Internal reinforcement in DIY backhoe boom?

[NearBeer]

Thanks for your time. I have access to some plate steel and have been sketching some ideas out for a stand alone mini-backhoe. Does anyone have any plans or pics of how they reinforced internally the boom? Seen lots of pics of a completed boom but none that shows where and what type of reinforcing pattern they used in fabricating the boom. Any help/advice is apprciated.

In search of my next cold one,

NearBeer

 

[J_J]

I am not sure what you mean by internal bracing. On my boom, each one of the rotating pieces had a DOM 1 in ID X 4 in tubing welded for the 1 in pins. On the bent section of the boom, 1/4 in steel plate was welded across the joint for reinforcement. It also depends on the thickness of the wall on the box tubing. For light duty, I believe they use 3/16. and 1/4 for med duty, and 3/8 for heavy duty in the DIY booms. If you have doubts about the strength of the tubing, you can add 1/2 in strap down all sides. I haven't done that yet, but might in the future. In my opinion, the box tubing should be 1/4 or better, and all end pieces and joints beefed up with 3/8 plate, with 1/4 in wall DOM tubing on all rotating joints, with grease fittings.

 

[NearBeer]

Forgive my lack of clarity in describing what I am trying to ask. If you were to take 4 equal width pcs of sheet steel and were to butt weld them to make a rectangular boom, would you add some type of bracing internally (attached to the inner walls/faces) prior to welding the final piece to complete the boom?

Still searching,

NearBeer

 

[kennyd]

No, the booms are hollow. Often a plate is welded over the butt-weld to reinforce the joint.

Maybe you should search for some plans instead of another beer

 

[J_J]

Butt weld a sheet metal boom , and lift WHAT????????

 

[NearBeer]

I haven't found the beer yet...wife is hiding it from me.

FWIW...not sure of actual fab procedures...my comment about butt welding was to better describe my question. Thank for the input

 

[Pooh_Bear]

You are talking about making square tubing?
And making seam welds?

If the steel is wide enough have it bent into a square channel.
Then weld the 4th side onto it.
Or have it bent into angle iron and weld two pieces together.
As long as the metal is thick enough I don't see why it wouldn't work.

Pooh Bear

 

[GT2]

I think he is refuring to fabricated booms etc. Like NH curved boom backhoes.
The booms are welded together from 4 pieces of pre cut steel plate ( not sheet metal! ).

 

[simplicityguy92]

you would have to stich weld the whole cuz of warpege and that would take awhile

 

[irvingj]

NearBeer-- from an engineering standpoint, you want to have as much mass as possible away from the axis of bending-- i.e., a hollow sructure. Unless you go for an intricate 3-dimensional internal triangle web construction (!!), you want to leave the inside empty.