Knock Off direction in F1

[Rob_LaMoreaux]

While standing around the front straight of Indy next to David Coulthards
McLaren Mercedes F1 car last Sunday I watched the crew take the tires off
the car and then put them back on. As they were doing this I got curious
which direction they turned the single nut that seats against the wheel the
same way as the knock-off on the Elan. Since they were using a 4-foot long
torque wrench it was pretty easy to tell that the nuts turn the same way the
Elan: direction of wheel rotation to tighten. While we all knew Chapman was
right about this, it is nice to see that it still applies to Formula One
today.

Rob LaMoreaux

MTS Systems Corp.
Powertrain technology Division
4622 Runway Blvd.
Ann Arbor, MI 48108
734-822-9696
Fax 734-973-1103
Main Desk 734-973-1111
www.mtspt.com
Work email: ***@***.***
Home email: ***@***.*** ***@***.***

[freddy22112211]

I believe it wasn't exactly difficult for Chapman to get it right -
Isn't it true that the wheels fly off if you get it wrong?
Gordon Nudd

In ***@***.***, Robert D. LaMoreaux wrote:
While standing around the front straight of Indy next to David
Coulthards McLaren Mercedes F1 car last Sunday I watched the crew
take the tires off the car and then put them back on. As they were
doing this I got curious which direction they turned the single nut
that seats against the wheel the same way as the knock-off on the
Elan. Since they were using a 4-foot long torque wrench it was pretty
easy to tell that the nuts turn the same way the Elan: direction of
wheel rotation to tighten. While we all knew Chapman was right about
this, it is nice to see that it still applies to Formula One today.
Rob LaMoreaux

[LotuSport]

--- In ***@***.***, "freddy22112211"
<2211@o...> wrote:

ISTR that there was a detailed discussion of this awhile back (on
this forum? Lotus_Cars List?) and the conclusion was that the pin-
drive wheels had to have the knock-on direction the same as the
direction of rotation.

OTOH, Rudge-type (splined) hubs required K-Os that had to be
tightened in the direction _opposite_ rotation. The explanation was
that a sort of "precession" caused the splined type to tighten or
loosen depending upon the rotation opposite the K-O direction.

The reverse is apparently true for our pin-drive types.

Can anyone confirm this (and give a better explanation)?

Best regards,
Bob
______________________________
***@***.***

[twincamman]

NO but thats why i use 4 bolt wheels ed law
----- Original Message -----
From: Bob Metz
To: ***@***.***
Sent: Friday, October 03, 2003 12:38 PM
Subject: [LotusElan.net] Re: Knock Off direction in F1


--- In ***@***.***, "freddy22112211"
<2211@o...> wrote:

ISTR that there was a detailed discussion of this awhile back (on
this forum? Lotus_Cars List?) and the conclusion was that the pin-
drive wheels had to have the knock-on direction the same as the
direction of rotation.

OTOH, Rudge-type (splined) hubs required K-Os that had to be
tightened in the direction _opposite_ rotation. The explanation was
that a sort of "precession" caused the splined type to tighten or
loosen depending upon the rotation opposite the K-O direction.

The reverse is apparently true for our pin-drive types.

Can anyone confirm this (and give a better explanation)?

Best regards,
Bob
______________________________
***@***.***

[rawcar2long]

To all,

The MGA Twin-Cam and MGA DeLuxe of '58-'62 had pin drive steel knock off wheels.
I had a '60 Twin-Cam back then. Can't remember wing nut direction.

RAW

-----Original Message-----
From: Ed Law [mailto:***@***.***
Sent: Friday, October 03, 2003 12:45 PM
To: ***@***.***
Subject: Re: [LotusElan.net] Re: Knock Off direction in F1


NO but thats why i use 4 bolt wheels ed law
----- Original Message -----
From: Bob Metz
To: ***@***.***
Sent: Friday, October 03, 2003 12:38 PM
Subject: [LotusElan.net] Re: Knock Off direction in F1


--- In ***@***.***, "freddy22112211"
<2211@o...> wrote:

ISTR that there was a detailed discussion of this awhile back (on
this forum? Lotus_Cars List?) and the conclusion was that the pin-
drive wheels had to have the knock-on direction the same as the
direction of rotation.

OTOH, Rudge-type (splined) hubs required K-Os that had to be
tightened in the direction _opposite_ rotation. The explanation was
that a sort of "precession" caused the splined type to tighten or
loosen depending upon the rotation opposite the K-O direction.

The reverse is apparently true for our pin-drive types.

Can anyone confirm this (and give a better explanation)?

Best regards,
Bob
______________________________
***@***.***

[Esprit2]

From: "Bob Metz" <***@***.***>

Sent: Friday, October 03, 2003 11:38 AM
Subject: [LotusElan.net] Re: Knock Off direction in F1


Rudge-type knock-ons use spline-drive and Lotus-type knock-ons used
pin-drive... but that's incidental to the knock-on direction issue. Use
"spline-drive" and "pin-drive" as identifiers, but don't confuse the
drive methods as having anything to do with the knock-on direction. Rudge
could just as well have used pin drive, and the knock-on direction would
have still been the same.

