Apex joint operating angle problems............

[jonny8]

The apex joint we have purchased only seems to operate up to an angle of about 35 deg where else we need it to go up to 65 degrees. The model is a MS20071 b12 purchased from Pegasus automotive.

Can it be modified to operate at higher angles?

Are apex joints made that can opaerate at an angle up to 65 degress?

How good a solution is using two and doubling them up?

Thanks for the help

[ben]

I would definitely run two back to back. I believe its called a double cardan joint.

Ben

[Marshall Grice]

sounds like you're joint is working exactly to spec. they're only rated to 35deg. make sure that when you double them up you get the phase right. (easy way, line up the inspection holes)

[mtg]

Don't run them at greater angles than they are designed for. I proved that a couple years ago- they wear out pretty quick when the misalignment angle is too high.

[Ben Beacock]

The Apex and FlamingRiver joints are both 'mil-spec' so I looked up the spec. They must be able to perform their life ratings at 30deg maximum angle. They may work at 35, but I made sure ours weren't being used past 30deg for reliability reasons. We used the double joint setup and worked hard to make sure each was at the same angle and then phased properly. The steering was much smoother and loose with the careful attention paid to bearing alignents and angles.

[TG]

First year team... so I have yet to come to this, but how much "slop" is introduced into the steering by each apex joint?

[Ben Beacock]

Originally posted by TG:
First year team... so I have yet to come to this, but how much "slop" is introduced into the steering by each apex joint?


Essentially none. I find it much more important to find (or make--if you have the resources) a quick release with as little backlash as possible. Also make sure the bearing mounts are stiff.

[GTmule]

Those Hex quick releases SUCK. Our used Stiletto rack, apex joint, and kinda homejob bushing are nice and ticght, out 3 year old hex put about 500 degrees of play in.

[TG]

Yeah I've heard of slop issues in the quick release. You want involute splines. I'm trying to write up a macro to do involute splines and gears (at any bevel angle). I talked to the guys at U of A to see what they've done and they have a button in SolidWorks that just lets them enter in values. I don't have it on mine and was wondering if it's because I'm running the student version?

[rjwoods77]

I have always dealt with sweet mfg. Their u joints and quick release are real nice. Needle bearing on the ujoints and the entire quick release with the steel spined connector are pretty good. Also they provide steel splined steering shafting that is cut to length for cheap. Prices are good too and very available. They primarily support dirt and asphault circle track. Check them out. Their ujoints have a max operating capacity of 35 degree as well.

http://www.sweetmfg.biz/

[jonny8]

Right,

So two apex joints is the way fwd.

What about joining the two together?
I assume it is better to have a short piece of steering column linking the two?(welded one end, pinned the other).

Thanks again

[Frank]

You have to be careful with indexing those little apex joints

They have "sight holes" at 90 degrees, which are true to their construction.

The stamp is applied randomly (it does not indicate the orientation for indexing)

Because you can't disassemble them easily (at all in my opinion), then you have two options to find the correct indexing

Option 1: feel through the rubber cover, there a pin, and the male section can also be determined. Do this to each joint and index them accordingly.
Warning: this is not easy.

Option 2: get them x-rayed.
Take a film with the index holes lined up, and a second shot with one of the joints axially rotated 90 degrees.
Mark the joints with A on joint 1. B on joint 2. C on joint 2 at 90 degrees.
Use lead markers on the films, identical to the pen markings, so you are sure which way the shots were taken.

Two indexed joints at the same angle gives speed balance. BUT, if the input, and final output shaft are not parallel (as is common with FSAE cars using a rack mounted below and behind the axle), the joints will be damaged by the moments and forces.

5/8" bore apex joints should last a year ok

Regards

Frank

BWT, I simply x-ray them at the uni vet school 50kv(peak) for about 1000mAs on fine grain film.

It dosn't "see" through the steel, but does through the aluminium and rubber, allowing you to see the "shadow" cast by the steel crosspin.