Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I never realized that by explaining how the friction wheel drive on another thread would cause such feelings of inadequacy in one poster that he felt compelled to pretend I had personally attacked him, which was never my intention.  But now that this has come to be a subject worthy of discussion, let's explore the comparison.   Most snowblowers of the two stage variety use the very simple, easy to understand friction wheel drive to propel them.  Here then is the system explained so we all can begin with a clean slate. 

  The snowblower engine drive shaft will have a pully on it to drive a Vee belt that is attached at the other end to a 'Drive Plate'.  So long as the engine is running, the plate is spinning thanks to that belt.   The wheels or tracks of the snowblower are connected to the drive system through a rubber faced friction wheel that rides at right angle to that 'Drive Plate', and the shaft the 'rubber faced friction wheel' rides on is one the rubber wheel can slide along from one side to the other.  That sliding motion then positions the rubber tire like friction wheel on the 'Drive Plate' depending on where you place it.  This is done with the cable running from the notched speed change lever on the operators console of the machine.  When you, the operator, squeezes the handle that engages the drive you are lifting that engine driven 'Drive Plate' into contact with the rubber faced 'Friction Wheel' and if the rubber is in good condition, and properly adjusted , it makes contact with the drive plate and the snowblower will begin to move.  How fast or whether you move forward or reverse is dependent upon that speed control that usually has something like 6 forward speed noitches, and two reverse.  That cable running to the friction wheel will allow it to ride across the drive plate at the center, for low speed, closer to the edge for high speeds, and even on the other side of the drive plate's center to make the friction wheel spin the opposite direction.  This puts the machine in reverse.  This then is what plays the role of a transmission on all 'Friction Wheel Drive' snowblowers.

The problem is that if the drive belt slips, the machine will not move.  If the rubber tire like friction wheel becomes hard and glazed, it will not properly grip the flat metal Drive plate, and you again, won't move.  In fact if the plate surface is slick from wear, or the friction wheel rubber is worn down, like when the tire on your car becomes bald it will again not properly contact the drive plate and transfer the engines power to those tracks or tires. Usually before this occurs you get a period of use when the machine requires the operator, You, to push it when it encounters greater resistance.  So it may move forward until it has to push itself into that heavy salt laden "end of the Driveway" pile, and then the friction wheels reduced 'Friction' ability causes it to spin no longer as the drive plate becomes polished from rubbing against the immobile rubber surface.  Here you have two options, first is you shove the 200 pound machine into the snow, or second, you stop, take it back into the garage where you better have the new friction wheel rubber and the tools and know how to replace the worn one that has rendered your snowblower useless.  This happens to such machines as a result of normal use, and depending upon how much wear that friction wheel suffers from the normal use of the machine.  Thus a snowblower moving light powder all the time will go much longer than the same machine used to throw, and push itself into wet heavy snow which wears the friction wheel more, and thus wears it out much faster.  If you happen to live in a climate where the snow is often wet and heavy, rather trhan light and fluffy powder, you should evalutae your ability to deal with this maintenance item.  Your owners manual will supply the repair procedure for this in most cases, as well as a parts diagram so you can order, and have on hand the necessary new rubber tire for that friction wheel.   The manufacturer supplys that information precisely because they recognize the fact that your snowblower will, at some point, require this work be done.  I personally understand all this from about ten years owning an Ariens Snowblower, followed by 15 years with an MTD built Sears Craftsman snowblower, both with the same friction wheel drive mechanism.    Where I live in southeastern New York State, wet heavy snow is the rule, light fluffy powder is the exception.  This resulted in having to change these friction wheel rubbers about every two years on average, so my next new snowblower choice eliminated the problem entirely, albeit at some considerable cost.

The alternative system employs an actual 'Transmission'.  My John Deere Lawn Tractor ( X-300R) has such a transmission, and it has been problem free for many years.  So I paid as much for a new Honda, hydrostatic Transmission Driven snowblower (HS 928 TAS) as I paid for that John Deere tractor.  The extra cost to me was worth it. 

Now I do not tell everyone to buy the same machine I did, or even to avoid the friction wheel drive system common to most other snowblowers.  I simply think that BEFORE you spend the money on that new snowblower you know what you are buying.  The manufacturers, store clerks, and even Consumer Reports magazine will NOT tell you, as I just did, the Reality of owning those simple less expensive drive systems.   By reading this you now understand : A)- How the thing works, B)- What To expect, and WHY, and C) - You now can buy based on an Informed Choice without discovering the hard way what will happen from normal use to your snowblower. 

JoelKlein  :

 Thankyou for your post.

I would call it "Paralysis by Analysis"

royster wrote:
My misunderstanding, I didn't really know what your point was about the RPM.  Because obviously "Cutting down the engine RPM is NOT the answer as this reduces power and would also slow down the impeller"

"The discussion was how do we make the first gear slower"  There wasn't really a discussion going on about how to make a first gear lower.  I simply made that comment.
It's funny how sometimes on these threads the discussions get so of topic. 
joelklein posted  "Friction Wheel" versus The Hydrostatic Transmission drive debate.  That isn't really what the debate has been about.
Because no one would debate that a Hydro system is a step up from a friction drive system.  As no one would disagree that an automatic transmission is easier to use
and more efficient than manual shift.  It's a fluid drive system versus a mechanical system.  In the fluid drives systems the effect of operator misuse on the systems performance
is greatly diminished.  And there are fewer external mechanical parts to wear.  And fewer external mechanical parts exposed to the elements.
The debate has really been about some of the misconceptions that were stated regarding the friction wheels durability.  In those somewhat questionable and very general statements.  It was inferred
that anyone buying a blower with a friction drive system should be made aware of the potential problems the system can have.  As if it's the system itself that is normally
responsible for the problems.  Which I would argue, is not in most cases the truth.  It's operator misuse and the age of the rubber on the friction disc. 
The same discussions could be had regarding a clutch disc in a vehicle.  Discs can last for decades or for two weeks.  Same car same engine.  The life of the disc in most cases
depends on how the vehicle is driven and how the clutch is operated over a period of time.  Old ladies don't blow clutches but a teenager will.
Of course the older lady may slip it and ride it till it burns up.  : )  If they understood what can happen if they continue operating the vehicle in that manner then they probably wouldn't do it.
Well, maybe not the teenager.  The same can be said for the friction drive systems. 

