Active rotors for a power tiller with their own hands
ACTIVE ROTORS. an unexpected assistant!
Unexpected because we didn’t hear about active rotors in Ukraine and our attention was called to them by the representatives of Meccanica Benassi during our trip to Italy on the International Seminar with Benassi.-х. exhibition. Emphasize: here we are talking about active rotors, not passive, which are widely used in tillage machines (read more about passive rotors at the end of this article).
Italians began to tell us that they also use them for high grass and, gesticulating intensely, tried to explain us how. The body language wasn’t quite clear enough for us, but we got one thing right: There’s something to it. So, on our return to Ukraine, we decided to check the rotors in action.
| Here they are, active rotors with spiral blades. The rotors are mounted on the 6-sided gearbox shafts of the Meccanica Benassi GEPARD. | |
| Tillage must be done before ploughing or no-till farming. Active rotors replace the hoe and prepare the field in the best possible way. | |
| Cutters are not up to the task. After a few meters of travel, the blades of grass get so wrapped up that they hide in them and don’t reach the soil surface. | |
| The same thing is happening on the right side of the rotor. | |
| Active rotors, on the other hand, do not get blocked at all. | |
| Grass and weeds of any height are handled by the active rotors. | |
| This is what you get after the active rotors have been driven through: The tall grass is cut down cleanly and shredded. | |
| Active rotors are good for mulching plant trimmings and incorporation of green manure. | |
| The degree of mulching can be adjusted by the rotor speed. |
The first thing we noted, active rotors are used exclusively on power tillers with 6-sided gearbox shafts (it is known that they are much more practical than round ones). But that’s not all. the single axle tractor should be able to fix the rotors with a special lock, thanks to which all the backlashes, both axial and radial, are selected. As a result, the rotors form a single unit with the motoblock gearbox, a monolith. Since the Italian single-axle tractor GEPARD by Meccanica Benassi was the best suitable for this purpose, we chose it for the rotor test.
The second feature of active rotors, the slats are made in the shape of blades, which are flat instead of on the ground, as we are used to see. We first tested the rotors on clean soil before driving into the grass. You put it in 1st gear and slowly drive off. HEPARD began to roll over the field on rotors. Here we saw the picture familiar to our eyes: the slats of the rotors slapped on the surface of the soil and broke large clumps of soil into smaller. We added gas single axle tractor rolled faster, the efficiency of the rotors increased. But we also saw a typical problem with rotors: if we came across a bump or groove on the way, the rotors would roll over them and wouldn’t level the field. That is, both the bump and the groove remained. That is why rotors are always used in combination with other working tools such as ploughshares, ripper tines, harrows, etc., that first loosen the soil and then the rotors level it out. But we knew the rotors were active. So we installed a coulter at the back, as for work with a mill, added gas and saw a completely different picture. Thanks to the coulter, which braked the single-axle tractor, the linear speed of the rotor blades became higher than the forward speed of the power tiller. The rotors were no longer just rolling over the field, they were beginning to loosen the topsoil, pulverizing it to a fine crumbly state. If there are leaves, stems or other plant debris on the path, the rotors mulch it together with the soil. And most importantly: the rotors cut bumps and filled in the grooves. That means the rotors have been levelling the ground! So, the active rotors actually acted as a rotor, a ploughshare and a ripper. That’s the beauty of active rotors! One working organ, and what an effect! After such a discovery, we realized that not in vain Italians tried so hard to tell us something. For this we went to a field with vegetation. In the first field we had grass and weeds up to our breasts. Of course, in order to do something in a field like this, it has to be prepared. And here we try to prepare it with the active rotors. Drive in with the rotors with the coulter in 2nd gear. The rotors started to chop and shred the grass. Pressing the rotors into the ground. To do this, we press the coulter deeper into the ground. The rotors went into the topsoil and started actively mixing the soil with the grass. This gives a result that a disc harvester cannot achieve in just three passes! What’s up?! We didn’t expect that. After 40 minutes of work let’s summarize. Active rotors are quite unusual tool, which thanks to its “active behavior” performs the functions of several passive tools at the same time, namely: plough-beam that levels the surface of the field; cultivator tines that loosen the topsoil; ring-rollers that crush lumps of soil into smaller pieces; husk discs that trim and shred stubble and other vegetation; milling machines that mix plant residues with the topsoil. In addition, in contrast to rotary cutters, which can mulch the soil with little plant residue, the rotors easily “digest” grass of any height and in any quantity. We were convinced of that after driving over the high grass with both rotors and milling cutter. The mulcher has already got tangled in the grass after 20 meters, but the rotors do not care. And then we finally realized what the Italians were telling us. The fact that in Western Europe is widely used siderates (green fertilizers of plant origin, easily assimilated by the soil). Before plowing into the soil the green manure should be cut and shredded. This is where the active rotors come in. As it turned out, they are ideal for this task. To be sure of this, we moved to another field, with green grass. Indeed, the grass, and it can be siderads, is chopped, shredded and actively mixed with the soil. And the more the rotors rotate, the more they mix with the soil. So the active rotors give us new opportunities to use the power tiller and new agricultural technologies. For information: Passing through the winter roads of Western Europe, we have repeatedly noticed the abundance of fields, sown with green manure. At the same time, we do not recall such a field in Ukraine, although in science with.-х. the literature talks about the enormous benefits of agronomic practices using green manure crops. And if our gardeners and farmers prefer to deal with manure and mineral fertilizers, the Western farmers, in our opinion, act more rationally. Given this circumstance, the Technical Center “Gardening and Vegetable Technology” gives each buyer of active rotors Recommendations on the use of grass seedlings.
