# Sharpening Discbine Blades



## askinner (Nov 15, 2010)

Hi all,

Just wanted to share a method of sharpening discbine blades I discovered today that works really great, and fast. I normally use a flapper disc on an angle grinder, but being lazy this morning, the grinder had a cut off wheel in it, so I grabbed my electric die grinder that had a flapper wheel in it and used it. It worked very well with an 1 1/2" diameter wheel, as it got right into the radius near the inside of the blade. Produced a razor sharp edge too







These die grinders are available in battery operated versions too, which would be even better.
Hope this helps someone!

Aaron


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## Vol (Jul 5, 2009)

Good idea Skinner....looks like the die grinder would definitely be better about holding and maneuvering one-handed. How's your growing season going in your part of the world?

Regards, Mike


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## askinner (Nov 15, 2010)

Thanks Mike, the positioning of the die grinder is perfect for a discbine, very quick to sharpen this way, and a whole lot safer than restling with an angle grinder with a curtain over your head!
It has been extremely dry down here, only had about 2 1/12" this season, thankfully for irrigation I have still had some really good yields, but at a cost. We are being bent over the barrel down here with electricity prices!!! Our "wonderful" prime minister decided a carbon tax would save the planet







A dairy across the river from me received a $15k power bill for the month the other day!! On the up side, the dry has driven hay prices and demand through the roof


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## mlappin (Jun 25, 2009)

_Here_ it ain't worth sharpening blades. Especially on lighter crops, once the edge is no longer square on the end of the blade it doesn't cut fine stuff near as well as a new blade with a square edge, not to mention with moles and what not I always have chips missing out of the leading edge. I go thru one new set a year, that includes flipping them over once.


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## urednecku (Oct 18, 2010)

Flipping the blades worked on my JD mo-co, but not on my Kuhn mower. I tried it for about 30-45 minutes, then came back to the barn to change them back, sharpened on the bench grinder while they were out.
I will check into a die grinder, all I have now is an angle grinder. I've been using it with a regular grinding disc. Right now that's all I have unless I take 'em off & use the bench grinder.


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## Nitram (Apr 2, 2011)

I had considered building a jig to hold at proper angle on a bench grinder. Is there a concern with heating and causing blade to become fragile?


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## swmnhay (Jun 13, 2008)

Put new ones in!!$2-3 each.

Alot of times the ends are getting rounded off or maybe they are bent a little.A new blade will cut much better then a rounded off,bent resharpened one.


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## CockrellHillFarms (Aug 30, 2011)

Its not worth sharpening just like swmnhay is saying!! Its not worth the time. Flip them if u can. If they are bent toss them and replace them. Way faster! And not worth the time and effort!!!!!!!!!!!


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## Vol (Jul 5, 2009)

Sharpening blades is a matter of opinion and circumstance. If you have a disc mower like mine, a Fella, it is a absolute PITA to remove and flip the blades.....which I do every year. BUT, many times I will hit them a quick lick and have a nice edge to mow with which I can do three times as fast as removing. Now, if I had the quick clip type blades, replacement would be a no-brainer....but I don't. I agree 100% when the corner edge starts bull nosing, it is definitely time to flip or replace. And Martin, your right about heating the blades with a disc grinder....its hard not to do it a little at best....that is why I think Skinner from Down Under has hit on a great idea about using a little die grinder with hard paper drums to grind with....much cooler and I would think the ease of handling and comfort would give a fella alot better ability on proper sharpening. One other thing, on my Fella disc mower, I noticed that I can get away with a rounding corner more on all the blades except the pair on the last(outside) disc(Hat). These have to be square all the time or the end becomes ragged for the next pass and causes a little ragged strip sometimes in finer grass, but I can get too picky about that stuff sometime. Kinda that way about mowing my yard too!

Regards, Mike


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## mgilbert61 (Nov 2, 2012)

Changing blades can get pretty expensive. I would think an occasional sharpen would be alright unless all the other mentioned issues. I'm going on my own and looking at a nh1411. I guess if you can leave them on it would be ok, but if you got to remove then you might as well flip.


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## urednecku (Oct 18, 2010)

So far I've had good luck sharpening. If you don't wait till they are too dull it only takes a few seconds per blade. Takes a lot longer to change them, and like Vol said it's a bit of a pain. Also the bolts & nuts are supposed to be changed every 3 or 4 times (best I can remember) they are taken off. I just spent $42 from TSC for blades, (I've been waiting for a month for the dealer to get some in.) and $38 for bolts from the dealer. (TSC) didn't have them.