A friction drive CAN SLIP when used in accordance with the operator manual and common sense IF THE MACHINE HAS A POOR DESIGN.  I see inferences that operator error is likely to blame. Could it be that they slip because moisture has accumulated on the drive plate? My Ariens 926 has so many holes, seam openings, cable penetrations and so on that it is unlikely not to slip because snow blows into the drive housing from all directions. I compleately dissmiss the notion of operator error here. It seems like one platform served many different models. There must be upwards of 20 penetrations to the housing. Last summer I closed them all, I'm sure I missed something though. FrigginSlipDrive.

O

Most snow gets in between the belt cover and engine.  Seal that up properly and there should be virtually no slipping.

My  Craftsman 33 inch 13.5 horsepower Tecumseh,worked very well for the first 13  years, only replacing the rubber clutch wheel  once  , regular maintenance.     .It  got a lot of hard use , heavy snowstorms, 30 inch or more  at a time.   most winters.   I never had a problem with the driven disc until the old Tecumseh started leaking , and blowing out oil through the breather..  I put an extension tube on the breather and let it run out down by the left wheel, This helped some, but I still had   to remove the botton cover, clean the disc with alcohol, this was getting to be a more often procedure in the last few years that I owned it.  I even put 4 bolts with wingnuts on the bottom cover so I could do the disc cleaning easier,.    However, this was not the fault of the "friction wheel" system.  it was just hard to keep the oil in the old Tecumseh, after many years of hard use.  I could probably have rebuilt the engine,  replacing  gaskets and seals  to stop the oil leaks, but  I gave the blower to my nephew who had a newer Tecumseh engine for it,   He has been using it for 2 years and tells me ,he  has not had any friction wheel problems ,  I thought it was time to upgrade so I purchased a Husqvarna  hydrostatic .

iLikeOrange wrote:
Without question the drive can and will slip if water gets into the belt area or onto the drive plate.  But slippage due to water intrusion is to be expected and not the fault of the friction disc design.
Your being very general by saying that the "MACHINE HAS A POOR DESIGN".  When it is actually just the drive housing that has to many places for water to get in.
Obviously that problem has nothing to do with the operator or how the machine is being used. 

From time to time there have been comments made here about that problem. 
Just recently, someone posted that one of the manufactures was putting a piece of some sort of rubber underneath the engine to stop that problem.  On most blower there
are a number of drilled holes that are not used underneath the engine.  And some holes that are totally exposed on the top of the drive train housing as well.  It's the holes on top that
most often are responsible for slippage due to water.  Any snow that hits the engine melts and runs right down onto the top of the drive train housing. Also a poor fitting belt cover doesn't help.

I in no way meant to infer that most snowblower disc drive problems are caused by operator error.  That would be foolishness and untrue.
Operator misuse can accelerate the wear on the fiction disc.  Which can lead to slippage.  Especially if the blower is older.  But even then, as the rubber wears down it doesn't really effect
the ability of the disc to grab.   The rubber getting hard and cracking or splitting is what can really effect the grab of the disc.  Or burning slight flat spots on the disc can cause it to jump just slightly.

borat wrote:

That was the first thing I did a few years ago. Either I didn't do it well enough or that wasn't the problem area.

>>But slippage due to water intrusion is to be expected and not the fault of the friction disc design.

Are you kidding?? TO BE EXPECTED??  thats nuts.

>>Your being very general by saying that the "MACHINE HAS A POOR DESIGN". When it is actually just the drive housing that has to many places for water to get in.

Gee isn't that part of the design?

>>And some holes that are totally exposed on the top of the drive train housing as well. It's the holes on top that
most often are responsible for slippage due to water. Any snow that hits the engine melts and runs right down onto the top of the drive train housing. Also a poor fitting belt cover doesn't help.

EXACTLY!!

>>I in no way meant to infer that most snowblower disc drive problems are caused by operator error

 VS >> It was inferred
that anyone buying a blower with a friction drive system should be made aware of the potential problems the system can have. As if it's the system itself that is normally
responsible for the problems. Which I would argue, is not in most cases the truth. It's operator misuse and the age of the rubber on the friction disc

Guess I read operator error again (and again) and that caught my eye.

O

iLikeOrange wrote:
Sorry I guess I didn't word that right.  I didn't mean "water intrusion" was to be expected.  I meant that if water does get in, the disc can and will slip.  That you can expect to happen.
>Gee isn't that part of the design?<   Yes it is part of the design, one part.  

Disk slippage is to be expected if water gets on it.  That's a simple fact.  However, water getting onto the plate is not expected. 

Jtrebor wasn't suggesting that water should get onto the disk.   He simply stated that if it did, disk slippage will happen. 

Think we've flogging this discussion far longer than necessary.  Nobody is questioning the superiority of hydro drive.  However, it's not so much better than a friction drive system to cause most people to spend the additional money.  Friction drive systems have been proved reliable, durable and relatively inexpensive to purchase, operate and repair.  If something works that well, why ante up for something insignificantly better?

Glad it's settled now  " : ^ )

O