I'll start with one. People who crank a valve open or closed HARD against the stop. As simple as a garden hose or a propane tank valve. The automotive equivalent is cranking the oil drain plug on insanely tight.

Rgds,
Chris W.
'95 E300D, 345K

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Objects in closer are mirror than they appear.

My wife is pitiful when it comes to mechanical things. Thankfully I love her for all the other things. I will say (proudly) that last week I talked her (on the phone) through jump starting the pickup.

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Jim

People who strip oil pan drain plugs, I mean come on its not that hard.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The friend who watched my '71 for me while I was overseas and couldn't tell that the transmission was slipping badly (due to him having run it out of fluid).

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Designers who use multiple datums on a 3 view drawing...

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1987 560SL
85,000 miles

Can you explain what that means ?
Is that something like someone saying ' they proved the null hypothesis ' ?
Something by definition they have done wrong if they are doing that ?

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

People who crank a thermostat or fan speed switch really far when they are uncomfortable, rather than making a small adjustment.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

I had a room mate once who did that. The bad part is he was a Construction Mechanic 1st Class in the Seabees. He finally stopped after about the third time I explained how the control algorithm for the AC worked.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Hope you instructed her to wear safety goggles.

It kind of annoys me when I see people hit the steering lock when turning, and keep on cranking the wheel hard against the stop.. you can usually hear the power steering pump squeal in displeasure

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1985 CA 300D Turbo , 213K mi

+1

my wife does this, And worse- when she is exiting our Subaru wagon (which has frameless windows) she closes the door by pushing on the window glass (not the heavy metal door...) it kills me.

I also dont appreciate the 'throw it to the stops' mentality when it comes to 'consumer' control systems. I was with a Machine tool Controls EE (!!) when he rented a Lincoln Town car with auto climate control- it was summer and he just couldn't wait for the car to sense that it was hot inside, he *had* to push the fan to "RLY FAST" as soon as he started the engine...and then back it down manually about 5 minutes later- never putting it in 'automatic' mode (the way it was intended to work). And he was a controls guy...




Datums and 3-view drawings ? my layman's translation would be - it means that if you are machining a piece of metal (drilling holes, cutting edges straight...), you need to measure something multiple times from different places before you are sure that the hole/edge is in the correct place. Better design (using 1 datum) involves more effort on the part of the designer, but requires less thought and checking during production - which is the way it should be done.

am I close ?
-John

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2009 Kia Sedona
2009 Honda Odyssey EX-L
12006 Jetta Pumpe Duse
(insert Mercedes here)

Husband, Father, sometimes friend =)

People who accelerate into stop lights. I see it all the time ... and it's even worse when someone floors it to pass you as you approach a stop light.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

My definition of "Mechanical Feel" translates to my trade as this...

Detail drawings in ACAD are generally done in a "3 view drawing", meaning 3 sides of the part are shown, so someone is able to machine the part and make it to print.

A "Datum" is a point on the part, usually a corner, where dimensions generate.

Someone who has no "Mechanical Feel", or mechanical experience will use multiple datums to dimension from for each view...meaning they will have some features dimensioned from the left side, some from the right side, some from the tip and some from the bottom. When this is done, it creates more work for the person machining the part, because they have to re-dimension the part to make it easier to machine.

Therefore, when someone lacks the "Mechanical Feel" they lack the experience to properly draw a part. They may be able to draw, but they cannot draw it in such a way that it can be made properly.

I hope that's clear as mud.

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1987 560SL
85,000 miles

They have to do it.......all of them.

The reason is the fact that the time sitting at the red light doesn't count in the overall trip time.

Got it?

I see your point as far as what you consider a datum. On ASME drawings you genrally have three datums, for Geometric Dimensioning and Toleranceing. Basically, you are dealing with a three dimensional or Cartesian cordinate system. So, usually two or three datums are needed. 'A' is usually the base, "B" locates in the 'X' plane or a hole and 'C' clocks the part or keep it from rotation. Mating surfaces usually have another datum. Usually, your dimensions come from 'B' or 'A'. On some parts, dimensions will be from another datum or feature. That signifies or keeps say bolt holes related to that feature. A good example would be bolt holes for a starter boss on a flywheel housing
Tom