Tilting Jig / Body Cart Combo Build

Happy New Year!

Front End Jig Installed

Kerfed Curve for Front End Jig

Internal Structure for Front End Jig

Revised Curve for Rear End Jig for Increased Strength

Wood Gluing and Laminating the Plywood Stack

It's been just over a month since I began working on the 240Z and progress was smooth until the Christmas holidays.  That's not to say that the holidays caused the slow down, rather, I was working out the design for a wooden tilting jig that was safe, strong, functional and affordable.  I'm happy to report that the jig is complete and performing exactly as designed.  

Watch the videos below to see the me roll the 240z easily on the 4.5" locking casters and tilt the car on its side with assistance from my brother.  I decided, after much internal debate, to go with a home-built solution for getting the car on its side.  A rotisserie would be the dream solution and something I intend to purchase in the future should I find that I am regularly needing to do this type of work.  For the present however, this is the ideal solution as it's cheap and super functional and will take a minimal amount of shop space to store later on.  

I spent a little over $300 on materials with 1/3 of the cost going to casters, so this is a setup that could be made for under $200 easily.  The price of screws caught me by surprise with a small box of 100 2.5" at Home Depot costing around $13.  Surprisingly I used nearly 200 screws per jig.  That may be overkill, but I wasn't being wasteful either so if anyone out there is planning to make something similar, maybe spend some time to design something less reliant on screws.  

I designed the jigs like I would design a wall with plywood sheathing and a double stacked 2"x4" header.  This is a design standard for wood frame houses and the loading capacities are well documented in the Canadian Wood Frame House Construction book (https://www.amazon.ca/Canadian-Wood-Frame-House-Construction/dp/0660195356).  The jig is not static like a building and must support the weight of the vehicle throughout a full 90 degree rotation and must be stable indefinitely while fully tilted.  In order to ensure that the jig was up to the task, I went with a stressed skin structure of 1/2" plywood sandwiching a 2x4 frame.  I fastened the plywood to the frame at 6" intervals or less for adequate shear strength.  

In order to prevent the bolts that hold the car and jig together from tearing out while tilted, I manufactured reinforcing plates of 1/8" steel to distribute the forces over a wider area which I placed under the double 2x4 header/beam.  

For mounting in front I used the existing 4 bolt holes and reinforcing plates at the front subframe mounting location.  In the rear I used the two stock bolts that hang down to accept the mustache bar ends at the bushings.  There were minor clearance issues with the rear at the spare tire well that were easy to troubleshoot and no issues in the front.  Both front and rear jigs have additional bracing to eliminate moment/rotation and to eliminate any flex in the connections that would otherwise lead to failure.

As you can see in the photos above, I used a kerfed curve for the front jig and a layered plywood laminate curve for the rear.  The kerfing proved inadequate and needed considerable reinforcing so I switched to the laminate method as any weak areas are reinforced in the layering process.  

Cost for Materials: 

2 sheets 4'x8'x1/2" plywood      $90

10 2"x4"x8' studs                      $50

Screws (2.5" x 400)                   $40

Lag Screws (1.5")                      $13

440# Casters (x4)                      $110

Total:                                         $303

The 4.5" polypropylene locking casters (from Princess Auto) allow the frame to glide around with ease and stay put when necessary.  I'm over the moon with the performance.      

Tilting the car is a 2 person job and requires about 100 lbs of lifting force total

Support beam mounted to right rear strut tower

The removable tabs/levers make lifting easy