Heavy Duty Jack Stands

No nonsense, not-your-mother’s, trust your life, set of stands.  Meant for heavy duty use, and heavy loads.

Base Section

The fixed portion of the telescoping assembly had to be designed using 4″ tubing.  In order to allow 3″ tubing to slide inside the 4″ tubing, a diaphragm had to be incorporated to make for a good tight fit.  The size difference in the tubing would make for a very sloppy fit.

Diaphragms are made.jackstands1
One is welded to the shorter piece of 4″ tubing.jackstands2
A second piece of tubing is cut, and fitted.jackstands3
The second piece, and the remaining diaphragm, are then welded.jackstands4jackstands5
The fixed tubing assembly is then welded to the base.jackstands6
There was considerable distortion during the welding.  This is normal.jackstands7
I’ve heard countless numbers of people claim to be able to control this type of heat distortion with clamps, strongbacks tacked to the material, etc.  Folks…it just ain’t so.  Where there’s heat, there’s distortion.  You can clamp the daylights out of something like this, and when you remove the clamps, it will still be bowed.

At this point, it’s time to get out the heating tip.  A BIG ONE.jackstands19

Heat is applied to the convex side of the bowed metal, then it’s allowed to shrink as it cools.  Cooling can be accelerated by misting the area with water.  This is the point where strongbacks come in handy.  They restrain the metal so that shrinkage actually takes place.  If the metal is left un-restrained, it will simply return to its original warped form.  Some heroes claim to be able to do this without restraints/jacking/peening, but there again, it just ain’t so.jackstands8jackstands20
The heating in the above picture was done in bands.  Working from the center of the piece to the outside.

Unless you want to change the molecular structure of the metal, you have to adhere to strict guidelines when it comes to heat application.heatt6The acceptable heat range is between 300-700c, or 700-1300f.  The above chart gives a good approximation for those who don’t have access to a high range IR thermometer.  Care should be taken when working in direct sunlight, it will mask the actual color of the steel.  The heated area should be shaded to see the actual color.  A dull red is a good indicator of the amount of heat that’s been applied.

Peening is not pounding.  The heated area may be peened to relieve stress.  This allows it to contract easier when it shrinks.  Don’t hit it like you’re driving fence posts. 😀  Hit it with light to medium force.

 A final word on heat shrinking.  IT IS NOT HEAT WORKING.  Heat working brings the metal to a plastic condition with a very large amount of heat, then it is pounded/bent into shape.  At these heat ranges, the molecular structure of the metal will change.

Telescoping Section

This section is adjustable for height.

Holes are drilled at intervals.jackstands14
Because the tubing is 3″, and the annular cutter only cuts 2″ deep, it’s necessary to find a way to be able to flip the tubing to make a cut from both sides.

The piece is measured, and scribed, at each hole location.  These serve as indexing marks.jackstands11
The milling vice is marked at its center point.jackstands12
The marks on the piece are lined up with the index mark on the vice.  Holes cut through one side of the piece.  Then the piece is turned over, lined up on the same marks, and holes cut through the second side.  These will line up perfectly, even though the piece has been moved to flip it.  The index marks assure you of complete accuracy.jackstands13

Ready to go to Work

Safety tangs are added to the saddle.  Really only necessary for lighter loads subject to shifting.  The shim between the pad, and frame rail, is to level the load where it happens to be sitting.jackstands17

The weight of the semi trailer falls very easily within the design capacity of the stands.  These are heavy built with safety in mind.jackstands16
misc,_stuff_020THE LOGO

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