Box blade length per hp?

[Phred]

So how big of a box blade do you guys run with a given tractor? I know that it depends on the construction of the blade, but I am just curious.

Here is a shot of my 7' modern box blade that I run with a TN70D (70 hp gross and ~60hp pto).
This blade is very strong and can easily handle this tractor, but the tractor could run a much bigger blade.

 

[Phred]

Here is a shot of the front.
To lower or rasie the ripper all you have to do on this blade is pull on the handle from the seat.
The zinc coating is a plus also since it is much stronger than paint.

 

[john_bud]

Phred,

Your BB looks good! I am a fan of the moving scar bar BB's. Depending on your soil type, it might be a bit light for your tractor's ability. I like to have ground engaging equipment in the 200 pounds per foot of width range. My Gannon Landscaper H-120 is listed as 65" wide and ~830 pounds, but when this one was made, they used 1/2" steel and not the usual 3/8" so it is probably about 900. I know it was built to order as the paint drips were still wet when it was delivered! With that much weight, it really can perform up to its potential. It's capacity is 3/4 yard and when full, you know it's back there.

With your horsepower (and 4x4?) you should be able to pull a H-415 or 420.
Gannon Manual scar bar BB

Have fun with it! If you are new to using the BB, the hot tip is to play with the top link and see how it reacts. Tipped forward, they dig more, tipped back they level the ground. Do you have a swinging rear blade? Bolting it down is good for leveling and swinging is good for cutting with the blade. Depending on soil and roots etc, you may want to use between 1 and all of the scarifiers. Once the sod is off, I usually raise the scar bar and just use the blade as that is faster, easier and uses less tractor hp. If you can adjust the drop rate of the 3pt, you may also want to play around with adjusting it and see what difference it makes. I usually just keep it at full fast.

jb

 

[Phred]

John,

Thanks for the reply.

Yes weight is part of the key. This tractor is a 4x4 with 16 speed tranny so if you drop it in the low range it will really pull.
This modern blade is also very heavy. I think it is also 1/2" side plates. They make a 1/2" version and a 3/8" version.

I also run a 9' rear blade with this tractor and it handles it fine.

So I guess a foot/hp number is hard to come up with since it would neglect the weight of the box blade.

 

[jcmseven]

Phred,

I run a 6' box blade on my 53 hp JD 4520. It does fine. I believe I could run a wider BB if the need arose. I think you are correct though. It is difficult to assess how wide such an attachment one could pull as it would be more a function of weight than HP.

John M

 

[PAB_OH]

So I wonder if you guys could help me then. I have a Kubota GL-21, not sure of the weight. I have manuals on order from Japan so I won't know for sure for some time. I know it's no light-weight though. D1403 engine rated at 28-29 HP depending on what source you believe (both are Kubota claims though). AFAIK, it's the same engine in the L2800.

I want to get a box blade for leveling my drive in the immediate future, with plans to smooth a good portion of the field that will eventually be my back yard. Soil is a bit rocky, mostly sandstone though. Not trees to contend with.

Do you guys think the Gannon H-120 would be a decent fit or will I be struggling to pull this thing? I forgot to mention I have a small FEL on my tractor too. I know I need some serious ballast on back right now as I am loosing traction a lot, especially when backing up my driveway which is pretty steep.

What about the HD-115? Weighs more but is the same working width. To me that = a good thing. I'm learning so if this is wrong please let me know. I'm itching to get one soon. Would the HD-115 be a better fit for me or should I be looking at medium duty BB's? I'm assuming these are the heavier duty models since they start at 65" working width.

Thanks

 

[jcmseven]

I am not directly familiar with the brands you mention, but I would think your tractor could handle a 60" box blade no problem, even on steeper terrain. My previous 4310 JD with 32.5 hp would pull a full 565# 60" box blade up grades as steep as 20% with the rear tires loaded (and in 4wd). Having been to Ohio, and being fairly familiar with its topography, I would say you would be fine with any brand of 60" blade as long as the weight were kept under 600# or so.

John M

 

[PAB_OH]

Thanks for the advice. I think the worst part of my drive is about a 60% grade (around 30 degrees, give or take) and the rest is right around 40%.

I still need to load the rears. Hopefully that will help with the traction too.

 

[wushaw]

I have a 66" Cammond BB, it weighs 830lbs, I pull it with a L2800, my rears are loaded and it pulls it but it can bring it to a stop with a full load in wet clay with the R4 tires turning I use low range most of time.
My previous BB was 65" and 510lbs and it wouldn't even slow the tractor down. I could pull in med range 99% of the time.

JIMO I do like the heavier BB better, although it probably should be behind a heavier tractor.

 

[albmn10]

I use a 72in boxblade with my ck30, I have R4s, havent stopped the tractor yet, even overflowing with wet clay , rears are not loaded.. If i got another id get one a little narrower though probably a 66in. staying closer to the tractor width .

 

[Phred]

I would just add that if you are using it to mainly smooth out gravel a much bigger blade is possible than if you are trying to cut in and level rough ground that has hidden rocks of unkown size. If you hang the blade on a big rock it will drag you to a halt in a hurry.

But if the blade is rated for at least the HP of your tractor, or even larger, then you will most likely not break anything.
Put a king cutter blade behind 100hp and it won't last 10 min without being bent up.

