Spring making from music wire

[Airpirate]

I have two spools of music wire made by Precision brand. One is.029 the other .041.
I am attempting to make a double torsion spring to release a mechanical device 90 degrees.
I have read all I can find on the subject including anealing, shaping, hardening, and tempering.
No problems except for tempering. I have a small dental over with a braod range and a digital controller so I think I should be able to produce a spring.
I place the hardened spring in my oven and raise it to 750F and hold for a hlaf hour. Remove the spring and it snaps or bends without any spring back, or I get mild springs that lose about 50% of their range ( they stay bent without springback)

 

[benmychree]

750 is too hot for a spring temper, should be about 600 - 650F. If the wire can be bent cold, it will make a good spring as is. In high school we had to make compression springs for one of our required projects, we used an undersized mandrel to allow for springback, and wound them in the lathe, using a tension device in the toolpost to feed the wire. The springs were made from spring tempered wire from PSW.

 

[Winegrower]

As Benmychree says, use a tension device in the tool post to feed the wire. I use a QC tool holder with a couple of Delrin pieces clamped around the wire, with the holder setscrews applying the squeezing to get the right tension.

Be a bit careful the first time as the spring can tend to unwind a bit, hitting some high RPM. Ouch.

 

[RJSakowski]

Music wire is already hardened and tempered. You simply have to wind the the spring on a mandrel. The mandrel will need to be smaller in diameter than your final inside diameter due to springback. The .041 will be a bit cantankerous. There are some designs for spring winding tools on line. I made my own.

A 4" length of 1/2 round is drilled to about 5/8" from the end and a 60º Vee notch is filed for the remaining distance. The tool is clamped in a QCTP holder and adjusted so the wire will be tangent with the bottom of the mandrel. The cross slide is adjusted to just clear the mandrel. The spring wire is fed through the hole and into the notch. I use a pair of vise grips to provide tension on the wire as it is feeding but an improvement to the tool would be to add a tensioning device at the back end. I usually close wind my springs and stretch them as needed but the power feed could be used to create precision coil spacing. When winding the spring, I will loosen the drive belt slightly so it will slip if needed. This gives me time to shut the lathe down

 

[Airpirate]

750 is too hot for a spring temper, should be about 600 - 650F. If the wire can be bent cold, it will make a good spring as is. In high school we had to make compression springs for one of our required projects, we used an undersized mandrel to allow for springback, and wound them in the lathe, using a tension device in the toolpost to feed the wire. The springs were made from spring tempered wire from PSW.

Thank you for your input. I'll give it a try.

 

[Airpirate]

As Benmychree says, use a tension device in the tool post to feed the wire. I use a QC tool holder with a couple of Delrin pieces clamped around the wire, with the holder setscrews applying the squeezing to get the right tension.

Be a bit careful the first time as the spring can tend to unwind a bit, hitting some high RPM. Ouch.

Thanks I'll keep your warnings in mind.

 

[RandyWilson]

 

[savarin]

When I wound some tiny springs I did the same as RJ but set the threading feed to give me the coil spacing I wanted.
It took a bit of experimenting to get the mandrel size for the correct spring back dia but that was the only difficult part. I didnt heat or temper them either.

 

[gjmontll]

Here's a website with two good articles on spring making...

Making Springs on the Small Lathe

 

[Airpirate]

750 is too hot for a spring temper, should be about 600 - 650F. If the wire can be bent cold, it will make a good spring as is. In high school we had to make compression springs for one of our required projects, we used an undersized mandrel to allow for springback, and wound them in the lathe, using a tension device in the toolpost to feed the wire. The springs were made from spring tempered wire from PSW.

Here's a website with two good articles on spring making...

Making Springs on the Small Lathe