Mounting question

[Black Bull]

ok, without getting into the nitty gritty of how, why or where.
I need to mount a coilover and a shock in such a way so that it can move 30-35 degrees from the vertical in all directions

any ideas ?

[Z()LTAN]

[joshy]

ok, without getting into the nitty gritty of how, why or where.
I need to mount a coilover and a shock in such a way so that it can move 30-35 degrees from the vertical in all directions

any ideas ?

Swivel mounts? Only person i can think off the top of my head running it is wayno.

[Black Bull]

ok, without getting into the nitty gritty of how, why or where.
I need to mount a coilover and a shock in such a way so that it can move 30-35 degrees from the vertical in all directions

any ideas ?

Swivel mounts? Only person i can think off the top of my head running it is wayno.

setup like that won't work, Think something similar to a Treg hitch standing on end, but has to be able support about 2x the weight of the vehicle and survive constant hammering

[Z()LTAN]

u building a destructive testing rig?

[rockcrawler31]

Gonna be a tough one,

Thing is you need to somehow adapt or mount the end to eithe ra Heim with a high misalignment spacer or a ball joint of some description.

Which would be fine if the shock already had a hard mounting method like a threaded shaft or summat but because it's going to already have a quasi heim in the end, anything you mount it to is going to have it flopping about on a double jointed abortion.

What is the range of movement in the existing bush/hole setup on a standard coilover?

[Black Bull]

I would doubt it'd be more than 10-15 degrees.

Basically I want to build a swingarm style setup similar to a trophy truck or prerunner which are mainly designed mainly straight line stuff, I need it to be able to flex as well, which is where the angle problems come in

[toughnut]

What about something like a uni joint? If you make something up like that you can use bushes instead of bearings and you'd be able to hammer it all day long.

[joshy]

Running the top and bottom mounts opposite directions to each other will help give alot more movement, might not need as much more as you think?

[Black Bull]

Running the top and bottom mounts opposite directions to each other will help give alot more movement, might not need as much more as you think?

On the top joint, no, it wouldn't be to bad, but on the bottom there will be a lot of angular displacement, my model shows me up to 30 degrees will be needed at full articulation

[80's_delirious]

have you looked at Johnny Joints (currie enterprises) with high misalignment spacers? I think they give 30 or 35degree range of movement in all directions


edit: 30degrees out of the box
http://www.currieenterprises.com/cestor ... oints.aspx

[rockcrawler31]

johnny joints and high mis spacers require a smaller bolt diameter than the original bushing or eye size in order to get the clearance. It's why a Johnny joint has such a high body diameter.

For example high mis spacers on a 5/8th heim end up using a 1/2 inch bolt, and since most coilovers are already 1/2" that would require going to a 3/8'th bolt which is just not big enough.

[V.W.Dave]

Hey BlackBull do you remember about 6 months ago I showed you the buggy in the states that was using tow balls that were in a machined 3 piece captive that was lined in polyurethane? They used it on the chassis end of the links on a 4 link buggy.

I have spent the last 2 hours looking for it. I think it would work for this.

[Matt]

this will be funny can't wait to see the spring lbs you end up with

[foxracing_is]

ok, without getting into the nitty gritty of how, why or where.
I need to mount a coilover and a shock in such a way so that it can move 30-35 degrees from the vertical in all directions

any ideas ?

have you looked at Johnny Joints (currie enterprises) with high misalignment spacers? I think they give 30 or 35degree range of movement in all directions


edit: 30degrees out of the box
http://www.currieenterprises.com/cestor ... oints.aspx

A Johnny Joint has 30 degrees of movement; (for example) 15 degrees to the left and 15 degrees to the right.
'30 Degrees from vertical in all directions' is 60 degrees all up.

2 standard eye and bush setup so that they are perpendicular to each other. A custom block would need to be made as the bridge joint.

