# New Idea Disc Mower Question



## Tired-n-dusty (Oct 22, 2010)

Last year I purchased a 10 yr old New Idea 5409 disc mower that seemed to be in pretty good condition. When I use it for cutting grass, I can cut through at any speed and get a nice clean cut. However, I have an 8 acre alfalfa/grass mix field and end up with the mower stripping off the leaf and leaving 10"-12" long stems, mostly in the areas where it is thickest. The tractor (JD5203 45 hp PTO) doesn't seem to bog down and I'm running it at 2400 rpm. I have replaced the blades with no change. I checked and blades are not backwards. It does seem to cause less of the stripping if I slow down considerably (2-3 mph vs 4-5 mph) but still leaves quite a bit. I switched to a disc mower from my haybine so we could mow faster, thus this kills any benefit to the disc mower.

Agco dealer suggested slowing the tractor rpm down to 1700 as he though that air circulation could be causing it. Does this sound right? Other thoughts?

Thanks


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## Josh in WNY (Sep 7, 2010)

I don't know how much help I will be since I run a disc mower/conditioner, not just a disc mower like you have. Typically with my mower, the thicker the crop, the better job it does. The manual recommends lowering the rpm and speed in thinner crop, the idea being that the air turbulance given off by the spining discs flattens out the crop before it is cut.

After looking at a few pictures of your mower online, I wonder if your problem might be the angle that your cutterbar is set at. Is there any adjustment to that? If it is set relatively parallel to the ground or even tipped back a little, the crop may be flattened by the safety curtains and end up being pushed to the ground by the cutterbar. If you tip the cutterbar a little forward, this would be corrected as the knives would pick the crop up off the ground better.

Like I said, I'm just guessing as I don't own a disc mower. Hopefully one of the other folks on here with more experience can chime in and provide some advice.


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## Greyhorse (Jun 22, 2009)

I don't know anything about cutting alfalfa but a lot of mowers have high lift blades with more angle on them to help lift the crop (at least that's my understanding); also some have serrated blades available for tough crops (don't think alfalfa qualifies as tough). I would try to see if you can find the high lift ones for your mower and see if that helps.


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## NCSteveH (Jun 30, 2009)

I ran into this once when we first bought our disk mower, turns out that we didn't have enough forward rake on the cutter and the bar was pushing down the heavy crop before the blades could get to it. About a 1/2 dzen turns of the top-link took care of it.


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## Tired-n-dusty (Oct 22, 2010)

NCSteveH said:


> I ran into this once when we first bought our disk mower, turns out that we didn't have enough forward rake on the cutter and the bar was pushing down the heavy crop before the blades could get to it. About a 1/2 dzen turns of the top-link took care of it.


I am not 100% sure of what you mean by "forward rake". I am presuming that you are referring to the tilt with a greater tilt forward solving your problem.


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## Tired-n-dusty (Oct 22, 2010)

It seems as thought the dealer's recommendation on rpm is opposite of what your comment is. Just from a logic point of view, your recommendation on rpm makes more sense.

I can adjust the angle of the cutterbar by adjusting the top link. I have been running just a little forward of vertical as the field has some rocks in it and I am trying to avoid them. I will try to tilt it forward and see if this corrects it. I also have been trying not to cut it too short, thus the near vertical tilt. Thanks for the advice.


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## hay king (Feb 6, 2011)

I take it this is a 3pt mower. with my 3pt mower havent used it in a few years though you need to angle the cutter bar forward a bit. As for hight of the cut you can set that with the 3 point hitch. angle the cutter bar forward and if it cuts to short pick up the 3 point a little that should help to cutt better. when i ran with a level cutter bar i had the same problem but i cut grass so alfalfa might be different.


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## NCSteveH (Jun 30, 2009)

Tired-n-dusty said:


> I am not 100% sure of what you mean by "forward rake". I am presuming that you are referring to the tilt with a greater tilt forward solving your problem.


yes you are correct, forward tilt.


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## Cliff SEIA (Dec 18, 2008)

Another thing you could check is the drive belt tension although if the belts were slipping that much I think you would be able to smell them. Alfalfa cuts harder than grass and if the belts are loose or glazed it's possible you aren't getting enough blade speed to get a clean cut.


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