Mowers for Scuts and cuts, an introduction
There are Mid Mount Mowers, Rear 3ph Finish Mowers, Rear 3ph Rough Cut Mowers, Flail Mowers and more. A look at what they are, how they should be used and mistakes often made when using these various mowers.
These mowers are specifically designed for use with a Subcompact tractor (SCUT) or Compact tractor (CUT). This article does not cover zero-turn mowers, lawn mowers, etc., which will be covered in a post of their own. The specific topics this blog will cover include these key points to help improve the general understanding of tractor-mounted mowers.
Ø Finish mowers and rough cut mowers and the mowers in these categories
Ø 540 rpm PTO speed and 2,200 rpm PTO speed and their differences
Ø Engine speed and its impact on PTO speed
Ø Stamped verses Fabricated decks, what they are
Ø Stamped verses Fabricated decks, costs, availability and advantages, disadvantages
Ø Why you should consider a Stamped Deck or a Fabricated Deck for your needs
Ø Rotary mowers versus Flail Mowers
Ø Mower use and price category examples
The two broad categories for the mowers for SCUTS and CUTS .
Finish Mowers – These are mowers that can produce a quality cut that would be suitable for a lawn or yard. These include the following mowers
Mid Mount Mowers
Rear 3ph finish mowers
Flail Mowers are unique in that they can produce a finished quality cut but also tackle rough conditions.
Rough Cut Mowers – These are the mowers that are purposely designed and built to tackle the toughest mowing jobs. Rough-cut mowers will usually cut small trees up to 2” or 3” in diameter, depending upon the tractor and mower size, along with overgrown weeds, etc. The rough cut mowers include
3ph Rear Rough Cut Mowers (also known as “brush hogs, brush cutters, etc.)
Articulating Side Mount Mowers (for larger CUTS)
Flail Mowers
PTO Speeds, 540 rpms to 2,200 rpms. What you need to know
540 rpm PTO - Most of the SCUTS and CUTS have a rear 3 point hitch and a PTO output shaft at the rear of the tractor. The maximum speed of most of these rear PTO’s is 540 rpms. Ultimately, the gear box, pulley size and belts selected and in use on a mower will also dictate its cutting speed.
2,200 rpm PTO- Tractors that offer a Mid PTO output shaft, which is most often used to drive a Mid Mount Mower or to power the front PTO to run a snowblower, etc., will be spinning at 2,200 rpm. As is always the case, the mowers gear box, pulley size and belts will have much to do with the mowers blade tip speed. Generally, the mowers that connect to the mid PTO are going to spin at a higher cutting speed than those connecting to the rear PTO stub. The higher cutting speed helps to reduce grass clipping size and debris which exits the mower deck. Most finish mowers are going to spin at a faster RPM speed and are going to be powered with the Mid PTO with a maximum speed of 2,200 rpms.
Important point – The tractor's engine speed will directly impact the mower's blade tip and cutting speed. If the tractor's engine is at 2,500 rpm, which is 80% of the engine's maximum rpm, then the mid PTO speed is very likely to be close to 80% of the 2,200 rpm speed.
The engine typically needs to be running close to its maximum rated speed to spin the PTO output shaft at its declared speed. For example, on the Yanmar 3TNV80 diesel engine, which is found in the John Deere 1025r machine, has a maximum rated speed of 3,200 rpms. In order for the PTO shafts to be spinning at their max declared speed of 540 rpms on the rear or 2,200 on the mid PTO the engine is going to have to operate at 3,100 to 3,200 rpms to reach the speed for the PTO .
PTO Overrun Clutch, what it is, and why you should own and use one.
A PTO overrun clutch is a small unit which you can hold in your hand which you connect to the tractors PTO output shaft. Then you connect the implement PTO shaft to the PTO Overrun clutch. The purpose of this device is to take the “shut down load” off the tractors internal PTO clutch. When you turn on the tractors PTO clutch by activating the PTO, you generally do so with the engine speed slowed down and once the clutch is engaged, you increase the engine speed to reach the desired PTO speed. While you are running the mower, the large blades under the mower are rotating. When you turn off the PTO, the internal PTO clutch is stopped by applying the PTO brake inside of the tractors case.
The issue is on many PTO implements, the rotating mass of the PTO implement will continue to spin despite the PTO having been shut down. As the large blades or a large counterweight on the implement continue to rotate as it slows down, the weight and mass of the implement spin the PTO clutch and wear on the PTO clutch brake inside the case. It also wears on the PTO clutch disc material itself. By using the PTO over run clutch, it allows the exterior implement to slow down, but not continue to spin the inside clutch disc and wear on the clutch disc brake.
