# NH 648 Net Wrap Problems



## bdm87 (Apr 1, 2012)

Recently experienced some problems with net wrapping operation on my 648 silage special. Baled about 300 bales this spring with nearly no problems. Then all of the sudden the net wrap started to either split or shred and get wrapped on various rollers prior to the duck bill or would just start wrapping during bale formation. Try all the necessary steps from changing pressure on the brake to duckbill timing. Changed out to three different net wrap manufacturers too. Talked with the dealer and they clued me in the duckbill gap was way too big...never had a problem in the last 3 years I've owned it and the gap has always been that big.

At any rate, I was out of town for a week and needed it fixed before I got back to haying so I took it to the dealer and they 'fixed' it by getting it back in spec and changing the grommets on the duckbill to fix the gap issue. Last week baled 15 bales and operated perfectly...except the net wrap is staying in about a foot on the right side of the bale and making some horrible bales. This is a new issue since they implemented their 'fixes'. Worked on it for about two hours to try and get it to wrap right but nothing I did helped the situation so had to borrow a neighbors to finish the field before we got some more rain. I hate borrowing other peoples equipment!

Here's what I see as I've watched it operate while wrapping while someone is running the tractor. To start, the netwrap is completely out to the edges on the spreader roller and in the duckbill. As the duck bill goes down and the netwrap enters to dimpled rollers, the net wrap pulls evenly into the bale about 3/4 from the left hand side...but the right 1/4 becomes slack and adjust toward the center of the bale. It becomes so slack that the spreader can't spread it back to the outside until about 3/4 through the wrap process. I have the bales set at 2.5 wraps and most of the time, it will not spread to the outside leaving a horribly wrapped bale. Sometimes it will spread, but only on the last 1/2 wrap...so by the time you kick the bale out, the bale tension loosens the wrap anyway.

Any help or comments would be greatly appreciated. Dealer came out to watch it as I left a full unwrapped bale in the last time and they weren't able to fix it.

Thanks,

Britt


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## mike10 (May 29, 2011)

The baffle on the duckbill may be too tight against the duckbill. The baffle is the plate with the notches on the bottom side of the duckbill where the net comes out. It is mounted in the rubber grommets you mentioned. You just want the baffle to touch lightly against the duckbill. It does not need to touch all the way to the edges of the duckbill, in fact there should be a gap at the ends of the baffle.

Also check the brake bar which rests against the net roll. The bar will stick in the pivots and not apply the needed braking force. The best way to check this is to remove the net roll and grab the brake bar and raise it up, It should freely fall when you release it. I am not talking about using the handle to raise the net bar like when changing rolls, but to grab the brake bar itself and raise only the brake bar. I have seen balers wrap good until the net runs out and a new roll installed. When you install the new roll you raise the net brake but when you release the brake against the net roll it does not apply enough braking force and you have problems spreading and cutting and also wrappiing on the spiral spreader roll. If your net roll momentarily continues to roll after the knife drops, you do not have enough braking force on the net.


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## bdm87 (Apr 1, 2012)

Thanks for the reply. I'll check the gap again but it should be right since they set it to spec. To make a bigger gap you tighten the bolts on the grommets right?

Have had the rolls out many times and checked the brake...no issues with it. I often find as the wrap changes in diameter I have to change the springs to increase/decrease tension so the brake works effectively like you mentioned.


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## mike10 (May 29, 2011)

You loosen the nuts to remove tension from baffle.

Don't confuse the brake mechanism you lift when replacing the roll of net with the brake bar. The bar has the rubber flap on in and rides against the net. Remove all the springs and only lift the bar where the rubber flap is to check if the bar is binding not the whole mechanism like when changing net. These are two separate pivot points. A little binding will make a big difference on the braking ability of the brake. Just looking at it is not good enough. It will appear to be down on the net but actually will not apply enough force to be effective.

If you have to change spring configurations during a roll of net, I would definitely look at the brake and would suggest sharpening the net knives.


