How to Wind a Coil Spring on the Metal Lathe

[Chucketn]

TomG,
Another vote from me for excellent video presentation! You make it so easy! Watched it yesterday, and spent another couple of hours researching spring characteristics and formulas. I would like to build a spreadsheet that would help me design springs given wire diameter, spring diameter, length needed and tension needed. Found lots of interesting information. Thanks for the stimulation. I will be building and trying your jigs!

Chuck

 

[Tom Griffin]

Thanks Chuck.

When you get that spread sheet worked out, I'm sure a lot of us would love to see it.

Tom

 

[kellswaterri]

thank you Tom for showing that...I am learning all the time.

 

[churchjw]

Great video thanks for posting. Need to try this at some point.

Jeff

 

[Chucketn]

Tom,
I'm busy making my version of your spring tools. My version of the guide will be mounted in an aluminum QCTP holder. Where do you set the height of the wire guide? Centerline of the 3/16" hole in the guide on lathe centerline, or on top or bottom of the mandrel?

Chuck

Edit: I just watched the video again and you say set the guide on the centerline of the mandrel (lathe centerline).

 

[4GSR]

Thank you Tom for a great video!

I toured a spring manufacture many years ago that is located in Houston, Texas. What a neat place to visit. What I found interested was several old cone head lathes that were set up just for spring winding just as Tom showed in his video. Watched them, from a distance, winding a spring made of 1/2" diameter Inconel spring tempered wire. The spring came out about the size of a front end suspension spring on a car. It started out as a piece around 30 foot long.

 

[Tom Griffin]

Tom,
I'm busy making my version of your spring tools. Mt version of the guide will be mounted in an aluminum QCTP holder. Where do you set the height of the wire guide? Centerline of the 3/16" hole in the guide on lathe centerline, or on top or bottom of the mandrel?

Chuck

Edit: I just watched the video again and you say set the guide on the centerline of the mandrel (lathe centerline).

Chuck,

The height isn't that critical with lighter wires, centered on the mandrel will be fine. Heavier wire needs to be closer to the bottom of the mandrel so you can get the wire started in the guide.

Tom

 

[Chucketn]

Thanks Tom. I just finished the guide/qctp tool holder. Tomorrow I'll make a mandrel and try it out. Pictures posted later tonight. Got to clean up and go to 'happy hour' with 'Her indoors'!

Chuck

 

[jgedde]

That's the nice thing about this technique John, tensioning is not required. The wire guide is simply a piece of 1/2" round with a 3/16" hole nearly through and a 60º V cut in the end to control the wire at the point where it wraps up on the mandrel. The hole through the center just keeps the wire from getting tangled as it feeds.

The photo below is a close-up of the business end of the wire guide.

Tom

Thanks Tom, the picture clears it up.

Is there any reason, when making a compression spring, that one couldn't set the lathe's gearbox to wind the spring with the desired pitch? For example, 8 turns in 1" of your 0.025" wire.

I'm thinking one could start the spring for a few turns with a pitch to make the spring lay wire to wire, stop, set the gearbox for a coarser pitch, wind the desired number of turns, then set the lathe back to "wire to wire" and wind a few final turns. That way a compression spring with a start and end coil could be made just by trimming back the ends.

John

 

[Tom Griffin]

Thanks Tom, the picture clears it up.

Is there any reason, when making a compression spring, that one couldn't set the lathe's gearbox to wind the spring with the desired pitch? For example, 8 turns in 1" of your 0.025" wire.

I'm thinking one could start the spring for a few turns with a pitch to make the spring lay wire to wire, stop, set the gearbox for a coarser pitch, wind the desired number of turns, then set the lathe back to "wire to wire" and wind a few final turns. That way a compression spring with a start and end coil could be made just by trimming back the ends.

John

I've never tried that, but I have seen it done. Don't see why it wouldn't work if you needed the ends of your compression spring closed. I would suggest keeping the end of the guide as close to the mandrel as possible to reduce "lag" when you start the feed. If you try it, let me know how it works out.

Tom