Square foot garden - Wow Dipper Drum Design

I need to come up with a new design for planting. I can't use regular seeders or such because  (for my story: terrace garden)
1- All my veggie plots are hand built on steep slope as terraces. They are 110-120 cm wide. There is not much walking paths.
2- I don't have a ton of growing space, so I have to use one of intensive growing approaches. Meaning I can't use regular row planting.
3- I don't have much time. Drip irrigation, timers, good soil all helps, but I need a tool that will help save a tone of time on things like planting.


Of all the methods, I think square foot gardening should work very well for direct seeding= radishes, spinach, Swiss chard, garlic and similar considering my situation. This summer drip irrigation proved to be best for planting seedlings (tomatoes, peppers, eggplants, and even corn). I might come up with another tool to optimize planting for drip irrigation- friendly veggies.

But square foot gardening is also a ton of work. If only seeds knew themselves where to  be planted. If only there were a tool that will make square foot gardening efficient.
There is one. A plastic plate with colored holes drilled, so you can spot where to plant, how many of them to be planted and such. It is a nice template. But it is one dimensional. It is not for planting in lines. You have to press the template for each square foot. Yeah you will not need it in the future but why as we can come up with something better.
Here is the template:


Assuming terrace beds are 120 cm wide (4 ft), I think it will be wiser to think a ft of it will be lost my row covers in winter, and one side getting baked by sun in summer time. So I have 3 ft wide beds that are 30-60 ft long.

While I was watching some youtube videos I came across to this enthusiastic couple who designed their own dipper drums for planting garlic. Their design might seem awkward at first sight/or to an untrained eye. Nevertheless, as any other original idea/variation, the design hosts many ingenious solutions. Some of witch I loved. To be fair it only looks awkward because it is a prototype. Thanks Tim!
Here are their videos, help them if you can. They do come up with amazing videos, many good new designs.





So I wanted to come up with a basic tool that will but holes on the ground as square foot design dictates. Then I can drop seeds without thinking a thing. Of course it is not perfect, and beds will be the same crop (or same space group of crops in one direction). But it is still way  better than pressing the template for each square foot.

I goal was to come up with one single drum diameter for all different spacing requirements. That way I might come up with a modular design, have a modular 3ft rotating template with 3 different, exchangeable templates. (please see the second picture)
After some basic calculations, a total diameter (drum + dippers) of 40 cms came up to be almost perfect. 25 cm diameter drum will perfectly fit.

So here are my hand drawings and a basic autocad screenshots. I don't know when I might have time build it myself. Maybe this year maybe next. But I wanted to put it out here for any ideas, and in case someone wants to build and test it himself/herself. Since it is inspired by Tim's original design, I call it, WOW'S DIPPER DRUM (or in long form: way out west blow in blog (inspired) dipper drum). Any ideas are appreciated. Very much so before cutting any steel.

Your work is greatly appreciated Sandra and Tim. Thank you!

And here are the autocad ss's
All in millimeters

Work in progress..

Update

I can't wait to see how this works out.

So I had time to play with what I have atm. Couple of design notes for future consideration.
- The circular part seems fine. A probable problem is, when it rolls over the handle part,  plate might cut through the horizontal pipe (that the dipper rotates). Adding bearings will be an over design.
- The horizontal bent metal pieces that are 4 cm wide seems quite right. What bugs me is that I need to have 4 different types of them. I can drill more on the ears (the end- bent parts) so that I can move it closer or further away from the center. 4cm wide section will not let it though, so the ears will need to be 2 cm wide.
- I have no clue how to design "tooth"'s, the dipper parts that will sink into earth. They need to be made in turning lathe and whether they are made from wood or metal they are expensive. I chose to have them made of wood, 4 cm long, section getting smaller in the last 1.5 cm's. It is wood so I can rasp If needed.

Here is where I am atm. Now I need to figure out how to connect wooden teeth with metal parts.

Really nice craftsmanship!  It is a pleasure to watch your work!

Thanks Phil!

I tried to connect wooden teeth with steel parts. I knew it would be problemetic as I broke the design rule of "consistency". I finally figured out how to make it work, but I'll need to correct the remaining 15 of them some time later on (after spending 2 days driving to get prices etc I don't feel like it). It wouldn't be a prototype without some drama, eh?

I made couple of trial runs! (screws doesn't work, gets loose etc - other type of connections failed too).

About teeth design. The wooden pieces have a constant cross-section of 2 cm diameter for the first inch (2.5 cm), then decreasing linearly for the last 1.5cm, giving it a conical shape. It worked perfectly in my mind, though not in the soil. I should have guessed it. Sandy soil remains "stable" till it reachs roughly 30 degree slope. Our dark soils - full with life will be a lot stable (45-60 degrees maybe?) and wet clay being perfect. I guess I was way too optimistic with 90 degrees for the first inch where the cross section reamains constant. If I were to design them again I would go for decreasing cross section for that part too. So this 4 cm long piece will have a decreasing cross section from 4cm diamer to 2cm then for the last bit 2cm to zero. I thought teeth will not sink in fully, but they had no problem in the seed bed trial. I think increasing the cross will not cause any prblems at all.

It is heavy enough to get into the soil, light enough to carry around. Moreover I don't want to spend more on the handle while I can come up with new designs for the teeth-parts. Besides it is not massive. It is easy to use it on sides of the terrace. Handles might get in the way.

I think it is time to call a full-stop for nuturing of this design. I have spent more then what I thought initally. Now I can pass to the third phase - trying to kill it. Let's see where it work, where it doesn't, cons, pros, fails etc. First fail is quite evident. 2cm constant cross section teeth design will not work in sandy and/or drier soils. It seems it is a good thing that I have clay soil. Way more then I want though! :)

Here are some intial trial pictures!

I planted garlic!
Couple of points,
-A handle would have been great. It doesn't need to be metal, wood will be just fine.
-Soil was not ideal, but it worked perfectly.
-It is a 120 cm wide bed (roughly 4 ft), so I needed to roll it 4 times in a weird position- no handle ugh!!. I guess it wont be any better if it had a handle though. I think what will be perfect for beds like this, a half a bed-wide tool. It is in modules, so modifying is no problem at all.

It was very easy to plant garlic. I planted over 500 cloves in less than 20 minutes. I spent most of that time rolling it. Planting itself took less than- say- third of it. It really speeds up the process, for you are not planting- but dropping - ideal holes- perfect depth and perfect diameter!

Here are the pictures,




Covered with mulch and etc:

That's really cool! Definitely looks like it will be useful for years to come