The key issue is how the knock-on nut meets the wheel... regardless of the
drive method. Whether the nut's mating face has a male taper and fits into
the wheel or has a female taper and fits over the wheel. Pins and splines
have nothing to do with it. It's whether the rotating motion is imparted
internally or externally.

Chapman demonstrated the principle to his designers by placing two
concentric rings on the table. He grabbed the inner ring and moved it in a
circle (oscillating/ orbiting rather than spinning/ rotating) large enough
to carry the outer ring with it. The outer ring turned/ rotated in the
same direction. Then he grasp the outer ring and repeated the movement.
The inner ring turned/ rotated in the opposite direction.

Another way to demonstrate Chapman's second trial (grasping the outer ring)
is to put a washer or large coin in the bottom of a shallow can and swirl it
around. The washer will orbit with the can... in the direction the can is
swirled... but as it rolls around the inside of the can it's rolling
"rotation" will be in the opposite direction. Swirl clockwise and the
washer will orbit/swirl clockwise but roll/rotate counter-clockwise.

The coin-in-a-can demo happens at higher speed and is harder to follow than
Chapman's rings-on-the-table demo. If you can't see it, paint a hash mark
on the washer so your eye can pick up it's rotation more easily. Or just
use Chapman's demo in the first place. It's better. He used it because
it was easier for non-believers to see... and it illustrated both effects,
driven by either the inner or outer ring.

Regards,
Tim Engel

[MikeC]

On Fri, 03 Oct 2003 16:38:23 -0000 Bob Metz wrote:


It was here, exactly a year ago - 03 Oct 2002 This is what I wrote
at the time:

The argument for Elan knock-ons being opposite to the standard rudge
wire-wheel arrangement, is that the Rudge has a male wheel and female
nut, but the Lotus has female wheel and male nut. The joint between
the two is apparently equivalent to an epicyclic gear, which rotates
differently according to whether the inside or the outside is driven.
There's a neat practical demonstration of this, allegedly devised by
ACBC himself, in Hugh Haskell's book "Colin Chapman - Lotus
Engineering".




As described above, the difference is not spline vs peg drive, but
whether the nut is male (Lotus type) or female (Rudge type).

Try this experiment. Find something with a circular hole in it, such as
a roll of tape, and place if flat on table. Now get something to fit
into it with some clearance, such as an empty beer glass. Grasp the
glass and move it in a circle clockwise so that it contacts the inside
of the roll of tape. Observe that the tape rotates and note its
direction. Now grasp the outside of the tape and move it in a circle
clockwise. Observe direction of rotation of the glass. (Try both again
anti-clockwise if you like.)

You may now fill the glass with beer and contemplate the fact that
although the direction of movement of the driving side was the same, the
direction of rotation of the driven side changed with the "sex" change.


HTH,

Mike
--
Mike Causer Email - mailto:***@***.***
GPG KeyID 1C2DDA07 WWW - http://www.mikecauser.org
Flood the fen again! - Wicken Fen enlargement - http://www.wicken.org.uk

[elansprint71]

Please explain "male nut". All nuts have a female thread.
Also in both Lotus and Rudge cases the wheels are "female" in that they both have a hole in the centre.
Surely the issue is between nut and hub, the wheel being incidental as it performs the same function with both spline and peg drives?

Pete.
----- Original Message -----
From: Mike Causer
To: ***@***.***
Cc: ***@***.***
Sent: Friday, October 03, 2003 7:33 PM
Subject: Re: [LotusElan.net] Re: Knock Off direction in F1


On Fri, 03 Oct 2003 16:38:23 -0000 Bob Metz wrote:


It was here, exactly a year ago - 03 Oct 2002 This is what I wrote
at the time:

The argument for Elan knock-ons being opposite to the standard rudge
wire-wheel arrangement, is that the Rudge has a male wheel and female
nut, but the Lotus has female wheel and male nut. The joint between
the two is apparently equivalent to an epicyclic gear, which rotates
differently according to whether the inside or the outside is driven.
There's a neat practical demonstration of this, allegedly devised by
ACBC himself, in Hugh Haskell's book "Colin Chapman - Lotus
Engineering".




As described above, the difference is not spline vs peg drive, but
whether the nut is male (Lotus type) or female (Rudge type).

Try this experiment. Find something with a circular hole in it, such as
a roll of tape, and place if flat on table. Now get something to fit
into it with some clearance, such as an empty beer glass. Grasp the
glass and move it in a circle clockwise so that it contacts the inside
of the roll of tape. Observe that the tape rotates and note its
direction. Now grasp the outside of the tape and move it in a circle
clockwise. Observe direction of rotation of the glass. (Try both again
anti-clockwise if you like.)

You may now fill the glass with beer and contemplate the fact that
although the direction of movement of the driving side was the same, the
direction of rotation of the driven side changed with the "sex" change.


