Re: [mowbot] Re: Gotta have gas to cut ??

Dave Everett (deverett nospam at
Fri, 07 Mar 1997 19:24:28 +1000

KEN_REED nospam at wrote:
> My experiments have shown that small dc motors will cut the grass just fine.
> My test cuts were done using a single dc motor, 12v nospam at 0.6 amps while cutting,
> will turn a 5" aluminum disk approximately 2000 RPM. The aluminum disk has 4
> X-acto knife blades sticking out 1/2" that do the cutting. The cuts were clean,
> and seemed easy enough. Now bear in mind that I didn't cut overgrown grass, but
> cutting off < 1" was easy enough.
> My LawnBot will use two such electric motors/cutters to provide a 12" cutting
> path.

Have you considered just making one blade bigger to get the same cut? I
recall that the lawnranger used 2 disks, I think to acheive a short
wheelbase. It would at least save you another 600ma of current drain.
> Its also my recollection that the commercial robot lawn mower used such a
> system, and it is solar powered. There is a link on the Mowbot Webpage to this
> commercial mower.

Yes thats almost exactly like theirs. The solar mower also had the
blades springloaded and they came out under inertia and retracted when
the motor spun down as a safety feature.
I have the solar mower patent (5,444,965) in GIF format. It is quite
informative, I was going to put it on the website, but there didn't seem
to be much interest.

Dave Everett.