Here is my take on DIY wheels cribs. This design variation has a few advantages.
- Stackable storage
- The smaller footprint provides a slightly lighter crib.
- The smaller footprint makes efficient use of 13 pieces of 8-foot 2x4s, and that allows for a wider crib, with longer top.
- Vertical load is closer to the stack of 2x4 frames, i.e. a lower bending load on the 2x4s
I do my own string alignments now with the Caliper Garage setup.
I just got in a Quickjack 7000TL, and so I thought that wheel cribs can help me with alignments. The cribs allow me to keep the wheels on while I raise the car on the QJ, and then do any alignment adjustments. Then I can quickly lower the car and roll it fore and aft before re-checking the string alignment numbers.
I reviewed some of the designs on 6g and watched a few YouTube videos. I decided to improve the common design as described here.
First I measured the needed overall span for the tires on top of the crib. 20.5" for the Mustang, and 22" for the Explorer. This dictates the overall front/back length of the crib. The small footprint allowed me to up-size the top to 24", and so the end blocks won't pinch against the tires.
Then I wanted to know the true footprint length for the tire - less than 7". This is to get an idea of exactly where the vertical load occurs.
Next I checked just how high my QJ can lift the tires off the floor. Over 12" for the front. (Same as for most DIY crib designs.)
But only 11" for the rear tires (even though the latest QJ models raise cars an extra 3"). That's a problem for a 12" tall crib, but fortunately there is enough clearance for the 3" rubber block. This means that a pair of 3" blocks for the rear pinch weld contacts will get me above 12".
And here is the cut plan.
(Cut_Plan also attached as black-and-white PDF for printing.)
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