8B Backhoe On A 4200?

[dfkrug]

...I was surprised how close the hoe came in. I could take off the bottom corner of the PTO shield and the hoe's lower steps and come in another 1-2 inches. But then the stabilizers would 1/2" or less from touching the tires. Thats probably too close, yes?

I tried to keep my closest clearances to the tires at no less than 3/4".
One inch is better. Remember, you may buy new tires at some point,
and you should allow for more tread or manufacturer variation. I get some
slight flex on the outriggers, too. My hoe is very forceful.

I trimmed my lower hoe steps in half on my Kioti, and eliminated them
completely on my 4300. I tossed the PTO shield....what a PITA that is.
If either of those is your limiting factor, customize it.

What do you think of adding a cross brace at the front of the frame that gets screwed to the bottom of the tunnel? There are two tapped holes there too. My initial concern is that it will be near impossible to remove this thing but my major concern is weight distribution.

A cross brace at the furthest point forward does not do much, since that
is where the forces are smallest. Also, since there are bolted connections
on both sides, it will have to be fabbed very exactly for width. Doable,
can't hurt, but more work. If you want to add more "rungs" to your
"ladder", add them in the middle. Your steel looks VERY thick there, so I
am not worried about twisting.

 

[RoyJackson]

Yes, 1.5" per side. Just figured that out the other week while I had the wheels off to air them up. The turfs on a 43/4400 are taller but narrower. I don't remember what Roy and I gained when we flipped his. I believe it was more than 3 total inches but I'm not sure. Roy?

We didn't measure it with a tape measurer, but I used the width of my hand (just under 4") between the tire and inside of the fender. We gained closer to 4" then 3".

 

[JCB]

Nice work arrabil. Even though dfkrug makes this stuff look routine, it's still a pretty gutsy project to get a backhoe then make a subrame.

Best of luck moving forward!

 

[arrabil]

The first side is built and it was a perfect fit. The front bolts screwed in by hand after the rears were tightened. No pictures though. It was too hot to do anything today so I'll start the second side tomorrow. The two bolts I need for the second side are on special order at TrueValue anyway. They only had two in stock yesterday.

Seems I'm getting lucky all over the place. The estimated distance between my rear extensions is 20 15/16". The distance over the old subframe is also 20 15/16". Watch it not turn out that way when I get both sides installed!

Your steel looks VERY thick there, so I am not worried about twisting.

Since the 970 doesn't have a frame I guess they compensated for it with those brackets. Welding that stuff is a serious PITA. I have little weld burns all over my arm. The spray of BB sized weld beads that bounces off it before it gets hot enough to take the bead is like 4th of July Sparklers. I guess this is why TIG is so cool. Doubt I have enough dexterity to control three feeds at once though.

We gained closer to 4" then 3".

Must have to do with the rims. I swear my shorter tires are wider so that would explain the rims being different. I think.

Nice work arrabil. Even though dfkrug makes this stuff look routine, it's still a pretty gutsy project to get a backhoe then make a subframe. Best of luck moving forward!

Much appreciated JCB!

 

[RoyJackson]

Welding that stuff is a serious PITA. I have little weld burns all over my arm. The spray of BB sized weld beads that bounces off it before it gets hot enough to take the bead is like 4th of July Sparklers. I guess this is why TIG is so cool. Doubt I have enough dexterity to control three feeds at once though.

That's why welders wear leather jackets or sleeves, Arrabil!
TIG is neat, but it would take multiple passes on steel as thick as you're welding. OK for short repair welds, but not much fun for longer passes.
If you beveled the areas you need to weld, the steel will puddle faster and you'll get better penetration. Preheating would help too, but that requires an oxy-acetylene rig with a rosebud.

 

[arrabil]

I got a welder's blanket that I cover up with but it slides off my arms as I move around sometimes. A whole welding suit is an expenditure I've yet to decide to make. Its frickin hot out there too!

I am beveling, btw. I wouldn't trust the strength of it without multiple passes here too. No ability to preheat though.

I didn't know about the limitations of TIG. Interesting. Gonna have to play with the brother-in-law's stick/tig/mig machine next time I'm out.

 

[dcyrilc]

With the tractor only 3.5 inches off the ground the seat already clears. Thats great news as it means one less thing to worry about.

And although I didn't get exactly centered during my trial fit, you can see the tires and PTO cover clearances. The 8B has the pivot cylinders sticking out behind the operator platform. Probably because its so far away from the 970 anyway. But I can get it really close to the back of the 4200. More great news.

I have a question here. On the 8B, do the ram housings pivot as the boom swings or are they fixed? If they pivot, you might have clearance issues with the tires when you swing the boom. Hopefully they're fixed and it won't be an issue.

 

[arrabil]

They're fixed. They pull a chain back and forth to swing the boom. I've heard the chain was a week link on the 8A but that it was fixed on the 8B. Hopefully thats actually true.

 

[RoyJackson]

I didn't know about the limitations of TIG. Interesting. Gonna have to play with the brother-in-law's stick/tig/mig machine next time I'm out.

TIG is great for thinner gages and non-ferrous materials (MIG is also great for non-ferrous). But, like gas welding, it's not really good for thicker materials or production welding (except for repairs and touching up welds).
I had my certifications for some alloys when I was in the Navy. I was an "OK" welder, at best...but it did help a lot when I was performing NDT of welds.
Haven't welded in years. Now that I have a pacemaker, I have to keep a distance away from electric welding equipment (due to the magnetic fields).

 

[dcyrilc]

They're fixed. They pull a chain back and forth to swing the boom. I've heard the chain was a week link on the 8A but that it was fixed on the 8B. Hopefully thats actually true.

Chain huh. Haven't seen that one yet. Hope your right about it being fixed as a weak link.:thumbsup:

Looks like that 8B is going to be a nice fit on your tractor. Keep the pix coming.:thumbsup: