Skippic Saturday

Here's my old love... a 1968 Buick Le Sabre,
Believe it or not but I've owned this beauty for seven years and took well care of her. It's about 15 years ago but still love the lines of it. This car has recently been body off and has a given a full restauration by his owner Marco. I will post some pics of that in the future... as soon as it's finished.

Ackermann Steering Principle


What does Ackerman Steering mean?

The Ackermann steering geometry principle is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radius.

It was invented by the German carriage builder Georg Lankensperger in 1817, then patented by Rudolph Ackermann, in the UK in 1818.

The intention of Ackermann geometry is to avoid slipping tyres when cornering.

The geometrical solution to this is for all wheels to have their axles arranged as radii of a circle with a common centre point.



As the rear wheels are fixed, this centre point must be on a line extended from the rear axle. Intersecting the axes of the front wheels on this line as well requires that the inside front wheel is turned, when steering, through a greater angle than the outside wheel. 

Rather than the preceding "turntable" steering, where both front wheels turned around a common pivot, each wheel gained its own pivot, close to its own hub.
While more complex, this arrangement enhances controllability by avoiding large inputs from road surface variations being applied to the end of a long lever arm, as well as greatly reducing the fore-and-aft travel of the steered wheels.

A linkage between these hubs pivots the two wheels together, and by careful arrangement of the linkage dimensions the Ackermann geometry could be approximated.


This was achieved by making the linkage not a simple parallelogram, but by making the length of the track rod (the moving link between the hubs) shorter than that of the axle, so that the steering arms of the hubs appeared to "toe out".

As the steering moved, the wheels turned according to Ackermann, with the inner wheel turning further. If the track rod is placed ahead of the axle, it should instead be longer in comparison, to preserve this same "toe out".

Simple approximation to perfect Ackermann steering geometry may be generated by moving the steering pivot points inward so as to lie on a line drawn between the steering kingpins and the centre of the rear axle. The steering pivot points are joined by a rigid bar called the tie rod which can also be part of the steering mechanism, in the form of a rack and pinion for instance. With perfect Ackermann, at any angle of steering, the centre point of all of the circles traced by all wheels will lie at a common point. Note that this may be difficult to arrange in practice with simple linkages, and designers are advised to draw or analyze their steering systems over the full range of steering angles.

Some race cars use reverse Ackermann geometry to compensate for the large difference in slip angle between the inner and outer front tyres while cornering at high speed.

The use of such geometry helps reduce tyre temperatures during high-speed cornering but compromises performance in low-speed manoeuvres.

Video From the Tube that explains it the easy way...






In Dutch

Het Ackermann-principe houdt in dat de hoek van een voorwiel van een voertuig in een bocht 90 graden staat ten opzichte van een lijn naar een denkbeeldig punt dat in het verlengde van de achteras ligt, om te voorkomen dat de voorwielen in een bocht gaan wringen.

Het Ackermann-principe veroorzaakt een (toenemend) uitspoor bij het nemen van een bocht. 

Het Ackermann-principe is ontdekt door de Duitse rijtuigbouwer Georg Lankensperger in 1817 en is gepatenteerd in 1818 Rudolph Ackermann, UK (1764–1834).  

Het Ackermann-principe is alleen van toepassing bij een vooras die voorzien is van fusees, bij een starre vooras zoals bijvoorbeeld een koets vaak heeft, is dit principe niet van toepassing. 

Het Ackermann-principe is een theoretisch principe.

In de praktijk wordt het denkbeeldige punt door constructeurs vaak niet op de achteras gelegd om betere rijeigenschappen te krijgen. Naast het camber en de balhoofdhoek (caster) is meer-, minder- of dicht bij nul Ackermann belangrijk voor de rijeigenschappen van een vervoersmiddel. Bij een eventuele verlenging of verkorting van het platform zoals bijvoorbeeld bij een buggy vaak gedaan wordt wordt het fictieve Ackermann punt verlegd. Hierdoor zullen de rijeigenschappen veranderen.

How To Find Water Leaks in Your vehicle?

Had some water coming in my Chevy causing a wet carpet...
I'd suspected it where the Rear Roll-Up Quarter Window Seals so I'd replaced them.

I used a drive in disco smoke machine... borrowed from a friend, to check if there where any more big leaks...
It seems to be much better now. Sadly I didn't film with the bad seals still in it, as it probably would be a better example,
But... Anyway, where smoke gets out, water can come in...

Searching for: How to Find a Leak in my car. Smoking Out water leaks? Bad door window rubbers / Seals / Sealing? How can find out where my wet carpet comes from.? What Causes a wet Carpet?
Replacing rubber... car seals and check if they're okay? Where is the water in my car coming from?
Check my vid...

M(ech)anic Monday

1938 Packard 120 Factory Plant / Assembly Line

Skippic Saturday


This week... burned some midnight oil, Did some bodywork / welding on the 1970 Impala, It had some serious cancer... Now She's Cured!

Happy New Year!

I Like to Wish Everybody A Happy New Year and all the Best for 2016
Go Out with a Bang & Keep coming Back!

Erwin and his Ford Roadster... in Breeze!



Today my Bud Erwin and his Ford Roadster appeared in Breeze...
Bigtwin ( Chopper Kult Pages) Magazine, Issue NR351, December 2015. All Photos and Interview by Sik Bloemsma.
# R.I.P Bob / # JestersCC / # EindhovenRodCity

the Funny Car...


How to Identify your GM rear end gear ratio?


How can I Identify my GMC or Chevrolet rear end gear ratio?

Well.. this can be done by the General Motors "Regular Production Option" codes, also called... RPO Codes. The codes are provided by a tag labelled “Service Parts Identification” that's usually located inside the drivers door panel or glove box. 

These plates contain valuable information about your GM vehicle. Assuming that the rear end previously has not been swapped or modified, you can use these plates for accurate identification  of your rear end / differential.

The list below is a partial list of typical GM RPO Codes, specifically the codes pertaining to Axle Identification, Differential Type and Gear Ratio.

The prefix is usually F, G or H when referring to Axle Identification.
  
Code
Ratio Description
Ratio
FA0
Rear Axle
5.77:1
FA1
Rear 2 Speed  
4.88:1/6.94:1
FA2
Rear 2 Speed  
4.88:1/6.94:1
G44
Rear Axle       
3.07:1
G72
Rear Axle       
2.14:1
G75
Rear Axle       
3.70:1
G76
Rear Axle / Posi / Limited Slip
3.36:1
G80
Rear Axle / Posi / Limited Slip
X
G81
Rear Axle / Posi / Limited Slip
X
G82
Rear Axle
4.56:1
G84
Rear Axle
4.10:1
G86
Rear Axle / Limited Slip
X
G87
Ring Gear
8.5"
G89
Ring Gear,
7.5"
G90
Rear Axle
3.15:1
G91
Rear Axle / Special Highway
3.08:1
G92
Rear Axle
3.08:1
G94
Rear Axle
3.31:1
G96
Rear Axle
3.55:1
G97
Rear Axle
2.37:1
GH0
Rear Axle
3.54:1
GH2
Rear Axle
2.29:1
GH3
Rear Axle
2.77:1
GH4
Rear Axle
2.92:1
GH7
Rear Axle
2.73:1
GJ1
Rear Axle
5.38:1
GJ2
Rear Axle
5.13:1
GK7
Rear Axle
4.78:1
GK8
Rear Axle
4.33:1
GK9
Rear Axle
4.63:1
GL0
Rear Axle
5.13:1
GL3
Rear Axle
6.17:1
GM1
Rear Axle
2.59:1
GM2
Rear Axle
3.44:1
GM3
Rear Axle
3.45:1
GM4
Rear Axle
3.67:1
GM5
Rear Axle
3.89:1
GM6
Rear Axle
4.22:1
GM7
Rear Axle
3.68:1
GM8
Rear Axle
2.56:1
GN9
Rear Axle
4.11:1
GS1
Rear Axle
2.73:1
GS3
Rear Axle
3.73:1
GS4
Rear Axle
3.70:1
GS5
Rear Axle
4.11:1
GS6
Rear Axle
4.56:1
GS8
Rear Axle
3.94:1
GT1
Rear Axle
2.56:1
GT2
Rear Axle
2.29:1
GT4
Rear Axle (Dup of 5X1)
3.73:1
GT5
Rear Axle (Dup of GT8)
4.10:1
GT7
Rear Axle
3.33:1
GT8
Rear Axle (Dup of GT5)
4.10:1
GU1
Rear Axle
2.41:1
GU2
Rear Axle
2.73:1
GU3
Rear Axle
2.93:1
GU4
Rear Axle
3.08:1
GU5
Rear Axle
3.23:1
GU6
Rear Axle
3.42:1
GU7
Rear Axle
2.77:1
GU8
Rear Axle
3.9:1
GU9
Rear Axle
3.91:1
GV0
Rear Axle
3.55:1
GV1
Rear Axle
2.73:1
GV2
Rear Axle
5.83:1
GV3
Rear Axle
3.08:1
GV4
Rear Axle
3.36:1
GV5
Rear Axle
3.55:1
GV7
Rear Axle
4.11:1
GV8
Rear Axle
2.72:1
GV9
Rear Axle
4.25:1
GW2
Rear Axle
2.56:1
GW3
Rear Axle
2.56:1
GW4
Rear Axle
3.31:1
GW5
Rear Axle
2.73:1
GW6
Rear Axle
3.27:1
GW8
Rear Axle
4.10:1
GW9
Rear Axle (Dup of GU3)
2.93:1
GX1
Rear Axle
3.70:1
GX2
Rear Axle
3.07:1
GX4
Rear Axle
3.75:1
GX5
Rear Axle
4.09:1
GX6
Rear Axle
3.53:1
GY2
Rear Axle
3.31:1
GY4
Rear Axle
4.53:1
GY5
Front Axle
3.65:1
GY9
Rear Axle
4.31:1
H01
Rear Axle
3.07:1
H04
Rear Axle / Single Speed
4.11:1
H05
Rear Axle
3.73:1
H12
Rear Axle / Single Speed
21000 Lbs
H42
Rear Axle
6.17:1
H43
Rear Axle
5.43:1
HA3
Rear Axle / Single Speed
5.29:1
HC4
Rear Axle
4.56:1
HC7
Rear Axle /  Single Speed
2.38:1
HC8
Rear Axle /  Single Speed
3.21:1
HC9
Rear Axle
5.13:1
HE3
Rear Axle / Single Speed
3.07:1
HE4
Rear Axle
3.40:1
HF7
Rear Axle /  Dana 70 /Single
4.56:1
HF8
Rear Axle
4.88:1
HJ1
Rear Axle
4.55:1
HJ2
Rear Axle
5.86:1
HJ3
Rear Axle
4.75:1
HJ4
Rear Axle
6.50:1
HJ5
Rear Axle
5.57:1
HJ6
Rear Axle
4.78:1
HJ7
Rear Axle
4.88:1
HK1
Rear Axle
2.87:1
HK3
Rear Axle
6.14:1
HK9
Rear Axle / Single Speed
5.86:1
HO4
Rear Axle
4.11:1
HO6
Rear Axle
4.63:1
247
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