DIY electric cordless grass trimmer

Black and Decker Li-Ion strimmer (which is a 36V drive)? Not sure of the RPM but it should be fast enough. I have one of these and the motor is pretty powerful (feels like a mains strimmer, at least for the 20-30 mins the battery runs for).

Might seem extreme buying a strimmer for the motor but you will get a battery carrier, battery, charger and motor speed control circuit to cannibalise too.

Take the vacuum hardware out of a Roomba. Add the RC car's wheels. Put the engine from a gas-powered trimmer on top, the business end underneath, and the wand in your junk pile.

Put it on your lawn, start it, and walk away. Retrieve when it runs out of gas or refill as needed.

Call it a Lawnba.

Mark L. Fergerson

--------------------------------------- Your idea is nice but to complicated :-)

I found one other solution :-) I can not stop laughing but the idea is great !

Look at this:

I can add one 12/220 1KW converter and that would do the trick. This would be really strong and effective.

The only negative part is the power consumption and the fact that i can not turn it on / off all the time. Hmm, am wondering how long would this run if i connect it to some 12/

GM

Den tirsdag den 7. juli 2015 kl. 16.56.15 UTC+2 skrev gm:

500W sound like a lot, I think the regular robot mowers are ~100W including everything

-Lasse

no safety features at all, good thing he remembered to wear his Chinese safety shoes ;)

-Lasse

------------------ i made one test with electric grinder. Damn that was strong. I used 800W - 11000 rpm grinder and i must say, this is a monster :-) This should be used for plowing and not for grass cutting :-)

I connected grass trimmer - grinder to 12V-1,5kw inverter and directly to 12V / 85Ah car battery. I dont know how long ( in reality ) would this accu hold but i guess that with some lower wattage ( let's say 500W grinder) i should be enough for cca 2 hours ? Maybe less because of inverter lost... What do you think ?

my electric strimmer (Stihl FE-55) has an 860W motor.

label watts don't determine the power draw of the motor much, mechanical load is a much bigger factor. get out your clamp meter and measure amps on the battery lead.

In a used electric lawnmower. 500W is over 1/2 horsepower.