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Re: Case D100 backhoe

Posted: Sat Apr 01, 2023 8:05 pm
by Eugen
I would be worried that the cast iron will snap when tightened. I think that a sandwich of plates, even welded together to get the thickness you want is better. I also think that 0.010 is too little to provide enough clamping strength.

Re: Case D100 backhoe

Posted: Sat Apr 01, 2023 8:15 pm
by thebuildist
So I'm hearing this group say that the u bolts are the way to go.


Check.

1/2" u bolts are not an option, for this reason: off the shelf they don't make 1/2" bolts in the "2 9/16"/"2 5/8" spacing that I need. You can get them custom made, but those are more like $100 for 4 of them.

So I could do the two 9/16 like I mentioned. But at this point I'm inclined to just do single 5/8 u-bolts on each side. I'm a little concerned that doing two sets of 9/16" holes in each set of collars might actually weaken them a bit. Balancing that against a single 5/8 hole, and believing that the single 5/8 bolt is more than strong enough, makes me inclined to just install a single 5/8 u bolt on each side.

And attach the center of the crossmember to the differential in the center. (probably I'll weld a tab or two to the 3pt hitch backing plate, which is well-attached to the differential)

And do the final machining after the split has been done.

As of now, unless I hear good arguments otherwise, that's my plan.

And thanks, everyone!

Bob

Re: Case D100 backhoe

Posted: Sat Apr 01, 2023 8:34 pm
by thebuildist
Eugen wrote: Sat Apr 01, 2023 8:05 pm I would be worried that the cast iron will snap when tightened. I think that a sandwich of plates, even welded together to get the thickness you want is better. I also think that 0.010 is too little to provide enough clamping strength.
By .010 being too little, do you mean that I should machine the collar to more than .010 undersize? You think I chould machine it .015 or 020 undersize?

Like you, I am concerned about the cast iron under that kind of clamping force after I've cut away 20% of it by drilling two big holes in it. But cast iron is pretty darn strong in compression. So I think that if I limit myself to one 5/8" hole, that it'll hold.

And I can't wrap my head around how to weld the stacked plates together. All I can do is weld them around their outer perimeter. And where the collar contacts the axle housing I think it needs to be seamless/solid.

Is there a way to think about it that I'm missing?

Bob

Re: Case D100 backhoe

Posted: Sat Apr 01, 2023 9:20 pm
by JSinMO
@thebuildist Sounds like you have kinks pretty well worked out. :thumbsup: not sure if this will be helpful but I took a couple of photos of the mounting plate on the back of my 648. My subframe bolts to the center of the rear end.
9DD140BB-D755-4E0F-A378-845340F49A6B.jpeg
A1E89F96-3420-40A6-A3FC-38E800B8EE34.jpeg
Looks like your planning is well past this point but I thought it couldn’t hurt to have a look!

Re: Case D100 backhoe

Posted: Sat Apr 01, 2023 9:57 pm
by thebuildist
Thanks, @JSinMO !

I really appreciate all the info I can get!

Bob

Re: Case D100 backhoe

Posted: Sun Apr 02, 2023 9:06 am
by Eugen
thebuildist wrote: Sat Apr 01, 2023 8:34 pm
By .010 being too little, do you mean that I should machine the collar to more than .010 undersize? You think I chould machine it .015 or 020 undersize?
Not the machining of the bore, sorry. I meant the distance between the two halves once you put them on the axle.

Like you, I am concerned about the cast iron under that kind of clamping force after I've cut away 20% of it by drilling two big holes in it. But cast iron is pretty darn strong in compression. So I think that if I limit myself to one 5/8" hole, that it'll hold.

And I can't wrap my head around how to weld the stacked plates together. All I can do is weld them around their outer perimeter. And where the collar contacts the axle housing I think it needs to be seamless/solid.

Is there a way to think about it that I'm missing?

Bob
I'm in a hurry to leave home now but I'll come back with a drawing.

Re: Case D100 backhoe

Posted: Sun Apr 02, 2023 11:53 am
by Eugen
Excuse the poor drawing

880AD1E5-581E-416B-A6D5-A7C2F257A41D.jpeg

Re: Case D100 backhoe

Posted: Sun Apr 02, 2023 3:31 pm
by thebuildist
I do have to admit that I hadn't thought about it that way.

I'm going to have to think about it for a little bit. The hole in the middle needs to be about two and 9/16. And the steel that I am working with is 4 in high. So if I split a single piece of steel down the middle into upper and lower collars, then the thickness at the very top and very bottom of the colors will be just a smidgen over a half inch. The cast iron I have is just a big 2-in thick plate. So I can kind of cut out whatever shape I want out of that. And I was going to have the collar be a minimum of 1 in thick all the way around.

So my choices are to go with cast iron with a full 1-in thickness around the whole perimeter.

Or use the steel plate with a single joint in the center line of the collar thickness. I can see how that single vertical joint running front to back shouldn't present any terribly big problems strengthwise. It might be a bit of a challenge to drill the holes for the u-bolt because they'll be going right down that seam line. But I could probably figure it out.

And if I do use the steel plate I can either consume 20 inches of the 1x4 bar, two pieces of bar for each side, and have half inch thickness at the top and bottom.

Or I can consume 40 inches of the 1x4 bar, four pieces of bar for each side, and have for 1 in thickness at the top and bottom.

I'm trying to get away with just buying a single 12-ft stick of the 1x4 bar. It's $200 per stick and I'd hope to just buy one of them. But if I do have to buy a second one it's not like I'd have no use for it.

And I don't really know where I'll be getting half inch bar. I'm getting the 1-in bar for about what you normally pay for half. So maybe I'd be best off not using half anywhere and just buy two sticks of 1 in and use it for the whole project.

I'm going to have to think about this.

Re: Case D100 backhoe

Posted: Sun Apr 02, 2023 3:53 pm
by Eugen
Another piece of bar top and bottom can be welded to make it thicker.

4AAF9084-C4F9-4509-B063-1C9142C36688.jpeg

More to think about. Also, consider what is $50-$100 extra for something you want to use many years.

Re: Case D100 backhoe

Posted: Sun Apr 02, 2023 7:38 pm
by Harry
Bob, you mentioned cast iron. I would think cast iron would be harder to work with than steel. :peace: Harry