I should have mentioned that my 'experiments' were with UNC nuts on Whitworth bolts, not vice versa. In theory there should still be galling, but I didn't find that in practice.
David W.
Mechanical Engineering Group
Nene Valley Railway
I'm surprised at the comments about the threads locking up.
A lot depends on the class of fit, of course, but in experimental tests I've found that Whit and UNC will run right up in all sizes from about 1/4" to an inch or larger, other than the 1/2" with its different TPI. But it should never...
I have received a most interesting view on the matter by email from Roger Cooke:
"My thoughts are that, whatever the spring rate, if the strut was assembled uncompressed, fitted to the vehicle, and the vehicle lowered onto its wheels, the strut would immediately compress until the weight...
DennisP,
Thanks for your very feasible suggestion. That will do for me unless someone comes along with a better answer.
David W.
Mechanical Engineering Group
Nene Valley Railway
True, the spring does have to be compressed for assembly and disassembly, but that wasn't the question I was trying to ask.
I'm trying to find out why the spring isn't made to a length that would allow it to be dropped into position (uncompressed) and the top flange pulled down to the stop, at...
desertfox - Interesting article but I can't see any explanation in the article as to 'why' the MacPherson strut is designed to have the spring compressed prior to assembly to the car.
NormPeterson - Good point about competition springs often being shorter, but surely the car makers wouldn't add...
MacPherson Strut front suspension was common on a lot of cars in the 1950s onwards. It is well known that the spring has to be compressed prior to, and during, assembly into the damper/spring unit and held in that state until the top flange-securing nut has been fully screwed down.
A simple...
