patorz31

Try dry PTFE lube for bike chains. Was a tip from some UK guys I know.

DavidNERODease

Do you have an Eclipse 2? Reaming this steering block would completely ruin it. It's not plastic. It's not a clearance issue. It's specially a coated machined aluminum work of art. The kingpins came highly polished from the factory - I had to dig out the polishing compound from the threaded hole in the bottom.

Erhard

At our Eclipse 2, the feel was good from the beginning, using Molycote (black grease). Molycote TM (aka MoS2, Molybdeniumsulfite) is a powder, similar to graphite,which is mixed with normal grease. To my opinion superior to Drylube, Teflon etc in metallic parts lubrication and run in process.
But still there was a slight stick slip effect, when pushing the wheel up.
I would not recommend to ream the steering block due to its coating.
What we did was improving the kingpins surface by grinding with an oil stone on low rpm in a powertool.
https://www.banemo.de/mueller-hart-a...00-x-10mm.html
and then polish with chrome polish.
(Polishing alone does not help to improve the surface flatness)
Now the parts are running perfectly smooth with silicon damper grease to adjust damping.

BR Erhard

cyclone

cyclone

Hey, I have attached my ending setup from the International Indoor Championship 2018, on high grip, CRC black carpet. Hope this helps you guys with a starting point!

The only difference between this setup and my 13.5 stock class setup was my tire choice. I used the JT2-32FJ and JT2-30RJ for stock.

Andy

Erhard

Hello Andy,
did you use a diff or fixed axle(spool), Was the motor really 3,5 turns !?
BR Erhard

DavidNERODease

It says spool in the diff tension comments.

Smoking motor..

If I may Interject....

If the center pivot slides in a slot ala the yrx12 assoiciated 12 r6 it should only affect the wheel base. If it dosen't it will affect the roll steer.The roll axis will be a line that goes through the roll center of the front and rear axel.

Erhard

Yes please! Its a discussion forum ;-)

I do not agree, the slot (Asso design) doesnīt change anything. The slot is because the system of links and joints without it is overdetermined and self blocking. In other cars, the links stretch a bit and there is some joint play. This does unlock the overdetermined situation also.

I certainly agree, itīs what I explained in an earlier post #53 also.

BR Erhard

DavidNERODease

On all solid rear axle suspension designs, the roll centre is controlled but the lateral axle locating device. Normally that is a panhard bar, Watts link, Mumford linkage, Jacob's ladder etc. Some cars use a triangulated 4 link design to locate the rear axle laterally which is what is causing the confusion here. The Eclipse and most other pan cars use a centre pivot ball to locate the rear axle laterally but because it is offset (forward a great distance from the rear axle) it allows the rear axle to be "steered" This wagon like steering ability is being mistaken for a lack of lateral axle location. The side links do not locate the axle laterally - the axle cannot move sideways. Think of the rear centre pivot as a badly offset kingpin - lots a wheel scrub during steering not actual lateral axle movement.

Erhard

That doesnīt confuse me at all. I can explain the examination of such a cars roll center too and its not what we are talking here.
Here this is Schumacher eclipse and all others with pivot joint and side links. Like its in the textbook and you can read about an experts explaination in the said book RC-Car Fahrwerktechnik: Grundlagen, Theorie Und Praxis | eBookRich.com

Before I give up, one last try!

I think it good to clarify first is the definition of roll centre, so we talk the same language:




Now from the side and a first step to the idea of tilting links and the result (we just lift the whole chassis to tilt the links and the roll center stays the the same, but. Ooops! now the pivot height has changed!




Now to bring back the pod pivot to initial height we have to lower the roll center!




This is what I can do to explain - if its good its good. If not - well I canīt help. Then you may just believe in an Physicist with a Phd in engineering and said book of the Porsche chassis designer. But we might be wrong.

BR Erhard

DavidNERODease

BR Erhard, you drawing lines through parts of the suspension that do not have anything to do with finding the instant centre or roll centre or roll axis. Side links do not laterally locate the rear axle - they are out of scope and not relevant to the discussion. It does look like we will have to agree to disagree. No worries.

Erhard

This is the mistake you make! Then you could as well mount the side links vertically, or not? If you do so, you will recognize, that now the pod can only do a steering movement and no more roll movement.

This shows drastically the roll movement has to do with the inclination of the links.

Here is the drawing from the book I refered to:
(Translation: Schwenkachse=rotation axis of the pod; Zentralgelenk=pivot joint; Rollzentrum=Rollcenter

Again you can see, the direction of the rotating axis is the direction of the links. Come on, the author is a chassis designer at the Porsche racing department, he knows what he talks about. Donīt you have any slight feeling you might be wrong?
If not, donīt just argue, bring well founded explainations in a scetch form.

Best regards, Erhard

grippgoat

iTrader: (8)

But what is the Schwerpunkt? I feel like I could insult someone by calling them that.

ScottE1776

iTrader: (10)

My only comment to this is that Porsche took 30 years to fix the trailing throttle oversteer on their 911's :P