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. 

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

I would much prefer a hydrostatic drive, but I'm not sure how much more I would be willing to pay to get one.  I had chest pains paying what I paid for my 1330SE, and it seemed like a decent deal with 10% off and 18 months no interest.  It might be fun to try and reverse engineer a hydrostatic drive.  I'm in my mid 40's, and pretty much every riding mower we ever owned had a hydrostatic drive.  I believe this is the first piece of equipment I've ever owned that has a friction disk drive.  Some of the self propelled push mowers we had when I was a kid may have had a friction disk system, but I'm not sure.

Stainless wrote:
I like high end OPE and appreciate the quality and performance that typically goes with it but I too dislike paying the premium price which is why I purchased almost all my OPE as used equipment and saved a bunch of $$$. Most people who purchase high end, high priced OPE as new, usually take very good care of the equipment and maintain it according to the op's manual. If they don't do it themselves, they have it done professionally. Most times they are selling off the equipment because they are upgrading to even higher end or bigger OPE to suit their current needs.

borat wrote:
Since the viscosity (slipperiness) of water varies with temperature, does the disk slippage occur always (if water dets on the disk), or just at a certain temperature range?  Do some blowers experience this problem more than others if the setup is such that the disk runs hotter on the problem blowers, thus melting snow that enters to the disk housing?

The disk slipping problem became prominent about five or six years ago when manufacturers switched engine brands/type that they used on their machines.  Most previous domestic snow blowers used the venerable Tecumseh Snow King L-head engine.   When the rumblings of Tecumseh's demise began, manufacturers switched over to B&S overhead valve engines.  In their haste to do so, they failed to ensure the belt cover fit correctly up against the front surface of the new engine.  Accordingly, there was a fair size crack for water to melt on the hot engine and make it's way down the front of the engine onto the friction drive system.  All of the talk about other points of water entry into the engine chassis seems a bit unrealistic.  At least in the case of the Simplicity/Snapper/JD machines based on the same platform.  All I did was to seal the crack between engine and belt cover and have not experience any slipping since.  On the Simplicity,  any other small holes on the chassis are neither large enough nor in a location to have any effect to allow water into the chassis.

I had a bit of slippage on one or two occasion with my Simplicity but in each case, I was blowing snow so deep that it was falling over the top of the intake and falling onto the engine from the side and melting at a considerable rate.  Fortunately, the slipping only occurred briefly and the machine regained traction in a matter of seconds.  

borat wrote:

     You are absolutely  correct.    My neighbour has a (new 2010) John Deere snowblower and he had that problem early last year, the melting snow on his motor was getting on his drive plate. 

But he is an industrial electrician and had many types of rubber insulation in his truck     He  found a suitable piece and cut it to size and sealed the crack in front of the engine ,. He had no more problems.

New_Yorker wrote:

This is an old thread but worth reviving. I agree with NY'er 100%. Strangely enough whenever someone delves into any depth of technical detail such as this, they are usually attacked and ridiculed on net message boards. It has become a modern phenomenon in its own right. Friction drive is a pathetic drive system, that works in spite of itself. It's a cheap alternative to a transmission with gears, or array of pulleys for gears. A hydrostat is like a drive found in a BULLDOZER. So there you have it. Moving the drive cog on the friction drive disc gives clutching and gear reduction variation all in one. But it is an inherently weak drive system best suited to a kid's toy, rather than power equipment. At one time they made CARS that way in the early 1900's until planetary gear automatic transmissions were perfected. If you are buying a used or new snow blower, ask what type of drive it has, and get a direct belt/gear drive setup if you can afford it. The problem with the internet is, people have largely become dumbed down victims of corp. advertising, after being talked into buying a FRICTION DRIVE unit, they don't and won't admit to themselves it's inferior, because it's what they bought. Admitting it's inferior, would mean admitting a mistake, and admitting getting taken for money, for a crappy product. So they attack the person who knows better, who is trying to calmly discuss and inform. A bad scene, and egos and pride get in the way of sound engineering. It takes a man to admit friction drive is a POS excuse for a transmission, and go look for a hydrostatic or direct gear/pulley/belt drive machine.

they tried friction drive in cars....they had to downshift to drive over a cigarette butt. no comparison to a direct drive with gears/belts or hydrostat http://blog.hemmings.com/index.php/2013/03/14/smooth-going-with-friction-drive/

Smooth going with friction drive David Traver Adolphus Mar 14th, 2013 The first time I had an inkling that friction drive might not have been an ideal solution was about seven years ago. I had just photographed Bill Sears assembling his 1910 Sears high-wheeler (HCC #36 ) and we were driving it around looking for photography locations. One possible location was across a lawn, so I had Bill drive over…or try to: When he attempted to climb the two- or three-inch ridge from the road onto the grass, the Sears just couldn’t make the grade. The engine was willing and the tall wheels would have rolled over it with no trouble, but in between was a friction drive. When the glazed-over disc was confronted with the need to transfer maximum torque (from a 10hp engine) from a standstill, it couldn’t do it. Eventually, we made it with a running start–there was no question it needed its transmission resurfaced. But there was also no question that the weak link was its friction drive. 1907 Cartercar chassis 1907 Cartercar chassis The principle in a friction drive couldn’t be simpler: At the end of the driveshaft is a large disc; to get power from there to the axle, you apply a second disc at right angles. Presto: you’ve turned longitudinal rotation into lateral. Increasing or decreasing pressure of one disc against another allows slip, like a clutch; and moving the axle disc in or out from the center changed the ratio. Aside from direct drive, it was also just about the simplest system imaginable to manufacture. 1907 Lambert chassis 1907 Lambert chassis For drivers attempting to operate a car for the first time, it was ideal. One lever with a mechanical connection made it instantly operable and very difficult to stall. Inherent slip eliminated jerky starts, a particular problem with the era’s touchy cone clutches, and that also protected it from rough handling. You can’t strip gears that don’t exist. Lastly, it’s a transmission that could theoretically incorporate a flywheel doing double duty. With only a handful of moving parts, it was potentially very inexpensive to manufacture. But on the other hand, there was essentially always slip in the transmission, increasing with load. More than being inefficient, that made heat and shortened the friction disc’s lifespan. They had to be surfaced with high-friction materials, usually a pressed board or fiber disc of some kind. Easily replaceable, yes, but not durable, especially under extreme conditions. And just think about what would happen if mud or oil got splashed onto the discs. 1907 Cartercar chassis 2 1907 Cartercar chassis. Disc and wheel friction drive helped a number of affordable Brass Era cars get a foothold in the market, especially runabouts, and some did well, including Brush, Cartercar, Metz, Lambert and Simplicity. Inventors continued to work on the idea for decades, and occasionally a car would turn up with a variation on the theme. By the Teens, it was actually the Model T’s planetary transmission that was the oddball of choice; and research turned to the development of true automatics, which started to look distinctly possible by the late Twenties. .- See more at: http://blog.hemmings.com/index.php/2013/03/14/smooth-going-with-friction-drive/#sthash.CXwAgC6t.dpuf