jeff9366
Super Star Member
- Joined
- Jan 14, 2011
- Messages
- 12,777
- Tractor
- Kubota Tractor Loader L3560 HST+ ~~~~~~~~~~~~~ 3,700 pounds bare tractor, 5,400 pounds operating weight, 37 horsepower
I have started several threads with the goal of learning about Disc Harrows.
I have learned more from Farmwithjunk's posts on T-B-N than from anyone else.
Here are three Disc Harrow posts I found useful. I copied them from T-B-N into 'Word' then pasted the consolidation back into T-B-N, therefore the posts are not in context, necessarily.
Farmwithjunk has had health issues and is not posting here, often, anymore. A loss to us.
Farmwithjunk also produced the most helpful posts on adjusting moldboard plows. I will excerpt plow posts, which will require a lot of cut & paste, in late summer before Fall plowing season.
Here is a LINK that will take you to the index of 3,773 posts Farmwithjunk has contributed to T-B-N:
http://www.tractorbynet.com/forums/search.php?searchid=1465481
Re: Buying a 3 point hitch disc
The secret to success with ANY disc is lbs per blade....Obviously, the heavier, the better they'll work. Old school thinking used to be having disc blades about 6" apart. Later on, they moved 'em out to 7" +. Some larger disc's will have 9" or even 11" spacings. Typically, the wider the spacing, the larger diameter the blades SHOULD be. Larger diameter blades will also typically have more "dish" to them.
Just about all "modern day" 3-point disc's are set with 7-1/2" disc spacings, although I've seen a few with 6-1/2". A very few will have 9" spacings. Those are generally (but not always) higher end heavy duty models. Most old "drag disc's" had narrow spaced blades. They tended to try to roll on top of the ground rather than IN the ground, creating the false sensation of being "easy to pull"....In fact they ARE easier to pull, but at the expense of not working very deep. Simple "fizzix" tells us that the less work you're doing the easier it is/the MORE work you're doing the more effort it requires....
Frame weight is somewhat relative to frame strength (but not as a hard and fast rule...) As with ANY ground engaging tool, there is a great deal of stress and frame loading when working. In many cases, BOLTED frames will allow some flexing without cracking welds. WELDED frames are so rigid, there's just not any "give" in most cases. With that. welded frames CAN crack.
Also worth attention is the upper 3-point structure. With mounted tillage tools, they tend to want to rotate up and over the lower link pins.....That puts top link and upper 3-point structure of the disc in compression. I've seen a few instances where the strut running from the top link attach point down to the rear of the disc will bend or buckle, allowing the rear of the disc to raise up (and over) When applying extra ballast on a disc, it's good to equally distribute the weight front to rear for this reason. Putting all the weight on the front of the disc frame will compound the problem in many cases.
Without a doubt, the best 3-point disc I've ever been around is an old design....The Massey Ferguson #25. It has enough built in weight, and is well balanced, so it does a great job without piling on additional weights.
3-point disc's, if set correctly and weighted sufficiently will do an excellent job. Their rigid frame levels better than a flexible frame (such as was common on older drag type and some early wheel disc's with floating gangs) After all, it's about doing the best job, not creating the easiest way to spend time....
Just make certain the frame is strong enough to handle additional ballast (if needed) and you have enough lift capacity to handle a ballasted disc.
Notched blades have an advantage when tearing up hard soils/turf. They have a DISadvantage with regards to strength and wear. If you have a lot of rocks, notched blades are more prone to breaking than solid blades. Also, with less metal to begin with, notched blades will wear down quicker. It's a common practice to put notched blades on the front gangs and solids on the rear as sort of a compromise. (As I have done on all 3 of my disc's......MF25 3-point, IH350 wheel , IH496 wheel)
Roller bearing/ball bearing disc's are great IF YOU HAVE SEALED BEARINGS....Open roller bearings need constant attention. Cast iron "boxings" can continue to function way beyond the point when wear is beginning to show. I've seen boxings with 1/2" of wear still operating with no issues. Just pump 'em full of grease before each days use and life goes on.
Re: Buying a 3 point hitch disc
Originally Posted by Bartcephus
How about some advice on the angle adjustment of the gangs.
Not every brand of disc will work the same way, but with all of 'em I've ever used, they seem to work best with the front gang set one notch less than fully "aggressive" and the rear gang TWO notches less than full tilt..... Set fully aggressive, they seem to dig plenty well enough, but leave the ground too out of level for my benefit. And personally, I prefer front and rear gangs to be operating at the same depth. Usually, front gangs will try to dig in and rears raise up to where the rear isn't as deep. That'll throw more dirt towards the outside than what the rear will bring back towards the center (if that makes any sense...) Play with speed to see what nets the best results too. I prefer 4-1/2 to 5mph in most cases. Too slow and you get little soil action. Too fast and the disc will try to ride on top of the ground instead of digging.
