Finally Building my Backhoe

[dcyrilc]

Take a look at the second photo when Iplayfarmer first began this thread. He calls it an angle and I called it a toe. I should have looked it up and used the same terminology, sorry. As for what it's for: I can't speak for Iplayfarmer, but in my case, it makes room for mounting the cylinder operating the boom. As I was putting the mockup together I could see a problem getting the boom, dipper and bucket folded up for transport. Adding that angled piece solved most of that, I hope.

Got it. Thanks for the explaination.

Now you have me curious to check the backhoes at work to see how Case addressed it.

 

[rcurrie]

Here is what i've got done so far (I'm not using plans, just building by the seat of my pants. I took some measurements from a Kubota Bx25):

 

[dcyrilc]

Got it. Thanks for the explaination.

Now you have me curious to check the backhoes at work to see how Case addressed it.

Guess I don't have to wait until tomorrow. Got to love the internet.

 

[NormL]

Got it. Thanks for the explaination.

Now you have me curious to check the backhoes at work to see how Case addressed it.

You're welcome. Right now I'm having fits trying to calculate the specs for the cylinders. Getting the right combination of stoke and starting length is stretching my meager capabilities in geometry and math.:confused2:

 

[NormL]

Here is what i've got done so far (I'm not using plans, just building by the seat of my pants. I took some measurements from a Kubota Bx25):

Thanks rcurrie. I can see you know your way around a welder. That has the look of a very sturdy machine! You called this a subframe. Are you ready to tell us what this going to get married to?

 

[dcyrilc]

Here is what i've got done so far (I'm not using plans, just building by the seat of my pants. I took some measurements from a Kubota Bx25):

WOW. That really is looking fantastic.:thumbsup:

 

[dcyrilc]

Guess I don't have to wait until tomorrow. Got to love the internet.

Before the use of ductile iron for the booms, the 580C addressed it a little differently.

 

[rcurrie]

I will be making a subframe for a Kubota Bx 2350. Hopefully when this is done it should hook up similar to a Bx24 setup. My welding skills aren't that good but I figure thats why grinders were invented.

 

[Iplayfarmer]

You're welcome. Right now I'm having fits trying to calculate the specs for the cylinders. Getting the right combination of stoke and starting length is stretching my meager capabilities in geometry and math.:confused2:

I admit, figuring out the cylinder geometry is hard. I found that drawing circles helps. Figure a location for the cylinder base and draw a circle with center on the base pin center and radius equal to the retracted length of the cylinder. Draw another circle with a radius equal to the extended cylinder length.

Now draw a third circle centered on the articulation joint to some point along the outer circle where you think you want the cylinder rod end pin.

Where the third circle intersects the inner circle is the limit of travel of the articulated joint. If the intersection of the third circle and the inner circle is not where you want it, start moving proposed locations of the pins until it works out.

I drew these pictures in sketchup, but you could do the same thing in any program or on a piece of paper. In my example the articulation travel is about 65 degrees.

By moving the base pin or the rod end pin relative to the articulation joint, you can change that articulation angle. It's a lot of trial and error, but by doing on screen or paper first you can go through a lot more trials in a short amount of time.

 

[NormL]

Iplayfarmer:

Thanks for those instructions. I will have to do it on paper as I have yet to get SketchUp working on here. Is there a formula I can use to calculate what length cylinder with what stroke I should be using? That, in large part is where my confusion lies.