Note to home handymen. We tried to make such rotors in Ukraine. Nothing came out of this idea. Firstly, the rotor knives are curved along the spiral mowing line, and the mowing lines themselves are located on a barrel-shaped surface. Therefore, to manufacture rotors with such blades, you need expensive equipment, and to do by hand is more expensive, as imbalance, which will certainly appear, will break the gearbox motobloka. Secondly, the rotors in no case can be put on the amateur series of motor blocks (these units have a round shaft under the cutter), as console mounting rotors and the inevitable backlash will also lead to failure of the gearbox motobloka. If you see on sale a single-axle tractor (or power tiller) with rotors, which are put on the round shaft of the gearbox is a knockoff of a serious professional equipment, or, to be more precise, “noodles on the ears.
For information. The rotors themselves have long been known. These are cylindrical rollers, which have rods or bars instead of smooth cylindrical surface. The rotors roll across the field and with their rods or slats break up the soil and smooth out its surface. As a working organ, they are part of many tillage machines for the fine crumbling of the soil and are widely used in agriculture (here we are talking about large, tractor-mounted machines). For example, rotors are used in harrow BP-8 and cultivator USMK-5,4, which we know from the Soviet times, and in recent years. German LEMKEN, Austrian FOGEL und NOOT grouper and combined SEPAK-PROFI machine.
Features of cultivator cutter blades
Cutter for power tillers (tiller). a device for tillage. The RTT 2 is mounted on light cultivators instead of wheels. For heavy models of power tillers or mini-tractors, they are made according to the type of attachment. tillers are used for crushing, loosening or leveling the ground. Well-proven attachments for the development of the virgin soil. It is also used for fertilizing and plowing green manure.
Kinds of blades for tillers
The construction characteristics of the mowing line determine the depth and type of ground to be mowed. For dense and hard soils, as well as celenium, thicker tillers are used. If you plan to work a deep topsoil, the long blades are used. Cutting attachment is curved for better grip. The direction of the fold can be to the right or to the left. 7 useful devices for the modern dacha ownerThere is an opinion that the work in the country house. is quite a tedious activity, which takes a lot of time and effort Cutter bar can be either demountable or monolithic depending on the way of its attachment to the mill body. The latter is an all-welded construction without the possibility of replacing damaged parts. practical is the collapsible version. In such a design, it is possible to replace a failed component. In addition, with a set of interchangeable blades of different lengths, it is possible to quickly adjust the unit to cultivate the soil to different depths.
Material for blades
In order to withstand high loads during work, as well as to be resistant to abrasion, the cutter blade is made of high-quality carbon steel. This material is well tolerated by heat treatments for strength and hardness. Hardening increases tool wear resistance by an order of magnitude. Some manufacturers produce the cutting part by forging. This part has a longer durability.
Exposing steel to forging pressure causes a stick-slip effect in the steel. hardening of the surface layer of the metal. It makes the cutting edge harder, and you need to sharpen such a tool less often than a stamped tool.
“Goosefoot
The second type of cutters is the model “goose feet”, which received such an original name due to the triangular shape of the cutting parts. Similarly with the saber type of device, the size and number of cutting components depends on the weight of the main unit. For example, it is recommended to install four or more parts for a MTZ power tiller, and only three for other similar models. In fact, you can put an unlimited number of knives as you see fit, but it should be taken into account that the power of a power tiller with a weak engine will drop significantly.