When you use a rear PTO implement which has rotating mass, the PTO over run clutch allows the implement to slow to a stop while not continuing to spin the internal parts in the tractors case. This prevent pointless wear and tear on the PTO clutch and brake inside the rear case. Make sure to use a PTO Overrun clutch to avoid wear which doesn’t need to happen from implements which have large counter weights or rotating mass in their operation.
Stamped Mower Decks vrs Fabricated Mower Decks
Generally, the taller the sidewall height of any mower deck, the increased air flow under the mower deck and the better the deck does at cutting the lawn or rough cut material.
In the case of cutting the lawn with a Mid Mount Mower, the taller deck height allows for more airflow under the deck, increasing the lift effect on the grass and helping it stand upright to be cut more effectively with the mower blades. This additional height provides more clipping processing room under the mower, which often results in the clippings being smaller in size and less noticeable on the lawn.
On rough-cut mowers, the taller mower side walls allow more material to be processed under the mower deck by the mower blade. This usually equates to better cutting of the rougher material, which means its chopped down more and less long length debris on the field when cut.
Generally, when given a choice, a taller side-wall mower deck will be preferred over a shorter side-wall mower deck. But, let’s talk about the difference between a “stamped mower deck” and a “fabricated mower deck”.
Stamped Mower Deck - Is precisely as it sounds, the mower deck is produced by having stamped a large single sheet of steel inside of very large stamping presses . The result is the commonly found rounded corners and rounded edges and top of the mower deck. John Deere’s garden tractors have stamped mower decks.
Fabricated Mower Deck – Assembled from numerous laser-cut steel sheets that are welded together to produce a mower deck with square sides, typically a flat deck across the top of the mower, and sharp corners. The steel sheet pieces that are cut are brought together and welded with 90-degree corners, and they result in a taller mower deck, has more flat sides and lines, and is obviously welded together when assembled. Many rear rough cut mowers are fabricated mowers, many brands of mowers offer the customer a choice of a stamped deck or a fabricated deck. John Deere’s product offering, the mower decks for SCUTS and CUTS, are almost universally stamped decks, which feature rounded corners, etc.
Cost to Produce – Stamped mower decks are machine-pressed and assembled. The stamped mower decks are faster to make, and they are a robust mower deck as the bends often add structural strength.
The Fabricated Decks are a series of cutting the different mower pieces out of sheet steel and then welding the steel together to build the deck. While most of this work is robot work, its still is a more expensive mower deck to produce because of the additional time and steps.
Comparing the Fabricated deck to the Stamped Deck, most use the very same gear boxes, same mower blade spindles and the very same pulleys, etc. The main difference between the stamped deck and the fabricated deck is going to be their height and weight, with the fabricated decks being taller and heavier.
Advantages and reason for use
The Stamped Deck is going to be lower in height, although it could be shaped to the very same height of the Fab Deck if the engineers desire. However, the stamped decks are easier to “drive over” due to their shape, which makes them very popular choices for the “Auto Connect” decks on Deere machines and other brands. The lower deck height and rounded top and edges allow the tractor's front wheels to climb over the deck and allow the mower deck to be positioned for its auto-connect feature.
Fabricated Deck – Commonly found on Commercial Zero turn mowers due to mowers tall height and improved airflow. Typically, the lower-priced mowers will have stamped decks, and the higher-quality, higher-priced commercial mowers will have fabricated decks. These decks are very strong and also very robust. Many fabricated mower decks are suspended with chains or a simple mount-style system.
This is a brief overview of these two types of decks, but its also important to point out the following about the mower deck styles.
Mower Blade Tip Speed – This is controlled by the gearbox, the selected spindles, and the pulley that drives the spindles. These factors are what determines a mower deck's blade tip speed, and the placement of the gear boxes, spindles, pulleys, and belts on either a stamped or fabricated deck will determine which has the highest blade speed.
Durability – This is a bit biased, but more stamped mower decks are going to experience damage and failure than will fabricated decks simply because the number of stamped decks is likely a multiple of the fabricated decks. Since stamped decks are less costly to make, the stamped decks are going to be offered on the lower priced mowers. Fabricated decks are going to heavier in weight, have thicker steel and their design makes them more robust. Generally, on SCUT and CUT tractors, you are most often going to find stamped mower decks due to the production cost and volume.
