Automated lawnmower rope circular mowing method - GIF

**Jon** · Oct 10, 2019, 04:42 PM

Automated lawnmower rope circular mowing method.

Previously:

Lawnmower agility course - GIF
Five lawnmowers in one - photo
World's fastest lawnmower - video and photos
1901 steam-powered lawn mower in action
Ride-on lawnmower motorcycle - photo

**mklotz** · Oct 11, 2019, 10:02 AM

I guess he's never heard of Archimedean spirals. Replace that rod in the center with a 55 gallon drum or similar and it would cut the whole patch instead of cutting and recutting the same path.

**DIYSwede** · Oct 11, 2019, 12:45 PM

Drum dia: 1/3 of the cutting blade width okay with you, Marv?

**mklotz** · Oct 11, 2019, 12:56 PM

Originally Posted by DIYSwede

Drum dia: 1/3 of the cutting blade width okay with you, Marv?

Well, the bible says pi equals three so, yeah, 1/3.

**DIYSwede** · Oct 11, 2019, 01:04 PM

Originally Posted by mklotz

Well, the bible says pi equals three so, yeah, 1/3.

Just wanted some safe overlap, but then that's just me - as my late granddad hated to see any ridges in a freshly cut lawn...

**Crusty** · Oct 11, 2019, 02:58 PM

There's a bunch of silly physicists that still use 22/7 for most calcs. It's close enough when you're usually starting with data that has a 10% or greater error band built in.

**mklotz** · Oct 11, 2019, 05:00 PM

Originally Posted by Crusty

There's a bunch of silly physicists that still use 22/7 for most calcs.

Well this physicist doesn't. I long ago memorized pi to the number of places the computers of my younger years could handle - 3.1415926535898

But if you want a rational fraction approximation, the best one is 355/113 = 3.14159292035, an error of 0.000008491 % !

The mnemonic I used to teach my duller students was to write down the first three odd numbers twice in a string (113355) and split it down the middle to form two three digit numbers (113 355). If you can't figure out how to divide these two numbers to get a number close to three, you have no business fooling around with advanced mathematical concepts like pi.

**Crusty** · Oct 11, 2019, 05:26 PM

Heh heh. Pi are round, cornbread are squared.

**ibdennyak** · Oct 11, 2019, 07:34 PM

I was gonna say, I used to make a really tasty pecan pi. Recipe was on the back of a Karo syrup bottle.

**Frank S** · Oct 11, 2019, 08:40 PM

I tried that lawnmower on a rope trick when I was a kid but I couldn't get my younger sister to push the reel type push mower for more than 1 revolution so gave it up as a bad idea