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## 8350HiTech (Jul 26, 2013)

mike10 said:


> You loosen the nuts to remove tension from baffle.
> 
> Don't confuse the brake mechanism you lift when replacing the roll of net with the brake bar. The bar has the rubber flap on in and rides against the net. Remove all the springs and only lift the bar where the rubber flap is to check if the bar is binding not the whole mechanism like when changing net. These are two separate pivot points. A little binding will make a big difference on the braking ability of the brake. Just looking at it is not good enough. It will appear to be down on the net but actually will not apply enough force to be effective.
> 
> If you have to change spring configurations during a roll of net, I would definitely look at the brake and would suggest sharpening the net knives.


I though the manual said that changing spring configuration mid-roll was a possibility?


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## mike10 (May 29, 2011)

8350HiTech said:


> I though the manual said that changing spring configuration mid-roll was a possibility?


Maybe it does. But, there could also be other causes for the need to change spring configurations. His description of the original problem exactly describes the problem I have seen when the brake bar is not totally free. Could there be other causes? Sure, but I know from experience you can not depend on sight alone when checking the operation of the brake bar. Last year I had a 688 which was doing what was described, ripping net, net wrapped around the spreader roll etc. I went out and I even moved the brake bar up and down and it seemed fine. All the customer had done was put a full roll of net in and the problem started immediately. When the net was cut the roll of net continued to roll and got loose in the net box. Then when the next bale was to be wrapped he had the shredding problem and wrappage on the spreader roll. I could tell we were not cutting cleanly and the brake was not engaging properly since the roll continued to spin some after cutting. The customer had even put a set on new knives in the machine. I finally just grabbed the roll of net and turned it in the direction of travel. The net almost freewheeled even though the brake bar was down on it. We removed the net and the springs and moved the brake bar. Was it totally frozen in place, no. You could move it but there was drag on it. We removed the pivots bolts, freed up the spacers reinstalled the bar and made sure the bar was free. We installed the net in the box and went to baling without any further problem.

Most net spreading issues can be traced back to lack of braking action on the net roll or the baffle under the duckbill is too tight to allow the net to spread out. The service manual tells how to initially set the baffle, but it is only a starting point.


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## bdm87 (Apr 1, 2012)

Thanks for the comments. Will try to look at all these this week. Was at the fair with the kids all week. I replaced the three knives before taking to the dealer to work on the duckbill gap and replace grommets. The roll stops as soon as it cuts now that the duckbill and grommets are replaced. Problem since the dealer fix is that the net when starting a wrap gets slack on the right side and creeps to the center. It eventually works back out but only at the end of the wrap so that end of the bales blows up a bit and makes an ugly bale.


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## bdm87 (Apr 1, 2012)

So here's what my bales are looking like....absolute crap. I had a chance last night to finally look at the baler after the dealer came out last week to fix what they caused. All of the linkages are working as required for the brake. When I lifted the rubber flap to look at the net going in to the duck bill, I noticed that nearly 3/4 of the net is tight as a banjo string. The 1/4 on the one side that isn't wrapping correctly is pretty loose. Before the repair tech started his process, my duckbill had a gap big enough to put your fingers in and my net was always loose. At that time I didn't have any trouble with badly wrapped bales, just problems with net starting during mid bale or the net falling out of the duckbill. Now that the grommets were changed and tightened you can't put your fingers in, but for some reason on this end the net wrap is pulling back and is loose behind the duckbill. When the wrapper starts, the net shifts to the center of the bale and either stays there or comes back near the end of the wrap, but not soon enough to get enough net on to keep the bale compressed. Should I be thinking about tightening this end of the duckbill more?


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## mike10 (May 29, 2011)

I can understand if you are hesitant to adjust the baffle on the duckbill, but that is the only way you are going to get the net to spread. There is no set dimension from NH on where to set the baffle. The service manual only says to tighten the nuts until 1 to 2 threads of the bolt are showing. Not exactly a precise procedure.