With the help of “goose feet” most often work difficult types of soil and virgin lands. But it is worth noting that if the soil contains a large number of branched roots, the system can clog and fail.
Every rotary tool type requires initial inspection and further careful handling
This type of cutter was widely used in the eighties in the days of the USSR, when the active development of homemade devices in the economic sector began. Farmers were forced to look for ways to increase productivity on their plots and for this reason learned to create tillers for power tillers with their own hands. It should be said that since then the design of the unit has not changed, which once again proves its timeless effectiveness.
How to assemble “goose feet”
The main element of the tiller is the drive sleeve, the parameters of which should be at least five mm of wall length, and the optimal value is considered about seven mm. Next, it is necessary to mill the inside so that it is easily dressed on the shaft, and make a special hole for the axial tube to a depth of thirty or forty mm.
As for the axle tube itself, it is usually made on the basis of the standard model AE25-32, but other similar parts are also allowed. There are two types of finished pipe: collapsible and non collapsible, it all depends on your expectations. But if you believe the reviews of farmers, the collapsible version is still considered the most effective, because it is always possible to add or remove the blade units. It is impossible to predict how a single-axle tractor will behave in a certain area, and for this reason it is better to have a backup version of the modification just in case.
Be sure to read: What’s the difference between a single axle tractor and a power tiller
Having chosen a suitable type of axial tube, it is necessary to install a special flange on it for further attachment of knife units. The total length of such a device will depend on the width of the knives and their distance from each other. The optimal width of triangular knives is about 60-80 mm, because larger sizes significantly increase the resistance of the unit to the ground and worsen its work. The knife inserts themselves must be made of solid steel and have a thickness of 3-5mm. Next, you should assemble the rack of the cutting element, which consists of a curved strip and a sharpened edge.
“Goose legs” are good for treating stony soils and destroying weeds
Connecting the cutter and the axial tubes you get the general construction of the modular element. Actually, this is the final stage of creating the “goose feet” and you can conduct the first “run-in” of the homemade installation. Also, before you start the procedure of making a cutter, it is worth making a small drawing beforehand to reduce the risk of spoiling parts. The necessary blueprint can be found in many automotive publications or on the internet, if you have a technical background and understand the design of the mill, you can make an approximate plan yourself.
Do you need to sharpen the cutters on a single axle tractor??
There is no clear answer to this question. It all depends on the individual characteristics of the power tiller, the soil and the conditions of use. For example, sharpening is not necessary when working on heavy soils with a power tiller with reinforced milling cutters. You will not see any tangible effects from this procedure, you will only waste time and effort.
For processing a site with a lighter power tiller with small cutters sharpening is not a bad option to improve the quality of work. But there are disadvantages too. First, sharpening only lasts a few hours, then the procedure must be repeated, which is a long and laborious process. Secondly, sharpened blades help break the roots of weeds, which in turn can only speed up their reproduction.
If you do decide to sharpen your tiller, take it off your power tiller and clean it from the ground. Very carefully sharpen each cutting element with emery paper, so as not to damage them.
Reviews
I built my first single-axle tractor back in 1985. Cutters made by the principle of “goose-foot. Since then four more modifications have been made. The harrows that are on the market do not meet my requirements. When I bought a modern single axle tractor I adapted my old “legs” to it. The result is great.
I made a mistake when making the cutter and thought I could do everything by eye. It made me rework the parts several times. In order to avoid my problems, learn the basics. I regret, that this article appeared to me after manufacturing.
Design
Blueprint for a power harrow
The harrow is a grid, to which the tines are rigidly welded or bolted. At the front has a hitch. usually a hitch with holes, which is inserted into the towbar tube of the power tiller and then secured with a pin. You need to weld a chain between it and the hitch. without it the work would be very hard for the plowman.
The harrow must be strong enough. It can be made of square or water pipes and corners. The thickness of the metal should not be less than 3-4 mm, otherwise the teeth, welded to a thin-walled pipe, will break out during the work together with the metal pipe.
The design of the grid may be in the form of a cage consisting of longitudinal and transverse elements. But better suits the grid, in which “bars” are welded at an angle of 45 degrees to the direction of the motoblock. such a grid will be less exposed to bending loads.
The mesh size should be selected according to the location of the teeth. It is better to think beforehand how you will locate the tines, and sketch it in the drawing, and then over them draw the grid, to which they are attached. The size of the frame should be so that it does not interfere with the tiller’s operation and walking behind it.
The harrow frame must not extend beyond the handles of the power harrow.
The dimensions of a hitch must be taken into account. It is not necessary to make the grating too wide. a single-axle tractor simply can’t pull more than 1 meter.
Tines should preferably be made of riffled reinforcing steel 10 to 18 mm in diameter. Each tooth length. 10 to 20 cm. The hitch height of the power tiller does not influence the tooth height. the harrow is attached by the chain. The longer the tine, the thicker it should be. It is advisable to sharpen the teeth before installation and be sure to harden them, because.к. Unhardened tines will bend during operation. For lighter soils you can use a harrow with unsharpened tines.
Their spacing should be no less than every 10 cm. if you do it less often, harrowing will be ineffective. It’s allowed to place the tines with a slight offset in a row, so they can be easily welded and provide the desired intensity of cultivation.
Hoes for your power tiller with your own hands
With the purchase of a power tiller the user has a desire to use it in all home works for dacha, vegetable garden, etc. Some people tend to buy the maximum possible set of attachments for the motor-block at once, while others buy only a minimum number, gradually acquiring the rest. The third category of owners undertakes to make by their own hands devices and additional devices. Sometimes they are in many ways superior to what the industry has to offer.
About the rotational speed of the tiller
The question about the tiller’s rotation frequency deserves a separate consideration, because lately appeared many contradictory publications on this topic, and some “writers”, whether by ignorance or with malice misinform the readers.
Let’s consider two schemes: a cantilever power tiller with an attached milling cultivator (left) and an axial power tiller (power tiller) with cutters mounted on the power shaft:
In the first case blades of the rotary cultivator participate in two movements: together with the engine unit they move forward with a speed V0, which is set by the engine unit, and relative to the axis of the cultivator they rotate with a speed V1, which depends on rotor speed and bit diameter D.
If speed V0 is less than speed V1, the cultivator tills (“mills”, “cultivates”) the ground normally.
If V0 V1, then the cultivator turns from an active tool into a passive one, i.e.е. into the “plough” and will not loosen but scratch the ground. That’s why all power tillers are equipped with such a speed that V1 is faster than V0, resulting in normal recultivation.
For example, a universal milling cultivator “Motor Sich” KV-1S mounted on motor blocks ARTANIA MA 300, Super 600, Goldoni, MTZ-05, MB-4,05 and others., Having a 310 mm diameter mill rotating at 300 rpm., provides its rotation speed V1= 4,2 m/s.
Kubota PEM. 140DI Power Tiller
The single-axle tractor moves forward at a speed of up to 1 m/s while the tiller is in operation.
Such significant excess of rotation speed over forward speed ensures stable and effective cultivation of the soil. The same applies to the RTT 2 cantilever scraper, which operates at 275 rpm. at 320 mm diameter, the ratio of rotational to translational speed is almost the same.
In the second case, the forward speed of the power tiller is determined solely by the rotor speed and the density of the milled soil. V2 is always less than V1 and in this case, irrespective of speed n, the milling cultivator is always an active tool. The rotor of an axial tiller can rotate at any frequency.
However, in this case, other considerations should be taken into account: if a relatively light power tiller will ensure that the tiller rotates at a frequency of 200 300 rpm., the operator’s arms and hands would get numb from vibration after an hour of work! First of all.
Secondly, a power tiller is usually a one-speed machine. If the wheels are installed instead of the cutters and a potato plow or potato plough is attached, and the speed of the wheels is 200 300 rpm., Even with a wheel diameter of 200 mm the rotary cultivator reaches a speed of 9 to 10 km/h. No slippage will help the operator work.
Third, the rotational speed of the tiller is increased up to 200 300 rpm. The power of the tine tiller does cause excessive crumbling of the soil.
Conclusion: RPM of a tiller attached to a cantilever power tiller should be no less than 275 rpm., and the rotational speed of the tiller should not exceed 130,140 rpm.
Homemade harrow on a single-axle tractor with your own hands
Harrow for power tiller is an attachment designed for crushing the soil layer after plowing or simultaneously with plowing. It may also be used for sowing seeds or for levelling ground after rough cultivation. e.g. after digging potatoes.
Such equipment is not used so often. most power tillers belong to the cultivator type, and after such processing usually does not require harrowing. However, large power harrows often require a harrow, especially after plowing virgin land, fallow land or after green manure. Harrowing speeds up the drying and warming of the soil surface, enhances the absorption of nutrients from the soil and improves the absorption of organic and mineral fertilisers.