DIY Rototiller/BoxBlade/RockRake

[sbest]

So I've gardened by hand for years, but recently bought a small farm. The fields were going farrow, so I needed to mow before they became forest. I bought a MF230 and a bush hog to solve this problem.

Now that I want to do some gardening, I needed to break some sod. I found a 2 furrow plow:

And then a disk harrow:

This still left the field too rough to plant. Sods and clods needed to be broke up. This meant rototiller, ideally 72" to fit behind the tractor. No reasonably priced finds to be had, what to do? Well, I'm a millwright by trade, so I'll build one. Better yet, lets have an implement that can rototill, grade, plow dirt like a box blade and even rake rocks if I need. All these use a box like frame behind the tractor. I don't have a PTO hookup and gearbox but I do have a 10hp Yanmar diesel sitting under the bench. Hooking up motors is something I've done a lot of. I did some drawings, so let's cut plate and drill holes:

A bit of bending:

Some store bought tines and shed 40 pipe:

A bit of welding and I had a frame:


Most of the assembly work was done in the field, so the frame also became my workbench. Note the vise.

 

[sodamo]

I like it. Good job

 

[Big Barn]

Nice work, sbest. And welcome to TBN!

 

[sbest]

A big problem with building any heavy machinery like this is doing the machining. Like most folks, I only have access to an 8" drill press and hand tools, so how to build the tine rotors that will need a 1.375" hole through 1/4" steel? It starts with layout and a pilot drill:

My drilling capacity is only 1" with this drill press, so I opted for the hole saw. Scary operation with a light duty drill press.

Lots of oil, slowest speed and clamp everything down tight.

Success. Now, eight more to do.

I opted for 24" (21.5" actually because of bearings) tine rotors and two bearing supports to keep the 1" shaft well supported. Three 24" sections work out fine for tilling center sections or just tilling on either side of a row. How the tines bolt on turns out to be important too, as bolting them on the long way takes a lot of power. This shows both ways of bolting the tines on.

I used 1/4" bolts to connect the tine rotors to the 1" shaft. I kept shearing them so had to up to 5/16" bolts to take the load. They still shear off when I hit a rock, so I built slipclutch out of 3 sprockets, which helped to solve this problem.

The modular design will let me switch from 72" tiller to center tiller to row tiller to box plow to grader to flail to rock rake.

 

[sbest]

Nice work, sbest. And welcome to TBN!

I've been on here for many years as a lurker, soaking up all the knowledge you folks have had to share. I need to thank all of you.

 

[sbest]

Buried between the two #41 sprockets that you see (60t and 48t) is a smaller sprocket (40t) that is connected to the shaft.
This acts as a slip clutch if I hit a rock. Not shown is guarding that protect if chain, bolts or grease fly off.
The tine tubes have 5/16" shear bolts as well.

10hp is not enough for all 72". I have to set the draught pressure very light, but it is ample for 24", so I tilled deep in the center before seeding.



Once things start to poke up I will remove the center tines and install both side 24" tine tubes to scratch the weeds between the rows.

A gearbox to drive off the PTO is in the plan. Certainly easier than coordinating an ICE motor, but has proven to work well.

Now, back to breaking rock the hard way...