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 .