 

[john_bud]

Phred,

Good discussion you started. All too often discussions on box blades focus on width or scarifier attachment method and neglects the implement weight all together. Unless you have a down pressure 3pt, weight is the driving force of a ground engaging implement. And you made an excellent point on the longevity of an implement as a function of weight. I have hit hidden boulders that stopped the tractor dead and the Gannon didn't even flinch (while I sure did!). I'm pretty sure that a "lesser" box wouldn't have come out so good.

The person with the Kubota asking about what blade to get. I think your in the size range of a B2900 or so. If that is correct, you might want to look at the slightly narrower HK-60 at 711#. Of course if you are only going to use it to smooth the driveway, the H-120 or HD-115 may work. I would worry that they might be too much to pull. You would probably loose lots of coin if you had to trade down! Is your tractor 4x4 and does it have ag tires, R4's or turfs? My L3410 has R4's, aggressive 2bar chains, filled tires and have to work with the front bucket full of dirt to get traction. I would like to get an additional 1000# of wheel weights for the traction. Of course, if you only go down hill, you won't have much problem at all!

Hk page


jb

 

[PAB_OH]

Makes sense. My drive is pretty bumpy right now and is mostly dirt with buried gravel with some good size sections covered in #3. There shouldn't be any big rocks in the driveway. Now the soon-to-be yard probably has some larger sandstone in it. That'll be a work out for my tractor I'm sure.

When running a box blade I'm assuming you normally run in low range right? Something doing that much work isn't going to be able to move at a good clip is it?

 

[PAB_OH]

jb,
My tractor is 4wd and has rice paddy tires on it still. Well, I think they are the newer(?) style rice tires. They are very agressive, especially going forward. I plan to load the tires but I don't want to have to wrok with the FEL full if I don't have to. It might be advantageous for me to stick with a more medium duty box with a weight around 500-600 lbs. I also worried about what would happen if I wanted to trade down. Another good reason to go with a more middle of the road box, if I decide to upgrade I dount I would loose as much on a mid-priced model come resale time.

I threw a Rhino LR 6' rear blade on it tonight and was amazed at the power that was put to the ground with the added weight. As far as size I' m not familiar with the B2900 but if it is anything like the 2910 I am way bigger than that. More in line with a NH TC29 or JD 4200. The only thing about mine is the tires are on the small size. My tractor looks almost identical to the attached picture of an L2900 and is the same size.

 

[PAB_OH]

Here is my GL-21

 

[PAB_OH]

Here is the Rhino blade on the back this evening. Looks rough but it was free. Hard to pass that up. /forums/images/graemlins/grin.gif I'm going to sand blast then tear it down and repaint it ('bota orange of course) this spring.

 

[Dargo]

I have an old 84" (unknown mfg) box scraper that uses 3/8" side plates (as opposed to the 3/16" pictured earlier - but I do love that setup for the scarifiers!) and 1/2" for all 3 pt. hitch areas that weighs in around 1400 pounds. On both a 50hp and 60hp tractor it will flat stop you in the really heavy clay soil I have in the areas around my house. Heck, it even flat stopped my neighbor's JD 2955 (85 hp 4X4) when it grabbed hard in the thick and heavy clay. At other property I own, the soil isn't as heavy and I can easily handle the 84" box scraper with even the 50 hp tractor. Therefore, I think the size of the box blade is more a function of what type of soil you have rather than hp. Most all tractors will spin their tires no problem when too much pulling is required.

 

[flusher]

This look like it's a non-linear situation.

I use a 4-ft KK BB on my 21-HP B7510HST and it works fine for scraping and digging, especially when I add about 100 lb of extra weight. This is roughly 5HP/ft of BB length (or width if you prefer).

If this were a linear situation (i.e. constant HP per BB length as BB lenth increases), a 50HP tractor should be able to pull a 10-ft wide BB.

From what I read in this thread and other BB threads, this is too much BB for that size tractor. A 6 to 7-ft wide BB is more like it.

Are 10-fti wide BBs even made for utility tractors? Sounds more like something for a construction-type tractor.

The attachment shows the equipment the contractor used last April to scrape the turf off my new driveway site. This JD210LE has about 75 HP (engine), IIRC. The BB is about 6-7 ft wide and has hydraulic scarifiers. That's more like 10HP/ft of BB width.

 

[have_blue]

Phred,

A good rule of thumb is the scraper should be ~1 foot wider than the tractor.

Each foot longer may be around twice as hard to pull as the previous width increment. That's because the length and weight are both increasing, a double whammy.

Something else to consider: Box scrapers usually work best when you keep the tractor speed up. I have found that if you have to run in a real low gear, it's much harder to scrape and spread the dirt evenly.

 

[john_bud]

PAB,

You are on the right track with the target of 600+/- 150 pounds. I think it was "have blue", that correctly pointed out the width should be about 12 inches or so wider than your tractor wheels. For you that will be what, 60 or 65 inches? The soil type does play a BIG role as was pointed out. That is mostly when using the scarifiers in the full down position. If you find yourself in that position, you can adjust them up a notch, take out some or raise the bar! A heavy box with only one sarifier down makes a great middle buster -- unless you bust it!

There is also a type of box blade that doesn't get much attention here, the "roll over". They are typically less weight that what was mentioned earlier and should be about in your target zone. If you like to shop, box blades are the implement for you! There are many to choose from!


Flusher - Please carefully read the parts of the thread that deal with the impact of weight as a determinant in the use or selection of ground engaging equipment.

jb