Bale Mover

[farmersamm]

Caps turned out ok. I really like this way of doing it.

There's a lot of locked up stress in the brackets. I believe 7018 has greater heat input than some wire processes. Ten separate welds in a tight area. Lotta heat that tends to create distortion.

Straightening had to be done at every step. Sometimes with "back beading" as above.

Sometimes "heat shrinking"..........running a dull red strip(or multiple strips), then using water to cool it rapidly. Causes the metal to shrink where it's been heated, which pulls the curve out of it.

 

[farmersamm]

Welding the lift arm pin brackets to the tool bar/beam bent it like a banana. (see the air gap below the brackets.....they don't rest on the bottom piece of tubing)

Today we're getting into the Black Arts.........................

The beam is analyzed to see where the bends occurred. In this case, they occurred at each weld point. 3 different places. Blocks are placed beneath the beam. Two to act as a reference, and one to act as an anvil to restrain the heat shrink bend. The middle block is the anvil.

Like I said, the middle block is the anvil. This block will prevent the beam from over shrinking when heated/cooled. The bend will stop exactly at the top of this block, and go no further.

Next, we add a force point to provide restraint when the metal is heated. The clamps prevent the metal from simply heating and expanding, and then simply going back to its original shape without relieving the bend. THESE CLAMPS ARE NOT BENDING THE BEAM.

The beam is heated at the APEX of the bend. Clear across the flange, and to the neutral axis on the web. This is a wedge heat.

Heating is to the dull red state (1200* F). Then quenched with water. I might note.........quenching of mild steel does nothing to alter its mechanical/chemical properties.

After quenching, the clamps are removed.............and we have perfection. The gap is closed, and this section of the beam is straight once again.

This is done another 2 times at different places...................................................

The beam is flipped over to check the work against a known straightedge.

We's in business!!!

This will be repeated after the next round of welding. I straighten everything as I progress. It's the only way to assure a straight build. If the steel is straight, as designed, it will better be able to resist any forces encountered when in service. And, it just plain looks better

I hate seeing sloppy work that looks like a bent noodle after welding.

 

[farmersamm]

Before I get outta here for the day, lemme explain some of the mechanics for those who aren't familiar.

Welding involves heat. We all know this.

A weld contracts when it cools, and exerts force on the surrounding metal.

If welds are one one side of a beam, they're in a state of imbalance. If identical welds are on both sides of a beam, they cancel out the distortion caused by the first weld. It's an equilibrium thing.

Mild steel has a yield point..............the point at which it bends, and does not come back to the original shape. This point is between 36Ksi to 50Ksi. That's a lot of strength. 50,000 pounds per square inch at the max.

A cooling weld will exert this kind of force. It's amazing actually. This force is what bends the metal. It's caused it to yield.

When metal is bent by this force, the apex(outside) of the bend has stretched. It's yielded. It's no longer in the intended shape it was as it came out of the mill.

To get the metal straight again, we have to correct that stretch. We need to put the genie back in the bottle.

How do you correct stretched metal? You need to shrink it.

Heating a small area causes the metal to expand. BUT IF YOU PREVENT IT FROM EXPANDING BY THE USE OF FORCE, OR THE WEIGHT OF THE STEEL......................it cannot expand. It causes "upset". The metal actually moves above the surface of the surrounding area because it has nowhere to go. When the heated area is cooled, it shrinks..........pulling the surrounding metal back into shape. It's like a very powerful mini come along.

Heating a small area, to move a larger area.

For another explanation see....................................

https://www.fhwa.dot.gov/bridge/pubs/hif23003.pdf

I discovered this in a reference in "The Bible" about 30 years ago...................... The Bible is the "Lincoln Procedure of Arc welding".

Procedure Handbook ''Fourteenth Edition''

www.jflf.org

I'm self taught...............welding, and machining. There are a large number of good references out there. But for welding............The Bible is the King. For machining............Machinery's Handbook

Machinery's Handbook - Industrial Press

Machinery's Handbook, 32nd Edition, Print & Digital (also see Combination Packages below) 32nd Edition Companion Guides & Original 1914

books.industrialpress.com

It's all out there, if you take the time to read it.

edited for spelling