- The roll cage must be a space frame of tubular steel. The required members of the roll cage are:Primary members :
- Rear Roll Hoop (RRH)
- Roll Hoop Overhead Members (RHO)
- Front Bracing Members (FBM)
- Lateral Cross Member (LC)
- Front Lateral Cross Member (FLC)Secondary members :
- Lateral Diagonal Bracing (LBD)
- Lower Frame Side (LFS)
- Side Impact Member (SIM)
- Fore/Aft Bracing (FAB)
- Under Seat Member (USM)
- All Other Required Cross Members
- Any tube that is used to mount the safety belts
- When minimal dimensions are given that is to the centerline of the members, and when a clearance for the driver is given, it is defined by the outside edges of the roll cage members less the padding installed
- Required dimensions between roll cage members are defined by measurements between member centerlines, except where noted.
To start with the designing of a roll cage, the first thing that has to be done is to create a new SLDLFP part for the weldments purpose of the roll cage. It has its own specified dimensions stated down by BAJA, therefore we have to design it ourself. There are two types of parts which you have to design, first for the primary tubes and second for the secondary tubes. If you have any confusion as to how to design an SLDLFP part, then check this article (Error: Library feature is empty! [SOLVED]) which will surely help you out with this. So let’s begin!
1.DESIGNING THE FIRST TUBE(PRIMARY TUBE):
Draw two concentric circles: Having outside diameter of the tube as 25mm(1 inch) and the thickness of the tube as 3mm(0.12 inch). Then save that file as SLDLFP part to C:\Program Files\SOLIDWORKS Corp\SOLIDWORKS\lang\english\weldment profiles\iso\TSI( This is the default path. TSI is a self-made folder by me, you can make a folder with a different name as well).
2.DESIGNING THE SECOND TUBE(SECONDARY TUBE):
Draw two concentric circles: Having a minimum outside diameter of the tube as 25mm(1 inch) and the minimum thickness of the tube as 0.89mm(0.035 inch). Then save that file as SLDLFP part to C:\Program Files\SOLIDWORKS Corp\SOLIDWORKS\lang\english\weldment profiles\iso\TSI. The files will be saved as shown.
3. Then starts the sketching of the roll cage:
Open SolidWorks and in a new sketch click on 3-D SKETCH. You will have a screen like this. Start sketching the roll cage abiding by all the rules of BAJA SAE India For the rules refer to the rule book by BAJA SAE.