Ok guys, I'm going to fit a rod end to my panhard rod. Any suggestions of size / quality / strength / Company to buy from???
Cheers,
For rod ends you will struggle to beat www.trackstore.co.uk (ring them they are very very helpful!!) for quality vs cost! You want the CMXR8 rod ends,
1/2" x 1/2". (£11 each)
Rally design do the cheap "Carborace" ends which are basically mild steel and are okish but for an extra couple of quid I'd go for the
CMXR8's which are top quality PTFE lined chrome-moly items.
Me,I'd use an M12 Thread(Easy to weld a M12 nut into the rod and retap,Dead standard).A 12mm hole thru the end for use with a 12mm bolt(not set screw)for firm location.These are standard items from the likes of B.S.L. or Wyco.I'd look local to you,Or on the web for bearing suppliers.Rs have them for £11 +vat +p+p and they are high priced.Shop around.The Rs stock is 198 9106 @ rswww.com.I'll try to attach a link.www.rswww.com
I got mine from Rally Design www.raldes.co.uk. They also do threaded inserts to match the rod-end and can supply suitable tubing, into which the
inserts fit, in meter lengths. I'd advise you to get one right hand threaded rod-end and a left hand threaded rod-end to match. That way you can
slacken the locknuts and just twiddle the rod (ooer!) until you get the desired position. Makes adjustment sooo much easier. RalDes do both LH and RH
inserts and rod-ends.
As for size, don't be fooled by cheap immitations as there are rod-ends and ROD-ENDS! You can get a good quality 1/2" rodend which has twice
or more times the strength of a poor quality one of the same size. Here are some examples from RalDes's catalogue (I agree that 1/2" teflon
coated is ideal btw):
Carborace - 5800lbs - £8.25
Nat'l MSM8T - 7106lbs - £7.20
Nat'l MAX8T - 16646lbs - £13.32
Nat'l MTSM8T - 6660lbs - £10.96
Nat'l TSMX8T - 16238lbs - £18.28
Nat'l UMAX8T - 23632lbs - £29.75
All part numbers are for RH thread parts. Left hand threaded parts usually have same load rating but cost only a few pence more. Load rating is USRL
(Ultimate Static Radial Load) and is in pounds force.
They all have different characteristics which are described in the raldes catalogue but I concluded that the MAX8T was the best for my panhard
application. Unfortunately raldes didn't have any in stock and substituted the carborace ones instead... I accepted them purely to get the car on
the road but I'll be replacing them straight after SVA is complete with something a bit meatier like the MAX8T. Trailing arms are not so critical
because there are 4 of them to share the burden but if the panhard rod breaks then you will have problems... I am using MSM8T's on my trailing
arms.
Get PTFE lined ends to avoid maintenance (just keep them clean) and I was advised not to fit rubber boots because they just trap dirt. The PTFE ends
are self cleaning.
Other things you will need are two 1/2" inserts (£2.32 RH, £2.46 LH) and one meter of tubing (£5.02). The inserts slide inside the tube and weld
around the edge. They are a "top hat" design and so are easy to weld as they don't slip too far in. You also need locknuts (£0.21 RH
and £0.30 LH)
I hope this helps,
Craig.
I used M12 from a local bearing supplier and a friend made me some knock in threaded inserts to put in the end of my trailing arms and weld in place. I used one in the axle end of the panhard rod as well. They advised against the lined ones for the sideways force of the panhard rod, o.k. for the up, down and sideways of the trailing arms.
If you have a look at my photo archive, the grasser photos will show a nice range of sizes/qualities of rod-ends, from carborace 5/8x5/8 (front wishbones) to full chrome-moly 3/4x3/4 ones on the rather nastily loaded rear trailing arms!!
Pete,
I'm not sure what "sideways" force you are meaning. Can you explain please?
If there is any axial (sideways) force present trying to dislocate the rod-end then IIRC it is usually rated to about 10-15% of USRL. Therefore it
would take around 1 ton of force to dislocate the MAX8T! That would have to be a seriously badly designed 5 link suspension design surely?