Flail Mowers are always mounted on either the rear 3 point hitch or on a special mount which positions the mower off to the side of the tractor on either an articulating arm, etc. Flail mowers are a completely different design in that they don’t have large flat steel blades that spin under a deck to cut the material. Flail mowers use a drum design that is roughly 12” to 18” in diameter, and the drum's length ties to the flail mower's width. Flail mowers have “hammers,” which are “T” shaped blades that attach to the drum and are perhaps 5” to 8” in length each. A drum can have 16 to 32 hammers that cut the material.
Flail mowers strengths include –
· Produce a very good cut quality and also can cut a range of material at the same time.
· Don’t have the rotating blades but instead use the rotating drum
· There is less potential debris or material to fly off the mower.
· Designed for offset to the side for ditch mowing, pond edge mowing, etc.
· Runs off the rear 540 PTO
· Flail mowers are also relatively quiet by comparison as they don’t have the airflow issues of a large blade mower deck.
· Can be used for rough cutting and finish cutting and produce good results.
Flail Mowers disadvantages include –
· Costly compared to other mowing styles.
· Hammers and forks require sharpening in a different style.
· Flail mowers are heavier due to their mechanical design.
· They are are more complex with moving parts based upon their design.
· Fewer choices as there are fewer companies producing them.
This is a cursory look at Flail Mowers and by no means covers all of their advantages, disadvantages etc.
If you are buying a new tractor, what type of mower should you be considering?
Your needs are going to be a big factor in the mowers you should consider.
Need a mower you can cut a lawn with and also cut roadsides and ditches?
Flail mower would be the leading candidate.
Mid Mount Mower would also be a strong contender
Rear 3ph Finish Mower
Need to cut rough areas which have been neglected and are overgrown?
Flail Mower as long as there aren’t too many trees over a 2” to 3” size
Rear Rough Cut or “Brush Hog” style mower.
What are the most robust mowers and able to be used in the roughest conditions?
Rear 3ph Rough Cut Mowers
Rear 3ph Finish Mowers
Which Mower produces the best cut quality to worst cut quality, in this order (Best to Worst)
Flail Mower
Mid Mount Mower
Rear 3ph Finish Mower
Rear Rough Cut Mower
How do these mowers rank in cost, from lowest cost to highest cost? And a sample of their cost for a 60” sized mower or mower size indicated with price.
Rear 3ph Finish Mowers ($2,400 for a 60” model)
Rear 3ph Rough Cut / Brush Hog Mowers ($2,500 for a 60” model)
Mid Mount Mowers ($3,900 for 60” model plus the cost of the connection method to the tractor)
Flail Mowers ($7,700 for a 42” wide model)
How does one shopping for tractors decide what mower they should consider?
1. How the mower is to be used, as either a MMM or a rear 3ph mower, etc.
2. What is its most likely use to be? Is it yards, ditches, roadsides, rough pasture, etc?
3. How do you want the mower to connect? Under the tractor, behind, etc.
In conclusion, mowers are very diverse, and depending upon the tractor brand and model, they can be very brand and model-specific, where you must purchase that tractor's specific mower if you want a mid-mount mower. The main thing that buyers need to focus on are the same that they should focus on with any implement purchase and make these issues priority on their selection.
Ø The mowers repair and replacement parts availability
Ø Servicing Dealers
Ø Reputation and History of the machine
Ø Your needs and plans for the implement.
Ø And while price is important, don’t let it be your sole purchase decision guide.
Mowers are an important part of the tractors' use and function. You need to ensure the mower is sized to match the tractor and that the make and model you consider have repair and replacement parts available. If you are considering the mid-mount mower for your new tractor, make sure you understand the mount and parts involved and the total cost. If you don’t plan on using the tractor for mowing often, make sure the mower is easily added and removed from the tractor.
Mower’s position on the tractor and its impact on its use.
Mowers mounted under the tractor operator's platform will be easier to maneuver close to trees and other “mow-around” obstacles. However, mowers that are behind the tractor on 3-phase or similar mounts will follow the tractor but require care not to strike items when turning, etc.
Mowers that mount on the rear 3ph and are positioned next to the tractor produce extreme side loads. Flail mowers and side-mounted articulated mowers are both examples of special mounts. Mowers that are side-mounted require opposite-side ballast. While most tractor owners are used to hearing about ballast on the rear 3-point hitch or to offset the front loads, having side ballast to prevent the tractor from tipping over sideways due to the loads is very important.
Please always follow all mower mounting, safety and ballast requirements to avoid machine damage or personal injury. If you have any further questions about mowers or other topics, please don't hesitate to contact us. We enjoy hearing from you.