Backblade upgrade!

[Tinhack]

Nice job! I planned to do that with my old Ford 782A blade after I finished the Ford tractor that will pull it.

 

[BackRoad]

Looks professional Mr. Aquamoose! Guessing you welded on the plate for the rod end of the cylinder to attach?
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To the TBN gallery...
With respect to sizing the cylinder, would a 2.5" cylinder be considered appropriate, or overkill for a 60hp with a heavy 8' EA back blade?

 

[Threepoint]

I know very little about hydraulics. Does the restrictor need to be on a particular line going to a double acting cylinder, or does one restrictor on either hose work?
This thread reminded me that I want to slow down the angling of my Land Pride blade.

Only one of the TSC restrictor fittings I linked to is needed for a double-acting cylinder, since the fluid must flow through the fixed, pin-size orifice in either directions, retraction and extension. It can be installed on either hose for the same reason. BUT, I think best practice is to put it on the hose leading to the cylinder end (closed end), rather than the rod end. This, because of some concern that excessive forces pulling on the rod end (e.g. forces from grading at an angle in this case) might induce a vacuum that pulls air past the gland seal at the cylinder end, into the cylinder as the fluid tries to exit at the rod end faster than it can enter at the cylinder end. Putting a restrictor fitting on each hose obviates this risk, as minimal and theoretical as it may be. The TSC fittings are cheap enough to just do that.

BTW, the same reasoning applies to using fixed-orifice flow restrictor fittings to slow down cylinder response on hydraulic toplink and sidelink (top 'n tilt) cylinders. Slowing the response makes fine adjustments easier there too.

 

[ovrszd]

I'm starting to get the notion that having 3 remotes would be a good idea.
Could one steal a loader connection for this? Perhaps even a loader 3rd function to keep the bucket useable for gravel/dirt?

Use an electric diverter valve and you can run two cylinders off one set of connections and lever.

 

[ovrszd]

Well, that was a catchy title eh?

Anyhow, I was tired of jumping on & off my tractor to make angle adjustments on my backblade so I went and added a hydraulic cylinder! I had to cut off a portion of the bracket up front (at the base)so the 10” stroke cylinder would sit in the optimum position. It’s configured so if I need to rotate the blade 180°, I can just unhitch the rod end, swing both the blade & cylinder to the opposite side and refasten. Took it out today to plow snow and it worked very well but when adjusting the angle, I had to be light on the valve or it’ll jerk around so I’m planning to add an adjustable restricting valve to slow it down.

Bolts are 3/4”, spacers are brass to position the cylinder higher to allow free movement in full travel. Cleaned it up & repainted to make it nice again.

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Are you able to unpin the table end, reverse the blade, repin?

 

[ning]

Use an electric diverter valve and you can run two cylinders off one set of connections and lever.

Right; I'm asking if it would be reasonable to run a (long) line from the loader to the back to operate this, so you can keep the TnT where you're used to them.

 

[ovrszd]

Right; I'm asking if it would be reasonable to run a (long) line from the loader to the back to operate this, so you can keep the TnT where you're used to them.

I guess you could.

My blade tractor has two rear remotes. One runs the hyd top link. One runs the blade angle and blade tilt using a diverter.

You could use two diverters on your TnT setup. For example, top link could divert to blade angle. Side link could divert to blade tilt.

 

[LD1]

Looks professional Mr. Aquamoose! Guessing you welded on the plate for the rod end of the cylinder to attach?
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To the TBN gallery...
With respect to sizing the cylinder, would a 2.5" cylinder be considered appropriate, or overkill for a 60hp with a heavy 8' EA back blade?

It isnt just the diameter of the cylinder. Its how its attached and the resulting length. Its all a function of leverage.

Take the OP's blade in this example because there is a picture with it where I can estimate some measurements. It looks as though the pivot point on the rod end is ~8" from the center pivot of the blade. Dont know his blade length....but I'll assume its a 6' blade.

Simple math 36"/8" = 4.5

That means for every 1lb of force on the edge of the blade (like snagging the corner on a tree root or curb) means 4.5 pounds of force on the cylinder.

Not even considering shock loads, Lets say his branson is capable of pulling with 2000# of force. That translates to 9000# of force the cylinder must hold. If that "force" is trying to retract the cylinder....that equates to about 5000psi in that base end hose.

Its alot worse if the cylinder is trying to extend. 2000# on the edge of the blade would generate about 9000psi in the rod end hose.

Best case scenario if something is snagged with the blade edge is a blown hose. Worst case would be a bent cylinder rod or ballooned cylinder.

To figure it backwards....lets say the safe limit of the cylinders and hoses are 3000psi. That converts to about 3000 pounds and 5300 pounds of force retracting and extending that the cylinder is good for. Now factor the 4.5:1 leverage ratio.....you get ~660 pounds and ~1200 pounds at the blade end for max force. And thats not hard to generate those forces with a 35hp 4000pound bare weight machine.

So with respect to cylinder diameter.....you can go with a smaller diameter IF you move the pivot point further out (which will require a longer cylinder). Moving the pivot further out reduces the leverage the end of the blade has over the cylinder. And figure the forces based on the retract force of the cylinder (deduct the rod area).

So....a typical 2.5" bore 3000psi welded cylinder has a 1.5" rod. That would be good for about 9400 pounds. If you have a 8' blade and mount your pivot 12" from the king pin (4:1 leverage ratio)....you'd be good for pulling with a force of only about 2350 pounds. And I can assure you a MX can pull alot harder than that.

I think my heavy 8' rear blade that I use behind my MX had either 3.5 or 4" cylinders for the offset and angle. The thing to do is look at existing blades of similar design and see what size cylinders they use for angle and pay attention to the geometry.
The landpride RBT35 series (good match for a MX) has a 3.5" bore, 1.25" rod, 14" stroke cylinder

https://cdn-assets.greatplainsmfg.com/ari/attach/lp/public/specs/301-251s.pdf

 

[ovrszd]

Good stuff LD1.

Another thing to look at is mounting tabs. If the tractor generates the type of forces that LD1 described, and the cylinder stands strain, and the hoses don't blow, all of that force is transferred to the mounting pins. Then transferred to the mounting tabs.

 

[Aquamoose]

Are you able to unpin the table end, reverse the blade, repin?

Yes, just as easy as doing it the original way. Unpin, pull off the cylinder rod (I choose the swivel eye for that reason), swing the blade around, and attach.

Looks professional Mr. Aquamoose! Guessing you welded on the plate for the rod end of the cylinder to attach?

Yes, I did. You could see the 1/2” plate that I welded. I could take the hydraulic assembly off in moments and return it to manual configuration quickly (and getting that stop pin back on)

How big/heavy is the tractor and how wide is the blade.

It's a nice fab job....but be careful with it. Real possibility of blowing a hose if you snag something with the edge of the blade with such a small cylinder.

Tractor is a 35hp, blade is 7’ wide. I’m noting the conversations about snagging the blade. Thank you for the warning!