Thwaites 2 Ton Two Cylinder Dumper Running On One Cylinder

[AdeV]

You mean to say you haven't trimmed your 4MT shanks down to 3MT?

Sounds like a job for the CNC lathe...!

[awemawson]

But I have 4 MT in the spindle of my Richmond 3 foot radial drill so why booger them up 

[mattinker]

Question of necessity really - when thing's are broke, and you are broke, no one else is going to fix them for you 

Having seen your workshop, I suspect that is also a certain amount of satisfaction in making things work!

All the best, Matthew.

[AdeV]

But I have 4 MT in the spindle of my Richmond 3 foot radial drill so why booger them up 

Wouldn't it be easier to sleeve up from 3 to 4 MT than to sleeve down from 4 to 3? 

Hmm... I have a big pile of drill bits/reamers with 4MT (and bigger) shanks on them, you interested in any of them?

[awemawson]

Question of necessity really - when thing's are broke, and you are broke, no one else is going to fix them for you 

Having seen your workshop, I suspect that is also a certain amount of satisfaction in making things work!

All the best, Matthew.

OK Matthew, you've got me sussed 

[awemawson]

So today's task was to make the spherical bearing holders, as the retaining circlips had turned up.

First I bored the full length of that bar to 1.625", being careful towards the end to 'wash the heat out' with suds. Bearings were a nice snug fit (phew 

Then a slightly hairy experience cutting circlip grooves 'blind by numbers'. Went round the houses a bit as my first grooving tool rubbed (not enough front clearance) and I managed to work harden (*) that bit of the bore  - careful application at low speed of the next grooving tool that I ground got me past the hard bit, then it was a case of parting off and repeating.

Clearing the burrs raised by the grooving operation was a bit of a pain - ended up using a very fine 'half round' file. Then it was just a case of drilling, spot facing and tapping for the grease nipples.

I decided to fit a locating 'roll pin' in the housing to aid in location when they are being welded. When I chop the end off the rod I'll mount it up in the lathe using lead slips to protect it, and drill a hole to receive the pin. The one in the cylinder I'll probably have to do by hand. The idea being that it's only too easy for thing to move when you start welding, especially when you can't clamp them very satisfactorily.

Note that the orientation of the grease nipples is different between the two holders to allow access.

(*) which proves my suspicion that this is more than mild steel, or it would not have work harderned

[awemawson]

Television was particularly boring this evening, so I escaped to the workshop for 45 minutes 

I decided to remove the old bearing eye from the piston rod and prepare it for welding. First job, unjam the jam nut that holds the piston assembly onto the rod, then remove all the components, sliding them onto a long ty-wrap to preserve their assembly order.

Then off to the cold saw to saw off the old bearing eye, protecting the rod in sheet lead so that the vice doesn't do damage. I deliberately cut through the old eye to make sure that I don't shorten the rod.

Then mount up in the lathe, again using sheet lead as a cushion, and turn off the old weld, put a 45 degree chamfer on it to enhance weld penetration, and drill the end 1/8" to accept the roll pin for centring. Cleaning it up, the bit of the old eye neatly fell away exposing virgin rod on the end surface, so no rod shortening 

(I will of course be dismantling the bearing assembly before welding)

[awemawson]

So cut off the cylinder eye then welding today - but first I had to go and pick up 250 kG's of Sow Nuts from the feed store and hump it into it's storage bin 

Set up the cylinder in the cold saw ready for chopping - problem is that being hollow you daren't tighten the vice or it will distort, hence the packing under the eye. Chopped off the old eye, cleaned up the raw end and marked it for a hole for the location dowel pin. Can't go in far as the end wall is only 5 mm by my measurements, so just a dimple really.

Clamped up and welded the new rod eye and cylinder eye. It would have been so nice if I could have 'rolled' the rod on the welding bench to run a neat bead round it, but obviously the surface of the rod would have suffered from the arcs from the bench contact. Had to do it in fits and starts, protecting the chrome with wet cloth (which steamed up my welding mask  )

[awemawson]

Then it was just a case of putting the piston assembly back together with new seals and a bit of a clean up.

