Diy rotavator!

[r_chez_08]

Hi all,
I wanted to make a homemade rotavator to male life easoer for digging up my pumpkin patch (i sell pumpkins at halloween, made about £100 last year!)
I have a honda g100 which was gutless on my mini bike. It puts out 2.2hp.
I was going to make it as cheap as possible, probably with no wheel/ $5 harbour freight equivalents!
What gear ratio do you think i will need to break up hard earth? I dont want the little engine dying all the time. I was thinking 1:25 or something low like that? Sound ok?
It would be direct drive and have 3-5 rotavator blades on a 3/4" or 1" bar, with pillow blocks or cheapo bearings/ maybe even bushes if it has such a low speed!
I would need a way of achieving such a low ratio, probably a jackshaft with a 1:5 ratio and then 1:5 to the axle.
What do you guus think?
Rob

 

[Doc Sprocket]

I think if it's "direct drive" with no wheels you're going to have the worst time starting it!
I guess what I call a rototiller you call a rotavator, by the description- It's for churning up the earth between growing seasons, right?

Maybe a belt-tensioner that locks into place to solve the above problem? You'll have to fab up a method to set depth, too... I'd go with cheapie wheels.

 

[Gillgamesh64]

I rember stubling across some old plans from a magazine once for a homemade motortiller once....I think your bigest problem will be your bearings

 

[r_chez_08]

@toystory: yeah rotavator, rototiller, tiller, whatever you call it. When i said no wheels i meant the travel ones for the front. I will probably have back ones though. I cant be bothered with a clutch. More expense and more time. If i spend too long on this, i may as well be digging the ground!
For depth can you not just let it sink deeper/ pull it up?
@gill: why do you say bearings will be hard to find?
Thanks guys
Rob

 

[redsox985]

I would get some type of push mower tires, maybe like the 12" ones some mowers use. Then just use a snowblower style belt tensioner. It shouldn't be too tough.

 

[karl]

http://www.vintageprojects.com/home-garden/roto-tiller.html

Check it out rototiller plans!

 

[Cam]

We had a masport rotavator with a 3.5hp briggs on it, was rather gutless and stalled under load, i think we stuck a juan dong diesel on that - got a bit dangerous though,

I recommend getting an old rotavator and putting a new engine on it, as its geared down something major, if you are going to make one or buy one, i also reccomend making the axle much wider, say 600 mil, and mount big phenumatic wheels, because it had a bad habit of capsizing, and took a lot of effort to keep in a straight line.

 

[r_chez_08]

Ok thanks. I could do a tensioner, i have a few belts and pulleys, but i wanted to make this simple. My dad is already saying just go and dig the land! But then i am left with a spare engine, that is not powerful enough for a vehicle of any description.
I will look at the plans, and draw up my own, taking the info from cam into accord.
Thanks
Rob
Edit: taken a look at the plans. It would probably be something like the 2nd one. I have some el cheapo wheels that i removed from my gokart. If they are trash i can get some plastic lawnmower ones from a local shop.
Edit2: what would be the cheapest way to achieve a low ratio? I could get #40 chain 3m for £15 and make sprockets for £5 per ft squared of material, but any idea of a cheaper way?
Edit3: i could go 6t on the engine:60t on the jackshaft then 6t on the jackshaft:12t on the axle.
That would cost about £5 for the sprockets, and £15 for the chain, then have spare chain for future kart chain. Then a couple of quid for a jackshaft, £10 ish for the axle, and then cheapest possible bearings. Starting to comsider to dig it myself now, as it will add up.
Rob

 

[fowler]

u dont need flash wheels
ours are plastic ones that are only held on by a split pin and no bearing
if u get big wheels they will get stuck in the dirt and make pushing it hard


also u want wheel axil infront of the blades otherwize the machine will get its self stuck

it should pull its self down and forward without much imput from u

on gear ratios
our has two redution boxes on the blade axil and on the motor

or u could go over kill and use the machinery we use

dig the ground with the scrapers and mix it with a big version of that spader

 

[Gillgamesh64]

@toystory: yeah rotavator, rototiller, tiller, whatever you call it. When i said no wheels i meant the travel ones for the front. I will probably have back ones though. I cant be bothered with a clutch. More expense and more time. If i spend too long on this, i may as well be digging the ground!
For depth can you not just let it sink deeper/ pull it up?
@gill: why do you say bearings will be hard to find?
Thanks guys
Rob

Bearings will not be hard to find, You will just have to use bearing seals or bush style bearings IDK what you had planed...

 

[robbie]

Here's an even better idea. Don't till your ground. Mulch the whole garden with about a foot of hay. When the season is over, cover it again with another layer. In the spring, make small holes through the hay for planting seeds.

This method will eliminate weeds and conserve water. Also the rotting hay will produce very fertile soil.

This will leave you with an extra engine. Sell it on craigslist and buy a pitch fork.

 

[Bluethunder3320]

IMO, find a old rusty roto tiller at the dump, and fix it up.

MUCH less time consuming, and you will save $$$

 

[flowerman]

I have an old 5hp rotovator that works really well that I got for £50. 2.2 would not be enough.

 

[B man]

I have an old 5hp rotovator that works really well that I got for £50. 2.2 would not be enough.

tell that to the mantis tiller.lol

 

[Cam]

Maybe like a 500 dia. pulley, then chain to the blades, what about a single or twin blade one? less rotating mass i guess..

 

[anderkart]

tell that to the mantis tiller.lol

Hey I got one of those with all the attachments, they're pretty dam cool but its not powerful or heavy enough to break up our rock-hard Colecchi soil here where I live. I have to break up the soil first by shovel and then let the Mantis do its thing finishing up the job.

 

[newrider3]

I don't know about you guys, but in my experience those front tine tillers suck. With our hard soil, they want to skip along the surface, and you have to use your whole body weight to get it to dig in.
The good ones I've used have rear tines, and driven front wheels. That way you can have the drive wheels doing the hard work, and run the tines in reverse to dig super deep.

 

[r_chez_08]

I have an old 5hp rotovator that works really well that I got for £50. 2.2 would not be enough.

Good point. I could sell the motor but it is missing a recoil, and i doubt anyone would buy it. I can now see the rotavator being more hard work to build and use than digging the soil!
This project is taking a backseat for now, as i need to fix my mini bike and do some work fitting up some things on our farm.
Rob