Interestingly the PTFE lined MAX8T has exactly the same USRL as the non PTFE lined MAX8 of the same size.
I'd still recommend PTFE lined rod-ends otherwise you will have to lubricate them and the grease/oil will attract dirt and very quickly wear the
rod-end. This is the advice I was given on this forum by those more experienced in this area than me.
Cheers,
Craig.
You are quite right Craig, I have had quite extensive experience of this sort of thing!! The only time I have had a problem with PTFE lined joints is
on the spherical top mounts on a car with McPherson struts (nova rally car with homemade eccentric top mounts). here the full weight of the front of
the car is trying to dislocate the bearing, and when landing repeatedly from a few feet up in a 1 tonne nova car in grizedale forest it pushed the
teflon liners out (we went to steel on steel bearings after that). However for anything at all on a locost, the loading is so light that PTFE is
definitely a benefit as is is smooth running and has no play like a steel-steel one.
The rear arm joints on my grasser are PTFE lined and they take a real hammering, they are still perfect after a years racing (and getting full of
soil!!)
incidentally, the advice to skip the rubber boots is no bad thing, as long as you wash any road salt off regularly.
ordered from trackstore - seemed a really nice bloke and if he's got them in stock I'll have them tomorrow (he's not 100% sure about 1
part, but if its not in stock i'll have them early next week).
Mike,
What size did you go for in the end? Do Trackstore supply threaded inserts or are you just going to weld nuts inside the tube?
Cheers,
Craig.
I went for the ones suggested by NS Dev (1/2 inch) for two reasons ....
1) all my suspension bolts are 1/2inch
2) NS Dev reconmended them - I've met him in real life and recon he might have an idea what he's talking about!
I ordered 1 left and 1 right rod end - CMXR8, two inserts & two nuts.
I'll let you know how I get on.
Hi Mike!!
Cheers for that! It is a bit strange to us metric brits to see UNF rod ends but nearly all of the rod ends in the UK are made in the USA, hence the
imperial measurements. The rod-ends fitted to 99% of competition cars are imperial, strange but true!
The horizontal forces along the panhard rod in cornering when it is being pushed or pushing into the axle as opposed to the up and down which is its
natural range. This was the advice from the man who sells the bearings and doesn't want someone coming back to tell him he sold them the wrong
thing for the job.
Rescued attachment rosejoint.JPG
Pete, I'm confused.....
are you saying that the rod ends i've bought aren't up to the job?
I thought the panhard rod was mostly a push / pull force compared to up / down.
Pete,
I think I just about understand what you are meaning but I don't think it applies to my own setup as my axle mounted rod end is not mounted in
the same orientation as yours. I've never actually seen a panhard rod mounted in the way you have mounted yours, most (in my albeit limited
experience) are mounted so that spherical bearing is being "rotated" by up and down suspension movement rather than "articulated"
if that makes sense. Therefore my "angle of misalignment" stays virtually constant during suspension movement.
Here's a pic to hopefully clarify:
and another close up:
Cheers,
Craig.
gotta say, thats a bloody nice back end craig. home made or part purchased?!
Aerospace and single seater teams still tend to standardise on UNF threads --- UNF bolts have advantages in that the core diameter is bigger than the standard ISO metric coarse thread in widespread use and ISO metric fine series threads tend to be too fine and tend to jam and seize in automotive suspension allpications..
Thanks Joelp, I'm sure your back end is equally nice...
It is a bit of both to be honest. I bought it from "ChazPowerSlide" from the LB forum who had I think bought it from someone who had bought
it from MK Engineering (can't remember the whole story now).
Anyway, When I got it, it came in 7 parts: The pre-bent de-dion tube, the pre-drilled and tapped sierra hub carrier plates, the pre-assembled de-dion
"Ears" and the big bit of black pipe through which the driveshafts run. Arguably the easy bit had been done leaving me with the tricky job
of aligning and welding it all together...
