tractor grader construction

[Renze]

Does anyone know a better construction to build a tractor drawn grader, that goes inbetween the standard 3pt grader and the motorgrader ? i want the functionality (tilt, swing and offset) but not the cost of slew rings and many pivots.

I have made some sketches, but i'm not sure how to attach the blade to the frame, and where the offset pivot must go: on the headstock, or should i mount the blade on a separate offset arm ?

The blade is 3 meter wide, 45cm (18") high. I have 5 inch round tubes to use for the frame.

 

[2smallbotas]

Have you looked at this one?

#1Double B Repair Pull-Type Road Grader

 

[MJPetersen]

Renze,

What about using a floating "A" frame with the point attached to a ball hitch (like a trailer hitch) near your 3pt) and the center pivot pin attached to a cross bar between the legs of the "A". (A center pin is necessary if you do not want a ring) The individual lift cylinders could attach to the legs of the "A" and rotating cylinder could attach to the "A" frame. To get your offset the easiest way will probably be to slide the blade, like flail mowers that have the sliding hitch arrangement. That would give you all the movement you are asking for. Well it would be difficult to get the blade swing and offset of a real grader without going to the ring, but it would get most of the action that you would need.

You might need to raise the bridge frame a bit to give yourself a bit more room for maneuvering the blade. That center pin and the attachment for the pivot will have to be very healthy to stand the torque of working with a corner of the blade.

A motor grader is really a marvel of movement. A good operator can do amazing things with the blade on one. We used to swing them off to one side and practically upside down in order to trim the cutting edge straight for finish work.

Mike

 

[Renze]

Have you looked at this one?#1Double B Repair Pull-Type Road Grader

That aint no good... a 5245 mfwd with loader, brings in at about 4 metric tons, and will warp it like a soda can..
I sure need the heavier variety: #1 Double B Repair Pull-Type Road Grader

I also want it 3pt hitch mounted, so it can push itself off the tractor and use its full weight to pull a ditch. A drawn grader needs a fair amount of weight to remain on the tires to prevent being pushed aside by its blade.

One thing i'm missing on this one, is the tilt feature....

What about using a floating "A" frame with the point attached to a ball hitch (like a trailer hitch) near your 3pt) and the center pivot pin attached to a cross bar between the legs of the "A". (A center pin is necessary if you do not want a ring) The individual lift cylinders could attach to the legs of the "A" and rotating cylinder could attach to the "A" frame.

I am also thinking in that direction.. i have an old lower link arm with Cat 2 hitch balls. I think that will do the job, because the biggest forces are applied when the ball is not in motion..
About the A frame with 2 legs, i think i would simply replace one leg with a hydraulic cylinder to get my rotation.

Another important design feature i want, is that the cutting depth must remain the same during side shifting on the move: I need this to pull the first ploughing furrow back from under the fence after re seeding a pasture. We use posts every 4 meter, which is a lot of movement.
My brother has just taken a contract on a major park landscaping job, and he can use it for the cost of building it, so we both end up cheap In the park are a lot of trees to manuever around, where the same thing counts: the depth must remain the same during side swing.

To get your offset the easiest way will probably be to slide the blade, like flail mowers that have the sliding hitch arrangement. That would give you all the movement you are asking for. Well it would be difficult to get the blade swing and offset of a real grader without going to the ring, but it would get most of the action that you would need.

Do you have a good example of a poor man's sliding blade ? I am afraid of the dirt getting into it, but i do like it for aforementioned reasons.

That center pin and the attachment for the pivot will have to be very healthy to stand the torque of working with a corner of the blade.

Thats why i want a simple construction... A turret that can take this abuse, will get too expensive...

 

[tlbuser]

You mean like the one Larry built and maybe add some guage wheels? http://www.tractorbynet.com/forums/build-yourself/95845-360-rotating-back-blade-project-21.html

 

[Dirtnut]

you can still get an off set by useing a three point set up like i have. with a seven foot blade that is wider than the tractor and using a three point hitch draw bar when i need to off set i hook the hitch to the outer most hole. this lets the grader run a few feet out side my track.

 

[dynasim]

Could you use a single wheel in the back, and use a three-point tilting mechanism(cylinder replacing a lift bar) to tilt the blade?

Chris

 

[MJPetersen]

Do you have a good example of a poor man's sliding blade ? I am afraid of the dirt getting into it, but i do like it for aforementioned reasons.

Cat puts a hyd cylinder there in their big graders for the side shift. Dirt does build up in there, but I do not recall ever seeing one leaking or needing to rebuild a cylinder.

I could not find a pic in a hurry, but I will post a couple of pics of Flail slides that I believe could be adapted behind a blade. Basically 2 parallel shafts and a hyd cylinder to slide the blade along those shafts.

Here is another idea for a grader in the pull type. Definitely heavy duty. Orrr? Maybe you just want to modify your tractor thusly.

Mike

 

[Renze]

I doubt if the mechanism of the flail mowers with the two sliding pipes is heavy duty enough...
The belly grader, it would limit the use to one tractor. My 3011 is used for all the small jobs because its compact and nimble, so a wheelbase extension and a 3 meter wide blade wouldnt do that any good, and the 5245 has a huge frontloader subframe which leaves no room for the grader mechanism.

The 3pt drawbar isnt my favourite either because i want to use the 3pt stabilisers to keep the blade on course when cutting a ditch.

about the single tailwheel, i am thinking in that direction too. My idea is to just drop the 3pt hitch all the way so it pivots between the tailwheel and the lower link arm attachments right under the rear axle ( no skips and ducks of the blade when the front wheels hit a pothole) but i dont know what the slop in the 3pt linkages do when i have a kingpin in the 3pt frame: It would put the 3pt off center of the line between the carrying points (grader wheels and the tractor rear wheels) which i expect, will make it wobble clockwise or anti clockwise, as much slop there is in the 3pt ball joints.

Maybe i need the grader wheels on a steered arm, which is connected to the 3pt headstock by a parallel arm... Then the frame steers into a Z.... i have to think over what happens then...

I have to do some calculated guesses on what will happen to a slider frame, made from C channel with heavy flatbar welded to the back, working like the fork sliders on a commercial forklift truck..


...But maybe the sliding design of two pipes isnt as bad as it looks, in a heavy duty execution.. We might have some piston rods and hardened bushes of an 18 ton loader at work.. Chromed 3" piston rods and hardened grenade motif bearings should take a lot of abuse...


On edit: a pull type grader with hydraulic lift at the rear wheels, hung from the standard trailer drawbar, might be even simpler. I would just steer the axle (maybe walking tandem) aside for the offset, and ballast it enough (fill the hollow 5" pipes with concrete and scrap) so it will pull straight..
There is no blade pull on the rear axle steering pivot, which would be a better place to pivot than the headstock.

 

[Renze]

You mean like the one Larry built and maybe add some guage wheels? http://www.tractorbynet.com/forums/build-yourself/95845-360-rotating-back-blade-project-21.html

Larry has built a great blade, but i dont have the resources (nor the friends ) to build it with a worm gear rotation...
The double pivot with sort of gauge wheels is my B route, I do keep that open as an option, but my worry is that mine must be able to take a bit more bashing, because our tractors outweigh his by a factor 3 to 4.... Thats why my A route is a fixed frame with a minimum of pivots... But if that means i have to use a blade slider, maybe the headstock pivot, up and away from the dirt, would still be the better choice...

As Mike said, a rotating mechanism must be pretty stout to take the forces when meeting a root when cutting a ditch with the end of the blade...