Homemade Backhoe for LS Tractor (XG3140)

[polemidis]

If you put a little thought, philosophically, we are all coping someone else! Maybe we put 1% of invention, but the majority has reinvented before!
So today I made some progress. Here are some pics.
So far, the boom+stick+2 levers+bucket adaptor weights 350lbs. With a random 0.25 plate, for boom and stick, and 0.5" for the levers. These are just a basic thickness no analysis on stress yet.
Bfreaky I moved the pin you suggested 2" further away but I lost a lot on the digging depth, so I put it almost all back. The angle is very small but, still the a 3.5" boom cylinder, with 1.75" rod (because It lifts on retraction) at 2500psi, creates 18000lbs pull force, but because the angle is only 11ｰ, it will be able to lift 3400lbs. Still plenty i think? no?. In these pictures I increased the boom cylinder stroke to 20" to increase the digging depth with loosing power. We will see. Maybe it will be too slow to operate now?
Anyway This is what I have for mesurements:

 

[BFreaky]

It looks much better now. I changed that distance when it was already in use because I noticed it loses alot of power. Digging depth is good, there is a problem with digging deep holes near your machine. At one point hole tends to collapse. I had 2 close calls, almost ended up in a 4 m pit with everything. I managed to hold the entire machine with the boom and pushed it away from the pit. Lifting height is much more important then the digging depth

 

[TMGT]

It looks much better now. I changed that distance when it was already in use because I noticed it loses alot of power. Digging depth is good, there is a problem with digging deep holes near your machine. At one point hole tends to collapse. I had 2 close calls, almost ended up in a 4 m pit with everything. I managed to hold the entire machine with the boom and pushed it away from the pit. Lifting height is much more important then the digging depth

Agree, I was able to balance mine between depth and height but if I was to build another one I would favor height a but more.

Mines a bit smaller then the one you built BFreaky, one of these days I really should paint it.

 

[Stimw]

Stimw, where's the fun if you copy everything?

I have owned a fabrication shop and still have a lot of the equipment.
I bought my backhoe attachment for $3400. because I could not beat the quality of it for the price.
I would rather be digging holes than engineering something that has already been R&D-ed.
Good luck on the powder coating too.

 

[BFreaky]

TMGT it would be nice to paint it...color is not expensive .
Stimw, each one of us choses his own way. I prefer to make mine because I just love to fabricate stuff and because I can't buy machine like this over here because no one makes it as an attachment. There are countless Volvos, JCB-s, Terex and Hydrema machines but they are 20x more expensive then this will ever be

 

[TMGT]

TMGT it would be nice to paint it...color is not expensive .
Stimw, each one of us choses his own way. I prefer to make mine because I just love to fabricate stuff and because I can't buy machine like this over here because no one makes it as an attachment. There are countless Volvos, JCB-s, Terex and Hydrema machines but they are 20x more expensive then this will ever be

Paints not cheap either! (Gonna do orange to match) I still have some odds and ends to finish up on it before paint.

I built rather then buy because I couldn't find anything I liked and would still have to modify it for a subframe and to make it fit like I wanted. Plus I enjoy expanding my skills by designing and building things when it makes sense to do so.

 

[polemidis]

I have owned a fabrication shop and still have a lot of the equipment.
I bought my backhoe attachment for $3400. because I could not beat the quality of it for the price.
I would rather be digging holes than engineering something that has already been R&D-ed.
Good luck on the powder coating too.

Thats one option, even though I dont believe I could buy a backhow for the cost of manufacturing it.

BUT, and thats a big but, I am designing this, (as I did the grapple, and the firewood processors) to open source them. So someone that has time but no money will be able to build it for a fraction of the cost. For example the grapple that you can buy for $2200, you can build it for around $1000 in materials, if you have a CNC plasma or for 1300 if not. Or like my CNC Plasma, I could buy it for around $13000, I build it for $2500.
For this backhoe a commercial equivalent cost about $12000 (bradco), I believe I will built it around $3000.

Its about offering to humanity, and it feels good!

 

[polemidis]

I am wondering if I could avoid the huge unique king pin. As I am designing that part of the backhoe, it looks like I could use 2 pins. One on top and one on bottom (between the green and the light blue parts).
For the swing cylinders I couldn;t find affordable "trunnion" type mount cylinders, so I went with a regular tie rod.
I made little progress this week, but I have figured out the majority of the geometry. When this is done I will start figuring out the plate thicknesses for each part of the backhoe.

 

[TMGT]

I used 2 separate pins for the swing, without trunion cylinders I don't think you'll be happy with the degree of swing.

Surplus recently had a few trunion cylinders for sale that should work well for that size BH. Haven't checked recently to see if they are sold out.

Other option is make your own trunions.

 

[BFreaky]

Make your own coupling, it's not that hard, this is how I did it