Case D100 backhoe

[DavidBarkey]

So I stumbled across this sign, and for the first time, it'll soon be true for me!

How cool is that?

LOL

https://www.amazon.com/dp/B07V1TMRP8

Bob

hahahaha, it does not really apply to us here in Canada, but I like it

backhoefirearms.jpg

Trudeau took away y'all's backhoes???????









Bob

yup.

[Eugen]

They gonna take away my backhoe FROM MY COLD, DEAD HANDS!

[RoamingGnome]

They gonna take away my backhoe FROM MY COLD, DEAD HANDS!

and I joke that we have the old Case backhoe to take care of whatever won't fit through the woodchipper... of course that was before I got the new chainsaw,

[Gordy]

So I stumbled across this sign, and for the first time, it'll soon be true for me!

How cool is that?

LOL

https://www.amazon.com/dp/B07V1TMRP8

Bob

I was looking at signs similar to that. My buddy who can be quite paranoid at times, said NO. If you had to put down a criminal and the cops saw those signs, even a crappy lawyer would use them to show prior intent on your part. Just the world we live in today


Gordy

[thebuildist]

Just an update on the backhoe project:

Step 1 is complete, I have the new tires installed.

Step 2 is to machine the outer axle bosses to receive the heavy clamps I'll put on them, from which the weight of the hoe will hang.

The bosses need to be machined perfectly round in order to eliminate any egg-shapedness or high spots. I need that 1100 lbs or whatever to hang on a smooth, clean journal on the boss, which will transfer that load straight through to the cleanl, smooth journal on the outer axle shaft. The axle tube is made of cast iron, and it'll crack if it's forced to flex. So that means no wiggling/jiggling of the clamp is allowed, and no point-pressure is allowed between the inner bore of the clamp and the outer bore of the boss. So I can't leave the irregularly shaped/lumpy cast surface.

To that end, I've built a jig to bolt to the wheel hub that contains a quill that can slide in and out. And I've machined the end of that quill with a femal R8 taper into which you can mount a small boring head that I use with my mill.

The quill sliding inward/outward moves the cutter across the horizontal length of the journal, and the adjusting the boring head cranks the cutter inward to increase cutting depth. A piece of 3/8" allthread acts as a driving screw. The driving screw engages a nut attached to the end of the quill, and turning the driver screw causes the quill to slide inward or outward.

In practice, I'm running the tractor and driving the wheel hub backward. While it spins, I grab the handle on the driver screw and hold it still, and that pulls the quill outward, across the length of the journal. Once it reaches the outer edge I stop the wheel hub, and use a drill to drive the quill back in, resetting it for another pass. I dial in the boring head about .040" deeper, and then proceed with another pass.

The quill itself is made up of some heavy 2" dom tubing that I picked up from the steel guy the other day. One of the trickiest things is getting the quilll adjusted to be parallel to the axis of rotation, so that you cut a cylinder and not a cone. To that end, the quill is suspended between a pair (inner and outer) of 3-point support halos. Each 3 pt. support halo is like a steady rest on a lathe, where it touches the od of the quill at 3 evenly spaced points. Each point of contact can be adjusted inward or outward. So by adjusting the position of the quill inside the inner or outer support halo, you can adjust the quill left/right and up/down.

So the process of getting the quill adjusted to travel true to the axis is very finicky. The passenger side is the easiest to work on, because there's no travel motor to contend with, which leaves plenty of room to work. So I'm doing the whole adjustment process on that side, and once I have it dialled in to run true, I'll transfer over and do the driver's side.

And I'm having to tweak the details and design of the tool itself as I go, figuring out that "that hole needs more clearance" and "that thing there is hitting that other thing there when I dial it all the way out." Etc.

So at this point I've done about 20 passes, and the outer end of the journal, which started out being .100 larger than the inner end, is down to about .030" thicker. So I'm getting closer. But my 3/8" allthread driver screw just stripped out, so I made up a new 3/8 driver screw and replaced the driven nut with a 1 inch long threaded sleeve. The long sleeve should engage many more threads, and ought to hold up to wear a little better.

