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Why do some combines of the same model have accumulators and others don't, what is the advantage/disadvantage?
 

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Early on (back in the L2 days or maybe earlier) corn machines came with accumlators due the weight of the corn head. As grain headers became bigger over the years accumulator became standard on all machines.

Adjusting the height of a 8 row corn head on an L2 was quite jarring with the accumulator turned off.
 

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So it's basically a shock absorber for the lift cylinders then? Do they need a charge of some sort? I remember by manual saying something about it needing nitrogen
 

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yes, it is a shock absorber for the header lift/ lower circuit. Its a floating piston with nitrogen on one side, and the hyd. oil on the other. charging directions are in the operators manual.

The reason some had it, and some didn't was due to options, as the accumulator was an optional part on the conventionals. AFAIK the rotaries had them standard, every one I have seen seems to have one. IIRC on the L2, it might have even had to bee a Corn plus to get the accumulator standard, I think it was even optional on the corn/soybean specials.

We love to use them as a float device in rocks, with a good accumulator and some Gaterman down grain guards, it will hop over a rock without damaging a guard or section.
 

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If you have AHHC, you need an accumulator. If you run heavy heads you need an accumulator. In the days of small light rigid grain platforms, leaving it off was one way the dealer (especially out west) could lower his price a bit and get your sale. Who ever thought to ask?
 

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We only run a 6 row Hugger and 20' flex heads on our R62. The accumulator is not necessary for the corn head, but very nice. It is necessary for the flex head though to smooth out the AHHC and prevent it from hunting. Taking the slight jerk out of raising and lowering the heads all day makes for a much nicer harvesting experience. We never run ours wide open except for road travel. Just open enough to take the shock out of head height changes.
 

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The Accumulator was invented by an old friend of mine named Leon Amman back in the 1950's. It is a shock absorber for hydraulic systems. Leon built sickle bar extentions for grain headers too. He also had many inventions that Boeing used during WWII.
 

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Have a couple of questions regarding accumulator on my R7.

First, in my manual for the L series I believe it says turn the accumulator off if you're using your AHHC. Jeff, on this forum suggests otherwise and I know he is very knowledgeable and I respect his advice. Just wondering why the old L ops manuals suggested otherwise?

Second, I want to charge up my accumulator on my R7. The kit sold by AGCO to do this does not include a Regulator. Is that because you can't buy a regulator that allows 1000+ psi through it or is there some other reason. My R7 's accumulator still has a charge but with our 3000 corn head we feel it needs more psi to stop the jerkiness when we lift it and lower it. Does increasing the charge psi make sense?
 

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Have a couple of questions regarding accumulator on my R7.

First, in my manual for the L series I believe it says turn the accumulator off if you're using your AHHC. Jeff, on this forum suggests otherwise and I know he is very knowledgeable and I respect his advice. Just wondering why the old L ops manuals suggested otherwise?

Second, I want to charge up my accumulator on my R7. The kit sold by AGCO to do this does not include a Regulator. Is that because you can't buy a regulator that allows 1000+ psi through it or is there some other reason. My R7 's accumulator still has a charge but with our 3000 corn head we feel it needs more psi to stop the jerkiness when we lift it and lower it. Does increasing the charge psi make sense?
Every header/lift cylinder/ accumulator combo is going to require a slightly different pressure to be perfectly balanced. With the header on and everything in field ready weight, without actually knowing how many psi you have in the system, you could just add or release accumulator until your header floats. Think of a spring holding your header up. If the spring is too stiff, the spring does not give and is like a solid link. If the spring is too soft, the spring compresses until it is fully collapsed and again is like a solid link. The adjustable nitrogen or hydraulic pressure allows you to find the sweet spot where the header weight and accumulator pressure are in balance at mid stroke of the accumulator volume, giving you a spring loaded header float. If you think your pressure is low, just add pressure to the accumulator until the lift cylinders start to lift the header.
 

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On the L and indeed clear up to the present, AGCO basically thought ON/OFF on the accumulator. Basically, the old AGCO manuals just wanted you to turn on the accumulator when transporting the head down the road, to cushion any large shocks (to prevent damage to the feeder!) They also only had AHHC on the flex heads. ON was too soft for accurate AHHC on a bean head. AHHC on a flex head, where a large percentage of the weight is sliding on the ground, is FAR different than smooth control of AHHC on a suspended corn head.

What we have found over the years is you not only need to have the correct pressure in the accumulator, you need to control flow into and out of it, rather than just on/off. Fully off is bad--Hard sharp jerks. Fully On (open) is also bad--the head can "do the wave", actually lag behind the sensor/control so much it always over shoots. Opening the accumulator valve just enough to take the shock/jerk out of the system but still maintain crisp response is ideal. Its hard to do with the AGCO 1/4 turn valve...usually for 1/4 to 1/3 open. We actually recommend replacing it with a 10 turn bi-direction flow valve for best control.

Charging the accumulator is usually best left to the dealer with the right tools and gauges, IMO. They should have a chart of pressure/head weight for your machine. Overpressure will be just as bad as underpressure. BTW, Lexion combines are SO dependent on proper pressure, I know of guys who have the dealer reset the pressure each time they switch heads!

Make sure your flow rates are set correctly--8 seconds up, 8-10 down. Slower may be necessary on larger heads.

One final tip...All the Gleaner combines up to the S88 had bang-bang valves. On a large percentage of the combines, no matter how slow you set the flow controls, the head tended to bounce. You could even see it in manual...it was very difficult to move the head less than 6-8" at a time...it would either not move at all, or move at least that much. Headsight released a PWM conversion for these machines last year to solve the problem. It also makes accumulator setting far less critical to good performance. If you simply cannot keep your cornhead from bouncing--call us.
 

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Thanks for the help guys! Bottom line -we should be using it, properly charged, on the R7 as well as the Ls

My dealer (which has been very good to me on my combine rebuilds) is not familiar with accumulator recharging etc..

They have ordered a recharge kit for me (valve and related hosing) but they don't have the capability themselves (at least that's what I understand). I'm kinda left to do it myself. The ops manual tells us how to do it -just wanting to be safe-hence my query on using a regulator.

Jeff, where can I get that 10 turn valve you mentioned. Now would be the time to install one.

Thanks again everyone for the help!
 

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our regulator is a precise hand on the knob. :)

Have the header in the air, add till the floating piston bottoms out, bleed off till it drops the proper amount.
 
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