Title
Oh-So-Easy Throttle-Return Springs

Author
Sir Shaggy

Published
Wednesday, July 9, 2008

People that see my 1:25 scale cars in person often ask me, "How did you wind the return spring that small?" Used to be I'd just show and explain…lately, I've been answering, "Victor did it for me." I'll explain… You see, the throttle return springs are the filaments out of a #1157 Stop-Turn-Tail automotive light bulb! (Made by Victor, one of many manufacturers). This is a trick I discovered years ago, and since I haven't seen anyone else use them, I thought I would share it with you. So, without further ado…let's get started!!

Step #1: Here's what you need:

A package of #1157 Victor-brand light bulbs, pliers, a sandwich-sized Ziploc bag, tweezers, super glue, X-Acto knife, safety glasses, and a well-lit, plain-surfaced, clean work area.



Step #2:

Take one of the bulbs out of the pack, insert it into the Ziploc bag and seal (with the excess air out of the bag). Apply the pliers around the base of the bulb (around the metal base as shown), and squeeze to crack the glass bulb. Keep in mind that you are working with glass here, and you can get cut very easily if you're not careful!!





Step #3:

Now from here is where it gets tedious! Now that the filaments are freed from the nice little globe of protective packaging the factory provided for us, the next step is to pry the filaments from the posts with the X-Acto knife. You really have to keep an eye on these units, because they are easily lost once freed.





Step #4:

The reason I prefer the Victor-brand bulbs is because I have been successful at spreading the filaments to emphasize the 'spring' feature, as well as shorten the spring,(other brands are usually too brittle, and you want to use fresh bulbs too!) because for most applications, they are slightly over-length. So we want to spread the spring at a point just off from the center with two fingers/hands (Fingernails are a must, or use a pair of cuticle-cutters, to get 'into' the spring to spread.) from the 'split-point', straighten about 1/4th of an inch of the spring material. Clip off the excess 'spring', and make a hook at the ends.



Step #5:

I have recently discovered that a DUAL throttle-return spring can be made by placing the secondary filament through the primary (Yes, it fits!!). Not all applications call for this, but when it does, know that it can be accomplished, adding a TON of realism to your build! When the application calls for this, you should only STRETCH the secondary filament (after shortening), while leaving the primary just stretched enough to emphasize the 'spring' feature, (see photo)



Step #6:

After our spring is stretched to the appropriate length(s) drill a small hole in the side of the carburetor linkage, and fashion an anchor off the motor out of scrap, or styrene. These will be the attachment points for our spring(s).



Step #7:

Using your tweezers, position the spring, add a dab of superglue, and we're done! Now you can move on to other aspects of detailing your engine, or your build. I have included photos of my Charger and Willys engines as example of dual, and single throttle return spring applications as well.







I hope this tutorial has helped you out. Any questions can be site mailed to me.