HTH,

Mike
--
Mike Causer Email - mailto:***@***.***
GPG KeyID 1C2DDA07 WWW - http://www.mikecauser.org
Flood the fen again! - Wicken Fen enlargement - http://www.wicken.org.uk

[summerinmaine]

Pete:

Male nut refers to the way the nut "penetrates" the wheel. On the
Elan, the nut nestles ever so gently into the central orifice of the
wheel, lightly caressing the interior regions.

On Rudge wheels (typically wire wheels like on my Morgan and A-H),
the female nut squats down over the male projection of the wheel and
envelopes it securely.

Great fun in either configuration, but important to remember which
way the screwing progresses.

Jim

--- In ***@***.***, "elansprint71" <elansprint71@b...>
wrote:

[MikeC]

On Fri, 3 Oct 2003 23:21:46 +0100 elansprint71 wrote:


The male/female relationship refers to the way in which the mating
surfaces of the nut & the wheel act, not the nut & the hub. I don't
know of an on-line diagram, but if it were possible for you to look at a
Lotus nut and a Rudge nut (or their wheels) side by side you'd see it
right away. Maybe a trip to the nearest Historic race meeting would
pay dividends? If this is not possible I might attempt some ASCII art
in the morning.

Or, as I'm supposed to be beta-testing a CAD program at the mo' maybe
you'll see a real drawing




Hmm, maybe the wheels should be declared hermaphrodite in this context?
Actually Lotus wheels have two X-chromosomes, Rudge wheels have X-Y.



I'm trying to think of a good analogy for you, but despite opening a
fresh bottle of Scotch, have failed The best I can do at the
moment is to say "Look at a Lotus (or McLaren MP4-17D) wheel and a
traditional wire wheel side by side."


Mike
--
Mike Causer Email - mailto:***@***.***
GPG KeyID 1C2DDA07 WWW - http://www.mikecauser.org
Flood the fen again! - Wicken Fen enlargement - http://www.wicken.org.uk

[twincamman]

im waiting for the in out part anxiously ed law
----- Original Message -----
From: Mike Causer
To: ***@***.***
Cc: ***@***.***
Sent: Friday, October 03, 2003 8:24 PM
Subject: Re: [LotusElan.net] Re: Knock Off direction in F1


On Fri, 3 Oct 2003 23:21:46 +0100 elansprint71 wrote:


The male/female relationship refers to the way in which the mating
surfaces of the nut & the wheel act, not the nut & the hub. I don't
know of an on-line diagram, but if it were possible for you to look at a
Lotus nut and a Rudge nut (or their wheels) side by side you'd see it
right away. Maybe a trip to the nearest Historic race meeting would
pay dividends? If this is not possible I might attempt some ASCII art
in the morning.

Or, as I'm supposed to be beta-testing a CAD program at the mo' maybe
you'll see a real drawing




Hmm, maybe the wheels should be declared hermaphrodite in this context?
Actually Lotus wheels have two X-chromosomes, Rudge wheels have X-Y.



I'm trying to think of a good analogy for you, but despite opening a
fresh bottle of Scotch, have failed The best I can do at the
moment is to say "Look at a Lotus (or McLaren MP4-17D) wheel and a
traditional wire wheel side by side."


Mike
--
Mike Causer Email - mailto:***@***.***
GPG KeyID 1C2DDA07 WWW - http://www.mikecauser.org
Flood the fen again! - Wicken Fen enlargement - http://www.wicken.org.uk

[MikeC]

On Fri, 3 Oct 2003 20:28:41 -0400 Ed Law wrote:


A description of how a hammer is used to consumate the relationship will
surely fail to get through most acceptability filters.


YMMV of course!


Mike
--
Mike Causer Email - mailto:***@***.***
GPG KeyID 1C2DDA07 WWW - http://www.mikecauser.org
Flood the fen again! - Wicken Fen enlargement - http://www.wicken.org.uk

["dandersonlotus"]

Mike Causer's explanation can be better understood
with a picture.

See
http://groups.yahoo.com/group/lotuselan ... 20nuts.GIF
for a picture

which is page 66 of
Colin Chapman Lotus Engineering Theories Designs and Applications
by Hugh Haskel.
Published by Osprey.

David Anderson

[richboyd]

Seemed clear to me (actually, very well explained, me thinks). The
male-female relationship refers to contact between nut and wheel, not the
threads. In the case of Elan wheels, the taper on the nut is male (convex)
and fits into the wheel's female (concave) taper. While this relationship
influences the left- or right-handedness (chirality?) of the threads, the
"male nut" is not a reference to the threads but to its wheel contact surface.

Rich Boyd


At 03:21 PM 10/3/2003, you wrote:

[Rob_LaMoreaux]

Colin Chapman Lotus Engineering has a good discussion of the reasoning, which I think I may have scanned in an put on the Yahoo Files section. The Rudge wheels press against the inside of the nut so they turn the nut the opposite direction of the elan where the wheel presses against the outside of the nut.

I have seen some racecars with only one nut that have all the nuts right hand threaded and then pinned, and I seem to recall one that had the nut surface like the Elan but had the threads the other way around.

Rob LaMoreaux
Ann Arbor, MI USA
(734)-971-5583
Cell (734)-604-9280
Email: ***@***.*** ***@***.***
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending adventure.