Building a flail mower

[Renze]

It was 8 years ago that i bought a municipal heavy duty flail mower, from a guy who mounted it on his wheeled 13 ton excavator but took it off again when it turned out to be so heavy that it kept pulling him towards the ditch. He bought a much lighter model on his excavator, so i got the mowing unit for 250 euro.

Several projects later, 5 weeks ago my friend saw a flail mower headstock on Marketplace, which i bought for 350 euro. It had all the parts i needed: Side swing, lift, and a jackshaft with 280mm 4x SPB belt pulley.

Last Wednesday i picked up a Holaras silage spreader for 250 euro, which has heavy duty gearboxes with 1.69 reduction. Off course these can also speed up 1.69 and together with a 125mm pulley on the gearbox speeding up another 2.2 will give me 2000rpm on the shaft.

I dismantled the silage spreader right away, cut out a few lengths of rectangular tubing for future projects, and loaded it back up for scrapping. Even though i'll get 25 euro less for it because its summer holiday (no demand from the industry) i wont load it up another time.

So i'm 850 euro in, will get some scrap money back, have a center gearbox to sell, and have a spare gearbox.

My neighbour is a machinist and has a lathe at home, he will lathe some bushings and pins, i must have some scrap laying around to make some hinge ears, so then i need some rolled bronze bushings and a taperlock 4x SPB 125mm pulley.

Later on i want to extend the swing arms, 60cm (two feet) of offset is fine to mow around street signs on the verge, but not enough to stick it underneath the barbed wire into the ditch along the field..

I have a three week holiday so i hope to get something done. Oh and my tractor will need an extra hydraulic valve to operate both side swing and tilt... Anyways, i can test without it.. tidying up is for later.

 

[K5lwq]

Thanks for sharing. This will be an interesting project.

 

[Renze]

Picked it out of the nettles, put it in the shop and put the least noisy angle gearbox next to it. Before sunday i want to know the splines of the rotor, whether i can slide the 6 spline PTO shaft right in, or that i will have to make an adapter from 6 spline farm shaft to single key industrial...

I opened the noisy angle gearbox for an autopsy, and found that someone put sealed bearings in an oil bath angle gearbox.... gears were fine, so i suspect the bearings are bad. I counted teeth (22 as you can see written in stinky old gear oil on the cardboard) 12 on 22 which means 1.83 gear ratio. With a 2 to 1 pulley ratio i will get 1976 rpm at 540 PTO which my tractor does at 2000 engine rpm. 2000rpm was the goal.

Its allmost 5 o clock here, which means beer time...

 

[K5lwq]

Your helper looks like he wants a beer too!

 

[Renze]

Your helper looks like he wants a beer too!

She will settle for a pet, though in the rain she stinks like a wet dog.

 

[Renze]

So... after grinding the weld off the spline sleeve to which the previous owner attached the hydraulic motor, welding an M16 nut to it and screwing an M16 rod in it to push the sleeve out, i found that they had it drilled out so there is no splines of any sort to work with.

Also, the bearing inner race rotated on the shaft stub, probably because it shrunk when they drilled the core out.

So i'm going to order a 6 spline PTO sleeve, have my neighbour lathe it out a little for centering, then weld a 35mm shaft to it. Once cooled, my neighbour can lathe the 35mm shaft down to true alignment at 34.1mm shrink fit. Then i can heat the shaft stub, throw the 6 spline sleeve with 34.1mm centering stub in the workshop freezer (with the BBQ meat) tap it in the flail shaft bore, and when its all the same temperature again, hopefully my bearing fit is restored... Then i weld once more around it for good measure (it cant distort much from welding when its shrink fit) and ive killed two birds with one stone...

 

[Renze]

Because of town fair, my shop neighbour (who lives in town) didnt pick up his phone so i had to get my lathe work done elsewhere.

When i picked up an arm full of bearings and seals, i asked the young self employed farm equipment repairman if i could rent his lathe. He said 30 euro an hour. I agreed. But then he asked: "Can you REALLY lathe ? Cause ive had them who thought they could, and they allmost broke my lathe"
I said sure, with an unfamiliar lathe you just have to turn some air to see what it does before yanking the auto feed in gear. He smiled which meant we were cool

Anyways, i lathed the press fit into a rattle fit so i had to find another mop of steel before i could press in one end in the recess i lathed into the 6 splined sleeve, then welded it, then lathed the pressfit to go into the rotor shaft at home. And i lathed down the sleeve half a millimeter to prevent problems when i ever have to change the bearings and the sleeve is painted or rusty.

The press fit will hopefully restore the bearing inner diameter because the previous bearing spun loose on the shaft. It was next to nothing so a hair should do the trick.

Tonight i'll go to the fair where in cafe "Marketview" (half of the villages over here have a pub or cafe called Marketview that you'd allmost think its a franchise) two of my neighbours will play rock and roll on guitar and accordeon in the band "Shot through the crappers window"

 

[BarryTX]

Subbed to see the progress of this nice build!

 

[Renze]

Subbed to see the progress of this nice build!

Not much progress. Last week i put a new garden gate in my friend and his neighbours garden wall, but in the 60s they put the foundation less than a foot deep and 8 inches wide. Now we cut the 1960s door opening of 3 feet to 4 feet, the T part of the wall isnt stabile enough and shakes, so early this week i welded two 4" cross tubes to be mounted between both sheds with provisions to bolt wood to so next year they can build a platform to mount some more solar panels on top, while the tubes are bolted with chemical anchor bolts to the wall.

Today i mounted the rotor back with new bearings and slid the gearbox onto it to decide the material i need to make the frame hinges on the center of the gearbox pulley...

 

[Renze]

The only progress so far: My neighbour lathed some hinges and pins, and i welded the head plates to it. June 6th 2022 i broke my skull and incurred a brain injury, which is VERY slow to heal and i barely manage to spend half days at work. It has its constant ups and downs.

But rest assured, i am like Bitterdock: You can knock me down, you can poison me, but in time, i will always crop up again