Long story short, I like th eresults from a good RIGID FRAME disc, running level side to side and front to rear, with gangs set not quite as aggressive as the maximum settings.
Re: best disc harrow?
There's a perfectly good reason(s) why those old pull types haven't been built for the past half century. JUst as good of a reason why most have ended up in scrap iron piles. They're VERY limited in capabilities. Even back in the day when smaller equipment was still common on farms, farmers found a better way. Most switched to wheel disc's or 3-point models simply because they work better.
Most of the problem comes with limited mobility. You just can't transport them without a LOT of trouble. Next comes slow, methodical use in the field. If you're discing a 5 acre plot in the middle of a 20 acre field, with all sorts of turning room, they aren't so bad, but if you're discing in a situation where you have to turn IN the field, you have to EITHER turn with disc gangs angled, which causes ridging, leaving you with an unlevel land, OR, Stop, unlatch the gang, make your turn, then go through the process of re-setting gang angle (which in MOST cases requires putting the tractor in reverse, backing up a bit, then latching the gangs) . Sound time consuming? It is. Sound like a lot of un-needed work? It is.
Is there a reason why a pull type disc would pull easier? Yep....'Cause they aren't doing as much. In most cases, those old pull types will have smaller diameter disc blades than is common on newer disc's, OR blades that are worn out far beyond good service limits. With the concave shape, a couple inches worn off the outer diameter, and you have less "dish" in the disc blade. They would pull easier because they're not moving as much dirt. You get soil action on the surface, but underneath, down a few inches, not so much. One of the principal reasons why disc's in general aren't as common on todays farms is they will CREATE a compaction layer just below their working depth. At best, you still end up with compacted headlands.
A shallow running disc is one of the WORST tillage tools one could use in many instances. (because of compaction issues) Even if you have a pull type with NEW blades, you still suffer from lack of mobility. Personally, after spending much of my youth (raised on a farm) and the first few years of my farming career with old pull type disc's, I would rather take a beating with a big stick than go back to that archaic way of doing things again.
Pull types do a decent job, but suffer from too far many shortcomings.
3-point disc's can be fickle. They need to be GOOD models, in GOOD condition. Proper adjustment is key in making them work right. They are the MOST mobile of all types.
Drawn type "wheel disc's" are USUALLY the "best" working type as far as soil prep and mobility. You just loose a tick in the mobility dept. when compared to a 3-point model.
I have learned more from Farmwithjunk's posts on T-B-N than from anyone else.
Here are three Disc Harrow posts I found useful. I copied them from T-B-N into 'Word' then pasted the consolidation back into T-B-N, therefore the posts are not in context, necessarily.
Farmwithjunk has had health issues and is not posting here, often, anymore. A loss to us.
Farmwithjunk also produced the most helpful posts on adjusting moldboard plows. I will excerpt plow posts, which will require a lot of cut & paste, in late summer before Fall plowing season.
Here is a LINK that will take you to the index of 3,773 posts Farmwithjunk has contributed to T-B-N:
http://www.tractorbynet.com/forums/search.php?searchid=1465481
ASSORTED DISC HARROW POSTS BY FARMWITHJUNK
Re: Buying a 3 point hitch disc
The secret to success with ANY disc is lbs per blade....Obviously, the heavier, the better they'll work. Old school thinking used to be having disc blades about 6" apart. Later on, they moved 'em out to 7" +. Some larger disc's will have 9" or even 11" spacings. Typically, the wider the spacing, the larger diameter the blades SHOULD be. Larger diameter blades will also typically have more "dish" to them.
Just about all "modern day" 3-point disc's are set with 7-1/2" disc spacings, although I've seen a few with 6-1/2". A very few will have 9" spacings. Those are generally (but not always) higher end heavy duty models. Most old "drag disc's" had narrow spaced blades. They tended to try to roll on top of the ground rather than IN the ground, creating the false sensation of being "easy to pull"....In fact they ARE easier to pull, but at the expense of not working very deep. Simple "fizzix" tells us that the less work you're doing the easier it is/the MORE work you're doing the more effort it requires....
Frame weight is somewhat relative to frame strength (but not as a hard and fast rule...) As with ANY ground engaging tool, there is a great deal of stress and frame loading when working. In many cases, BOLTED frames will allow some flexing without cracking welds. WELDED frames are so rigid, there's just not any "give" in most cases. With that. welded frames CAN crack.
