Flail Mower Flail Hammer Sharpening...

[bjcsc]

Tomorrow I begin running through a used Bomford B457 flail mower that I just bought. The flail hammers all look to be in good shape, but I am not sure how sharp they should be, or how much of their original length should be there (when is too worn?). I would assume sharpened similarly to my bushhog blade, but don't know for sure. I also don't know if I should check them (or the pattern of how to check them) for weight regarding the rotor shaft being balanced. Any advise from the flail users? The flails are the type pictured below (#1) and about as sharp.

Lastly, this is a twin pump unit. I am considering re-plumbing the hydraulics so I can control the three cylinder from my 3 rear SCVs instead of using the cable setup/valve. Bad idea?

 

[MtnViewRanch]

This is just my opinion, but I would not take the time to sharpen the cutters. A fresh edge is sharp, but it doesn't stay that way for long. Unless you plan on sharpening them each time that you use it, it's just a waste of time. If you are using it to mow lawns, then you have the wrong style of cutters. I have the same style of cutters that you have shown, and I just run mine.

Just my opinion and it is not worth all that much.
Good luck

 

[bjcsc]

I pretty much feel the same way. I won't be mowing lawns, I'll be cutting ditches, ponds, the sides of my 1/2milelong ever encroaching driveway, etc...

Do you balance yours? or check it?

 

[sandman2234]

I just happen to have one sitting on my desk that is new so I shot a quick picture of it. It appears to be about a 40 degree angle but I would have guessed 35 if I hadn't of measured it. Mine came with some pretty worn out blades, but after pricing them, I decided to give the old ones a sharpen to see how they would do. They were pretty dull, with a rounded 1/4" flat face doing the cutting instead of a knife bladed edge. It would still cut trees, so that must be atributed to the weight and speed of the cutters, more than the cutting edge. The new set that came with my mower, although incomplete, is a lot of money and I would seriously run those for as long as possible. I turned my mower on it's end, and sharpened each blade with a 4.5" right angle grinder. I learned on the first one that if the grinder slips, it will remove a good portion of thumbnail and flesh before stopping. Nothing serious, but it did hurt like it was. I decided that holding each blade with a pair of vice grips would be a better idea, and suggest that highly. Also a good full face shield to prevent flying debris from entering your eyes. Although a lot of trouble sitting on a stool while working, it is probably hands down better than trying to remove them and reinstalling them. Most of the bolts and nuts will be damaged during removal, so sharpening on the machine will probably work out better.
David from jax
http://img.photobucket.com/albums/v177/sandman2234/tractors/Turnerflailblade.jpg

 

[J_J]

Tomorrow I begin running through a used Bomford B457 flail mower that I just bought. The flail hammers all look to be in good shape, but I am not sure how sharp they should be, or how much of their original length should be there (when is too worn?). I would assume sharpened similarly to my bushhog blade, but don't know for sure. I also don't know if I should check them (or the pattern of how to check them) for weight regarding the rotor shaft being balanced. Any advise from the flail users? The flails are the type pictured below (#1) and about as sharp.

Lastly, this is a twin pump unit. I am considering re-plumbing the hydraulics so I can control the three cylinder from my 3 rear SCVs instead of using the cable setup/valve. Bad idea?

Your picture is showing two different type blades. The hammer type is used for rough cutting. The twin blades are used for finish cutting. Some of the blades are designed to be reversed for a new cutting edge. It would be very hard to balance your drum roller with all the blades attached. You are slinging around a lot metal. If you experience a lot of vibration, look for a missing hammer cutter. The twin finish cutters are cheaper. If you do a lot of grinding on those hammer cutters, you could really unbalance the whole thing.

 

[sandman2234]

I didn't do any sort of balancing on mine, except trying to grind somewhere near the same angle and amount on each one. No problems noted.
If you decide to replace the cutters on yours, send me the old ones as I have figured out they are worth somewhere between gold and platinum.
David from jax

 

[atgreene]

I never have sharpened mine on my Kuhn Flail mower. Blades are an expendable item, I'm in business to make money and if I spend more time to sharpen something than I can buy it for, I'm falling behind.

BTW, there is another type blade. When I bought my mower it had the double knife style but with no shackle to connect to the drum. It bolted direct and was longer. The style that bolts direct do not do well around rocks at all.

 

[bjcsc]

Thanks for the pic David. I'm with you on the grinder (BTDT with the finger, too. Best part is it doesn't bleed, but sure hurts the next day). If I decide to sharpen them, I would definitely do it in place. I can raise it completely vertical and to whatever height (up to 15') once I go through the hydraulics. I'll get some pics of the hammers and post them here tomorrow so you guys can see what I see...

 

[MtnViewRanch]

I pretty much feel the same way. I won't be mowing lawns, I'll be cutting ditches, ponds, the sides of my 1/2milelong ever encroaching driveway, etc...

Do you balance yours? or check it?

I have done nothing to mine but use it, grease it and wash it off. So far so good.

 

[tallyho8]

The hammer you show as #1 in your photo is for rough cutting and probably should never be sharpened. The blades in #9 are for smooth cutting and when one side gets dull and worn down you just turn it around and use the other side. By the time I wear both sides down there is usually nothing left to sharpen.