Jump to content

One link suspension setup without a panhard rod


Recommended Posts

There is no frame flex at all, its a box chassis with a multipoint cage tied into it.

Looks strong, well built and ought to be fairly rigid. I only mention it as it would be unusual in something so short and with that type of construction but in the first and last photos where you can see the top of the cage it looks slightly twisted down at the front at the driver's side and down at the passenger side at the rear corresponding to the movement of the wheels and the crossmember with the towball on it doesn't look parallel to the top tube either again corresponding to the wheel movement. Might just be an optical illusion with the way camera lenses work too maybe. All frames flex a bit if they're made from metal and have a torsional load placed on them, just some move more than others depending on the design.

Link to comment
Share on other sites

How much does it weigh in all?

Is that REALLY a jimny? :)

That looks good Diesel! Very well balanced - which is a very under-rated attribute by vehicle builders.

My first Suzuki build (with the Indi Suspension) weighed in at 950kg including 37" tyres and two winches and my current Jimny weighs 1117kg with Toyota 80 Series Axles, 37" and winches. If you start with a light vehicle, it's much easier to keep it light than to lighten a heavy vehicle!

Better than that though - you can buy a Jimny with MOT for less than a new steering wheel for a Defender! Surprisingly few people build stuff out of them, so when they start to look a bit too tired for the Supermarket, the price falls like a stone!

Si

Link to comment
Share on other sites

Looks strong, well built and ought to be fairly rigid. I only mention it as it would be unusual in something so short and with that type of construction but in the first and last photos where you can see the top of the cage it looks slightly twisted down at the front at the driver's side and down at the passenger side at the rear corresponding to the movement of the wheels and the crossmember with the towball on it doesn't look parallel to the top tube either again corresponding to the wheel movement. Might just be an optical illusion with the way camera lenses work too maybe. All frames flex a bit if they're made from metal and have a torsional load placed on them, just some move more than others depending on the design.

Well spotted Jamie, The cage is a litle bit twisted, but it mostly doesn't look right becasue it doesn't quite fit the jimny chassis perfectly.

The cage started off as a partially spaceframed fiat panda that i built for my youngest brothers 12th birthday, The cage was built to fit the slightly battered panda not to be nice and square, when the panda finally died the cage was grafted onto the jimny chassis, that was 8 years ago since then its done a lot of trials and suffered quite a few heavy rollovers, at some point whilst its been on the jiminy the front hoop developed the twist

I'm pretty sure these 2 pics were taken in early 2000

buxplayday007_zps164afa8f.jpg

buxplayday003_zps9eca883e.jpg

Link to comment
Share on other sites

  • 2 weeks later...

I was thinking about the 1 link with the a frame.

Rather than a sliding joint, a 2nd a frame with the bottom of the a on the axle or 1 link.. joined to the other 1 link with a ball on the chassis one and the socket on the axle one

The axle a frame would pivot forwards and backwards, similar to the sliding part.

Would all depend on clearance, but as long as the separation between the chassis a frame and the 1 link wasn't to much it would be minimal.

Link to comment
Share on other sites

Nice work dirtydiesel, great to see a different approach to things like this.

A quick question, and I dont mean to hi jack your thread, but it relates to one link with no panhard. Some may have read a thread on pirate about "3 link with wishbone lower"

http://www.pirate4x4.com/forum/general-4x4-discussion/1112415-3-link-wishbone-lower.html

I asked the question that if they ran the wishbone with its single end at the chassis (like a one link) and just had straight/parallel upper links, what would do the lateral location? They are saying it is just like if the single end is at the axle, no difference and that the straight/parallel uppers will control lateral movement. Im saying not.....

Link to comment
Share on other sites

Straight/parallel uppers will control lateral movement in the above scenario, to allow lateral movement the uppers would have to become longer on one side and shorter on the other. If all joints were very large and compliant bushings you would get some minor lateral movement but rose or ball joints would eliminate that

Link to comment
Share on other sites

here is where I have the problem (haha). The arc that the wishbone/one link would scribe when pivoting from the chassis, would have side movement in it, much more so than if it had the single/pivot end at the axle centre. I would have thought the missalignment in the rose/heim joint would allow this lateral movement to occur?

It seems Im wrong on this one :mellow:

Link to comment
Share on other sites

here is where I have the problem (haha). The arc that the wishbone/one link would scribe when pivoting from the chassis, would have side movement in it, much more so than if it had the single/pivot end at the axle centre. I would have thought the missalignment in the rose/heim joint would allow this lateral movement to occur?

It seems Im wrong on this one :mellow:

I have just woken up, so I am having problems getting my head around it too Serg. Without drawing it out, my minds eye sees that bushings with any compliance at all will allow lateral movement, or rose joints would be stressed laterally, a direction they weren't designed for. I think the bloke on Pirate who suggested to look at it as keeping the chassis centred with the axle, as opposed to keeping the axle centred with the chassis might have a point.

Anyway, we know that rose joints are not legal for registered vehicles in Australia, so a similar system must be made to work safely with compliant bushings.

PS, after a cup of coffee I am thinking more clearly, so ignore much of the above.

