I have searched and read every thread on 1/4 elliptical front suspension and for the life of me I can't figure out how the leaf spring attaches to the axle. All the pictures I have found are taken from the front and I can't see the "back" view of the axle. So, how does the spring attach to the axle...say a Model A axle for example? Any pics? Shackles? Thanks
Posies sells shackle and perch set for that.I used them on my car.Drilled 7/8 hole in axle,( I-Beam)stuck through and tightened locknut.Line everything up as straight as possible.You will need a panhard bar too so theres no sideways bind.I can send a picture to a email address.Car will be at detroit autorama jimsgotdirt21@yahoo.com
Again,You will also a sleeve welded in drilled hole.Weld that in axle and then install mount.I think I got those at posies too Fedcospeed
Quarter ellipticals use shackles so you would simply have to attach a mounting point to the axle. Drill a hole, use a perch.
Found this picture almost immediately just doing a search for "quarter elliptical" Here's the thread: http://www.jalopyjournal.com/forum/showthread.php?t=146112&highlight=quarter+elliptical
The worst part is that I have that picture saved on my computer and have looked at that thread at least a dozen times...... Sometimes I just fry my brain thinking about this stuff.... Thanks!
HAHA! Know the feeling man! Just a butt load of info on the HAMB and I'm guilty of this very same thing!
I built all of mine, they really work good and it rides pretty good, its a little hard to figure your spring rates but I'm glad I tried it.
They can be mounted without a shakle if you use an equal length control rod. Do some searching on here or do a google search
You can use two of the holes in a drilled I-beam. Sorry for the bad picture ... Then you can hide them with a grill shell.
This would make the spring locate the axle. Good use, not ideal in a handling sense, but more than adequate for the average rod. With 1/4 elliptics, you do NOT use a panhard rod, the angles will lead to binding. As the panhard rod moves up and down, in an arc, that arc tends to pull the axle towards the pivot. Properly located 1/4 elliptics will not allow such movement, putting the axle in bind. Think of 1/4 elliptics much as you would 1/2 elliptics (normal leaf springs), without the roll control. They offer as much lateral control, but allow the axle to roll, which means you need to use radius rods, or the aformentioned control rod in parallel with the spring. Cosmo
Mine is completely home built but I have hit some nasty pot holes and it stayed togeather. you can get the idea here, I drilled the axle and built a bracket and swivel, I used a shackel.
No, because the average 1/2 elliptic is twice as long (at least), and would, by virtue of the length, not be as resistant to lateral movement. Both ends of most 1/2 elliptics are mounted in rubber, whereas most 1/4's have but one end mounted in rubber. And the large end of a 1/4 is the one mounted securely, not the whippy end. 1/4's are stiffer, and generally offer less travel, so a harsher ride. Were travel to be made equivalent, the 1/4 will scrub the leaves just about twice as much, still leading to a stiffer spring. 1/4's do offer better unsprung weight ratios, and the promise of a shorter chassis, as both axles can be cantilevered beyond the frame ends. Roll stiffness will be a bit better, owing more to the inherent spring stiffness than anything else. However, roll stiffness in comparison to a stock Henry suspension is far better. The stock Ford setup offers little in roll stiffness as the chassis tends to roll about the spring mounts. Cosmo
I used a set of 52 GMC pickup springs cut off 3" past the center bolt hole on our O/T BMW rod project here at the school. The springs slid right into 2 X 3 X.188 wall box tubing (the frame rails) cut down to the height of the pack. Lateral control is excellent, BUT the shackles off the axle must be bridged, or the side load will fold the shackle plates around the spring eye. The front axle centerline is 16" past the end of the rails, and it's more solid than the traditional hairpin/buggy spring setup we have on our T-bucket project.
Definitely shackles. Been workin on mine for a while e-mail me with any questions, I'll help if I can. Here's mine; Rick.
Hey exwestracer, can you explain what you mean by "Bridging" the shackles, & about the shackles wrapping around the spring eye? I'm guessing the shackles would bend sideways? Shouldn't the radius rods take that load? Rick.
