tractor grader construction

[Taylortractornut]

Renze the grader wheels had to be angled by feel. Depencing on the cut and the material you were in. I used a longer steering cylinder and could really put the angle into it. I also got a hold of a set of high ribbed implement tires off a Ford tractor front end. They really increased the steerablilty of the grader. While Ihad the grader and the larger tractor here I graded alot of road and re terraced a small garden I use. With the rear steering axle I also got the added benefit of the blade following the tractors
tracks. When using a drag scraper you can turn too sharp and the corners dig in and duck walk and the blade wants to jack knife. when turning you can steer the lever over left or right and the blade would track and follow in more of an arc. I recently found a mud axle Hydraulic assist 4 wheel drive unit for a combine. Its got planetaries I thought of making another grader for our 4000 Ford at work when it get overhauled. That way when doing the grading I could use the pto pump to run the rear axle with the steering and the drive for the extra push should make a good combination. I really wished I still had my old pictures of the grader at work. Im planning to build another one some time this summer to go behind my 30 HP Yanmar.

 

[Renze]

Tractortaylornut, just to be sure: You mean that when the grader blade pushes material to the left, the grader pushes itself to the right, so you steer it to the right untill the forces are in balance ? Or do you simply countersteer trying to keep it straight behind the tractor ?

 

[GT2]

Tractortaylornut, just to be sure: You mean that when the grader blade pushes material to the left, the grader pushes itself to the right, so you steer it to the right untill the forces are in balance ? Or do you simply countersteer trying to keep it straight behind the tractor ?

Tractornut has a good point.
If you put a lot of castor in your steerable wheels, as you turn them the blade will dig in ( not stay at the same level), because the extreme caster flops the wheels " over center" ( for lack of a better term).

 

[Taylortractornut]

Thats one point, even on a motorgrader like our DD Allis Calmers the wheel lean will also adjust the blade height to. With the trailed grader I simply liked the steering axle becaause of the manueverability and the anti duck walk in the turns. I practiced with a similar set up like a grader but didnt get gooed results plus I already had the combine axle.

 

[Renze]

I have a 3 ton rigid axle available with 10-15 wheels. Those will do, a center pivot axle wont change blade depth due to caster angle.

Ideally, it would have hydraulic forced steering, like a trailed rake has (euro style dual spinner)
The rear wheels countersteer in the corner so the mid of the machine (where the rakes are) follows the tractor track. When this forced steering system uses two hydraulic cylinders instead of a push/pull rod, i could add oil to one side of the circuit to offset the grader, but it will still automatically follow in corners even in offset..

Dont know if i have enough cylinders to do that... And a forced steering system would limit the grader to one tractor that has an extra mount for the master steering cylinder, or would force me to go 3pt hitch mounted...

Tractortaylornut, did you make the graders 3pt mounted, or lower drawbar ? I'm afraid that 3pt hitch mount is too far back, pushing the rear of the tractor over, and reacting more violently at dips and bumps that the front wheels of the tractor hit.

 

[RegL]

You mean something like these ?

YouTube - Using a 1932 Allis Chalmers Tractor

YouTube - Adams Leaning Wheel Grader No. 1C


Thats yet another option to concider... thanks !

The road crew in town modified one of those pony graders by removing the front wheels and welding a hitch to the front end of the main beam.In use, you can set the angle of the blade with the wheels and adjust the height as you go along with the tractor 3pt.

 

[Renze]

The road crew in town modified one of those pony graders by removing........

Our towns road crew had a grader 30 years ago, but sold it for scrap to a local agricultural contractor who cut off the front end right in front of the cab, welded a tow eye to the frame and hooked it to a tractor, pulling it reversed, with the blade turned around 180 degrees on the slew ring.. that would actually be my ideal tool, but they dont want to sell it even though they do most contract levelling with a laserblade on a payloader.

they now use a front 3pt mounted, fixed 45 degree angle blade to crown the road, and a land drag in the rear 3pt to finish it... the front mounted crown plough often puts the front end of their Deere 7610 into the roadside ditch....

its allways the 16 year old apprentices that get to play in the dirt, the older guys arent interested... Myself, when preparing pasture for reseeding, my father keeps reminding me that its going to be a horse pasture, not a billiart sheet...
The only guy that knew how to do a road in our town dept, was retired with his aforementioned grader, 30 years ago...
Roads are a mess in spring time. With a sufficient grader i could repair two farm roads we use, in 3 passes back and forth, and do regular maintenance on the sandy dirt roads with just 1 pass.

