Hello Randall and co.,
Will comment in Caps
At 01:27 PM 29/07/2004 -0700, Randall wrote:
> > IS THERE ANYONE IN THIS GREAT CIRCLE OF BOUNDLESS KNOWLEDGE WHO HAS A
> > SOURCE OF ADVANCE SPRINGS?.
>
>I have several magazine articles on winding your own springs. Might take
>some experimentation to catalog spring rates given by different wire
>diameters and alloys, but the rest seems easy enough.
I WOULDN'T MIND SEEING THE ARTICLES
> > I might add that I have tried to have some springs made but that exercise
> > ended up as a total (and expensive) disaster
>
>Having them made is perhaps a bit trickier ... you need to completely
>specify the spring in terms of free length and spring rate. If your
>manufacturer agrees to your spec, and is unable to supply springs that meet
>it, you should not have to pay for them.
THE SPRING MAKER I WENT TO HAD NO TROUBLE WINDING THE SPRINGS FROM SAMPLES,
THE DIFFICULTY;IS IN FORMING THE SPECIAL "LONG LOOPS" ON THE ENDS. THE
EXACT OVERALL LENGTH OF THE SPRING IS IMPORTANT TO MAINTAIN THE CORRECT
SPRING TENSION AT REST.
THE SPRING MAKER, WHO IS A PROFESSIONAL WITH ABOUT 40 YEARS EXPERIENCE TOLD
ME THAT THE ORIGINAL ENDS WOULD HAVE BEEN MADE WITH A JIG BENDER ON AN
AUTOMATIC MACHINE. SIMPLE LOOPED ENDS ARE EASY TO MAKE. I HAVE A SET OF
LOOPING PLIERS AND HAVE IN FACT SUCCESSFULLY MODIFIED STANDARD SPRINGS FROM
SPRING ASSORTMENTS BUT, BECAUSE A DIFFERENT DIAMETER/GAUGE OF WIRE WILL
THEN BE REQUIRED (BECAUSE THE NUMBER OF TURNS FOR A GIVEN "AT REST" HOOK TO
HOOK LENGTH WILL BE DIFFERENT) THE WHOLE THING BECOMES MUCH MORE COMPLICATED.
THE REAL ANSWER WOULD BE A GOOD SELECTION OF SPRINGS AND A LOT OF PATIENCE
>I don't know where you would find that information for the original springs,
THERE USED TO BE A LUCAS SPRINGS MANUAL. THE LAST ONE I SAW WAS AFTER
FLOODS IN THE CITY OF HOBART IN 1960. IT WAS VERY SOGGY, I DIDN'T TRY AND
SAVE IT, BUT I NOW WISH I DID
THE INFORMATION WHICH I WOULD NOW REALLY LIKE TO GET HOLD OF IS THE ADVANCE
CURVE SPECS FOR PRE 1946 LUCAS DISTRIBUTORS. I HAVE MOST INFO POST 1946.
>but with the help of a distributor machine and a spring winder, it shouldn't
>be too difficult to make a spring, measure it, then install it and observe
>the results.
I HAVE A SET OF TENSION BALANCE GAUGES AND CAN MEASURE THE LIFT OFF
TENSIONS OF SPRINGS, WHICH ASSISTS, BUT IT IS NOT AN EXACT SCIENCE BECAUSE
OF THE NEED TO HAVE A CRITICAL "AT REST" HOOK TO HOOK DIMENSION.
> Just a few such results should be enough to characterize what
>spring you need.
>
>Randall
>THANKS FOR YOUR INTEREST AND REPLY
Barry Riseley
Tasmania
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