Making Distributor Advance Springs

[Jack_K]

I need to recurve some Lucas distributors. Because they are basically custom applications, I can't just order them from the distributor doctor etc. They are different models to the original ones meaning different mechanisms so the original springs are different.

Everyone seems to just make their own springs but nobody seems to say how. Maybe I'm missing something?

Where do I start?

 

[zzr1200]

Buy lots of small springs, it's called "Trial and Error".......that's how most modifications start out like this......

 

[8ob]

Add or subtract weight to the counterweights.

Bob

 

[Jack_K]

Buy lots of small springs, it's called "Trial and Error".......that's how most modifications start out like this......

I've been using what I've got lying around. All the random springs I find online aren't remotely correct unfortunately but I'm still looking. If I can make some springs when required it would be great.

 

[Agroshield]

Where do I start?

Summer, Autumn or Winter might not be the best time of year.

https://archive.org/details/19springdesignmanufacture is a reasonable introduction.

Comprehensive selection:

Internet Archive: Digital Library of Free & Borrowable Texts, Movies, Music & Wayback Machine

archive.org

Lots of model engineering-type people make their own springs, so in and around that area is a good place to look. I think music wire (piano wire) is a good material.

Also here:

Making Small Compression Springs

today I had a go at making some small compression springs as I wasn't prepared to pay the minimum order quantities for half a dozen so thought I'd have a go at making my own. I need stainless steel springs so got some hard drawn stainless steel. this is available from the far east via ebay etc...

www.mig-welding.co.uk

Spring Winding – Retro Tech Journal

Posts about Spring Winding written by Kurt

retrotechjournal.com

Spring winding jig

POTD was repairing some Erector set parts for sale on eBay. One thing leads to another; I needed some springs and could have gone the finished product route, or wind them myself. I’ve had making a spring-winding jig on my “list of good intentions” for 30+ years. Finally got around to it! I made...

www.hobby-machinist.com

https://www.cgtk.co.uk/metalwork/calculators/spring from Dr Al of this forum

 

[daedalusminos]

If you match all the physical attributes of the original you won't be far off. You can wind them on a lathe using piano wire relatively easily.

 

[dave h 2]

Add or subtract weight to the counterweights.

Bob

Simple solutions are obviously not required here.

 

[Melvyn Best]

I made springs years ago when I was still at school using a slotted mandrel in a hand drill , just put a piece of (I think) piano wire of a suitable size into the slot then wind the handle keeping the wire tight against the mandrel. Wouldn’t be too difficult to produce some of various tensions perhaps fine tuning the advance curve by adjusting the weights?

 

[Farside]

Trial and error by observation.
If you fit a spring that's too strong, no harm.
Too light, otoh, not good.

 

[Jack_K]

The question isn't about how to select springs, just how to make them. When I was searching, all I kept finding was compression springs which are a bit different.

Modifying the weights is a last resort. The distributor that I'm doing at the moment has longer and strong springs than most distributors. They are VERY strong, not simple to increase the weight enough. I did another distributor which I am considering increasing the weight as the weak springs it requires can't control the advance well.

Summer, Autumn or Winter might not be the best time of year.

https://archive.org/details/19springdesignmanufacture is a reasonable introduction.

Comprehensive selection:

Internet Archive: Digital Library of Free & Borrowable Texts, Movies, Music & Wayback Machine

archive.org

Lots of model engineering-type people make their own springs, so in and around that area is a good place to look. I think music wire (piano wire) is a good material.

Also here:

Making Small Compression Springs

today I had a go at making some small compression springs as I wasn't prepared to pay the minimum order quantities for half a dozen so thought I'd have a go at making my own. I need stainless steel springs so got some hard drawn stainless steel. this is available from the far east via ebay etc...

www.mig-welding.co.uk

Spring Winding – Retro Tech Journal

Posts about Spring Winding written by Kurt

retrotechjournal.com

Spring winding jig

POTD was repairing some Erector set parts for sale on eBay. One thing leads to another; I needed some springs and could have gone the finished product route, or wind them myself. I’ve had making a spring-winding jig on my “list of good intentions” for 30+ years. Finally got around to it! I made...

www.hobby-machinist.com

https://www.cgtk.co.uk/metalwork/calculators/spring from Dr Al of this forum

I clicked on the first link and it looks great. I'm always looking for stuff on archive.org but I never thought to search for spring stuff on there.

I do know a guy down the road who makes model steam engines and makes springs. The problem is he'd do it for me but that's obviously inconvenient with the trial and error approach etc. On top of that, he's 90.

 

[Misterg]

Where do I start?

Assuming we're talking about fairly small diameter wire here (<1mm):

You need a supply of 'piano wire' and a mandrel that's smaller than the ID of the spring you want to end up with. How much smaller depends on the wire you're using. There are tables and calculations for this, but some trial and error is needed anyway, so just take your best guess and start from there.

Put the mandrel in the lathe and fix one end of the wire to it somehow (I usually have a hole through the mandrel for this, but a clamp screw works better if you need a 'tail' on the spring.)

Lead the wire through the tool holder and clamp it between a couple of pieces of hardwood using the tool clamping bolts. The wire needs to *just* be able to slip. Turn the lathe by hand (or very slow speed) to wind the wire onto the mandrel. For compression springs, you can use the screw-cutting drive to space the coils out. If you do, it's neater to make a few turns close wound at either end (or wind all the coils close and stretch the spring afterwards). Cut the wire once you have got enough coils (shouldn't need saying, but the end will flick around violently when you do).

Take it off the mandrel (snip the wire if the end is poked through a hole) and dress the spring ends. If it's too big or too small, then modify / make a new mandrel.

There are various arguments about whether the spring needs to be tempered again after winding, but I've never been convinced enough to bother.

ToT describes it well. (skip to ~5:00 if you want to skip the whimsical intro):

 

[piman]

Hello Jack,

personally i would just send it to the Distributor Doctor, tell him waht specification you require and let him set it up. I would say it's worth all the cost to do without the hit and miss of doing it yourself. He has the springs, equipment and experinece.
I have found over the years its not worth doing everything yourself, its either sub standard or just takes far too long.

Alec

 

[Jack_K]

There are various arguments about whether the spring needs to be tempered again after winding, but I've never been convinced enough to bother.

This is one of the things I was confused about. I started reading arguments and gave up.

 

[Jack_K]

Hello Jack,

personally i would just send it to the Distributor Doctor, tell him waht specification you require and let him set it up. I would say it's worth all the cost to do without the hit and miss of doing it yourself. He has the springs, equipment and experinece.
I have found over the years its not worth doing everything yourself, its either sub standard or just takes far too long.

Alec

That would certainly be easier but I do everything myself even if it makes no sense. If I only had a couple of distributors to do, it would make more sense to send it to someone. I have four cars myself with distributors and then there's another five cars/trucks/tractors that I work on.

 

[dave h 2]

I take the selection boxes of springs have proved useless.

 

[8ob]

I suppose the key to success is finding a way of calibrating/calculating poundage of a spring at a given length with a good degree of repeatability, making the spring is the easy bit, a bit like a valve spring height/poundage gauge in reverse.

Bob

 

[Newlands]

You need a supply of 'piano wire' and a mandrel…

This is exactly the way we made a spring in our metalwork class at school. I recall heating the last coil on each end to make the piano wire soft enough to bend an eye in it, and then subsequently hardened (cherry red and quench) and tempered these (to blue heat) to return them to a harder state. Obviously not very precise but it worked well enough. I remember it well because using the lathe in screw cutting mode to get the right pitch made the finished spring look very professional - it’s easy to impress a 14 year old I guess, or at least it was in those days!

 

[Erie Fred]

di-acro spring winder at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[northwest]

You can make your own soring winder from this kit:

Universal Spring Winder - hemingwaykits.com

Unique projects for the small workshop owner. Please browse our Toolroom and Engine Bay for our latest project kits.

www.hemingwaykits.com