 

[Taylortractornut]

Renze I just mounted it on the drawbar that goes on the lift arms. I didnt have the time or material at the time to make it mount o nthe lower draw bar. I could have mounted it there and put a pivot hinge in the toung with a cylinder to crank it up and down. plus another thing was when pulling in a tight circle one hooked to a lower draw bar that doesnt go past the wheels the tounge can get into the tires in a hard turn. I dont think it would put too much stress on your lift arms. google Hoopers engineering land plane graders and scoops they have some neat pictures of large simple pull type graders there they are in Australia.

 

[Renze]

I just figured i might have a problem with the 3pt hitch drawbar mount:

I have only one external hydraulic valve on both our tractors, so to adjust angle and tilt on the go, i'd need to fix the tractors valve to constantly feed the 3 spool block on the grader.

Problem is that using the power beyond feature of the Zetormatic hydraulics, would make both circuits (3pt lift and external) very slow and unresponsive: at least, not responsive enough for proper grading because there is no predictability and touch in the hydraulics anymore.

When operating the grader from the lower drawbar, i'd need an extra joint, cylinder and external function for the raising/lowering.. And means that i'd have to buy myself a new valve block with 4 functions...

Attached is a PDF with my thoughts so far...


===edit: meanwhile i am thinking of making a swivel drawbar with a two way joint, so it will do both the up and down movement as well as side offset. Then the rear part can be all fixed to the rear wheels, making it easier to place the rear axle closer to the blade for shorter turning radius and better angle before the blade hits the tires.

 

[Renze]

O.K. guys, after seeing a photo, Googling the manufacturers name and lurking around on their website, i am totally sure of how i need to build the grader: A manufacturer in Brazil has already tried and tested my design ideas, and showing off in their video, it works great !

:: GTS do Brasil - tecnologia de valor ::

The video shows their lightest model, but i will use the design style of their biggest model (though downsized) :: GTS do Brasil - tecnologia de valor ::

The reason is, i want a rigid frame from drawbar to the blade swivel point right behind the blade: This will avoid joints in high stress areas. I can make the articulation joint also behind the blade, where all it will ever do is carry the blade, not transfer blade pull from the drawbar to the blade.

But i dont see any side drafting at all: Maybe it is the agressive R1 tread they have on those tires (i have ribbed implement 10-15 tires available) but the side forces seem to be limited, especially when the grader wheel runs in the ditch, which gives it side support.
They can make a huge ditch in only 2 passes...


Oh, by the way: I've been welding most of the saturday afternoon, to weld a big 6x6 inch angle iron (15mm thick, 3/5 of an inch ?) to the back of the moldboard: My welder is only 180 ampere, so welding a full bead will mean overheating the welder in 20 minutes, so the thermal protection shuts it off.

 

[rdbrumfield]

To me the simplest way to offset would be to us an axle you can steer. By turning the wheels left or right it would take it out quite a ways, would be great for slopes or ditching. Go take a look at a motorgrader and take a look at the front end. They are double jointed so you can steer and lay the tires over so they can grip better in soft ground. You could accomplish this by using a large universal joint, say off a large truck, welding one side to a spindle, the other to an axle tube and use two tierods. One for steering, one for tilt. Fact is one side is already fixed up if you use the driveshaft for an axle. Put a hyd cyl on the steering and backing would be a breeze.

 

[Renze]

To me the simplest way to offset would be to us an axle you can steer.

