Kuhn Disc Mower rough cut

[brandonh]

Got a 7'10in Kuhn GMD66 Disc Mower. I put new blades on it and it still cuts crappy. It cuts but it just kinda leaves the field looking shaggy. Its almost like its just riding over some of the hay. Ive tried different speeds and rpms and adjustments and just cant figured it out. Any ideas?

 

[Chuck Daniels]

belts could be slipping.if mower is running right rpms with new blades it should be cutting fine

 

[Casey in Ky]

I've got the same mower and I've never had that problem other than if the crop was way late and layed down, and it still did a fair job. If I'm not mistaken, the Kuhn blades are reversible. Some of the after market blades might not be, so you might check to make sure you've got the new blades turned the right way. For what its worth...

Casey

 

[brandonh]

The new blades are two sided so you can switch them around when they get dull. It seems to cut the big stuff better. I'll check the belts and see. They chirp a little when you turn it on but it runs quite. And the bblades seem to be running up to speed Ive watched it cut with the cover flipped up. The guy we bought it from said he noticed it to but never could figure it out. He thought it was the cover being kinda old and torn here and there. He said the thought the cover help make a vacuum or suction. But Ive seen a guy run a caddy mower with no cover at all. I dont know what it could be. But I'll definetly check the belt. Its a good quite mower. But it should cut better I think. Ive tried running the mower nosed down in the front, tried it level, and leaned back slightly and nothing seems to help. Its doesnt cut terrible. But Ive seen mowers cut way nicer.

 

[RodinNS]

Stupid question.... but you do have the blades installed in the correct direction? For example... each outside disc will always turn towards the inside of the mower bar so it drags hay clear of the mower frame... and each knife is directional... so you install them with the arrow pointing in the direction of rotation. I'd check that.
The belts need to have 3/4" deflection at their midspan. Just poke through the hole in the shield. Also make sure they're not turned on the pulley... They really shouldn't chirp.

Next... check that all the skid shoes are in place and that the bottoms are smooth. If it has ragged or damaged shoes it can sometimes drag hay and that will cause a ragged cut.
Top link is the next thing... If it's cutting long you can try shortening the toplink. You can shorten it right up until the bar probably leads 5-10 degrees down at the nose...
Lastly... the curtain does need to be pliable. I've used heavy belt on mine and it will push grass over and the mower won't cut it then... but if you have the curtain flipped up that should not be a factor.

Rod

 

[brandonh]

Actually the front started to dangle so I trimmed it of. It has the kuhn canvas on all sides, top, and back, and is open in the front. So that shouldnt be an issue. The blades are bi diectional. So they cant be put on backwards. Unless I got them up side down????The flat part of the blade is down with the angle up. Which I nearly postive it right. I'll check the belt. Thats pretty much the only thing I havent looked into. The skid pads on the bottom are nearly new. Hasnt cut a whole lot since they were replaced. Im stumped

 

[showcrop]

I'll add one to Rod's list, Make sure the discs are all on in the right positions. When I got my discbine two had been swapped so that the lifters were turning backwards. The breeze lifting the grass was weak in that part of the header.

 

[RodinNS]

Are you using the flat (light duty) blades or the twisted (heavy duty) type? The heavy ones have an arrow indicating direction of cut. They ARE double sided... you just flip them over to use the other edge... but they are most definitely directional. They also cut poorly if used in the wrong direction. I've done that MANY times as they still cut better than a bent/broken balde.

If you're using the light duty (straight) blades... then that may be the problem itself. Iv'e used them for one season on a discbine and I never found they cut worth a damn.

Also be sure that you have the correct length blade as there are at least 2 different lengths... The ones you need will almost touch the next disc when parallel to the bar.


Rod

 

[Shetland Sheepdog]

Showcrop, The GMD66 doesn't have lifters like the discbine does. All the discs are identical, regardless of direction of rotation, except for the end discs with the "hats".
HTH, Dave

 

[Lew Best]

Ok I'm curious; what is the purpose of the "hats? My old vicon don't have them & the 66 I bought at the auction about a week ago has one hat totally rusted off.

Lew

 

[RodinNS]

The 'hats' move the swath inwards to narrow it up. Supposedly... I never noted that they made a lot of difference.

Rod

 

[Lew Best]

OK thanks; I knew I'd seen many cutters without them so was just wondering their purpose.

Lew

 

[Ken Macfarlane]

The two sided twist blades have left and right style. You need both types.

 

[brandonh]

Yea Ive got the straight lite duty type. When we bought it the guy threw in a whole new set of blades and bolts so ofcourse I put them on. They like about 1/8 inch touching the other disc. They seem awful light weight. Maybe the durn blades. Hopefully I'll find a few rock this summer so I'll have an excuse to get a new set of the heavy blades. I have a whole set of a different style. Almost tempted to sharpen them up and put them back on. Because this thing is leaving a good 4 inches of hay. And just aint making a clean cut. Almost like when you mow a lawn with a riding mower with the throttle at MIN and the speed at MAX. Just kinda clips it and lays it down!! In high thick hay it cuts ok.

 

[Lew Best]

I bought the "twisted" blades; whole set something under 20 bux (iirc something like 1.19 each?). Anyway came back with change from my 20.

Lew

 

[RodinNS]

You didn't get Kuhn then...
I don't think it matters much for all that but I find most times the Kuhn blades are more like 2-2.50 each I think.

Rod

 

[Lew Best]

That I can't answer; they came from the local Kuhn/JD dealer

Lew

 

[RodinNS]

If they're genuine they'll have Kuhn's name on them inside the diamond.

Rod

 

[Lew Best]

Thanks; i'll check them out when the much needed rain quits in a few days (we're sposta get up to 2 inches over the weekend)

Lew

 

[Anonymous-0]

If they came from one box then they could be wrong, you must have right hand and left hand..or clockwise and counter clockwise

 

[Shetland Sheepdog]

(quoted from post at 07:57:24 05/14/10) If they came from one box then they could be wrong, you must have right hand and left hand..or clockwise and counter clockwise

And you will need 6 of each! I genally buy a box of each, soes I got spares!

I can give you specifics on which blade goes on which disc [u:174dd9e07a]if[/u:174dd9e07a] you want, but only if you want!

HTH, Dave

 

[randallk]

Your problem could very well be "thin hay". Most disc mowers do a poor job in thin hay. If all the knives are on correctly, the belt isn't slipping and you're running at correct pto and ground speed, I'd almost bet it's thin hay...........since you say it cuts good in tall heavy hay. 'Good chance your mower is just fine.

 

[brandonh]

i believe your right. It seems to better on thicker fields.

 

[robersw]

What are you cutting?

In our bermuda fields, our first spring cutting, (two weeks ago), always end up looking shaggy because we are just getting the rye grass off the top and it gets rather stalky. After baling, you can just glance over the field and see the areas that were heavy in rye.

After the second cutting, the fields will look smooth. They have done this for as long as I can recall. Didn't matter if it was my 12 yr old Lely mower, a borrowed JD (Krone), or our 3 wk old Vermeer (Lely). They all left the field the same way.

I would wait til your second cutting before stressing too much over this.

Scott