Rebirth of a 6 Foot Flail Mower

[tom osselton]

Hehe 

Hey AdeV
Hows this one!

[Will_D]

Great build Andrew!

Talking of blood, fingers and workshop accidents in general:

Question came up in the rugby club tonight:

When we watch my (Will_D')s favorite tea time program "Wheeler Dealers" Program on Sky at 5 pm why does Ed China never ever ever slip a spanner, or scrag off a screw driver etc. and draw blood?

[awemawson]

Thanks for the kind words chaps 

Another delayed start in the workshop today. Yesterday afternoon our Klargester private sewage plant decided to pack up - fortunately we have a comprehensive support contract, but the chap couldn't get here until 07:00 this morning, so no showers and certainly no loo flushing overnight    Anyway once he was off site it was back to the workshop to try and finish the flail.

First I re-fitted the flappy plates. I can see why they had got so mangled - when the flail is lowered to the ground, they hang upright, and unless the flail moves either forwards or backwards at this point the weight of the flail comes to rest on the plates - fine if you are moving as you lower it - odd design 

Then I set too making a new rear curtain - the old one was torn and perished, and I'd managed to source a bit of 'retired' conveyor belt. Just a case of cutting to size, punching some holes in the right places and bolting it back with the new retaining strips I'd made a couple of weeks back.

Used my 'wad punch set'  - a most useful boot fare find decades ago back when the countries behind the iron curtain were selling us heavily subsidised goods. Works very well but the steel quality is questionable !

[awemawson]

So still to do:

a/ decide what to do with the lift arm adaptors - those 'H' shaped things. Ideally I should re-bush them as they're rather ovalled out, but that might come at a later date.

b/ sort out the dodgy PTO shaft & cover - this is waiting for when I can mount the flail to a tractor to make sure that the length is correct

c/ sort out and re-fix various labels, and re-create a missing one

[awemawson]

Today was the day of reckoning 

I'd refixed the labels, sourced new mounting pins and it was time to see if it worked. I had two potential issues:

 1/ Would the tractor lift it - Ford 4000 is quite small

 2/ Would the PTO shaft fit

Pleasingly the tractor lifted it off the ground quite happily AND the PTO shaft was the correct length so now I can invest in some replacement safety covers for it.

Trotted out to the field and cut about 1/3rd acre of grass heavily infested with rushes down to a short 3" staple - seemed to cope quite well but I do need to be careful to remember that this flail has a bigger 'offset' than my other one, so it would be easy to forget and swipe a gate post! The weight with it off the ground is pretty well on the limit without front balancing weights - it has light steering and it's easy to do wheelies 

After it had cut the 1/3rd acre the gear box was mildly warm - certainly not hot so that probably shows that I got the bearing pre-loads about right, however I noticed that there is a minor oil leak from the oil level plug - just needs a turn of ptfe tape.

So in all that probably concludes this re-build - if I manage to find pto shaft covers I'll post a picture but other than that it's now ready for next seasons grass management 

[Spurry]

Don't what they say in Sussex, but if it was Norfolk, it would be "Bootiful". 
Pete

[mattinker]

As always, an interesting thread. Thank you! Now you'll have to find another sweater to unravel!

All the best, Matthew

[RobWilson]

Looks good as new Andrew 


Nicely done 


Rob

[Pete W.]

Hi there, Andrew,

I agree with the others - you got a good result.

What news on the proposed new tractor shed? 

[awemawson]

 Thanks for the kind words chaps 

Pulled the PTO shaft off just now to measure up for new covers, and it's a totally obscure, no longer made relic. So it looks as though it's a case of buying a complete shaft. (CAT6 ie 90 HP at 540 RPM x 1200 mm closed). SPAREX are the people who usually sell these things, but not to me this time - they want £440 plus VAT  where as a place in Ireland has them for £80 - more my cup of tea so I'll give them a call on Monday.

http://www.amadirect.co.uk/PP/01732.html

Pete, the local planning authority have to respond to my 28 day notice  by 23rd Nov else it goes my way by default.