[awemawson]

Then I got a bit enthusiastic and decided to give it a coat of paint. Quick clean and degrease using IPA, mask it up then a coat of etch primer, which was given an accelerated drying time by using a heat gun.

Followed the etch primer with a aerosol can of satin black that covers a multitude of sins - matt black is even better but I'd run out 

Bit of a cook with the hot air gun, take off the masking tape and put it back on the machine, giving everything a good grease up. I hate grease guns - they always run out just as you want to use them, then putting in the new cartridge, which should be so easy, always seems to end up with grease everywhere 

Never mind - ram is back on and pivot pins and bearings greased up, hydraulic fluid bled though, and woo-hay - she works  Steering is so much more positive, less jerky AND there are no leaks from the ram. It won't last for ever, as there are a few dings on the rod - if I'd realised I'd have made a new one as it's only 1" hard chromed rod stock with a shoulder and thread at one end.

Still - I'm a happy bunny. Just need to ponder  whether I can be bothered to sort out the centre articulation bearings - looks like at least two skinned knuckles if I do 

[Spurry]

Another brilliant job, Andrew. Thanks for sharing.
Pete

[awemawson]

Thanks Pete for the kind words.

.... but a bit of thinking has left me deciding that that centre pivot definitely needs sorting - there is at least 1/4" play in the bearings - perhaps more, with the result that the thing clanks all over the place.


The front of the machine is hinged to the rear by three self aligning spherical bearings arranged at two levels. The lower pivot, which seems to have very little play in it, is just a single bearing. Whereas the upper arrangement is a bit more complicated - it has a 'fish plate' of 1" thick 3" wide steel 17" long, each end of which has bearings inset into the thickness. There are grease seals jammed above and below the bearings which are lubricated by co-axially drilled grease runs in the pivot bolts

The whole upper bearing assembly is available as a repair kit, but at £293 it's rather pricey 

[awemawson]

Now I've rather ignored this problem for a long time, as it's not the easiest of things to get off and work on.

Firstly, undo it, and the dumper falls into two bits 

Secondly, the rear fixing of the 'fishplate' is very badly obscured by the hydraulic steering orbitor.

Now in a flash of inspiration I've decided that, so long as I leave the lower bearing intact, and suitably weigh down the bucket so it tends to collapse backwards (weight at the moment empty tips it forwards) I can support it on axle stands if I can somehow get at that rear fixing.

Now here comes the clever bit - slice the entire steering support assembly off with an angle grinder and put it to one side - finish the pivot repair, then weld it back on 

This has the advantage of killing two birds with one stone. When we moved here, the very helpful hi-ab driver LeRoy foolishly tried to lift the dumper off his lorry using this steering support assembly, and pulled it entirely off the machine 

It had to be quickly welded back so the machine could be moved as it was obstructing everything else, and the only welder to hand was my old MIG BUT NO GAS  It didn't help that it was pouring down as well. So it got glued on as a temporary fix eight years ago, and has never been re-done 

They must be the grottiest welds I've ever made, but they have at least lasted, so this gives the opportunity to cut them off and hide the evidence 

[awemawson]

I bit the bullet at the weekend and ordered that expensive top link kit. I'd intended to pull out the old and see if I could re-manufacture it, but realistically I don't have the time as I can't measure the bearing until it's out, then several days waiting for bits, meantime machine cannot be moved. Costly but I think probably expedient.

The kit won't arrive until Tuesday or Wednesday so I've been giving some thought how to control the two halves of the dumper when I remove the original. I had thought that to weld a temporary strap between the two halves would be the way, but in practise I'll need to adjust their spacing in order to get the large pivot bolts installed. Just relying on axle stands is a bit dodgy, as they tend to slip as you strain on things balanced on them.

