Flail Mower Let's talk flail mowers

[Steave]

Spent all of yesterday and most of Saturday finishing my tractor so it's ready (finally!) to bring up to my house. Spent a couple of hours getting the flail mower ready to go (JD 25A). Had 4 shattered knives, mostly around the center. That should have clued me in. I replaced them, greased everything, noticed the rear roller needs new bearings but the bearings for the drum are still good. (whew!)

I hook it all up to the 3pt hitch, keep the RPM very low and feather the clutch a bit so it spins up very slowly, now I know why four center knives were shattered. Upon closer inspection, it appears that the previous owner may have clipped an immobile object with the leading edge of the mower, as it's bowed in ever so slightly- but just enough for some of the center knives to make contact once they spin out with force.

Debating the best way to bend it back. If its' rusty enough (maybe?) it may just bend easily. If not, it'll take a lot of heat with the O/A torch and lots of persuasion. Or, as a last resort, take the plasma cutter and cut a vertical line in the center to relieve the pressure from the bend, pull it back out one side at a time, and then weld/plate it for more strength. Anyone have thoughts on this?

No pics, it was pouring rain for a good part of the day, I was soaked, covered in grease and grass clippings, and was overall in a bad mood after my grease gun exploded all over the place. That was interesting...

Lot of pressure on those grease guns and most of use don't think much about it. I know I don't. Sounds like to me either way you mentioned about straightened out your bent deck is worth a try. Try the easiest one first. I have a small dent on the rear of mine and tried hammering it out but it's built pretty tough. It did move some so I just left it for now. Unlike yours it don't interfer with the operation.

On the bent part there's no good way to get a porta power set up to help as there's nothing opposite to press against. Can't push against the cutting shaft (rotor) without causing more problems. So I guess it's BFH time.

 

[sgtboz]

I just ordered four links and knives from FlailMaster and wouldn't you know the links aren't the same size as what's already on my Ford 917.


This is a new-to-me flail for which I paid zero dollars. It runs great but from the two times I've used it I've lost an average of 6 links/knives each time! But the hangers are all still there. Weird.

My questions is are their lots of link options and I just happened to order the wrong ones? I sure can't find any other options. For reference, the new (long) ones in the left of the pic are about 3" in length. They are beefy and very nice. The other problem is that I can't raise the cutting height enough by extending the toplink to keep the knives from contacting the ground. The roller on my flail is not adjustable so I just shorten and lengthen the top link to change the cutting height. Am I right on that?

Let me know what you think!

 

[leonz]

OK, lets back up a feet feet.


Can you upload a few pictures? Gearbox, front, rear, left side, right side and under the mower shroud taking pictures of both sides of the flail mower rotor and the knife mounts? That will halp a lot and tell me what model you have.

About your flailmower, does it have 2 mounting points and six sets of holes on the mounting points for a caster wheel?????

You cannot really adjust the mower this way. If you have the caster wheel mounts you need to order a pair and then you can rest easy and mow away to your hearts content.

About your knife hangers:

Take one of them and trace it on a piece graph paper and fax it to flailmaster with a cover letter explaining your predicament; they should get you the right ones after this.

 

[hawkeye08]

Somebody built a flail for a Gravely,,, I have considered converting a tiller to a flail,,,
the tiller is pretty close,,, The speed might need changed,,,

I have a couple of those tillers,,, Hmmm,,
Some bearings, a roller,,,
Just belt drive a new shaft to speed it up,,, steal a few knives off the 390,,,,, :confused2:

... perhaps get an adapter for hooking it on the front of a Gravely rider. I have some attachments that I used on my Gravely riders that were built for 2 wheel walk behinds. The sickle mower is one of my favorites, but a word of caution, you have to run just above idle or it will tear the sickle mower up. I was in a hurry and increased the throttle to try and finish a field faster and went from all is good to worn out wobbler arm. I never finished repairing it, got the parts off ebay from east coast seller, but have not put them on yet (gotta be honest, once we got the Kubota, the Gravelys have been sitting. I will likely sell them to someone that can get some use.

Flail mower would be interesting though...

 

[sidecarist]

Well, I pulled the trigger and ordered a Woodmaxx FM-78H toay. 4-6 weeks for delivery... I'll give a report when I get it. I ordered it with the duck foot fails and a full set of Y grass blades. I also ordered a few of each as spares.

 

[shaeff]

Lot of pressure on those grease guns and most of use don't think much about it. I know I don't. Sounds like to me either way you mentioned about straightened out your bent deck is worth a try. Try the easiest one first. I have a small dent on the rear of mine and tried hammering it out but it's built pretty tough. It did move some so I just left it for now. Unlike yours it don't interfer with the operation.

On the bent part there's no good way to get a porta power set up to help as there's nothing opposite to press against. Can't push against the cutting shaft (rotor) without causing more problems. So I guess it's BFH time.

Yep, you're not kidding. It sure made for a miserable rest of the day. I'll try hitting it with a BFH and some heat. Barring that, I may be able to weld a triangle of steel (if I can find any scrap) coming off the back side and use a come-along to pull it back out past straight so it'll spring back to centered. Either way, I think it may need something sturdy on the leading edge to prevent this from happening again. Thanks!

 

[IslandTractor]

Yep, you're not kidding. It sure made for a miserable rest of the day. I'll try hitting it with a BFH and some heat. Barring that, I may be able to weld a triangle of steel (if I can find any scrap) coming off the back side and use a come-along to pull it back out past straight so it'll spring back to centered. Either way, I think it may need something sturdy on the leading edge to prevent this from happening again. Thanks!

How about just drilling a 3/8" hole in the middle of the bend, attaching a eye bolt and pulling on the it? Just leave it open afterwards or weld it closed.

 

[shaeff]

How about just drilling a 3/8" hole in the middle of the bend, attaching a eye bolt and pulling on the it? Just leave it open afterwards or weld it closed.

That's a good idea, I may just try that first. I'll have to set it against something solid enough that I can pull hard to bend it back straight but not damage the mower.

 

[IslandTractor]

That's a good idea, I may just try that first. I'll have to set it against something solid enough that I can pull hard to bend it back straight but not damage the mower.

If you used a piece of threaded rod you could just build a metal frame and use that for leverage. Bolt under mower then rod through the frame and a tightening bolt on the outside of the frame. That would allow very gentle but strong "persuasion". It would be ideal if you had a chunk of big steel square tube and just drill a couple of holes through that as the pulling frame. You could shim the square tube off the mower deck a bit so any spring back could be accommodated.

 

[Fallon]

Another thought that may or may not work... Find a stump, back up to it. Brace a chunk of wood between the stump & the back side of the hood. Back up a bit more so the wood pushes the dent out.