That's just what works _for me_.


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## haybaler101 (Nov 30, 2008)

mgilbert61 said:


> Changing blades can get pretty expensive. I would think an occasional sharpen would be alright unless all the other mentioned issues. I'm going on my own and looking at a nh1411. I guess if you can leave them on it would be ok, but if you got to remove then you might as well flip.


Really? Two dollars per blade is expensive? Mine takes 20 blades and 30 minutes to change. Usually start season with new blades and flip half way thru. Probably get 5 to 700 acres per side. Usually replace a few in between from damage. Only change bolts when cross threaded or stripped.


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## askinner (Nov 15, 2010)

I personally have a fair amount of sandy country, and it rips the edge straight off the blades, long before they warrant replacement. I also like to have a razor sharp edge each time I cut, It cuts the stems, rather than rips them IMO. And as urednecku said, it only takes a few seconds per blade. On the flip side (paron the pun), I don't flip them. If they're off, they're going in the bin! I like the peace of mind they're all balanced and have no fractures etc...
On the bolts, that being the only thing between those blades travelling 180 mph and my head, I will pay the extra $$ to replace them every change!


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## cdhayman (Jan 25, 2011)

we have sharpened blades in the past. it does help, there is no doubt about that. but anymore we usually just flip them over. we will hopefully go through no more than 3 sets of blades per season. i mean this year each machine will cut a little over 3,000 acres, so if we only do 3 sets i think we are doing pretty good.


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## Teslan (Aug 20, 2011)

Whatever you do. Putting in new or sharpening, they are sure better then the old sickle sections and guards to have to replace.


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## mlappin (Jun 25, 2009)

Teslan said:


> Whatever you do. Putting in new or sharpening, they are sure better then the old sickle sections and guards to have to replace.


Amen.

20 to 30 minutes to change or flip the 20 on mine. Takes practice is all, first time sucked.


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## askinner (Nov 15, 2010)

mlappin said:


> Amen.
> 
> Takes practice is all, first time sucked.


And a cordless impact wrench! They are great for the job.


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## Nitram (Apr 2, 2011)

I have to admit the quick clips on the vermeer 1030 is fantastic for ease of flipping and removing. I guess some of my father settled on me as I try to save where I can sometimes its not worth it. But I flipped the blades and then put a new set on in the 200 ac this year and the blades I removed look nice except for a few dings and dull edges. Martin


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## Iowa hay guy (Jul 29, 2010)

i tryed to sharpen them in my macdon but at $1.37 each you cant afford not to replace them 
especially when the sharpened ones lasted half as long because the case hardening was all gone 50 acres and they were shot and a new set will last for 400 or 500 acres before i say its time to toss them

so far i have quite a pile of old bent and dinged up blades that i could throw in an old junk car to scrap someday


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## HALLSHAY (Nov 30, 2008)

Teslan said:


> Whatever you do. Putting in new or sharpening, they are sure better then the old sickle sections and guards to have to replace.


I tend to disagree! How often do you need to replace guards and sickles? Was it that hard? A top serrated sickle section continually sharpens itself as it wears. I believe you get a more consistent cut job field after field with sickle mowers.

I really haven't expressed my opinion about disc mowers on this forum because so many people like them and I do not want to offend. Here are the main reasons I don't like them from a hay BUYERS standpoint:

If you changed blades every 250 acres even on 1 ton hay, you have less than .50 per ton of hay in blades. If guys keep them nice and new and slow down a hair and cut a field clean, they work great.

What I see happening on a regular basis is a high speed hay cutting job with blades that are semi-dull that leaves alot of stripped alfalfa stems. Next cutting comes around and that dead stem gets cut with the pretty green hay, and you end up with it mixed throughout. Does it really affect the quality of the forage? Not really. Is it ugly? Hell yes, I can look at about any green load of 2nd or 3rd alfalfa and tell you whether it was cut with a disc or a sickle the time before.

The next big one I see is the dirt and rock content in hay, especially sandy ground. We get hay in here that is littered with sugar sand. You can run load after load and never find one clod of sand, but there is sand everywhere on the floor as we clean. Disc mowers don't slow down for gopher mounds and sprinkler tracks and that dirt ends up in there also.