You can count the number of flats you turn the nuts, that way you can always go back to where they are now. I would start by loosening the nuts 1 turn or 6 flats. If this does not give you a gap between the baffle and the duckbill, then loosen them a flat at a time until you get a gap all the way across the duckbill.

I don't know how many nuts are across the baffle on a four foot machine. There are five on a five foot machine so I would think there are probably four on a four foot machine. Tighten the center two nuts until the baffle lightly touches the duckbill in between the two nuts. Slightly tighten the outer nuts, but not to the point where the baffle is touching the duckbill. Preferably there will be a gap on each end of the baffle. Reguardless if there is a gap or not, you do not want the ends of the baffle tight against the duckbill.

When the baffle is tight on the end it will restrict the free flow of the net. That is why the net is loose on one end. The net is pulling easier through the duckbill on the one side so it is tight but the other end is being held back and thus loose.

You don't have any thing to loose except a little time and you can always go back to the way the dealer has it set.


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## bdm87 (Apr 1, 2012)

I was working on the baler about the time you were posting...and then some. I looked at the gaps in the duckbill before I disassembled the top baffle and there was more gap on the duckbill at the edges than in the center already. After taking the top baffle off, I noticed a few things. It was shiny most of the way across where the net had contacted it...except one spot...about the spot where the net was getting slack and getting sucked toward the center of the duckbill. That spot still had original paint on it. My guess is the duckbill was never set up quite correctly by the factory and never adjusted by the original owner ever, so the net never wore evenly across it.

I put a wire wheel on my drill and took down the high spot with paint. Took off any other nicks and rust as well. Then took sand paper and took out any scratches. I put a straight edge across the baffle and found there were some dips and dives in it, so I lightly adjusted with the press and hammer/wood block method. It should be as good as it ever was. Pulled the net off the lower baffle and sanded it too for good measure even though it was okay. Put the straight edge on and it was waffled a bit too, so I bent as needed to get it straight. Plan on putting back together when I get home tonight and asked the neighbor if I could come over and bale some of his hay to see if I've got it back working correctly before I need it tomorrow.

Mike10, thanks for the posts and keeping me moving forward on this. Just an FYI...the 4' duckbill has 5 grommets top and bottom. We'll keep our fingers crossed, but I think this will do it now that I found the time to just look at it myself. Dealer indicated he cleaned up the duckbill wear surfaces, but they clearly didn't. Was one of those situations where my dad in his haste at 75 made an executive call to take it to the dealer when I was out of town before I had time to logically look at what was going on. Gotta love him, but man that episode cost some cash to have them fix nothing!

Will keep you posted if I fixed it. Thanks again.


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## mike10 (May 29, 2011)

Since there are five nuts on the baffle, I would alternately tighten nuts 2 and 4 until the baffle contacts the duckbill lightly. I then would tighten the other three nuts to take up any play between the washers under the nuts and the grommets, but not enough to add more pressure to the baffle.


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## bdm87 (Apr 1, 2012)

Baled a few bales for the neighborlast Friday and it was pretty inconsistent. Wrap on one side still meandered toward the center for 2/3 of the wrap process.

Took it home for the night and removed the duckbill for another readjustment. Next morning started on straw. First few bales I got the same. Got out, looked at it, scratched my head and baled 10 more with probably one every 5 with an issue. Baled 80 the next evening of both straw an hay with an issue about every 10 bales. Still concerning but not as bad as it was


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## 8350HiTech (Jul 26, 2013)

Mike10, on the advice of this thread, I checked my duckbill/baffle gap on my 644 and decided to replace my grommets and reset everything. The gap you'd like to see on each end, I'm assuming is more of an art than a science. Anything specific you have to recommend other than bale some hay and see what happens?


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## mike10 (May 29, 2011)

Baling is the only way to know if you made the problem better or worse.


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