I am looking at the One link I have been fabricating.It is standing up vertically on the ground, bolted up to its pivot on the removable chassis crossmember. I'm visualising a straight upper link beside it perpendicular to the crossmember of the same effective length as the wishbone with a vertical separation of 150cm. The straight parallel link is 70cm long bush to bush, where as the distance of one of the legs of the V shaped one link wishbone is 87cm, measured from bushing to central pivot axis. As the axle moves laterally relative to the chassis, that 87cm will scribe an arc more perpendicular to the crossmember, trying to push the axle further forward on that side, and the leg on the other side of the wishbone will try to pull the axle rearwards. But the parallel straight links won't allow either side of the axle to move for/aft, because the straight link on one side will try to roll the axle housing forward whilst the straight link on the other side will try to roll it rearwards. This would require the axle housing to be twisted in opposite directions, which for the purpose of the mental exercise we will call impossible.

Clear as mud, yes?

Link to comment
Share on other sites

In a nutshell Serg. pirate is right,

The system that is being described is exactly the same as whats fitted to the back of any coilsprung landy, the geometry of the links is the only important factor, the arrangement makes little or no difference.

whether you have the wishbone (A frame) converging at the axle or the chassis, in either the upper or lower position, the lateral movement of the axle will still be controlled to exactly the same degree.

The only thing you will alter is the amount of axle walk you will get under articulation.

which is another lovely advantage to the sliding A frame, Zero axle walk :D

Link to comment
Share on other sites

I was thinking about the 1 link with the a frame.

Rather than a sliding joint, a 2nd a frame with the bottom of the a on the axle or 1 link.. joined to the other 1 link with a ball on the chassis one and the socket on the axle one

The axle a frame would pivot forwards and backwards, similar to the sliding part.

Would all depend on clearance, but as long as the separation between the chassis a frame and the 1 link wasn't to much it would be minimal.

I think you may be over thinking the problem Mark, the work involved in creating a linkage that stopped the two A frames from fighting each other would be huge, and I'm pretty sure within the bounds of packaging and wear resistance a system such as you describe would be unviable,

Link to comment
Share on other sites

I think you may be over thinking the problem Mark, the work involved in creating a linkage that stopped the two A frames from fighting each other would be huge, and I'm pretty sure within the bounds of packaging and wear resistance a system such as you describe would be unviable,

You may well be right!!

I realised just moments ago the 2 aframe with 1link would in effect be a triangulated 4link but with the fixed axle due to the 1 link lower, all the packing issues associated with the 4 link would still be the same.

The forces shouldn't be any more than with a single a frame setup so a normal wide angle aframe ball joint would do it.

For a normal landy it probably wouldn't fit the front.. just like a triangulated 4 link.

Link to comment
Share on other sites

Argh just to throw this out there...... ditch the top sliding link setup and just make the one link pivot from a spindle with another spindle crossing it... a bit like a large UJ

first spindle controls rotational movement (articulation), second controls up and down (bump compression) the springs and bump stops will stop it rotating

this doesnt need a panhard bar

Or have I over simplified this lol

Now for my opinion lol your barking up the wrong tree.... this system as it extends creates huge anti-sqaut figures.... I feel this is bad for climbing especially with a short wheel base.... my thoughts are that you want to setup antisquat so as the suspension extends it decreases

In a climb as your nose goes up your CoG goes up compared to the rear suspension the links (or link lol) angle increases this places more weight vectored down the links this takes weight off the suspension at speed this means your wheels dont stay in contact as well (this doesnt mean much if you crawl up hills) competition wise this is big

as the suspension extends you compound the problem etc

this is why I built my back end the way I did

Link to comment
Share on other sites

Argh just to throw this out there...... ditch the top sliding link setup and just make the one link pivot from a spindle with another spindle crossing it... a bit like a large UJfirst spindle controls rotational movement (articulation), second controls up and down (bump compression) the springs and bump stops will stop it rotating this doesnt need a panhard bar Or have I over simplified this lol suspension extends you compound the problem etc this is why I built my back end the way I did

Thats basically what I was saying

Link to comment
Share on other sites

Hey DD, seen pic #3 on this page?

http://www.zuksoffroad.com/ZOR1link-basic-kit-one_p_175.html

That vertical link seems to be doing exactly what your upper link is? Was interested as it offers other, but not necessarily better packaging solutions :)

Looks like its the hydraulic ram design someone mentioned, it also seems to do the limiting strap's and bump stop's job also

Link to comment
Share on other sites

What are those tall slim vertical links doing? Some kind of anti roll bar or forced articulation setup?

It just appears to me to be some kind of shock, possibly a gas shock, to provide a variable height central pivot point for the axle to articulate around. Similar to the original Boge self levelling unit.

Link to comment
Share on other sites

Look like sway bars to me, you can just see the lever in the top right of the third pic if you zoom in.

Bill, I think what you're referring to are pretty standard gas shocks, can't pick the name out on them though :/ *edit* after a quick google image search I think they are 'King' shocks :)

On an unrelated note, I have decided I need one of these: http://www.zuksoffroad.com/Zombie-BRAIN-SAW_p_211.html

:)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy