skeeter_ca

[&:]Is it possible to build a homemade spring starter like the ones that came with the cox .049s. Could you wind up some music wire like the old spring starters or would you have to make it then temper it to a spring steel hardness? It could be a nice simple project or get very complicated.

skeeter

digital_trucker

Isn't music wire spring steel already?

rainedave

My Feedback: (1)

This is a very good article that everyone should take the time to read.

http://www.spmrc.com/HeatTreatingMusicWire.html

I think by annealing the wire, coiling it and then bringing it back to spring temper, it could be done successfully.

RocketRob

My Feedback: (1)

Dave, Great article - thanks.
The .049 springs come up on evilbay for about 5 bucks.

digital_trucker

Considering the gauge of the wire you'd use for a spring starter, it probably could be used in it's stock state by winding around a dowel mandrel. That shouldn't work-harden it much if at all.

vicman

My Feedback: (10)

If you should try to wind one do not put any intentional spaces between the coils, they will form naturally. Also use a 30% (approx) smaller mandrel than the id size of the spring. The way I have done this in the past is to chuck the mandrel in the lathe with the end of the wire clamped by one of the jaws. Yes this will cause the mandrel to run out, but we are not going fast at all also we are not machining anything so it doesn't matter. Hold the wire square to the mandrel (this prevents intentional spacing mentioned earlier) firmly and allow the rotation of the machine to feed the wire onto the mandrel. You will want to pull with a good bit of force against the mandrel to to get a nice tight coil. I usually hold the wire with vise grips. When doing larger spings it helps to have a helper to turn the machine on and off for you as you tend to be very busy trying to keep the coils in line and tight.

I have also used the same technique in milling machine chuck and a heavy drill press, something that can have a lot of power but go slow.

I would be slow to attempt the comound coil of a starter spring using the torch heat treating method. You will be very lucky to get a consistant hardeness all over the part and risk brittle areas. Brittle areas lead to rapid un-expected failure and starter spring looking projectiles going places quickly. If you try it wear you glasses and let me know before you do.

dieFluggeister

Great article Dave.

I know a couple ol boys back home that would thow steel in a pile of burning tires to 'carbon it up' and quench it in old crankcase oil to harden it to spring temper for machinery repair. Do you think the EPA would have a problem with that?

I definately wouldnt recommend doing that for the spring starter project - way too hard to find tires that small.


Hey skeeter, if you just need some spring starters for Cox motors I can send you a bunch of 'em from my parts bin. Just PM me.