Homemade Backhoe for LS Tractor (XG3140)

[polemidis]

Hello guys, I was thinking to make a backhoe for a while now and I was always postponing it, but I read Bfreaky's post last week and I decide to go ahead and do it. I will definitely need your help because there are so many stuff I do not know. For the history, I have my homemade 4'x8' CNC Plasma cutter, so I can cut steel up to ｽ" thickness.

Here is the preliminary design. Its a rough outline. No time was spent on details (nice curves etc) as these will be added as soon as the main geometry is final. I haven't work on anything below the king pin or the mount (tank, swing, sub-frame details etc). But I am pretty close on the geometry on the boom/ stick/bucket, and the Prince Hydraulics cylinders (Wolverine line) fit perfectly. (If later on I found cheapest cylinders I will adopt for them, but I thought its a good idea to use a common size cylinders)

The width/profile/thickness is just an estimate, I will try to make a rough analysis on the stresses now that am leaning towards to use 3.5" diameter cylinders.
One thing that I do not really know is the pin/bushings fabrication. Where do I find these? I tried Mcmaster but I am not sure what I have to look for. One possible scenario that I am thinking is to get 1.25" cold roll round steel for pins, and then for use DOM 2" OD with 0.375" wall for bushings. Any other ideas?

The grey box except the main mount, it will double as a reservoir as a PTO pump will provide flow to the BH.
I am not rushing with this project, as I am working on it on my free time, and it has a lot of details to be filled in, but I couldn't wait and I wanted to share it with you guys!
Bfreaky its all your fault man, you infested me with that virus!!! (Of course I used your post as my "research" to Backhoes, many many thanx!!)


I am open to any feedback and criticism of course

EDIT: The files are open source for personal non commercial use. Once this project is done, I will be glad if you replicate it for your own use and save some money. You can access them here. Any contribution to this project is appreciated (feedback,comments, ideas, mistakes to be avoided etc)

 

[BFreaky]

I'm very happy it's my fault . One thing I have to comment...your lifting cylinder geometry is bad..it will lose alot of force at the highest point. Pull out your lowest point of the boom at the swing mechanism. Angle between lifting cylinder and boom is way too open

 

[polemidis]

I'm very happy it's my fault . One thing I have to comment...your lifting cylinder geometry is bad..it will lose alot of force at the highest point. Pull out your lowest point of the boom at the swing mechanism. Angle between lifting cylinder and boom is way too open

Do you mean this one? Its 4" horizontal distance now

 

[BFreaky]

Yes, that's what I mean

 

[ptsg]

Having built a backhoe myself knowing a lot less than I do nowadays, I definitely have an huge consideration and respect for everyone who builds this. I will be following this thread for sure!

So far looks very nice. And I agree with BFreaky on the lift cylinder. I will also suggest that you make the bucket close a bit more either adjusting the linkage or redesigning it, because if you try to dump a full scoop of dirt into, lets say, a dump trailer, it might fall quite a bit when you lift the stick.

Again, looks very nice so far. Looking forward for more updates.

 

[polemidis]

Thank you guys. I forgot, the project is open to anyone for non-commercial use! You can download the CAD files from here You need Freecad to open/edit them.

 

[BFreaky]

Ptsg, I agree. Bucket has to close all the way, movement angle of the bucket is almost 180 deg. Otherwise you spill alot of material when lifting high

 

[Stimw]

Find a local dealer with an attachment, go there, take lots of pics and measurements then build it.
Or you can just reinvent one.
Someone else has done the R&D and it is much easier to copy it.
Check out Surplus Center for hydraulic supplies, they are a sponsor here with great prices.

 

[ruffdog]

I would be more apt to start with something like this smaller Case attachment for less than $3k.

Backhoe - farm & garden - by owner - sale

 

[BFreaky]

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