Same mechanics as this hitch
http://ozhitch.com/" onclick="window.open(this.href);return false;

[Black Bull]

this will be funny can't wait to see the spring lbs you end up with

Why would I end up with huge springs, during normal use the coilovers won't be at any more of an angle than any other linked setup, even at full travel there's won't be much difference to your normal 3/4 Link setup
Yes the springs will be a bit heavier than normal due to the cantilever effect of the design, the angle issue comes into play in how and where I want to attach them. (Ie not on the diff housing)

standard eye and bush setup so that they are perpendicular to each other. A custom block would need to be made as the bridge joint.

Same mechanics as this hitch
http://ozhitch.com/" onclick="window.open(this.href);return false;

Pretty much, I used a Treg hitch as an example on another forum.
But..
I see two inherent problems with that sort of a setup though, one is stopping it from trying to invert and either bending the shock shaft or snapping the end off. the other is hammering out whatever bushing is used during prolonged high speed stages and at the same time not adding a huge amount of unsprung weight

[Matt]

this will be funny can't wait to see the spring lbs you end up with

Why would I end up with huge springs, during normal use the coilovers won't be at any more of an angle than any other linked setup, even at full travel there's won't be much difference to your normal 3/4 Link setup
Yes the springs will be a bit heavier than normal due to the cantilever effect of the design, the angle issue comes into play in how and where I want to attach them. (Ie not on the diff housing)

standard eye and bush setup so that they are perpendicular to each other. A custom block would need to be made as the bridge joint.

Same mechanics as this hitch
http://ozhitch.com/" onclick="window.open(this.href);return false;

Pretty much, I used a Treg hitch as an example on another forum.
But..
I see two inherent problems with that sort of a setup though, one is stopping it from trying to invert and either bending the shock shaft or snapping the end off. the other is hammering out whatever bushing is used during prolonged high speed stages and at the same time not adding a huge
amount of unsprung weight

Cool sounds differant. I don't understand what your trying to do

[-Scott-]

Does it really require 30 degrees in ALL directions? Or is 30 degrees the worst case in one particular direction?

[rockcrawler31]

I think the aforementioned Treg Hitch style of joint with two opposing bolts is just going to collapse on itself. Great in tension for towing, can't see how it's going to hold up in compression holding up a car. Frankly without seeing what it's going in to or why it needs to have that much ROM i don't think you'll get any real good solutions. I know there might be some proprietary issues or wanting to keep it all schtumm so fair enough. My rear tri-four link gets the rear steer from hell and the sway bar heims have a lot of mostion to pass through in all three directions and they still cope ok.

Without seeing your set up i'd tentatively say you need to design the suspension better if it's got that much ROM in all directions.

[Black Bull]

Something similar to this, but it needs to flex as well




Hard to explain exactly what I'm trying to build, basically the prerequisites are for high speed stability (160-180kph)
needs to be able to flex as good as most weekend warrior rock crawlers.

So far, I've designed air operated & Adjustable sway bar disconnects, have most of the parts needed to complete them, just need to find somebody who can broach/spline some 300M stock bar.
To mount the shocks so far it seems a spherical bearing is going to be the best option for mounting the shocks, but I'm concerned about longevity and strength.

[rockcrawler31]

I think i see where you're going with this and it sounds suspiciously like you're building a hammers/U4 style rig.

If that was the case i'd be having a quiet PM to Ben Napier (Napsta on here) about how the guys in the KOH rigs are doing it.

If it's going to be a trailing arm set up like that then i'd look at maybe running the bolts rotated 90 degrees to what is shown there. That's assuming your rear axle is going to articulate past 20 degrees per side. It looks like a LOT of the ultra 4 rigs are running it in that configuration without any hassles though so why change a good thing. My first instinct is that the up/down rotation is unlikely to go much past the 30 degrees allowable in a normal coilover rod end so if the mount is rotated 90 degrees then it leaves side to side articulation free and unlimited.

Perhaps another option would be to find out from the manufacturers if you can go to a 5/8th hole in coilover and run high mis spacers down to a 1/2" bolt. But that sounds very unlikely to me or exxy at best.

[foxracing_is]

I see two inherent problems with that sort of a setup though, one is stopping it from trying to invert and either bending the shock shaft or snapping the end off.

I think the aforementioned Treg Hitch style of joint with two opposing bolts is just going to collapse on itself. Great in tension for towing, can't see how it's going to hold up in compression holding up a car.

