Saturday, 6 June 2015

DIY - Make a pair of Jack stands

I use wooden blocks to strut the car up whenever I lifted the vehicle. 
It is a form of safety procedure. 
It is not good leaving the car on the jacks. 
When the jack seals give way, good bye to dear life.

This is a photo of my finished jack stands.
Finished Jack stands with enlarged 12" base plates

Survey

Here are some jack stands which are commonly available.

Ductile iron ratchet bar with welded steel frames (Usually made in China)
Light weight Aluminium stands. Downside - It topples easily due to small footprint.
This is my initial inspiration.
This is a more sturdy design of the above - made of steel, and the foot print seems small as well.

My initial thought was to purchase jacks online, however shipping was costly.
Hence i decided to fabricate mine.

Fabrication
6" sq. plates x 10mm thick plates welded to 2" square tubes x 5mm thick of 10" length 
Reinforced with 5mm thick vertical plates for strength
Got some 13" length 38mm square x 3mm thick hollow tube.
Bored 12mm holes for pins and M12 engine bolts as retainer pins.
It could have been better if the 38mm sq pipes had thicker wall like 5mm.

Load tested on a 10ft lorry 3.5ton. Per jack holds about 900kg for the lorry.
The footprint was small, so there will present stability issues.
C-channels were welded onto 2" square tubes
and later welded onto 38mm square tubes for strength.
A larger 12" base plate was later added for stability and safety to prevent toppling of jacks resisting sideway force.

Front view: Jacks on my MPV, front axle
Side view: Jacks on my MPV, front axle
The welding needs a bit more work for aesthetics. But the welds hold up.



Consideration
At its first extension of 15" i can comfortably go under the vehicle to work on motor & transmission oil changes.

0.5mm shims were added into the tube space to reduce horizontal play. The ID of the square hollow tube was 40mm and the extension hollow tube was OD38mm. Hence 1mm was on each side and could magnify when extended higher.

As mentioned, it would be great if the extension tubes were thicker, but since it sees extension of only 5 inches, it would be stiff enough to hold.

I have about 4 inches of extension tube retained in the jack stand holder.