul 2015
    Location
    St. Paul, MN
    Posts
    195

    Default Re: gas/petrol to elecric tool conversion

    A new 25cc 2 stroke is about 1 hp. Standard conversion is 5hp gas = 3 hp electric. So a .6 hp or a 124 watt electric motor should work. Rpm on 2 strokes are around 5000 so an equivalent rpm electric motor. There is so much torque on electric motors that you could probably get away with smaller than 124 watt but I’m not qualified to make any recommendations.

  4. #4
    Join Date
    Mar 2018
    Location
    Annapolis, MD, USA
    Posts
    61

    Default Re: gas/petrol to elecric tool conversion

    Two suggestions that might help (they work for me):

    - Always add gas stabilizer to your small motor gas can when you fill it up. Available in most hardware stores.

    - When finished with the device, shut off the fuel and keep it running until the carb runs out of fuel. If there is no fuel shutoff, dump the fuel in the tank back into the gas can and then run the machine until the carb is empty. Either way, don't leave it sitting with fuel in the carb for any length of time.

  5. #5
    Join Date
    Jan 2005
    Location
    Deepest Darkest Wales
    Posts
    23,509

    Default Re: gas/petrol to elecric tool conversion

    Quote Originally Posted by Jfitzger View Post
    A new 25cc 2 stroke is about 1 hp. Standard conversion is 5hp gas = 3 hp electric. So a .6 hp or a 124 watt electric motor should work. Rpm on 2 strokes are around 5000 so an equivalent rpm electric motor. There is so much torque on electric motors that you could probably get away with smaller than 124 watt but I’m not qualified to make any recommendations.
    0.6 hp is about 550 watts.
    I'd much rather lay in my bunk all freakin day lookin at Youtube videos .

  6. #6
    Join Date
    Jul 2015
    Location
    St. Paul, MN
    Posts
    195

    Default Re: gas/petrol to elecric tool conversion

    Quote Originally Posted by P.I. Stazzer-Newt View Post
    0.6 hp is about 550 watts.

    No idea why I wrote 124. My understanding is 1 hp = 745 watts or .6 = 447 watts. Is there a difference between American and British HP?

  7. #7
    Join Date
    Jan 2005
    Location
    Deepest Darkest Wales
    Posts
    23,509

    Default Re: gas/petrol to elecric tool conversion

    There are several different HP figures and at least two dramatically different ways of measuring it - by mechanical output or electrical input. Such that anything between 450 and 650 watts is sort of justifiable.

    A simpler approach to check the rating plate on an equivalent electrically powered tool - I have a modest string type cutter rated at 500 watts - but I'd want a bit more were I hacking brambles.
    I'd much rather lay in my bunk all freakin day lookin at Youtube videos .

  8. #8
    Join Date
    Jul 2015
    Location
    St. Paul, MN
    Posts
    195

    Default Re: gas/petrol to elecric tool conversion

    Quote Originally Posted by P.I. Stazzer-Newt View Post
    There are several different HP figures and at least two dramatically different ways of measuring it - by mechanical output or electrical input. Such that anything between 450 and 650 watts is sort of justifiable.

    A simpler approach to check the rating plate on an equivalent electrically powered tool - I have a modest string type cutter rated at 500 watts - but I'd want a bit more were I hacking brambles.
    Thanks for the explanation. Makes sense.

  9. #9
    Join Date
    Feb 2001
    Location
    Seattle, WA USA
    Posts
    14,051

    Default

    1 mechanical horsepower is the power (motive force) required to lift a mass of 550 pounds at a rate of 1 foot per second at 1 g, and works out to be just about 745.7 watts.

    A 15 amp, 120 VAC circuit can deliver about 1800 watts before blowing a fuse, and so can deliver about 2.4 HP max.

    Look at the normal power draw of the electric motor in watts, de-rate that by some percentage for efficiency loss and divide by 746 and you'll get the rough horsepower of the motor (assuming that it's a 120 VAC motor).
    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •