Ferrari - Tractors C.I.E.
"Appropriate Technology for Agriculture"

PO Box 1045   Gridley, CA 95948

office (530) 846-6401

fax (530) 846-0390

The Spader

Spader Benefits

     The spader (i.e. digging machine AKA Vangatrici) was designed as a primary tillage tool that could produce results much like those achieved by hand double digging. That is, a loose broken top soil with crop residues and surface applications well mixed so that air and moisture speed the decomposition of vegetation.  At the same time breaking up and opening the sub soil admitting air and moisture to increase water holding capacity and improve fertility.  The faster deeper rooting of crops increase plant vigor and reduces drought risk and soil temperature fluctuations.  The absence of a plow pan allows roots to continue to reach deeper for nutrients they need.

     All these benefits are achieved in a single pass without inordinate horsepower and without tire slip regardless of soil surface.  The tractor provided the input of power and resists the torque of the spades, but does not actually pull the spader forward.  The spader is tending to push the tractor forward.  The absence of wheel slip is important because wheel slip smears the subsoil much as a rototiller's tines would.       
      The Spaders penetration of hard surface allows it to work very dry compacted soils that rototillers, plows, and discs can not.  The spaders system of operation also allows it to work in extremely wet even flooded fields such as those found in wild rice cultivation.

     The spaders ability to incorporate very large dense masses of vegetable matter is a single pass makes the machine ideal for rapid reclamation of depleted soils.  The high degree of aeration helps dry-out wet soils and helps volatilize some pollutants.  Shallower digging spaders benefit from mowing cover crops while deeper digging models can often take down very tall standing material.

     More specialized variations of the spader are used to cultivate standing crops by straddling the growing row.  When you want to create an even finer seed-bed in the same single pass, a secondary tilling attachment can be mounted on the rear of some spaders.  This straight tined tiller breaks up clods into smaller clods by striking them with blunt tines.  The secondary tiller is adjustable so that only the top inch is treated - so that very small shallow seeded plants can be sown.


     When you get your spader from the factory it is generally ready to work i.e. has oil in the gearbox and all bearings are greased at factory) - in fact, the factory runs each machine for a few minutes at a stationary work station at the end of the assembly line.   However, you must check tightness of all bolts because some are loosened to fold spades or allow 3 PT components to move to make a more compact shipping package.  The

parts book has a picture of what the machine should look like ready to work. Do check the oil in the gearbox and make sure gearbox has a functioning breather.  Some machines are shipped standing on 3 PT "A" frame (again to save space in shipping) so some oil spillage can occur.  Oil level is half height of gearbox when gearbox is level in working attitude.  Oil should reach halfway up crankshaft where it comes out of side of gearbox.  Such a level insures that major bearings are well lubricated.  Overfilling of gearbox causes too much internal pressure when machine works and will push oil out breather or in an extreme case pushes oil seals on PTO or cranks sides of gearbox.  

     Hook up spader to tractor 3 PT system using stepped pins provided by spader maker (they allow either cat I or cat II systems to be used).  Adjust top link so that "A" frame of spader is vertical, gearbox will then be horizontal.  Lift machine with tractor 3PT to check that spader attitude is correct.  Raise or lower spader until PTO input of spader gearbox is directly behind tractors PTO (i.e. they are in the same plane).  Shut down the tractor engine leaving spader as above.  

This is a Most Critical Issue

        Safety of operations and protection of expensive tractor components and protection of the spader gearbox all hinge on proper attention to PTO shaft and clutch (or shear bolt mechanism).  Installation inattention and carelessness with PTO's kill and maim more people than drive by shootings in the USA.  Misuse of PTO shafts contribute substantially to making farming more dangerous than underground mining,  law

 enforcement and all other occupations in the USA.

     When PTO of gearbox and PTO of tractor are on the same level and opposite each other the PTO shaft will be the shortest it ever is, as the spader is raised the PTO shaft must lengthen and when lowered to digging depth the PTO shaft must lengthen.  So the second critical issue is that there must be enough overlap to give adequate surface for the two sections of PTO shaft to transmit the required power.  On smaller spaders, 4" is usually enough, but each manufacturer gives their own guidelines so you should follow it. 

     If you are to have a problem with fitting the PTO it is most likely to be that the PTO shaft supplied is longer that you need.  The major makers of PTO shafts supply them to implement makers in standard lengths.  When a PTO shaft is too long, it is cut down by shortening both the male and female pieces.  Unless you fully understand the many sorts of drive shaft materials and designs, you should take the shaft to a tractor dealer of drive line shop to have it shortened.

     If you should break a drive line, you can not just have anybody weld it together.  The proper alignment of yokes must be maintained and when splined PTO shafts are used, attention to the reference spline is essential.

     Once the shaft is installed correctly, you are ready to run the spader fir half and hour test to determine if your slip clutch is properly adjusted or not.  The tightness of the spring loaded blots control how much resistance is needed to make the clutch slip.  When PTO shafts are

 built, the slip clutch if set arbitrarily and you can not assume they will slip when they should.  You must check it out.

     Start tractor, lift spader just high enough to clear ground with all spades.  Engage PTO and bring RPM to level that gives 540 RPM on PTO, spader will rock side to side a little but should run smoothly.  Lower spader into ground slowly so that it digs full depth i.e. when skids are raised to top position and skids are resting on unworked ground.  Spader will have dug itself a trench and most side to side rocking will have ceased.  Put tractor in low forward gear (.7 to 1.0 MPH), drive forward, spader will dig throwing dirt to the rear making an even bed.  Even when you are working average soils, in the course of 1/2 to 1 hour running time, the spader will likely have encountered some hard spots that requires slip clutch to give or slip for an instant.  The driver may not even notice the incident so one must stop machine and check to see if cutch has heated up. When you feel the clutch it

 should be warmer than the spader frame.  If it is the clutch is working, you can go to work.  If it is not warmer, the clutch must be adjusted by loosening springs on the clutch in 1/2 turn increments and retested by digging for another 1/2 hour.

     If slip clutch was too loose, it would screech and smoke and rapidly blister the paint from clutch assembly. Thus, a loose slip clutch does not go undetected.  A too tight slip clutch can go undetected until something breaks. Therefore, you must take the time to adjust it.  After the spader is parked for an extended period the process must be repeated because rain and 

moisture in the air cause clutch lining to become stuck to clutch plates.

Proper Operation

     Now you are ready to spade for 50 hours before spader should need service (PTO crosses must be greased every 24 hours of work time).  The spader is run only in a straight line and lifted free of the ground before any turn is made.  When working properly, each spade raises above unworked ground and takes a new bite.  If the tractor goes to fast, tips of spades may strike working face of soil rather than reach over the top of the unworked soil to take a new bite.  Either speed or trying to work spader deeper than design depth can cause damage to spader.  Your warning will be broken top bolts that attach spade to spade arm.  Generally two bolts hold each spade onto arm top one generally shears when tip of spade hits unworked ground on its forward motion, the lower bolts acts as a fulcrum and the top one shears.  If this occurs only once in a great while, it was likely just caused by the nut loosening, but if it repeatedly happens, the cause is wrong speed or wrong depth.  The bolts used are metric grade 8.8 domestic metric bolts, may be marked grade 5 (the two are equal).  Never use a higher grade bolt (10.8 or 12.8 or grade 8) you want them to shear as a warning that you are abusing the machine.  Treat the cause, not the symptom.

     Mow your cover crop and crop residues if you can and spade once, all the spaders promise is delivered in a single pass of max design depth.  A second pass with the spader begins to undo the good things done in the first pass.  In my view, a second pass can be justified only if in pioneering some very difficult ground and the extra 2-3 inches of penetration you get on a second pass, is going to get you through a hard pan layer.  If you regularly spade twice, you need to get a deeper digging spader because you are not getting full benefit from the spader you are using.

     An ideal arrangement is to put a front mount mower on your tractor and run spader on rear 3PT.  Cover

crop mowing and spading then becomes a one pass operation.  One early adopter of the spader has been Driscoll strawberries and they have retrofitted a 70 HP Kubota with a front 3 PT and PTO so they can run a 8' wide shredder on the front of the tractor and an 8' Falc spader on the rear.  They rotate strawberries with two cover crops per year. i.e. a winter cover of oats, vetch and field peas and a summer cover of Sudan grass.

     At one mile per hour and 8' wide spader works and acre 12 or 14 inches deep, in only one hour.  In 50 

hours the spader has accomplished a great deal of work and deserves your attention.

     At these 50 hour intervals you should take the time to clean the machine thoroughly, the pressure washer is the ideal tool (not steam cleaner) failing that, use a garden hose and long handle scrub brush.  You want to be able to see all joints, grease points and bolts.  The inspection as well as the grease or oil you apply avoids down time later and keeps repairs minor.  Some oil (or melted grease) will weep from joints in hot weather and from regular use of the machine, but you want to note real leaks or damage to seals.  Starting work with a clean machine every 50 hours makes that visible.

     Nearly all small spade and many intermediate size machines use grease in the bearing journals.  The grease you use is the chassis grease used on trucks and cars.  The common form is a tube you load into a hand pumped

grease gun.  I like "Sta Lube" universal grease but there are dozens of brands.  What matters most is that you get it into bearing journals clean.  The grease fittings on the spaders are of several types, some are common zerk fittings and some are button types and some are plugged and must be opened to insert a zerk long enough to grease journal then removed and replugged.  The standard grease gun is designed for zerk fittings.  Button fittings are the predecessor of the zerk, but work on the same principle i.e. a spring loaded ball valve that lets grease come into the fitting but not out.
     A button fitting looks like a hex nut head, but has a groove cut in the underside of the head to allow a special grease gun tip to lock on for greasing, the spader maker supplied the special adapters.

     Do not over do it, a couple of strokes of grease gun handle puts about all the grease a given journal is likely to need.  If it takes much more grease, look closely, you either have a seal problem or you are creating one, even a hand grease gun creates a great deal or pressure and you can push seals out of place, etc.  Each spader has three journals for each arm, crank end of arm, mid arm and lower frame opposite that arm.  There will also be one for each frame mounted bearing between arms.  (Your owners manual points them out).

     As you get into the heavier duty spaders, they begin to use liquid grease not solid grease.  The journals

are oil baths and have a plug (actually several plugs) so  you can top them up with spader arm in any position.  The liquid grease is 180 weight oil ( a very thick syrup like consistency ) again I like "Sta Lube 140/180" in quart container with pump that has a plastic tube that lets you reach where you need to with little spillage.  The gearbox oil level should be checked and will rarely need oil added.  Some machines have a dip stick and some you make your own, a white coat hanger wire makes a good one.  Observe the oil color and consistency.  Each oil company dyes the oil, that's not the issue, you want to be sure no water is in the oil (leaking in via breather cap?).  Oil with water in it looks like coffee with cream in it

and becomes foamy.  If you find or suspect water in the oil, set gearbox horizontal and drain oil via plug in bottom of the gearbox.  Refill to proper level with gear oil 90/120 weight.  That is what you would fill car or truck rear axles with.

     While machine is clean and you are up close and involved, look at all bolts, tighten and replace if need be, use same grade and correct size.  They are metric so you must learn the size and buy the correct tools.  For a given machine, there are just a few specific ones you need so the expense is minor.

     All machines currently being imported have guard systems on them, keep them in place when machine is being run.  They are often made of sheet metal so they rattle and flex, keeping them tightly fastened requires attention.

     The only part you will regularly and repeatedly change during the life of your spader are the spaders themselves.  They are made of cast steel and are very tough, they rarely break, but they are eventually consumed by their work, literally.  Replacement is simple - two bolts hold each one to its arm.  Each manufacturer has his own design so they do not interchange from make to make.  Replace bolt and lock nuts when you change spades.  Go Dig.