Using a balancer on a mower blade

[MBDiagMan]

The only place I have seen derogatory things said about the decades old method, nail or fixed pivot, is in manufactures marketing of their 'better idea'...

No matter how you do a 2 dimensional static balance it will be equally good...
If there were any benefit to a perfectly balanced blade you would find dynamic blade balancing ... As far as I know, no one has came up with that unnecessary service ... YET... :smile:KennyV

Kenny's first sentence is very, VERY true.

I have no doubt whatsoever, that the fancy Magna Matic 1000 (sounds like it should be a Binford model number, huh?) will give a more accurate balance than will a nail. Does that mean that a nail does not give some level of balance? Is the nail balance adequate? In my mind, whether or not the nail balance is adequate is the key question.

I do NOT have the mentality of a salesman, although I sold HMI software for several years in the middle of my career. I was successful only because I knew how to use the product and took care of my customer, not from salesmanship skills. I'm not the salesman that would be selling refrigerators to Eskimo's. From that experience, however, I do understand how zealous one can get about their products and/or technology. I'm sure that Magna Matic is a good company with good people and good products. Where I have my doubts, however, is if the added balance accuracy is REALLY necessary.

If a blade is balanced to the thousandth of a gram, how long does it take to become unbalanced? How much imbalance occurs when in operation? Is that degraded level of imbalance, more imbalanced than a nail balance?

The problem with the analysis of the MagnaMatic balance vs. the nail balance is that we have no quantified data to do actual and meaningful comparisons.

More power to MagnaMatic. They came up with some good ideas and are marketing their products, making profit and jobs. The American way, and I love it, but I would like to see some quantifiable data.

Larry

 

[motoman]

Is the nail method tested to determine how much imbalance it misses? I looked hard at the "5/8" bolt shank method on the star type hole on my Intek and found it misses 1/2 oz of imbalance. I believe that is due to drag of the bolt shank on the star hole circular ID, and would also miss with non-star center holes. So what? Good question. The Intek V twin sump bolts come loose, but not known if the blade imbalance does it or if it works along with the inherent imbalance of the "harley" V design.
I do know the tractor is much smoother running after balance (down to 1/8 oz.).

 

[MBDiagMan]

Thanks for doing the testing and sharing your results motoman. It's great to see numbers rather than opinions and sales pitch.

Larry

 

[Fish]

I have had and use a balancer just like a magnamatic since 1992, and have found some blades horribly out of balance. When
I went to work at one of the largest dealers in Louisville, they had one of those little useless cones. I brought mine and mounted
it above my tool box, al of the mechanics would come and check their blades, The M Shop refused to buy one.

They also borrowed my Neway Valve tools, which got old, as those are tools that should be provided by the dealership.

They charged 8$ to reface a valve.

All they did was clamp it in a drill press and hold a piece of sandpaper on it!!!!!!!!!

 

[phcaan]

I have had and use a balancer just like a magnamatic since 1992, and have found some blades horribly out of balance. When
I went to work at one of the largest dealers in Louisville, they had one of those little useless cones. I brought mine and mounted
it above my tool box, al of the mechanics would come and check their blades, The M Shop refused to buy one.

They also borrowed my Neway Valve tools, which got old, as those are tools that should be provided by the dealership.

They charged 8$ to reface a valve.

All they did was clamp it in a drill press and hold a piece of sandpaper on it!!!!!!!!!

This has been a great discussion, I have been thinking about all you guys have said and had an idea. When I owned a motorcycle I had a motorcycle wheel balancer that consisted of a stand with a steel shaft that sat on roller bearings. There were different sized aluminum cones that fit over the shaft and you would install a cone, slide the shaft through the wheel, install anther cone on the other side and sit the shaft on the roller bearings. I am going to dig that thing out of the shed, clean it up and see if the cones will work on my star hole blades. I'll let you know how it works.

 

[Carscw]

With my MTD blades I can not use the nail way because of how the star sits. And with using the nail you only see what end is heavier you don't know if it is out of balance front to back.

I use a cone that sits on a nail so I can see end to end and front to back I get them as close as I can.