So I came up with the idea of taut lifting strops arranged so I can adjust the tension as I install the bits. The 'skip' has suitably tough handles welded to it in convenient places that will take shackles, and on the rear half a pair of 10 mm  deck hold down bolts were in just the right place to mount brackets. It was a simple job of boring holes in a bit of 6 mm thick 50x50 angle iron and bolting them, on 

With a tourniquet rod put through the lifting strops and turned, I can fine tune the relative position of the front and rear halves of the machine, all the while keeping the lower pivot assembly in place

[smiffy]

Hi I have enjoyed reading you posts ,for many years I worked on all manor of plant both large and small .When changing the centre pivot bearing I would tip the skip  onto a block of wood and lock the ram of with a length of angle ,them place a jack in front of the pivot,place a trolley  behind the pivot ,remove the bolts through the pivot and wheel the rear end backwards .If i remember correctly  this can be done without removing an of the pipe work , usually took about 2 hours from start to finish.
On a completely  different note many years ago i was the mechanic for the  coastal defence work near you at Fairlight cove which involved unloading 250,000 tons of stone shipped in from Norway on barges each carrying 10.000 to 15,000 tons. The barges were floated in at high tide the bilges pumped full of water so they settled on the sea bed them the stones ,each weighting a minimum  of 10 tones pushed over the side and at low tide they were loaded onto dumptrucks run  up the beach and unloaded and positioned using 5 tine grabs on 75 ton excavators. Very punishing work for both men and machines ,if i can find some pictures I will try to post them .Over a 6 month period we had 3 machines break down and go and get a swamped by the tide , a real recover problem as one was a D8 The other 2 both 75 ton excavators . Happy day

[awemawson]

Hi Smiffy thanks for your posting. My wife walks the dogs at least once a week at Fairlight

Small world - I'd be interested in those photos that you mentioned.

[awemawson]

Pivot bearing kit not arrived yet, so I thought I'd get ahead of myself and cut out those horrible welds.

First I whipped off the floor board to give better access, then unbolted the steering orbitor and the cylinder that I re-built, and swung them out of the way onto the body of the machine, protecting the ram with thick cardboard against sparks.

Then I had at it with my 9" Makita angle grinder, followed by a bit of finesse'ing with the 4 1/2" grinder in places the big one couldn't reach. I had intended to remove the master cylinder and have it swinging on it's pipe, but in the end decided there was just about enough clearance to go under it 

Finally cleaned it up with a grinding disk on the big Makita  - I've not yet touched the column itself.

I'm tempted to make it 'bolt on' when it goes back - the column will need extending anyway as it's lost material (The steering orbitor was a jam fit, squashing it's hoses), so I'm thinking to weld some heavy angle to the column, slightly off the bottom, and drill and bolt it to the dumper chassis. Then the welding can be done on the bench even if it is raining 

[awemawson]

This afternoon I attacked the Steering Column Stanchion. I'd intended to just grind back the grotty welds, but I decided it would be more satisfactory to slice off a section back to clean metal. The base angle was a bit squiffy - I decided to try and make it so that the face of the stanchion was approximately parallel to the back of the skip, as that's how they seem to be in various illustrations.

By the time I'd 'adjusted' the angle and got back to solid metal, at least 1" has gone from the length. This doesn't matter as the steering hydraulic orbitor mounts on a bracket that fixes on the two holes you can see in the face of the stanchion - all I have to do is drill another pair of holes a suitable distance further up, and, as the steering column just threads through a large grommet in the top of the stanchion it will just poke through a bit more and the wheel should end up about the same height.

I've abandoned the 'bolting on' idea - I'll just glue weld it back on otherwise it gets too complicated

[awemawson]

.... now about that bracket idea .... I used to be undecided, but now I'm not sure 

My objection to fixing the stanchion back with brackets was having somehow to bend an odd angled one for the front edge due to the rake of the assembly, and getting a hand in to fit nuts to the bolts. But hang on there chappy - if you had a plate welded on the base, with suitable holes to fix it to the chassis, NO NEED for bending at all  and the chassis is thicker than the nuts - so tap the holes

I rescued a bit of 1/8" plate that had been kicking about in the stable for a few years - it was the back of an electrical control panel, so had a fair few holes in it, but is was available 

Propping the stanchion up with a bit of wood to get the angle right, I marked out a suitable bit, cut it with the small angle grinder, and drilled M8 clearance holes in it. Then offering it up to the chassis I drilled and tapped the first hole to keeping it from moving about, then drilled and tapped the other eleven holes.