Here are some photos of a slick little T with Quarter epileptics. The photos were taken in 2005 and I didn't get to talk to the owner of the car at the time.
I can. It simply means that the shackles need to have a sheet bridge (1/4") from one side to the other, thereby making them one piece. That way they won't be able to move separately. Not at all. The radius rods keep the axle from twisting under braking loads. Now, heres the thing: you must use radius rods that solidly locate the axle, or four bars. You can use 1/4's direct on the axle, but you then must allow the radius rod a pivot similar to a four bar; in essence, it becomes half a four bar. A front axle must move in one direction: vertically. Yet both ends must also be able to move independently. Add braking loads trying to twist the axle, and steering loads trying to push the axle out from under, and you have a pretty picture of what you need to resist. And, even more complicated: you should not put the axle in bind at any time, or you will break something. Modelling the whole makes it easier to visualise. So, with a 1/4 leaf-suspended car: the leaves resist the lateral (steering) load; the four bars resist the braking loads, yet allow for independent movement. Radius rods will force the axle to act as a swar bar, which will break something eventually. I have seen big Danas twist the tubes out of the center section when located by ladder bars. Ladder bars are the same as radius rods, we just call them that when they are locating the rear axle. Too wordy by half, sorry, but I haven't had my coffee, yet. Cosmo
Cosmo did a great job of explaining it. Here are a couple of pics. We are using 42" hairpins to locate the axle. The springs provide the lateral stability. You can see the bridge plates in the shackles in the close-up. Don't bother bashing the car...I've heard it all before and I'm just tryin to answer a question.
Thanks for the info guys (& sorry if I'm hijacking this thread, but it seems like quite pertinent info to the original question). So the bridge connects each individual pair of shackles (not both pairs together) correct?. I was planning on doing that. My shackles are off a '57 truck, & have a bolt hole in the middle made for just that. Since this is my first time using an eliptical setup, (& if you don't mind), can I get an opinion on my setup? For the radius rods I used a rubber bushing connection at the frame, & hard bolted to the axle.;
Here's one mounted Miller style http://www.jalopyjournal.com/forum/picture.php?albumid=11584&pictureid=134762
Hmmmmm...I am a bit confused....imagine that.....can you explain how the radius rods must locate the axle solidly? Are you saying that radius rods/hairpins should not be used and a 4-bar is better? I would like to use hairpins and an I-beam axle...will that work? Would I use batwings to mount them?
This is exactually the wrong way to do it . If you use a hairpin or radius rod the leaf spring must allow movement because of the arcs that the radius rod moves in , this needs a shakle or floated on the spring end. This setup has the leaf spring fighting for movement and will be very stiff ride and eventually break something.
Yes, four bar is better, but with 1/4's, you can use just one per side, parallel (or so) to the spring. A bit more: yes, radius rods and an 'I' beam can be used together, as the 'I' beam will twist enough without hurting it, BUT, this makes tuning the suspension a bit more difficult, as you have effectively added a sway bar. And it is true that light rods (such as this is) won't really put that much sway into a chassis. But just because the application won't put that much sway into the axle, is not good excuse to build improperly. I do know that 'T' buckets CAN ride well. And the center of gravity is so low that cornering, even with generous suspension movement, it still feels slot-car like. Granted, most rodders aren't that interested in tuning the suspension per se. Yet it should be known. Split radius rods and a tubular axle are not to be used together. Think about what happens to a tube when you twist it. Yes, that 'T' pictured should have either shackles, or the 'half a four bar' I mentioned earlier. The way it is set up now forces the springs to either telescope or bend unnaturally. However, looking at it more reveals: the car is very light, and the spring pack is far too heavy, so that front end really doesn't move. IOW, it really has no front suspension. Modelling is your best friend. No need to be exact, but tight tolerances on the pivots, or exaggerated movement will show up the deficiencies in most setups. You can go extra fancy and play with the spring length vs. the locating rod length to adjust the anti-dive in the front. Using just one locater in front (centered) and two 1/4 elliptics has been done, but good braking will twist the axle and likely cause axle hop under braking. Cosmo
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