The biggest problem i run into, when using a conventional steered axle, is that the axle swings outward when offsetting the grader. When i tilt the blade as well, to cut a roadside onto the crown, the wheels would run way outside the cutting width of the blade.
When cutting a watering ditch, the wheels wont run in the ditch so ditch cutting depth is very restricted.

Because i have a 3 meter blade (dont want to go wider, its a pain when doing 5 meter wide roads) i already have this problem even with an articulation joint behind the grader blade.
I must change my idea and make the articulation joint in the drawbar, even though its less favourable because its in the line of power, from blade to tractor drawbar.

The idea of using the U joint, i dont think any welds will hold on the (cast iron ??) crosspiece, to weld the steering arms to it.... ???

 

[rdbrumfield]

Those are of cast steel, big difference, after all, the shaft is welded to it. One thing, the tierod and canting rod will have to be double jointed at the ends. If you are putting the articulating joint in front, just mount the axle rotated 90 degrees, that way it will lay over but not steer.

You are most likely right about putting the articulating joint in front of the blade as you are pulling it instead of pushing.
I am a finished blade hand with a road grader, so I understand the need to sometimes get the tires in the ditch following the blade with the steering up on the shoulder.
Depending on how much offset you need, or want, you could also suspend the blade table from a couple of ears that are a few feet above so the table and blade can swing out to the side and be locked by a slide tube with holes along it for a pin to drop in. This could also be done for the drop tubes to give you more drop or hieght beside the drawbar, especially for ditching it might come in handy.

 

[Renze]

Those are of cast steel, big difference, after all, the shaft is welded to it. One thing, the tierod and canting rod will have to be double jointed at the ends. If you are putting the articulating joint in front, just mount the axle rotated 90 degrees, that way it will lay over but not steer.

I have a rigid axle which has cost me 10 Euro... I am not going to buy a steered axle, i'd rather invest the, lets say 150 euro, to get a relative lathe me some bushes for the articulation joint.

I am a finished blade hand with a road grader, so I understand the need to sometimes get the tires in the ditch following the blade with the steering up on the shoulder.

With a tractor drawn grader i would do this the other way around: i'll have the tractor up on the shoulder, and the grader wheels will get lateral support by the ditch side.

Depending on how much offset you need, or want, you could also suspend the blade table from a couple of ears that are a few feet above so the table and blade can swing out to the side and be locked by a slide tube with holes along it for a pin to drop in. This could also be done for the drop tubes to give you more drop or hieght beside the drawbar, especially for ditching it might come in handy.

With an articulation joint in front of the blade, i can get about 3 foot of offset, that should be enough to cut ditches, and to swing it under the horse fence to pull back the first ploughing furrow from the edge, when grading after ploughing a paddock.
Thats the most important reason i want the articulated frame: a conventional grader with A frame and slew ring, will allways require depth correction when swinging the blade under the fence row.. We have posts every 4 meter so its a lot of work...

About ditching, with about 4 ton pulling, and an 18" blade, i dont think i am going to cut huge ditches in one pass. Running the grader wheels in the ditch will double the max cutting depth as well as the tilt angle in the second pass.

 

[Renze]

a design update: i sketched a mid articulation joint, and after doing some strength calculation, simplifying the design of my drawbar. I think i'll weld the two 5 inch pipes onto each other like a figure 8 and then close the sides with plate, to create a big rigid oval tube, which will be filled with concrete for ballast.

This setup will give me about 60cm of offset (2ft) at 20 degrees articulation.

I am happy with the design from drawbar to the articulation joint... From there onwards, i need to think it over a bit, and think which design is best doable with the steel in my scrapbin...

 

[rdbrumfield]

That looks pretty good what you have going on there. I do think I would have the blade a bit back of the articulation point as you might want to have some sort of table to be able to swing the blade a bit for casting. I can see where you will want the offset to be away from the tractor too as it won't want to turn one way as you will be able to be square the other.
I have to laugh, I have built a lot of things and I always want it to do it all. Never achieve total success, but it does the work.
good luck with it, looks like it is going to be a well thought out project.