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My Elio Alternate Project Is Underway.

3wheelin

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1950s large American cars had as much as 4" of scrub radius, that's why.

Scrub radius means the center of the tire is further from the center of the turning pivot.

If you hold a tire still and just rotate it on it's center pivot with your hands, you will find it hard to rotate because the tread is gripping, but if you put the tire on a stick and rotate it in a circle around you, it's very easy to turn. That's scrub radius.

And that is why scrub radius affects the weight of the steering in car parks and slow speeds.

Problem is the more scrub radius you have, the more the wheel deflects when you hit a bump because of the leverage factor, balance must be found, or add power steering.

This is the sort of scrub radius older cars with no power steering had (example only), you can picture in your mind that the wheel rolls around the steering axis (thick dotted line). Most modern cars have very little, and will leave blacks marks on the road when turning stationary, but the power steering overcomes that, and front wheel drive cars are mostly inside the steering axis for other reasons.

View attachment 25420
The more I follow your tread err, thread (:D) the more I learn! Scrub radius will be a good conversation topic for my car nut friends.
 

Mark BEX

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The more I follow your tread err, thread (:D) the more I learn! Scrub radius will be a good conversation topic for my car nut friends.

Don't mention it to your wife though, the instant reply will be: "Well with all that knowledge, how about you start scrubbing some dishes and floors ...."

They never miss a chance ....
 

AriLea

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I'm a programmer. So the term I have heard in relation to uninvited conversations relating to work is....(wait for it...)
'Computer Widow'. As in, "I feel like a 'Computer Widow' when your head is stuck in there ALL THE TIME!"

So yea, avoid forcing your wife to become a....
'Auto Widow', err ah 'Car-Tech Widow', ... something like that .... lol.

Hey! It can be very cathartic to scrub some dishes... (a reference to 'The Razor's Edge')
 
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Mark BEX

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After seeing all you are doing on this build, I wonder about your definition of "handyman".

Was relative to the steering rack. One only has to disassemble it, make one cut with a hacksaw, and clean it, and that's it, or even easier, disassemble it, and slip the new internals into the old housings.

There is nothing in the chassis that any side street light metal fabrication shop can't make.

I'm just figuring the hard stuff to make it easy, you don't have to do that side of it.
 

Mark BEX

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It's the little things that count.

One of the only issues left on the steering rack, is where the steel tube (black) sits in the now reversed pinion housing (red arrow), the issue being the steel tube is much smaller than the housing hole so is sloppy.
I have been scratching my head, and tried a number of methods of how to rectify it without modifying it, but today got a win!

A standard 32mm/1.25" threaded female water pipe connector is an interference hydraulic press fit over the steel tube, and the threads grip into the steel, perfect, no glues, no welding, no rivets or pins, and the large end needs just a touch on the grinder to fit into the pinion housing, and all for a $1 :-)

rack 17.jpg
 

AriLea

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Mark,
One of the things I did for Boeing was support the users of their production control software.
That included Emergent Production Planning.

At some point do you document all these details into a plan that is given over to a future factory?
Or is this thread 'de-facto' that production plan, at least in the short term?

Actually, I'm not asking, more noting you should copy out all these pages into a thumb drive.
I have found that things do not last forever on the internet. When nobody is looking, snap!, they are gone.

I'm guessing, pretty soon, you will have someone shadow you and document what goes into the final plan.
That way the transition to production is less a serial process and more in parallel. All these materials take as
much time as actual prototyping and are the bulk of production R&D for most companies.

You have all these skills and knowledge. Planning is the process of putting all of it into a can, for others to reuse.
But.... you know about all that. Just curious what you are doing about it.
 
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Mark BEX

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Mark,
One of the things I did for Boeing was support the users of their production control software.
That included Emergent Production Planning.

At some point do you document all these details into a plan that is given over to a future factory?
Or is this thread 'de-facto' that production plan, at least in the short term?

Actually, I'm not asking, more noting you should copy out all these pages into a thumb drive.
I have found that things do not last forever on the internet. When nobody is looking, snap!, they are gone.

I'm guessing, pretty soon, you will have someone shadow you and document what goes into the final plan.
That way the transition to production is less a serial process and more in parallel. All these materials take as
much time as actual prototyping and are the bulk of production R&D for most companies.

You have all these skills and knowledge. Planning is the process of putting all of it into a can, for others to reuse.
But.... you know about all that. Just curious what you are doing about it.

4 things:

1/ Most of it is in multiple CAD drawings, I never delete them. If I make a change, it becomes a new CAD drawing and the old one is on file. This is on number 15 file. And of course I keep all my cnc laser cutting files.

2/ The length of the upper dash tube is 800mm, on the car I built 25 years ago. The car's lower control arm length is 310mm from pivot to ball joint on my built in about 2009. I can remember almost every single tube length of almost every car I have ever built, pivot heights, angles, etc. In fact I forgot to bring my USB home last night that I drew some stuff at work on CAD, no problem, I drew the new parts on my home computer completely from memerising all the measurements. My brain is just wired that way, I make stuff, I rarely forget it, and yet I can't remember appointments I might have, or what day it is.

3/ There are people who can count, and people who can't.
 

Bert

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I've built a few stock cars over the Years, rebuilt street cars, as well as rolling cage to track ready. But, nothing I've done is as impressive as what you're doing here. As has been noted, I may end up being one of your customers once you're ready for production!
I'm glad to say I follow you clearly on axis inclination and triangulation. Preset weight distribution, body roll and weight transfer. Preset camber and castors, and yes, scrubbing..
 
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