But my quill has become very hard to slide, and I haven't yet figured out why. Both my 3-pt halos aren't super snug. So I think the quill is rubbing on the housing itself somehow. So before I reassemble, I'll pull the quill all the way out and see if it has galling/wear that I can see. And address whatever is binding.


Meanwhile, the boss itself is way off center. Not even close. The extra thickness on the front side of the boss has now been completely cut away, while the back side of the boss hasn't even cleaned up for roundness yet. As soon as I have machined out the cone-shapedness, I'll just stop there. The top surface is the real key, that'll hold all the weight. I think it'll be 100% cleaned up on top, in front, and underneath. There will just be a few pockets at the very rear edge. The big new clamp, once it is bolted on, being machined to within .005" or so, will restore full strength and rigidity to the axle housing/boss. But until then, the housing is weaker than it used to be.

I'm considering attaching the clamp to the axle tube permanently, using JB Weld to fill any gaps between the axle tube and the clamp.

I'd love to hear people's opinions about using JB weld.

Bob

[Harry]

Nice ramble Bob. Always a pleasure to read your posts. Harry

[Eugen]

I am confused about what you are trying to do Bob.

[Spike188]

Bob, Reading through your post, visions of JB weld kept popping into my mind. This is a perfect application for it. Make a paste and apply to the axle housing, then before the paste is set, clamp the brackets down and torque. I have a lot of experience with using this method for shaft rebuilds.

[thebuildist]

So... I haven't made any progress since June. It's getting where I don't really recall the full details of precisely what I planned to do. It's not that I think I can't do it. It's that I haven't yet gotten real clarity/comfort on precisely what to do next.

So I'm thinking about admitting a measure of defeat, and going a different route, namely the "towable backhoe" route.

There's nothing preventing me from coming back later and doing it the original way. But this way would be way faster to accomplish, and I think I could dig right in. So to speak.



I just need to
1. mount the backhoe onto a towable axle. Easy to do.
2. procure/install essentially the same hydro lines I would have used before, to power the hoe from the tractor's hydraulic system. Easy to do, just plug the lines into the same quick-disconnects that the loader runs off of now.

3. replace some/all of the hoe's hoses, and get the control valve cleaned up and working, etc. I have to do that anyway.
and
4. make a way to mount the backhoe to the tractor's 3-pt hitch. Not to drive around with it, it's way too big for that, but a way to stabilize the hitch end of the hoe so that when you push or pull on the boom, the hitch end can't just jump and flex and move all around. Kind of a way for the hoe to use the tractor as a counterweight to push and pull against.

i built the 3point pretty rugged, but this will be asking a lot of it. Especially the top link. I think the top link mount is the weakest link, no pun intended. But I don't see an easy way to reinforce the top link very much. It's mounted to the 3pt backplate, which is mounted to the transaxle. So the top link is basically attempting to rotate the transaxle forward and back. And I'm given to understand that that's a bit of a weak link on these machines.

That was one benefit of my planned under-axle mounting plan, was the heavy 1 inch steel mount plate would be bolted to the transaxle, and serve to tie together and reinforce the entire back end.

I suppose I might forego the 3 point approach and instead go with a really long trailer tongue? So that by the time the force of movement reaches the tractor hitch, it's at the end of a long lever, and it takes relatively little tractor "effort" to make the hitch end hold still? I'd have to build the tonge pretty beefy, but that's not too hard.

Any thoughts or advice about this approach?

Bob

[RoamingGnome]

Bob - up here in the great white north our version of Harbor freight (Princess Auto) sells a towable excavator that sounds very much like what you're describing - here's a link to a YouTube video of it in action https://youtu.be/4zPn9E6hit4?si=QSvymIVM6TftfbbJ

The actual listing is here - https://www.princessauto.com/270cc-tow ... 008936726

You could make the stabilizer legs swing together, under the excavator part and use them for a tongue to tow it with - kinda like the split tail of a towable piece of artillery...