Also worth attention is the upper 3-point structure. With mounted tillage tools, they tend to want to rotate up and over the lower link pins.....That puts top link and upper 3-point structure of the disc in compression. I've seen a few instances where the strut running from the top link attach point down to the rear of the disc will bend or buckle, allowing the rear of the disc to raise up (and over) When applying extra ballast on a disc, it's good to equally distribute the weight front to rear for this reason. Putting all the weight on the front of the disc frame will compound the problem in many cases.
Without a doubt, the best 3-point disc I've ever been around is an old design....The Massey Ferguson #25. It has enough built in weight, and is well balanced, so it does a great job without piling on additional weights.
3-point disc's, if set correctly and weighted sufficiently will do an excellent job. Their rigid frame levels better than a flexible frame (such as was common on older drag type and some early wheel disc's with floating gangs) After all, it's about doing the best job, not creating the easiest way to spend time....
Just make certain the frame is strong enough to handle additional ballast (if needed) and you have enough lift capacity to handle a ballasted disc.
Notched blades have an advantage when tearing up hard soils/turf. They have a DISadvantage with regards to strength and wear. If you have a lot of rocks, notched blades are more prone to breaking than solid blades. Also, with less metal to begin with, notched blades will wear down quicker. It's a common practice to put notched blades on the front gangs and solids on the rear as sort of a compromise. (As I have done on all 3 of my disc's......MF25 3-point, IH350 wheel , IH496 wheel)
Roller bearing/ball bearing disc's are great IF YOU HAVE SEALED BEARINGS....Open roller bearings need constant attention. Cast iron "boxings" can continue to function way beyond the point when wear is beginning to show. I've seen boxings with 1/2" of wear still operating with no issues. Just pump 'em full of grease before each days use and life goes on.
Re: Buying a 3 point hitch disc
Originally Posted by Bartcephus
How about some advice on the angle adjustment of the gangs.
Not every brand of disc will work the same way, but with all of 'em I've ever used, they seem to work best with the front gang set one notch less than fully "aggressive" and the rear gang TWO notches less than full tilt..... Set fully aggressive, they seem to dig plenty well enough, but leave the ground too out of level for my benefit. And personally, I prefer front and rear gangs to be operating at the same depth. Usually, front gangs will try to dig in and rears raise up to where the rear isn't as deep. That'll throw more dirt towards the outside than what the rear will bring back towards the center (if that makes any sense...) Play with speed to see what nets the best results too. I prefer 4-1/2 to 5mph in most cases. Too slow and you get little soil action. Too fast and the disc will try to ride on top of the ground instead of digging.
Long story short, I like th eresults from a good RIGID FRAME disc, running level side to side and front to rear, with gangs set not quite as aggressive as the maximum settings.
Re: best disc harrow?
There's a perfectly good reason(s) why those old pull types haven't been built for the past half century. JUst as good of a reason why most have ended up in scrap iron piles. They're VERY limited in capabilities. Even back in the day when smaller equipment was still common on farms, farmers found a better way. Most switched to wheel disc's or 3-point models simply because they work better.
Most of the problem comes with limited mobility. You just can't transport them without a LOT of trouble. Next comes slow, methodical use in the field. If you're discing a 5 acre plot in the middle of a 20 acre field, with all sorts of turning room, they aren't so bad, but if you're discing in a situation where you have to turn IN the field, you have to EITHER turn with disc gangs angled, which causes ridging, leaving you with an unlevel land, OR, Stop, unlatch the gang, make your turn, then go through the process of re-setting gang angle (which in MOST cases requires putting the tractor in reverse, backing up a bit, then latching the gangs) . Sound time consuming? It is. Sound like a lot of un-needed work? It is.
Is there a reason why a pull type disc would pull easier? Yep....'Cause they aren't doing as much. In most cases, those old pull types will have smaller diameter disc blades than is common on newer disc's, OR blades that are worn out far beyond good service limits. With the concave shape, a couple inches worn off the outer diameter, and you have less "dish" in the disc blade. They would pull easier because they're not moving as much dirt. You get soil action on the surface, but underneath, down a few inches, not so much. One of the principal reasons why disc's in general aren't as common on todays farms is they will CREATE a compaction layer just below their working depth. At best, you still end up with compacted headlands.
A shallow running disc is one of the WORST tillage tools one could use in many instances. (because of compaction issues) Even if you have a pull type with NEW blades, you still suffer from lack of mobility. Personally, after spending much of my youth (raised on a farm) and the first few years of my farming career with old pull type disc's, I would rather take a beating with a big stick than go back to that archaic way of doing things again.
Pull types do a decent job, but suffer from too far many shortcomings.
3-point disc's can be fickle. They need to be GOOD models, in GOOD condition. Proper adjustment is key in making them work right. They are the MOST mobile of all types.
Drawn type "wheel disc's" are USUALLY the "best" working type as far as soil prep and mobility. You just loose a tick in the mobility dept. when compared to a 3-point model.
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