scraper / grader plans?

[crofutt]

I had an earthmover come out and basically build up and level an area 2000ft x 50ft for a grass runway. Problem is, it's not really smooth enough to land a plane on despite having a grader used to build a little crown in it. I need to knock off the little high spots and fill in the little low spots but using a 6ft box scraper just doesn't work well, it's too short coupled where as if the front wheels raise up a little the scraper digs in. If the rear wheels lift a little, the scraper lifts. If I set it to float, it takes too deep a bite. Normally not a problem landscaping or on a driveway, but when touching down at 70 mph on a not all that long runway on 3 wheels makes for a less than ideal situation.

Now that you know what I am doing, here's my question. I need to make some kind of scraper that is not rigidly attached to my tractor, probably mounted on wheels. I have seen the DR Power Grader that is pulled behind almost anything and that seems like it's just the ticket. It has small scarifer teeth to break up the ground a little then an adjustable height scraper blade behind levels it. Anyone seen plans for something like this? I tried searching here but didn't see anything.
Thanks for the help!

 

[MrJimi]

I have good luck pulling a spiked harrow on a chain and what do you have for a plane ? I have a Mooney

 

[crofutt]

I have good luck pulling a spiked harrow on a chain and what do you have for a plane ? I have a Mooney

You mean the spiked harrow is not attached to the 3pt rather pulled with a chain? Is that smooth enough to plant grass and use?
Right now a Tripacer, but an RV10 in the future.

 

[MrJimi]

I made mine out of old re-bar , Its 7 feet wide and 5 feet front to back and it will just shaves those little high spots and I pull it both ways, This is one of the better working attachments I have made, I love it.
It drags dirt off the highs and fills the lower ones. Take a look at northerntool.com they have a small version of the one I built almost 15 years ago and I still think they got the idea from me? LOL

Spike Harrow


Both nice planes
Jim

 

[RonMar]

You need to run the scraper in float on the TPH. In float, the box will rise and fall on it's own, but the geometry of the TPH will keep it orientated parallel with the tractor frame. The length of the toplink should allow you to control how agressive the blade digs in. You could also try adding gauge wheels out on extensions behind the box(or extending the side skids out behind the blade)to control the depth of cut even more. The scraper/grader I built has sidewalls that extend past the rear blade. Mine has a front blade also that protrudes below the sidewalls about 3/4". The front blade on mine does all the cutting and the toplink very precisely allows me to control the cut on level ground. Gauge wheels would basically turn your standard box into a small grader(with TPH in float) as any high spot that passed between the rear wheels of the tractor and the gauge wheels would be scraped off by the blade and any depression would be filled in by loose dirt carried along by the blade as it passes over it.

I have found that a flexible chain harrow will tend to follow the contours of the dips and rises. It will cut more agressively on the tops, but it will dip down into the low spots as well. Pieces of pipe attached parallel to the direction of travel at several points along the drag will help keep it from dipping down into the low spots.

Good Luck on the runway

 

[crofutt]

RonMar, perhaps I am doing something wrong with the toplink because mine does NOT work like yours. I have a Jinma 354 with a 6ft box scraper. No matter what I do, when it's on float the box scraper digs in so deep it literally is overflowing out the back and sides. I normally set the top link so the scraper is level. Can you give me some advice on setting it? I am by no means an expert with this.... Thanks

 

[DDT]

crofutt
This is what you need.http://www.tractorbynet.com/forums/build-yourself/93026-show-tell-7-speed-mover.html
Set the depth and leave it there.

 

[RonMar]

Shortening the toplink(tilting the box forward) should lift the rear of the box(and blade) and force it to ride more on the front of the side skids. In my opinion box blades are better at ripping up and dragging around loose soil. That is why I didn't build a traditional box scraper. The best answer for you would probably be a set of gauge wheels though as it would allow much finer control, leave fewer drag marks(most all the weight is rolling on the gauge wheels) and force the box to only cut into the high spots. Here is a link to Homebrews pictures of one of the nicer sets I have seen attached to a box scraper.

Yahoo! Photos - Box Scraper Gauge Wheels

Here is a link to the thread with pics of grader I built. http://www.tractorbynet.com/forums/build-yourself/77820-rons-grader.html?highlight=rons+grader
The front blade protrudes below the side rails and does all the cutting. I can lengthen the toplink and force the thing to ride on the rear of the side rails to control how deep the front blade cuts. Anything cut by the front blade rides up and over into the box and spreads out in front of the rear blade as it builds up. When the box starts to fill, the material flows over that second blade and is distributed pretty evenly(or I can drop the gate and move material like a regular box). This works really well with gravel. Clumps of sod tend to hang up on the top of my triangular blades though and regular shaped blade/cutting edge would have worked better with sod(but wern't readilly available where I live). These triangular blades are very rigid though and I have rolled out some pretty good sized rocks and stumps with the front blade edge.

 

[RedRocker]

, but an RV10 in the future.

I had an RV-4 tail kit many years ago, but never got very far with it and finally sold it. I like those planes and lust to this day for an RV-8.

 

[schmism]

perhaps a grademaster would work

as its much longer it wont dig in like a box blade. with the shallow cutting edge the excess easly spills over the top and is evely distrubuted.