Welding gauge? wishbone to frame

[Phil1988]

Hey everybody,

got a important question. How do you arrange it that your supension geometry is the same as in the kinematic programs in the fabrication process?

As an example: How do you get the wishbones to the right point on the frame? Do you have any gauges? Do you have pictures of them?

Regards Phil

[Ben K]

Some teams use FARO/ROMER measurement arms. Some teams do very careful measurements. Some teams use lasercut jigs to hold the tabs in the right spot. It all depends on what kinds of funds you have available and how much effort you want and need to put in. It might be worth doing a sensitivity analysis to determine what kind of tolerance you can deal with and still be satisfied.

Fact of the matter is you can be dead on with your suspension points, but ultimately tuning the car long term will truly give you the performance you desire.

Ben

[Warpspeed]

Phil, You will need to build your chassis on a rigid chassis table, and use jigs to very carefully position and hold the various parts in position while final welding.

With a bit of thinking ahead, planning, care, and patience, it is possible to build a reasonably accurate chassis with fairly simple equipment.

Once all the suspension pickup points have been attached to the main frame, you then use adjustable links (or shims) for final adjustment.

[Will M]

No matter you do you will never match CAD exactly.
It may be worthwhile to do a sensitivity analysis on your pick up points and see what level of accuracy is needed.
In most real world settings you first set quality goals and then choose the method of manufacture.

A tape measure and pencil may prove to be sufficient.
Or a 5 axis CNC may be needed.

-William

[Ben A]

Well, you can use a 3D mesuring instrument like Faro or so. Or you can build some mounting device where the points to each other have the exact position like your hardpoints. And then adapt your pick up points to the frame. Or use folding yardstick and a good pair of eyes.

[Jan_Dressler]

Hi Phil,
I agree with everything above. You can also contact us at http://highspeed-karlsruhe.de/index.php?id=273 and talk to our suspension guys, or simply come and visit us - we are just 30 km away from you! http://fsae.com/groupee_common/emoticons/icon_wink.gif