[awemawson]

New PTO shaft got delivered today from Northern Ireland - looks just a bit tidier than the original one 

Bit of a bugger to fit as everything was new and a bit stiff - but on she went and is working fine.

[seadog]

I think it needs a coat of paint Andrew, it's showing the rest of the rebuild up 

[Pete W.]

I think it needs a coat of paint Andrew, it's showing the rest of the rebuild up 

As it's a rotating part, I think it should be painted with 'Barber's Pole Stripes'!          

[awemawson]

Ah - but no Pete - it's NOT rotating - that's the whole point of the safety cover. Shaft turns inside but cover stays still to preserve life and limb 

[Pete W.]

Ah - but no Pete - it's NOT rotating - that's the whole point of the safety cover. Shaft turns inside but cover stays still to preserve life and limb 

Oops!          

[jcs0001]

Andrew

Beautiful job.  You sure are one persistent gentleman, working through all those interruptions to finish a big project.  It would have driven me (even more) mad .

John.

[awemawson]

... not so sure about persistent - more anal 


Well when I re-fitted the labels i'd removed before grit blasting, I realised that one was missing - probably fell off years ago, but it left four irritating holes that annoyed me !

... so google research - what was it.  Well some of these flails had a label there that was the original selling distributor, and others just bore the name of the flail 'Turner Turbomower 72HD in rather florid handwriting. Having now repaired the chiller on my laser engraver hopefully I could make something similar.

The eventual label was on 1 mm stainless sheet using the 'Dry Molybdenum Di-sulphide' process that I detailed in my 'Laser Marking Steel' thread. However it wasn't without it's problems. First try was on aluminium (like the originals) but it just rubbed off. Then I tried galvanised steel with the same result. I was beginning to doubt the process, and even dug out the original form tool I'd previously marked, and marked another face of it successfully. Hence moving to stainless steel.

Another issue I had was the scanning speed of the laser. It should go at a controlled speed while the laser fires, and faster when not firing.  However with the program speed set to 3 mm / Sec it was actually doing 15 mm / sec firing and 3 mm /sec when not, the result being that that label took 6 1/2 hours to produce 

Another issue was that the 1 mm stainless ended up dished from heat of the laser but I reasoned that as the corners were raised, they would pull down flat when riveted, and this proved to be the case.

... more investigation needed but at least those holes are now filled 

[AdeV]

Looks like it needs a wash & wax already! 

Seriously nice work again, though. Are you sure you don't want to play with a lathe again?

[awemawson]

Kind offer Ade, bu I'd hate to deprive you of all that fun 

[awemawson]

Resurrecting an old thread, but this is the logical place to put this information:

Flail has been working exceedingly well, but one job that I never did do when I rebuilt this mower was to sharpen the swinging flail arms. There are 52 of the little blighters, and they should present a flat cutting edge to the grass.  Age has taken it's toll and they were all somewhat rounded off. Of course getting at them is not easy as they are enclosed apart from where the grass touches - it needs either turning on it's back or standing on it's end.

So with some extremely dodgy rigging I got the flail stood on end allowing access to the 'underneath' - I kept the fork lift attached - 'just in case' as this animal is heavy.

Nothing too complicated, no primary and secondary angles - just hold the swinging flail steady with a welding clamp, tickle it with an angle grinder and move on to the next. Somewhat monotonous but an hour and a half saw them done and the flail back on terra firma.

Did it make a difference? To be honest it's hard to tell - I suppose it must have but the trial cut of the paddock that I've just done didn't seem a lot different to me   

[AdeV]

Maybe you got the chip clearance angle wrong? 

A quick google reveals there's a hell of a lot more to flail mowers than meets the eye...

[carlquib]

Looks to me like they just need to be replaced. You have lost too much of the cup part of the flail so they won't suck material into it like it should.

My name is Brian and I'm a toolaholic.

[awemawson]

52 flails at £15.50  EACH - no I think you are mistaken 


- anyway it is working superbly - just cut another ten acres before breakfast 

[NormanV]

Andrew, surely you could make them yourself for a fraction of that price?

[awemawson]

Yes Norman I could.  But they don’t need changing ! I