My website give all the gory detail of how I did it and I got someone with a nice big Mig welder to seam weld it once I had it tacked into position.
My 120Amp welder wasn't up to the job and neither (arguably) were my welding skills...
There are drawings and plans on my website detailing how to build your own de-dion axle just like this one if you like it so much. I should also point
out that this picture is from nearly a year ago so it has moved forwards a bit since then. I'm busy painting my chassis and suspension and will
post a more recent picture soon.
BritishTrident, I agree that 1/2" UNF is ideal for suspension as it is a nice half way house between metric and metric fine in terms of
threading. Somehow it just feels "right" and gives you confidence that the bolts aren't going to break or fall out anytime
soon....which is good!
Cheers,
Craig.
Here's a more recent pic before I stripped the chassis for painting:
quote:
Originally posted by craig1410
Here's a more recent pic before I stripped the chassis for painting:
Thank you kind Sir!
You could always use a Nissan bluebird raduis arm extended with 19mm seamless tube. Cost me about £3 for the whole rod, and fully adjustable.
The rod end is taking the weight of the car on its contact point with the bolt whichever way up you mount it. It takes a battering I mounted mine so
it would be in true double shear. I saw one panhard rod bent by enthusiastic driving and would move the joint to the axle end of your bracket by
moving the other end out a bit if it was mine. The bearing may be up to the job but the dealer I bought mine from thought the battering (push/pull as
you call it) would eventually compress the teflon and allow the inner to come out as on the Nova of NS Dev.
I'm not sure what "sideways" force you are meaning. If you aren't going to get sideways you should be alright.
Peteff,
Sorry mate but I'd have to disagree with you there. Whilst I agree that the bend in my de-dion axle doesn't permit a perfect alignment of my
panhard rod, I would rather have the axle end mounted a couple of inches away from the axle on a double shear bracket than end up with my PH even
farther away from being parallel to the lateral axis of the car.
Ideally the PH should be level with the ground at ride height and parallel to the lateral axis. This is surely the best way of avoiding any bending or
sideways forces.
Rod-ends are designed to cope well with radial loads (ie. loads in the same plane as the long axis of the PH). It is axial loads which you
should try to avoid as I mentioned earlier because the rod-ends are only rated at about 10-15% in the axial direction compared to the radial
direction.
The other thing to bear in mind is that by mounting the rod-ends in the orientation which you have you may run out of "misalign angle" on
full bump or full droop. Rod end max misalign angle is usually specified between 10 degrees and 20 degrees and the more angle you have, the less load
the bearing can sustain. Eventually the through bolt will foul on the rod end outer casing which will place very high bending loads on the rod end,
brackets and panhard rod. IMHO it is better to mount both ends of the panhard rod in the same orientation with each mounting bolt passing through the
rod end in the longitudinal axis of the car. That way the rod end is simply rotating during suspension travel instead of articulating.
That said, if it works and passes SVA then who am I to argue...
Cheers,
Craig.
I don't think the little fillets on the back of the bracket are doing much towards making it stronger but the bolt thickness should hold it on
its own. With 3" of suspension travel the articulation on the rod end is less than 4 degrees. The other end of mine is a poly bush mounted
normally. I know in the ideal world we would mount the rod parallel and in line with the centre of the axle on its wheels and loaded but it's a
car built from bits of other cars out of what we can get so there are bound to be compromises. We all do things other people would do differently. I
would have welded a piece of 50mm RHS with the end plated with 3mm and a captive nut to the back of the carrier to space it out or with the bracket on
the front instead of 19 washers but that's me. It's a forum and if we all built a car between us it would probably be perfect in somebodies
eyes.
are you saying that the rod ends i've bought aren't up to the job? I didn't say anywhere that they aren't up to the job but
what did NS Dev swap his Nova ones to, the same as my supplier recommended for the panhard rod. He's probably a belt and braces guy but I trust
him, he wasn't trying to sell me the dearest but thought they were best suited to the job.
