It is rare for one to browse through any article or review video concerning riding mowers without encountering talk of PTO. These three letters are a vital cog in the overall machine…as it were.
Electric PTO systems are newer innovations to the mechanism that transfers power from the engine to the mowing deck and the blades on most modern mowers. Electric versions of a PTO setup are superior in many ways to manual ones due to less parts to fail and more reliable operation.
Hop on! As we give you a rundown on the basics of PTO, with regards to your lawnmower. We also dip our toe into one of the hottest debates in the sport of cutting grass…electric vs manual.
What Is A PTO On A Lawnmower?
Let’s start by looking at what PTO actually means.
PTO stands for “power take-off”. This means the transfer of power from a vehicle’s engine to an attachment/implement like a mower deck. Through the use of a switch or some sort of lever, an operator can engage or disengage the implement controlling blade movement.
In the case of a lawnmower, PTO allows you to turn the blades on and off, which is more than handy. An operator can empty clipping bags or navigate over non-mowing surfaces without switching off the mower entirely.
The PTO system links from the engagement switch or lever to the PTO clutch via two main ways: electrically or manually. We will discuss both a bit later.
The PTO clutch is made up of two plates that sandwich an engine-driven flywheel. The lower clutch plate is directly connected to the mower deck spindle and blades.
Engaging PTO causes the lower clutch plate to move towards the upper plate. However, the lower plate latches onto the flywheel in the middle, which causes it (and the mower blades) to spin. Disengagement results in the lower clutch plate dropping away from the flywheel, which causes your blades to stop spinning.
So, in a nutshell, PTO is the means by which a mower’s blades “borrow” power from the engine.
What Is An Electric PTO?
Electric PTOs are, at this point, the industry norm. Traditional manual PTO setups, which incorporate direct joint connections, can still be found on several multipurpose vehicles.
However, most residential and commercial mowers use electric setups, which link the engagement/disengagement switch to the clutch via a series of electric cables.
How An Electric PTO Works
Just as described above, the clutch in an electric PTO setup is made up of an upper and lower plate, with a flywheel in the middle. The upper clutchplate, which usually sits directly below the engine drive pulley, houses a large electromagnetic solenoid.
The lower plate features a flat metal disc that is attracted to the solenoid. The flywheel features gaps on its surface to allow the magnet on the upper plate to attract the lower plate.
When the PTO switch/lever is engaged, an electric current is sent to the solenoid via electric wires. This activates the solenoid’s magnetic field, which results in the lower plate (and its attached implement) moving upwards towards the upper plate.
Of course, the lower plate never actually touches the upper plate because of the flywheel between them. Once latched on to the flywheel, the lower clutchplate and its attached implement begin rotating.
Therefore, the solenoid provides the force that causes the lower plate to latch (and stay latched) onto the flywheel.
Disengaging The PTO
Disengaging the PTO switch cuts off the electric signals to the solenoid, which turns off the magnetic field and causes the lower plate to drop down, halting the implement.
You also have brake magnets that sit directly below the edges of the lower clutchplate. These brake magnets are not strong enough to disrupt the solenoid’s pull on the lower plate when PTO is engaged. However, when PTO is switched off, the brake magnets cause the lower plate to drop down faster.
Brake magnets are also responsible for ensuring the lower clutch plate and blades do not spin freely when not engaged.
The PTO Switch
The most common PTO setup, particularly on riding mowers, features an electronic PTO switch. The typical PTO switch is made up of a toggle knob, a housing case, and pins that are plugged into an interface attached to the wiring that goes to the clutch.
PTO switches often feature eight pins arranged in three rows. Two rows feature three pins while one only has two. The outermost rows are labeled as “normally open” (NO) and “normally closed” (NC).
To see more great articles, check these out…
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Is An Electric PTO Better Than A Manual?
Now, it’s time for a brief comparison between the two PTO types. Is electric really better than manual?
Well, for the most part, yes!
Electric PTO setups are much more efficient and reliable than manual configurations. Electric wires provide the power needed operate the clutch whereas with a manual version the work must be done by the operator via a system of joints and levers. There are also fewer parts to an electric PTO.
For starters, there are fewer moving parts in an electric PTO system. The main components are your PTO switch, the clutch, and the length of cables joining them together. Most of the heavy lifting is done by electricity and most of the moving parts are in the clutch itself.
In contrast, a manual PTO configuration features all sorts of parts apart from the PTO clutch. You have your pedestal connection points, U-joints, implement input connection interfaces, and much more. In our experience, more moving parts mean greater capacity for trouble.
For many people, determining what’s “better” depends primarily on cost, particularly when it comes to repairs.
Overall Costs For Electric Versus Manual PTO Systems
Electric PTO systems are now much cheaper to repair thanks to how common they are. Many equipment repair shops can easily address most problems, which drives down the price of the service.
Additionally, parts that are most likely to fail, such as the switch, are very cheap to replace. Switches, in particular, are also easy to replace by yourself, which cuts the cost of having a pro do it for you.
We highly recommend anyone having electric PTO problems to test the switch for continuity with a multimeter. Oftentimes, the problem is the switch.
Manual PTOs feature a wider range of parts that are usually cheap and easy to source. However, because of the decreasing popularity of manual PTO, some parts may be hard to find. If you are unlucky, you might run into greedy dealers who take advantage of the rarity of some parts.
PTO Repair Comparison
Electric PTOs also have an advantage when it comes to ease of repair. This is because most of the setup is a series of wires that is fed from the switch to the clutch. Therefore, you only really need to access one of these two points to make repairs. The wires can easily be pulled out if they need inspecting.
With a manual PTO, you pretty much have to strip off large chunks of the machine to even inspect certain parts, which makes the task much more laborious.
Your choice between electric and manual also has a direct impact on your equipment’s performance.
PTO Performance: Electric Versus Manual
Since electric PTOs are mostly comprised of wiring, they tend to add less weight to the equipment than manual setups, which feature several metal parts. The heaviest part of an electric PTO system is the clutch itself, whereas manual systems have shafts and other things that add bulk.
In the case of a lawnmower or garden tractor, the reduced weight of an electric PTO allows for greater top speeds and easier maneuverability, which helps with getting jobs done quicker while lessening any potential strain on an operator. The opposite is true for machines with manual PTOs, which often make a machine clunkier and less agile.
Finally, we have the issue of safety.
PTO Safety: Electric Versus Manual
Manual PTOs often feature a lot of exposed joints and spinning shafts, which present real hazards to people and animals. There are countless reports of PTO-related incidents every year.
One particular problem is entanglements. One can easily get a jacket sleeve, trouser leg, shoelaces, or even hair stuck in a pushpin or spinning shaft, which can have horrific consequences. These systems have harmed all sorts of people, from seasoned operators to overly curious children.
Manual PTO systems require operators and anyone working near the equipment to be well-versed in safety practices to minimize the chances of disaster. These include:
- Walking around the equipment/vehicle rather than walking over the PTO setup.
- Installing guard shields around moving parts
- Regular driveline tests. The driveline must NEVER be stuck to a spinning shaft, for instance.
- Use recommended parts for your machine. Not all components are interchangeable from manufacturer to manufacturer or even from model to model.
- Minimizing sharp turns that stress out the joints on rotating shafts.
Electric PTOs are less dangerous for the most part because most components are not exposed. While the risk of shock can always be associated with these setups, the voltage level involved is negligible (12V). The main thing you have to worry about is ensuring that the sheath around your wiring is intact.
The Final Touches On Electric PTO Clutches…
Now that we understand the workings of a PTO, the advantages of electric versions, and what is entailed in their repair and upkeep, you should be better prepared to choose the best option for your mower. Older mowers may come with manual PTO setups or you may find the rare version on a newer model.
Electric PTO systems are the norm in most new mowers though, and you will more than likely have to specifically search for a manual option. To be honest, the benefits of an electric PTO make the search unnecessary.
All in all, an electric PTO is the way to go.
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