What stops the usual heim jointed shock from collapsing to the side? The Endcap and shaft.
I guess having the pivot point directly in the center reduces the load/leverage GREATLY. But there must still be some side loading of the shaft/endcap to some degree.

It is just a question of whether the shock is up to the task of handling the bending moment.

Synopsis:
There is no reason that the 'Treg Hitch' style of joint will collapse on itself.
It may add a great load onto the shock itself (likely resuling in a bent shaft or broken end cap).

[zukIzzy]

I see two inherent problems with that sort of a setup though, one is stopping it from trying to invert and either bending the shock shaft or snapping the end off.

I think the aforementioned Treg Hitch style of joint with two opposing bolts is just going to collapse on itself. Great in tension for towing, can't see how it's going to hold up in compression holding up a car.

What stops the usual heim jointed shock from collapsing to the side? The Endcap and shaft.
I guess having the pivot point directly in the center reduces the load/leverage GREATLY. But there must still be some side loading of the shaft/endcap to some degree.

It is just a question of whether the shock is up to the task of handling the bending moment.

Synopsis:
There is no reason that the 'Treg Hitch' style of joint will collapse on itself.
It may add a great load onto the shock itself (likely resuling in a bent shaft or broken end cap).

You can keep the link from rotating 3 ways.

make sure the lower shock eye bolt is below the center line between the link mount bolts. This makes the natural force of the shock supporting weight keep the link straight and has the advantage of the link rotation on the heims to match the shock angle. It is not good for ground learance of the link and that is why most U-4 cars do not use this setup but desert cars do.

You can use a polyurethane bushing on the frame end of the link if you are going to mount the shock eye above center of link bolts. This works well and is what most U-4 and a lot of desert cars do. You do wear bushings fast with this set up but they are cheap and an easy prep Item.

You can use a bushing on the lower shock eye to keep the link straight with the shock. This is the system Bomber Fab uses on the Bomber cars and while I was sceptical at first you can't argue long with success. It works great on Ben car for 3 years or more.

To be Honest the shock on the link is not the most stable way of setting up suspension. As in everything it is a compromise and can be made to work well enough. The real reason for mounting the shocks on the link is to slow the shaft speed down. This keeps the moving piston valve below the vapor seperation speed for a give parameter of conditions where a shock mounted on the axle would excede the vapor seperation speed at the piston over the same bump at a given speed or whatever set of parmeters you have.

WE can dicuss if you want if not I will go away.

wayne

[rockcrawler31]

WE can dicuss if you want if not I will go away.

wayne

Awesome discussion and tech mate, by all means keep it up. got any pics of said setups?

[zukIzzy]

Well for the OP then you are way over thinking it. With poly bushings on the frame end of the lower link I can completly flex a 14" shock mounted 2/3 the way down a 48" link without binding the shock eyes. This nets an honest 18" of travel from full stuff to full droop. I never ramped it cause well I didn't care but it was enough to win a prorock comp and complete King of the hammers twice.

I dont' do many pics sorry. I'm just a crazy redneck maybe Ben will help us out there.

[Black Bull]

cheers for the Input guys,
As Milo knows I have a habit of over-thinking and over-engineering a lot of things, but it usually goes a long way towards getting me home, in 4 years My truck has been towed home once, 900km, and that was only because I had only 1st and 2nd gear....could drove but woulda been hell slow

I have yet to work out exact link lengths, but I'm aiming for about 24" of total travel on the rear with about 10" of droop from ride hight.

The Ultra 4 Rigs you guys have mentioned are sorta similar to what I'm aiming for Except
I need to be able to handle up to 10 days of continuous racing with anything up to 4 stages and 1000km per day. I don't want to be having to change out bushes every night.

After countless discussions on the matter over previous weeks, what I'm thinking at the moment,
For want of a better way of putting it, a "bucket" mounted on spherical bearings inside the lower link that will allow movement to the left and right of the link centreline, and the normal shock heims mounted to that, and if greased regularly should last reasonably well. mounting the Shock pin centres 1/2 inch or so lower than the "bucket" centreline should hopefully stop any unwanted side loading on the shock shafts/ends

I should be able to keep the link weight down to little more than a standard style link and if greased regularly the spherical bearings should last ok too.