After a bit of a clean up it was reasonably presentable, so I welded it onto the stanchion, drilled the replacement orbitor mounting holes a couple of inches further up, then sand blasted it. It's really too big for my cabinet sand blaster, and too small to be bothered getting the full size one out, so I struggled in the cabinet. It fits but it's mighty hard to see round it to make sure everything is blasted.

It came out not too badly, and got a coat of zinc rich primer which I left drying while I made bacon sandwiches for lunch ... mmmm.

Then it got a top coat of bright orange. I have a few rattle cans of this colour left over from another job - it was a close run thing, it nearly got satin black 

It's hanging up in my improvised paint drying oven, otherwise known as a 4 kW fan heater balanced on some fire bricks 

[mattinker]

A better solution!

Regards, Matthew.

[seadog]

You realise that the more parts you paint, the more you'll need to paint. Bite the bullet and give it a full respray 

Another interesting thread by the way.

[awemawson]

... oddly enough it looks as though it's been that violent orange colour before, distinct shades of it were revealed as I sand blasted the stanchion 

Seriously though I don't see the point of a complete re-spay. A quick blow over is '10 yards pretty', but close up looks terrible. To totally dismantle and do a 'proper job' is a major task that  not only do I not have the time for, but frankly it's not worth it. It's next job is to move a pile of pig poo to the compost heap, followed  by a load of saplings I'm grubbing out from a stream bank to plant up a hedge. Following those jobs it won't look very pretty even if it had been painted !

[lordedmond]

Great resurrection job again Andrew

But please tell me where to buy the clock you use that can expand time to enable me to fit 50 hours of work into 24 

Mend this , look after the live stock , maintain the plant , maintain the cottages and house and keep the wife happy not for getting the viber's

Keep at it one day you may be able to put your feet up

If you need a chalange I would have sent you down my uncles Jersy bull ( killer , black head and black by nature ) we use to tie his ring to the front of the fordson major to get him out of the loose  box , but if the cows were in the yard he would come though the door smashing the place up

Stuart
Stuart

[awemawson]

It's not that relentless Stuart 


However just as things seem to be going well, there's always a 'Gotcha' to come along and nibble your nether regions 


Today the tracking data told me that ParcelForce were due to deliver the replacement centre link / pivot / bearing thingy, so I thought that the sensible thing to do would be to loosen the pair of 1" bolts that hold it on. A bit tight but my 3/4" socket set and a scaffold tube got them turning  Then the HORRIBLE TRUTH dawned on me - the rear bolt has it's nut on the upper side, so the bolt has to come out DOWNWARDS. But the transfer gear box is in the way  Whether this is by design or a mistake at original assembly I don't know - the front bolt (that is EASY to get at) is the other way up ! It does seem that there is room for the nut to be at the lower end.

Now the transfer box is held on by four bolts onto the chassis that are fairly hard to get at, and the three prop shaft flanges would need to be removed - not impossible, but definitely a pain in the rear.

Only alternative I can see at the moment is somehow to cut the head off the bolt in-situ, and install the new one the other way up, but cutting through a 1" bolt in a very cramped spot won't be easy.

I'd just cleaned my self up to type this when Adrian the ParcelForce man arrived with the new pivot bearings.

So any suggestions, or volunteers to drop the transfer box, are welcome - don't be shy

[mattinker]

Andrew,

is the reason it's that way up so that you can get at the grease nipple? What ever, it has to come out, wouldn't it maybe wiggle pas the drive flange with the prop shaft off, or even with the output flange pulled?

I won't be over till the end of the month maybe a bit late to help!

Good luck! Regards, Matthew.