3CX JCB 1997 Maintenance questions

[Gecko]

If you do have someone putting pressure on it while someone else swings a hammer make sure it’s someone who won’t survive to old age as the percussion that comes through the bar rattles all your bones

I've got two mates who confirm the truth of this.
Sensibly, I was on the sledge

 

[V8Druid]

View attachment 43793

spot on .... and I'd make up a suitable piece to turn it into a six sider and weld it in place once on the nut for a closed spanner, stop it spreading and transfer the grip to all six flats of the nut

 

[Gecko]

project is on hold - ran out of time - back to asia on friday.
my plasma torch failed to do anything useful to 1/2" plate.
I'll hunt for a spanner to butcher or get a plate CNC cut and finish the job next visit.

 

[Gecko]

Plan B.

 

[V8Druid]

Plan B.

View attachment 48529
View attachment 48541
View attachment 48530

very idea

it

I'm borrowing that

 

[Gecko]

Thanks (let me know if you want the CAD file).

So I found out why the nut was so tight (my full weight out past 1m ~ 1000Nm)

I'm seeing 9mm deflection

I'm guessing this got bent before I bought it, but what does it take to bend the boom ram?
(What is the fix - straighten or replace?)

 

[V8Druid]

Thanks (let me know if you want the CAD file).

So I found out why the nut was so tight (my full weight out past 1m ~ 1000Nm)

I'm seeing 9mm deflection
View attachment 48606

I'm guessing this got bent before I bought it, but what does it take to bend the boom ram?
(What is the fix - straighten or replace?)

I've straightened worse than that in my 60t press in work ... that shouldn't take a lot of pressing straight ... just need a good bloke on a decent press ... 's a nice long bow

 

[Mick-the-fitter]

It’s possible to bend out that 9mm with a press and hard wood blocks

 

[Gecko]

It’s possible to bend out that 9mm with a press and hard wood blocks

I took it to a place in town and apparently they hadn't heard of hardwood.
I got the rod back with the bend down to 0.1mm , but several witness marks showed they'd used steel supports with sharp edges.

I took the worst off each one with 400 emery and put it back together. Getting the cylinder back in was as much a PIA as expected, but the machine is up and running again.

Thanks all for your helpful suggestions.

 

[Mick-the-fitter]

Hardwood doesn’t leave any witness marks! Teak for one!

 

[Gecko]

Hardwood doesn’t leave any witness marks! Teak for one!

There is no excuse here - all the common timbers are hardwood.
They used steel because it's easier I guess.