[Edited on 23/4/04 by Peteff]
Peteff,
I agree on the comment about the washers and they are only there temporarily until I can get my hands on a lathe and make a proper spacer. I am also
rethinking the "little fillets" as they come too close to my 19mm wheel arch rear tubes. I am going to fillet across the U bracket instead
whilst making sure the rod-end has enough room to move up and down without hitting the fillet. As you said the 1/2" UNF bolt should be man enough
for the job but I don't like single shear.
Let's face it, the back end of the Locost isn't heavy (maybe 300Kg's effective mass) and thus even at 1G lateral acceleration it would
only get about 3000 Newtons of force along the panhard rod. Once I've filleted the double shear bracket I think it will cope easily with this
amount of stress.
Cheers,
Craig.
This was what I meant in the second idea with the bracket on the front. It would provide the strength IMHO.
Rescued attachment panhardend.jpg
Well guess what turned up today ?
yep - everything i'd ordered from the grasstrack boys....
excellent service and the approximate price given on the phone ended up being a couple of quid higher than what he charged me so ......
could we have a consensus of opinion as to how i fit the things
I'm thinking the end on the car side the same as in the book. The end on the axle side to be inline the car side. In my mind the panhard rod is
stopping the axle doing sideways as it goes up and down. Their should be very little force going front to rear of the car..... in this configuration I
think i'll be ok - the issue I think I have is with how much the rod end can take the angle of the panhard rod - the less angle the
better.....
ASCII art
************************
O------------------------O
as opposed to
***********************
O------------------------=
where
* means the axle looking at it from the rear of the car as if stood behind it 12" from the ground.
O means I see through the bolt
= means the bolt goes vertically through the mounting
(and the rod is parrallel and inline with the axle in reality)
Is that right ??????
Peteff, the Nova sphericals were in a terribly loaded application compared to yours!! The Nova ones were just a spherical, not a rod end, and mounted
with the macpherson strut through the centre as what is known as a "spherical bearing top mount". This then uses the spherical as the swivel
for the steering at the top of the strut, but tries to push the "ball" out of the side of the bearing with the full weight of the front of
the car, plus the forces incurred when landing etc. Landing from several feet up in a 1 tonne car repeatedly (forces probably in excess of 8 - 10
tonnes) is what pushed the liner out. In any case the bearing did not fail, the liner just removes play so the bearing got rattly and the steering a
bit wobbly until we replaced them.
For any joint on a locost, especially one which is used on the road, I would use a PTFE type bearing.
Hi Mike!!
As long as the panhard rod angle (that needed to avoid the diff dome cover)doesn't "bottom out" the rodend through bolt on the outer
race at the axle end (which it shouldn't) I would certainly go for>>
************************
O------------------------O
However, as long as the same thing doesn't happen at the extents of the axle movement if the joint were the other way up then it doesn't
really matter. If you think properly about it, the panhard rod can only work in compression and tension, and either way you are loading the joint
correctly so don't worry too much.
The only thing to really avoid is the joints bottoming out with the outer races on the bolt. (this is what usually knackers rod-ends!)
Next question, are you in this evening? Might pop over if you are as I'm in the vicinity!!
oooh errrrr misses .....
yeah I'm in.
Well I think my opinion on this is already clear but just to confirm, I would mount both rod-ends in the same orientation to remove any worries about
the rod-end outers binding on the bolts due to excessive angles.
ie.
************************
O------------------------O
Also, I recommend you either arrange an axle bracket to have double shear or if using single shear, make sure you have a nice big fat penny washer
(3mm thick at least) and big enough to ensure that it would not pass through the middle of the rod-end outer casing if the rod-end did dislocate.
Cheers,
Craig.
NS_DEV said pretty much the same when he popped over before - get two blokes talking about cars and its amazing how the time just flys!!!!