The Craftmans Shop > New from Old
It's BIG, Yellow and digs holes! JCB 3CX Project 8 is joining the Tractor Shed
awemawson:
So I've just crawled back to the house after 7 solid hours fighting the hydraclamps and that strange bracket. It turns out that the bracket supports the breaker return hose that passes under the back actor to stop it dragging in the mud.
I'd intended to do one side at a time as the 38 mm through bolt (which I was replacing) can only come out at the extreme ends of the channel that the back actor slides on so doing both lower ones for instance means keeping on sliding the whole rear arm on it's mounting. Not only is this a fag, but it means that you need plenty of space either side of the machine as the rear arm is used to push the mounting side to side.
However with that pesky bracket on the two lower bolts / hydraclamps I had to do that pair and suffer the inconvenience - which is one reason I've only done two of the four in a seven hour stint.
Once the bracket is removed (it then dangles on a heavy hose) the back actor has to go to extreme left and the 38 mm bolt then can pass through a cut out on the front of the rear rail. The new bolt can then be inserted, however it has an anti rotation lug sticking out that has to be aligned (by feel!). Then the back actor has to be slid to the extreme right and the process repeated.
Then comes the tricky bit that took absolutely ages ! The one piece bracket thing has to be placed over the left and right hand bolts without either pushing them out of the channel or disturbing the location of the anti-rotation tabs. Meanwhile it's heavy hose is pulling it out of your hands and the bracket is springy so the hole spacing needs tweaking . . . . :bang:
Needless to say it was an iterative process involving an excess of frustration, but I got there in the end.
Actually rebuilding / resealing the hydraclamp units was simplicity itself - douse everything in hydraulic fluid and press them together. The old ones were a bit manky !
Hopefully the upper hydraclamps will be much easier, and in fact I may not replace the bolts as they look to be in better condition than the lower ones.
awemawson:
Well the good news is that the Hydro-clamps no longer leak :thumbup:
But the bad news is that they probably will soon as they are not sitting flat on their seating :(
Why - well it's all down to that blooming bracket that I spent most of yesterday wrestling with. It's obviously not original but I now (having crawled under!) see why somebody installed it. It gives a forward support to the flexible 1" BSP breaker return hose stopping it dragging in the mud. Sadly whoever made it got it slightly wrong :bang:
The body of the bracket fouls on the base of the back actor carriage forcing it into an uncomfortable angle resulting in the 'tabs'with 38 mm holes for the hydra-clamp bolts to not be vertical - thus they are not sitting flat.
I've decided to make longer tabs to hold the bracket a good inch or more lower - by cutting off the original tabs just below their 38 mm holes I can leave an upright bit to bolt my new tabs to. By slicing the forward part of the bracket I can get it off the machine without draining all the hydraulic oil and it can be bolted back together.
This way the currently one piece bracket will be in four separate pieces greatly aiding refitting it - and the entire caboodle can sit at least an inch lower no longer risking fouling the base of the carriage.
I was manoeuvring 8 mm plate on the plasma cutter to make the new tabs when I managed to dig a small chunk of skin out of my finger - a very small wound (but deep) that won't stop bleeding so I've stopped for the day to let the platelets do their work !
awemawson:
So with the bleeding stemmed this morning I've completed 'phase 1' remove the bracket, prove that the clamps seat properly with no bracket fitted, and slice the bracket ready for modification.
The tabs on the bracket are fairly grossly bent - I suspect whoever made it didn't leave enough bending allowance for the 8 mm plate that its made from resulting in it fouling the base of the back actor. To get it to fit over the 38 mm clamp bolts the tabs had to be bent which is why we are where we are.
Still enough forensic engineering - what to do? Draw up and cut longer tabs with the 38 mm holes, slice off the originals and arrange holes in tabs and bracket to fix them on. But first I need to bend the tabs to true 90 degrees so my longer replacements sit vertically. This may involve heat - I may have to fire up the ceramic chip forge but I'll see what a sledge hammer does first. best done before cutting the old tabs off to give more leverage.
However other matters now demand my attention so play will have to cease :(
awemawson:
I managed to sneak away for another half hour. As I'd feared blows from a sledge hammer failed to give the results that I wanted. I tried the 60 ton press but not really suitable, so . . . . . fire up the Ceramic Chip Forge :bugeye:
It's many months since I've used it and I was delighted how easy it was to set up and quick to get up to heat. Once those bends were glowing it was dead easy to coax them to shape - too easy really as I overshot and had to bring them back again.
The angle is now much closer to 90 degrees - I only want the bottom 1" straight as the rest is getting cut off anyway.
(amusing to think that the propane bottle that I used came with me from Bromley in 2007/8 when we moved here - old gas :clap: )
Got to resume other duties so the rest will have to wait :(
tom osselton:
:thumbup:
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