All I am trying to say is that a sharp blade and a clean cut make for a better product.


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## Teslan (Aug 20, 2011)

HALLSHAY said:


> I tend to disagree! How often do you need to replace guards and sickles? Was it that hard?


When we had a sickle machine we replaced the entire sickles and what guards needed in the spring. And yes it was hard. First to pound out the old sickle, put in the new one make sure the guards were adjusted right so the sickle bar wouldn't rub any where. Took a couple hours easily.

Then there was field breaks with rocks. To replace a section took at least 20 minutes. More if I actually had to take the sickle out to replace a section knife. This used to happen at least once or twice in a field. Then sometimes a guard would get broken or bent also. Since 2002 I have yet to have a rotary knife break in the field. And if one did break. It would take about 5 minutes to replace it.

Though I have yet to replace any turtles or anything which I imagine is not fun.

With a sickle machine I would plug up cutting grass hay and then that left streaks in the grass far more then the rotary machine does. Since I have yet to get plugged up.

Most of the time when a field is cut badly with a rotary machine it is due to the operator. It takes a bit to figure out how to get the most uniform cut in various crop conditions. Dealers and sales people in my experience don't help with this because their advice to me has been exactly opposite of what really needs to be done. Plus one must keep an eye on the knifes as well. Operators sometimes go too fast in the field just because they can. Then if there are any bumps or if the field isn't too smooth the whole head will bounce and make an uneven cut, which like you said, will turn up in the next cutting.

As for sand and dirt. I think it is about even. At least on our ground as we don't have sandy soil or many gophers. When we had the sickle haybine the dirt and rocks would just pile up behind the knife section. Especially if the ground was kind of damp or the crop was a little damp. This means to me that they were going through into the windrow just as much as now with the rotary. I routinely used to hear rocks going through the conditioner on the haybine. On the Rotary I don't hear that at all, but see the front curtains get hit forward when a rock is kicked back.


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## barnrope (Mar 22, 2010)

$1.65 apiece last year right from New Holland. I went through naybe a couple boxes of each direction last year. Less than $150 worth of blades over a lot of acres with rocks and gopher mounds. I wouldn't be able to afford to sharpen them.


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## askinner (Nov 15, 2010)

I disagree on the part that most people mow too fast with discbines. I personally find they make the cleanest cut in heavy going flat chat. I do not know why, perhaps it's because it doesn't blow it down, but the only way I cut lodged alfalfa is fast. I can take some photos of some headlands comapared to normal cutting speed for the disbelievers to prove it. As I said, I'm not sure why, but I do know, discbines weren't designed to go at haybine speed, they work best at their designed speed (~10 mph).
I believe stripped stems is related to a couple of things - cutting too late (lodged), and pto speed too high, or ground speed too low. Too low of ground speed in long hay will cause the rolls to grab the stems before it is cut, and rip the leaves off too. If my hay is lodged, I cut at the lowest setting, that will stop the stripped stems also.

JMHO of course!!


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## askinner (Nov 15, 2010)

Oh, one more thing, keep an eye on your crop lifters on discbines, if they wear down and break off, replace them! Without them, they streak, not to mention the balance issues it must put through the bar. They aren't cheap though. Amazing how quick they wear out in sandy country too.


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## MartinKrog (11 mo ago)

haybaler101 said:


> Really? Two dollars per blade is expensive? Mine takes 20 blades and 30 minutes to change. Usually start season with new blades and flip half way thru. Probably get 5 to 700 acres per side. Usually replace a few in between from damage. Only change bolts when cross threaded or stripped.


We do sharpen the blades on a knife sharpening belt sander, it works well and its possible to get the angle perfect. The blades here in South Africa is about 8$ a piece for the NH discbine so for us its worth the while to sharpen. We also do the Claas disco blades although they about a ⅓ of the price of a NH blade. After each cutting of lucerne we either sharpen or replace depending on the blade condition. Sharp blades prevent shatter on the stems and regrowth benefit from that. We do 10 cuttings per pivot per season so for us it makes sense to sharpen.


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## ozarkian (Dec 11, 2010)

Let's face it, disc mower blades are one of the cheaper parts we have to replace. I use one side then flip them unless they are bent or badly damaged. I like keeping new blades on the cutter.


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