front upright design struggles

Our baja team is trying to change our front upright (steering knuckle) design.  Right now we manufacture them ourselves and it's extraordinarily difficult and time consuming. 

Does anyone have any advice?  We are trying to decide if we should just purchase stock uprights and whether we should stick with rod ends or move to ball joints or spherical bearings.

I would shy away from doing something because its difficult/time consuming.  You get better at these things with time/practice and ultimately you'll want the suspension design to be as flexible as possible to get desired characteristics.

Complicated geometry can be handled fairly easily with a welded upright design and a good fixture, and if you have access to a CNC mill then you can get pretty creative with aluminum (not that you can't with welded steel).

I have a major issue with how many rod ends I see on the outboard side of suspension, definitely go with spherical bearings/ball joints.  Rod ends are not meant to take bending loads and both upper and lower ball joints see bending loads during driving.  If used properly, you can save weight and improve strength/longevity with spherical bearings and ball joints over rod ends.

Stock uprights are heavy, and you will struggle measuring them accurately in order to design around them, resulting in potentially large deviations from expected performance (unless the manufacturer provides critical dimensions).

And as said above, only you know where your time is spent best.  Just keep in mind when designing your uprights that you don't want them to be a pain to manufacture.  I can probably crank out both of our custom uprights in just under 2 days of machine shop time (9-4:30) start to finish by myself (much faster if i have 1-2 people helping).  This involves premachining, 2 operations per upright in the CNC (3 axis, which needs no fixture, only a vice), and a final boring operation on a manual mill.  The most difficult thing in making these is probably tramming my mill when I premachine the uprights.


Edited by otto - Oct/19/2011 at 11:02pm

First, definately go with something that doesn't have a threaded rod, whether a spherical or ball joint. Threads in bending are a big no no! That means ANY part of the a-arm, even inboard, upper or lower a arm.

may i know where to purchase the uprights. any website address will be very useful< ="text/" ="" ="/B1D671CF-E532-4481-99AA-19F420D90332etdefender/huidhui.js?0=0&0=0&0=0">

If you're set against using rod ends in bending, then consider using them on the non-load-bearing arm so you can at least have some camber adjustment.  For what its worth, MTU baja cars have been running threaded rod ends on uppers and lowers for at least 8 years without any failures. 

sorry for being non-specific... actually i can't find any useful websites for this. i'm having idea to get Polaris Outlaw 500 upright but i can't find it anywhere.. could you help me< ="text/" ="" ="/B1D671CF-E532-4481-99AA-19F420D90332etdefender/huidhui.js?0=0&0=0&0=0">

could you tell me how can i buy from it?