So I did a thing... Agria 8900D
- Thread starter ptsg
- Start date
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ptsg
Super Member
Well, the last big one was in 1755. Magnitude of 7.7 and along with a tsunami and consequent fires, it completely wiped out our capital, Lisbon. We're kinda due for one of those.Blame Africa
(not really joking, considering the plate tectonics involved)
MTGreen
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- Deere 5220, Ford 1720, Deere Progator 2030
Hope not, that effectively ended Iberian global hegemonyWell, the last big one was in 1755. Magnitude of 7.7 and along with a tsunami and consequent fires, it completely wiped out our capital, Lisbon. We're kinda due for one of those.
ning
Elite Member
I think "Iberian global hegemony" was finished before 1755 (not saying they weren't trifles to be reckoned with, but they didn't have "global hegemony" any more); it was heading downhill in the second half of the 17th, and then you had the
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ptsg
Super Member
Before I got the head back and shifted my priorities back to the engine, I was working on the rear half of the center section.
This is the half that holds the bearings for the king pins. As I've shown before, the bearing on the top ear was destroyed and so was the bore. Also, both top and bottom faces of the housing were wore out.
The initial plan was to recut the bore and faces on the milling machine, but after a closer look, turns out the face where it mounts to the transmission is not square with the king pin axis. They did it on bot halves of the center section, I suspect this is to raise the front of the tractor a little bit so it doesn't sit so low. While this is still doable on a milling machine, I have very little tooling available and even less holdown hardware or a big enough angle plate.
So my next plan was the lathe. Using the good ear and bolt it on a mandrel on the lathe, so I could machine the other side, then flip it over and tackle the other ear. Experienced machinists can tell from a mile away the lack of rigidity issues.
This was the plan I went with. So I preheated the casting, built up the face and bore with weld and set it on the lathe to machine. In order to balance the casting on the lathe, I welded a flat bar from one ear to another so I could bolt up some weights.
Cutting the face went already. Some minute chatter but easily overcame that. The bore on the other hand gave me an hard time. Lots of vibration and chatter, specially as got close to some hard spots on the weld, but kept going till I had very little left to finish size and decided to rig a toolpost grinder with a die grinder. This worked excellent, not only it came out perfectly on size, it also produced a beautiful finish.
Then was a matter for doing all over again for the other size. All in all, I super happy with the results.
I'll have more lathe sketchy setup coming for the other half. That will be interesting too but I have a plan and on this part I can use the live center to support it, so I should go a lot better.
Note the angle I was talking about. A couple of degrees. And of course, forgot to take pictures of the ground finish I was getting.
This is the half that holds the bearings for the king pins. As I've shown before, the bearing on the top ear was destroyed and so was the bore. Also, both top and bottom faces of the housing were wore out.
The initial plan was to recut the bore and faces on the milling machine, but after a closer look, turns out the face where it mounts to the transmission is not square with the king pin axis. They did it on bot halves of the center section, I suspect this is to raise the front of the tractor a little bit so it doesn't sit so low. While this is still doable on a milling machine, I have very little tooling available and even less holdown hardware or a big enough angle plate.
So my next plan was the lathe. Using the good ear and bolt it on a mandrel on the lathe, so I could machine the other side, then flip it over and tackle the other ear. Experienced machinists can tell from a mile away the lack of rigidity issues.
This was the plan I went with. So I preheated the casting, built up the face and bore with weld and set it on the lathe to machine. In order to balance the casting on the lathe, I welded a flat bar from one ear to another so I could bolt up some weights.
Cutting the face went already. Some minute chatter but easily overcame that. The bore on the other hand gave me an hard time. Lots of vibration and chatter, specially as got close to some hard spots on the weld, but kept going till I had very little left to finish size and decided to rig a toolpost grinder with a die grinder. This worked excellent, not only it came out perfectly on size, it also produced a beautiful finish.
Then was a matter for doing all over again for the other size. All in all, I super happy with the results.
I'll have more lathe sketchy setup coming for the other half. That will be interesting too but I have a plan and on this part I can use the live center to support it, so I should go a lot better.
Note the angle I was talking about. A couple of degrees. And of course, forgot to take pictures of the ground finish I was getting.
oldnslo
Super Member
I like your ingenuity on getting things done with the equipment you have available.
OP
ptsg
Super Member
This engine comes originally with an alternator mounted behind the flywheel, just like a motorcycle engine.
The regulator was long gone and the alternator had some melted wires, so at one point, someone very crudely mounted a regular car alternator on the shroud of the engine. Terrible welds, along with lots of vibration caused the mount to crack and break the shroud and the tensioner.
There isn't really any good alternatives to mount the alternator on this engine, other than some crazy setups I've seen online that put the alternator way out in the side of the engine and really exposed. I didn't want that.
I ended up cutting a strip out of the shroud and replaced it with a thick piece of flat bar. This bar is curved to match the shape of the plate where the starter mounted to. It is then bolted with 5 or 6 bolts. This should make for a nice place for the alternator to be mounted.
Next was the belt tensioner. The previous one was welded to the shroud and also broke, so I had to make a new one regardless. I went ahead and used the hydraulic pump mount to provide a solid base for the tensioner bar.
I also started fixing the exhaust. It was a mess. Broken and "fixed" multiple times in its existence. Probably hit lots of things too. Had way too many patches on the curve that welds to the muffler. I redid this bend using stainless steel pipe and some pie cuts. I may clean the welds a little bit.
It's still missing a bracket down low to provide more support to the exhaust. That's tomorrow's plan.
The regulator was long gone and the alternator had some melted wires, so at one point, someone very crudely mounted a regular car alternator on the shroud of the engine. Terrible welds, along with lots of vibration caused the mount to crack and break the shroud and the tensioner.
There isn't really any good alternatives to mount the alternator on this engine, other than some crazy setups I've seen online that put the alternator way out in the side of the engine and really exposed. I didn't want that.
I ended up cutting a strip out of the shroud and replaced it with a thick piece of flat bar. This bar is curved to match the shape of the plate where the starter mounted to. It is then bolted with 5 or 6 bolts. This should make for a nice place for the alternator to be mounted.
Next was the belt tensioner. The previous one was welded to the shroud and also broke, so I had to make a new one regardless. I went ahead and used the hydraulic pump mount to provide a solid base for the tensioner bar.
I also started fixing the exhaust. It was a mess. Broken and "fixed" multiple times in its existence. Probably hit lots of things too. Had way too many patches on the curve that welds to the muffler. I redid this bend using stainless steel pipe and some pie cuts. I may clean the welds a little bit.
It's still missing a bracket down low to provide more support to the exhaust. That's tomorrow's plan.
MTGreen
Platinum Member
- Joined
- Oct 12, 2022
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- Montana, USA
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- Deere 5220, Ford 1720, Deere Progator 2030
Nice work. I like the elegant alternator solution.
Mandrel bent stainless J and U sections are available pretty cheaply online or at a muffler shop would save a substantial amount of work
Mandrel bent stainless J and U sections are available pretty cheaply online or at a muffler shop would save a substantial amount of work
OP
ptsg
Super Member
Indeed those are available. I just checked, 6€ for a curve like that. Probably have more in stainless steel rods. Oh well. I thought, what am I doing next? Exhaust! So I just went for it.
Only took me like an hour and half to the finish exhaust. Not too bad.