What you guys think ?

[rockcrawler31]

I think i've got a handle on what you're suggesting with the bucket, if it's what i'm thinking it'd work but i'm wondering if the complexity and extra axle in the bucket is worth the trouble of manufacturing if existing set ups would do the job. I"d be pretty interested to see the project you're planning, is the truck for you or a customer? I'll be getting a TIG at some point so i'd be interesting in fabbing some components for you if you're interested.

MILO

[zukIzzy]

Sorry but I still don't see how 24" is giving you 30* at the shock where on the link are you putting the shock? Are they at 90* to the link plain at full bump? How much triagulation are in the lowers? Are the shocks going to be verical to the chassis or do they lean toward the center of the car?

Just trying to help so if you don't want to answer no problem.

[Black Bull]

I think i've got a handle on what you're suggesting with the bucket, if it's what i'm thinking it'd work but i'm wondering if the complexity and extra axle in the bucket is worth the trouble of manufacturing if existing set ups would do the job. I"d be pretty interested to see the project you're planning, is the truck for you or a customer? I'll be getting a TIG at some point so i'd be interesting in fabbing some components for you if you're interested.

MILO

Got a Big 3 Phase Lincoln Tig here Milo

Sorry but I still don't see how 24" is giving you 30* at the shock where on the link are you putting the shock? Are they at 90* to the link plain at full bump? How much triagulation are in the lowers? Are the shocks going to be verical to the chassis or do they lean toward the center of the car?

Just trying to help so if you don't want to answer no problem.

I tried drawing the setup in paint, my cad and computer drawing skills suck

The shocks will be canted forwards slightly and should be minimal leaning in.

The lower links will be parallel, I may have over simplified the "over 30 degrees in all directions", but I'm pretty sure that it'll need that much in at least 3 directions
From compression to droop should be close to 30 degrees and with full flex in either direction it should be too although the link will rotate and reduce some of that

My main concern is that this will be a full chassis/body rig with all the fruit and will weigh around 2.5 tonnes if not more when loaded for bear and having this sort of setup on the rear is going to place to much strain on the bottom links of the shocks

[zukIzzy]

I think i've got a handle on what you're suggesting with the bucket, if it's what i'm thinking it'd work but i'm wondering if the complexity and extra axle in the bucket is worth the trouble of manufacturing if existing set ups would do the job. I"d be pretty interested to see the project you're planning, is the truck for you or a customer? I'll be getting a TIG at some point so i'd be interesting in fabbing some components for you if you're interested.

MILO

Got a Big 3 Phase Lincoln Tig here Milo

Sorry but I still don't see how 24" is giving you 30* at the shock where on the link are you putting the shock? Are they at 90* to the link plain at full bump? How much triagulation are in the lowers? Are the shocks going to be verical to the chassis or do they lean toward the center of the car?

Just trying to help so if you don't want to answer no problem.

I tried drawing the setup in paint, my cad and computer drawing skills suck

The shocks will be canted forwards slightly and should be minimal leaning in.

The lower links will be parallel, I may have over simplified the "over 30 degrees in all directions", but I'm pretty sure that it'll need that much in at least 3 directions
From compression to droop should be close to 30 degrees and with full flex in either direction it should be too although the link will rotate and reduce some of that

My main concern is that this will be a full chassis/body rig with all the fruit and will weigh around 2.5 tonnes if not more when loaded for bear and having this sort of setup on the rear is going to place to much strain on the bottom links of the shocks

Make sure the shocks are 90* to the link bolt plane at full stuff so a slight forward cant is probably correct, you want the spring and valve rate to progressively rise thru the travel till it is at its max at full stuff. Try to keep them vertical instead of lean in but a bit either way wont hurt.

You have to make a fairly beefy lower link. like 2"x.250 wall 4130 then plated like the ones in your pic of the desert truck. the axle mounts take a huge bating in this set up so make them strong and if clearance in not an issue hang them from the tube not straight off the front. Iff clearance is a issue make them straight off the front and strong as an anvil.