Tater digger/rock picker

[Millwood]

I just can't bring myself to buy a new Spedo CPP-T spud digger for the 3pt on my Kubota. I noticed the one you are building Muddstopper for the walk behind. Got a couple quick questions. Your screening rods look like 1/2 inch round stock. Any reason so large diameter? Would it make any difference to weld your rods underneath the cutter to prevent spud damage? Overall, I like the concept and design and plan on similar.

 

[OldMcDonald]

Following on from Millwood, I had, and still have, an enormous rock and stone problem all over this place, evn after 10 yrs and several thousand tons of rocks removed. I have also grown many acres of potatoes in my time and have used several different tractor mounted lifters as well as seen many more. I built a stone rake of two sides 18" high, with 1" rebar attached at 12" spacing and 6" inches into the ground. 10 feet long and 2 feet wider than the tractor outside wheels. I had to add a lot of weight but it worked great. I built a pick-up box on similar lines to mudstoppers idea, but rear mounted so I had to reverse into the windrow of stones. I again used 1" rebar, 2" gap between, but ground one end of them flat and sandwiched them between two plates so that there was a smooth top and bottom in use. The rods were 80cms (say two and a half feet) long and fixed at the tractor end too. Solid back and sides to the box.

I think the 1/2" is the minimum I would use for potatoes. On the little information I have found on the net it seems to be a common size. For rocks I would definitely up the size unless you only have potato sized stones to deal with. I take it from your set-up that the blade will be vibrating too. This dramatically reduces the power needed to use the digger.

 

[Millwood]

Well, I guess the 1/2" round stock rods make sense if the attachment is doing double duty as a spud digger and stone picker. Since this is my first crop on my land, I did my 200K ton of rock removal last fall when I ripped it up and amended the soil for growing. Now, my thoughts are in harvesting the spuds.

The process requires removing the dirt from the spuds and back onto the ground. How one does this is open to different designs. The chain method is what I'm used to seeing in large scale agribusiness on Burbank Russets with thick armor skins, but the concept of shaking it off makes more sense to me, since Yukon Gold spuds have a thin skin and rolling up a chain conveyor will tear them up. That's why I was impressed with the design of the Spedo CPP-T, one row harvester. It brings dirt, rock and spuds up, low to the ground in a basket that moves laterally within a rigid frame, front to back to shake off the dirt, then drops them gently back on the ground for manual pickup. That's the design I'm building.

 

[CliffordK]

I wonder if there would be an advantage of making a tater/rock accumulator. Even if you dumped it back on the ground, follow the system with a non-shaking bin that would catch the taters, then when full, you could simply dump into a nice pile, then go again.

If you made it removable, you might be able to even dump it into a bucket or cart.

 

[Millwood]

I thought about an accumulator/catcher, that would be very low profile, to catch the spuds coming out the back, but since my soil is ancient river bed, I still have lots of rocks about the size of golf balls. and I'm afraid the catcher would be a 50/50 split between crop and rock and not worth the effort to build.

I wasn't joking when I previously said I'd done my 200K ton of rock removal when I opened up the ground. 6 were the size of a Volkswagen Beetle and took a crane to lift and remove. Then I removed every other tine on my rock rake to get the next bigger sizes and hauled out 14 dump trailers full, replaced the tines and went again for 21 more trailer loads for the rest. It took two months, plus 475 yards of top soil and manure to fill the ground to level, but it seems the rocks have percolated up from China to replace the ones removed, so for me just shaking the spuds and laying them on the ground with the rocks is my best bet.

 

[CliffordK]

How much abuse will the taters take?

Perhaps if you shook the accumulator too, you'd get a bucket that had spuds on the top, and rocks on the bottom.... solve two problems at once Except, perhaps the smaller taters would still sink some.

 

[muddstopper]

Been away for a few days. Picked up a 7hp engine at Harbor freight today. On sale for $119. Havent even looked to see what kind of pullies I need. I'll just compare to what is on my other troybilt and pickup what I need. I think I have it figured out. Have to wait till Thurs. for the metal store to open to get what I need. Probably spend most of the wkend working on it. My son and grandkids are coming in tonite to spend the 4th with us. Bringing the new Great Grandbaby with them. Going to have a housefull for a few days. To many women in that crowd, Shop might start looking pretty good after a day or two. LOL Might get something done. Wonder if grandsoninlaw knows how to weld. Wonder if I can talk the crowd into helping split my winter wood. ah em, what about a few of my other projects. Sure hate to waste good help. Got to start planning.

 

[muddstopper]

I will comment on the 1/2in rods and my method for mounting on top. I think it was already touched on, but I plan on this digger doing double duty, picking rocks as well as taters. Might try it on onions to just see if it will work. I am mounting the rods on top mostly because i didnt think of mounting them on the bottom to start with. Oh well. Anyways. I intend to build the ends of the rods up, blending them into the plate using a hardfacing rod. My original thoughts where that digging in hard rocky soil might vibrate the rods lose as they wear if they are mounted on the bottom. Hadnt thought about brusing the taters with the ends of the rods. Might change it, might not, I aint growing hundreds of bushels and we eat them as fast as they grow anyways.

I am spacing the rods on 2in centers. I figure anything smaller than a golfball isnt worth worrying about and a golf ball is 1 3/4 dia and should roll on top of the tines. I am still trying to guess just how far the digger should travel or shake front to back. Probably just make the eccentric with a adjustable pin to adjust stroke. Might just drill a few extra holes in the trailing arms going down to the digger plate as well. Easier to just pull a pin to adjust travel than tear it apart and drill holes later.

I am still trying to figure out a way to catch the rocks and taters as they come off the shaker. From the utube videos, it sets awful close to the ground in the back, dont know how much angle I can get away with to get the rock to catch in a trailer. I will probably just make a small skid to drag behind the digger and let the rocks roll into it and drag it to the edge of the field to empty. Wonder just how much weight the old troybilt will drag.

 

[CliffordK]

Presumably your digging depth is below where most of the taters will be. Otherwise you run the risk of cutting some in half, and missing others. Of course, I guess that is the digging depth of the blade, not necessarily the screen. Tapering the ends of the rods will likely give substantial protection to the taters, and rods too.

Thinking about this more, even if the blade is run at an angle, the depth of soil on top of the blade will remain more or less constant. So, if you're cutting 1" below the taters, they should be fine, even if the blade is set at an angle.

 

[muddstopper]

Struggling with just how deep to make the blade go. I cant seem to get the view I want watching utube. I'm just going to make the attachment arms extra long with plenty of extra holes and do the trial and error method. I'll cut off what i dont need once I get it figured out. I am going to use some small tires in the back with height adjustment to help control cutting depth and lifting the digger up for transporting from shed to field. Going to the machine shop in the morning to get a shaft made to replace the current tiller shaft. The tiller shaft is made with a taper on each end, I'm just going to make a straight shaft to make mounting a pulley easier. The machinist agree to give me a few lessons on running a lathe and mill while he makes it. I own a old monarch lathe but seem to break more than I make.