Do a test balance your blades then cut a acre of grass and check the balance do not clean any grass off the blade before you recheck the balance

The only way to get a perfect balance is to have something that tells you where to take some weight off not just take some off anywhere on one end.

(( cowboy up and get over it ))

 

[MBDiagMan]

Well, this whole blade balancing issue has ignited my curiosity. I feel that I have a reasonably good understanding of balance. I have had my own Coats 1001 Computer wheel balancer for over 10 years. I bought it because many of the tire store guys insisted on using weights on the back of my wheels only, not providing a dynamic balance. It came to be one of those "if you want it done right, do it yourself" type things. I understand the difference in a static and dynamic balance on a vehicle wheel.

I can't imagine the economics ever making sense to a point where someone will develop, build and sell a dynamic mower blade balancer, but stranger things have happened.

I have used a nail for probably 40 years or so with acceptable results. Once I saw all the magnamatic discussion, I became quite curious. To begin with, if I were to open a mower service shop, I would have a magnamatic on the wall before I opened the door for business. If I were sharpening blades for hire, I would want to do it efficiently and be able to give my customer the best job I could for their money. I believe that the magnamatic will do that. What I do NOT know is how much more accurate it will balance a blade.

With my curiosity aflame, I took one of the spindles I removed from an old grasshopper deck and disassembled and cleaned everything. With the stiff grease gone, I used two very smooth bearings and oiled them with light, synthetic oil. Synthetic, so that it will not gum up over time. I then mounted the spindle with the shaft horizontal on a support post in my shop. Higher on the same post is a thin finish nail, carefully driven in level.

I put a 21" grasshopper blade on the nail and the left end went down about an inch. I rotated the blade 180 degrees and the right end went down about an inch. I then put the blade on the spindle and one end went down an inch, rotated it 180 degrees and the other end went down an inch.

This was a preliminary test, but it follows the same principles as the magnamatic, a smooth turning, CENTERED mount on the blade.

I will do more testing and will report more results as I learn them. I want to use some wheel weights to try and determine how much weight it takes to balance a blade statically. On a car wheel, you always know just how much weight is required. I will try to make the same determination for the blade balancing.

If I had the coin I would buy a magnamatic so that I could satisfy my curiosity and try to quantify the difference between the balancing methods. It is doubtful that magnamatic would be willing to loan me one for the test.

Will report results as I get it.
Larry

 

[motoman]

This has been a great discussion, I have been thinking about all you guys have said and had an idea. When I owned a motorcycle I had a motorcycle wheel balancer that consisted of a stand with a steel shaft that sat on roller bearings. There were different sized aluminum cones that fit over the shaft and you would install a cone, slide the shaft through the wheel, install anther cone on the other side and sit the shaft on the roller bearings. I am going to dig that thing out of the shed, clean it up and see if the cones will work on my star hole blades. I'll let you know how it works.

Look in this forum for thread "that trick blade balancer cost how much..." It is a wooden version of your motorcycle wheel balancer.

 

[phcaan]

Look in this forum for thread "that trick blade balancer cost how much..." It is a wooden version of your motorcycle wheel balancer.

Yes I saw that but since I already have the motorcycle balancer I am going to mess with it as soon as I get the time.

 

[MBDiagMan]

I got a few minutes to experiment further with my spindle balancer. I started by using a torpedo level to adjust the face of my spindle to be perfectly plumb. I grabbed a different blade and put it on the nail and it went down on one side about three inches. I put it on the spindle and it went down about the same distance.

I then started grinding off the heavy end and got it level on the nail, even holding up a torpedo level to get it as level as possible. I then put it on the spindle balancer and it was dead level there as well.

I will be hustling tomorrow to catch up so I can take my wife to the doctor on Wednesday, so if I don't get a chance for more testing, I should be able to get back to it on Thursday.

If I were unable to do any further testing, my conclusion or at least what my testing tends to point toward, is that the nail method is worthwhile, and I see why it was actually published in some old John Deere manuals. It is CLEARLY better than no balance at all.

Larry