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I've been removing blades for sharpening for years. I never really checked them for balance or set the blade back on at recommended torque, just as tight as I could get it. Lately I started trying check the balance using the nail-in-wall method, shich doesn't seem too accurate to me. In the real world, just how vital is it to balance and torque the blade to exact specs?

The question how vibration can you and the mower take?

The nail is not very good at balancing. Here I use a cone on a pointed pin but that even more accurate than the nail. NOw I do have problem mounting holes that are not round. Many that can afford uses a magnet type balance the uses a ball bearing. The less the blade is out of balance the less wear and tear of the mower part take. Ever drove your vehicle with the tires out balance it is the same that happening to the mower when the blades are out of balance.

As for torquing it is important as you don't want a blade spinning off especially the round types. The star mounts are more forgiving as the blade is lockin with the star but they still torqued to specs.

i use the Stens cone 750 042... $6.99 and never had any vibrations... but 99% of the time i sharpen push mower blades which most have the round hole. some don't., and replace ride on blades... seems ride on owners like to mow dirt.
if a blade is heavy on one side i do a little grinding on that side.

mine's a push mower, with a star-type (not round) hole in middle to mount, plus a small round hole on either side of center, that fit over 2 round guides(not sure of technical term lol) on the adapter thingy.

sometimes, on the nail, one side (say, the right side) will drop.
but then when i flip it over say, right-to-left, now the side to the right (which WAS the left side) will drop!
go figure lol!

Same as Star & Scrubby
A cheap cone balancer and try to balance the blade left right & front back
Vibrations kill spindle bearings very quickly

jargey3000 said:

I've been removing blades for sharpening for years. I never really checked them for balance or set the blade back on at recommended torque, just as tight as I could get it. Lately I started trying check the balance using the nail-in-wall method, shich doesn't seem too accurate to me. In the real world, just how vital is it to balance and torque the blade to exact specs?

Click to expand...

Do you balance the tires on your car? Engine? Check book?

slomo

bertsmobile1 said:

Same as Star & Scrubby
A cheap cone balancer and try to balance the blade left right & front back
Vibrations kill spindle bearings very quickly

Click to expand...

Absolutely correct !
Another thing to think about is make sure the surface the balancer is on is - level -..

Using a grinder will necessitate balancing. Grinders remove a lot of material. Then you can talk about killing the temper of the steel.

Best to use a fresh double cut mill bastard hand file. I can sharpen one in a vice about the same time as a grinder. Balance doesn't get off near as much. Easy on the electric bill too. Don't have to store a big grinder either.

Course a belt sander with fine paper could be used.

For balancing I use a real accurate digital cooking scale. Measures down to 1 gram or 0.05 ounce. Never a wobble.

slomo

Slomo,

You find out why just replacing .250 blades is cheap to replace as and much less time consuming when you spend 1-1/2 hrs sharping and balancing three them. And blades do get out quite bit according the cone balancer but I looking into one the balancer that uses ball bearings.

Personally I don't see how a digital scale is going to balance a blade unless it a hand balance style and I don't they make one. It wont easy to use blade balancing either.

I use one for checking swing back blades
They are supposed to be balanced to within 5 g of each other

bertsmobile1 said:

I use one for checking swing back blades
They are supposed to be balanced to within 5 g of each other

Click to expand...

Now that makes sense...

StarTech said:

Personally I don't see how a digital scale is going to balance a blade unless it a hand balance style and I don't they make one. It wont easy to use blade balancing either.

Click to expand...

It's pretty easy really. Solid object on one end (same height as scale) and the scale on the other. Level the blade out with a simple shop level. Take a weight reading on one end. Lather, rinse and repeat for the other end.

Nails and those junk cone jobs are not even close to the scale method. Some blades don't even have a round hole in the center as you know. And my cheap azz isn't paying $250 for the good ceramic bearing balancer tool LOL.

slomo

slomo said:

Nails and those junk cone jobs are not even close to the scale method. Some blades don't even have a round hole in the center as you know. And my cheap azz isn't paying $250 for the good ceramic bearing balancer tool LOL.

slomo

Click to expand...

Hmmm the Magna-Matic MAG-100 is only $170 or you could get the Maxpower 339075B for $90 or the Oregon 42-047 for $103.

My scale accurate to 1 gram or 0.05 ounce costs like 13 bucks.



slomo

Well went out this morning and did some testing with 20.5" blade on my cone balancer since I had a some spare time. It is just as accurate as the scale n post #15 if not better as I weighed the nuts is took to get any defectiion. One got the blade move off level but took two of the nuts to get my digital scale to register the 1.5 grams of both nuts so I seen this movement at 10" with .75 grams. Not bad for a $2 tool. Also found the blade was only 7 grams out balance @ 10" which is a lot considering the amount the tip was showing out balance by.

StarTech said:

nly 7 gra

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StarTech said:

my cone balancer since I had a some spare time. It is just as accurate as the scale n post #15

Click to expand...

Riiiiiight. Maybe your cone tool is better than mine. Mine was plastic and had a lot of stiction in it. Never fit the blade hole exactly. Threw it in the garbage.

7 grams at 10+ inches is fairly large. Every gram counts as we know.

I get a 0 balance on each end for perfect no vibe mowing.

Thanks for checking the scale method out StarTech.

slomo