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- Nov 23, 2014
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POTD was done yesterday; ironically “spring time” on the first day of summer. My wife has a coworker who bought a KitchenAid mixer that is missing a spring at the mixing head (for securing attachments). He found a replacement spring on line for $35 and was complaining about the cost. We have the same mixer; I was volunteered to make a replacement (or two).
Our KitchenAid; compression spring helps secure attachments
The stock spring was made from 0.041” stock, OD of ~0.615”, wound at 4 coils per inch, RH wind, 2+ complete coils and flat “starter coils” at either end. I don’t know the proper terminology, feel free to feed me the correct verbiage! I referred to the coil as a RH wind which is my description. I look at winding a spring like cutting a thread; this spring was wound like a RH thread, so a RH wind. Also, “starter coil” is properly not the correct name. Just my term for the start of the compression spring; “starter coil” is flat so the spring doesn’t side-load when compressed.
I posted a POTD a while back on my spring winder. It’s an aluminum round with a drilled/tapped hole at the end for a MIG welding tip. Music wire feeds through the aluminum rod/MIG tip as the mandrel is turned. There’s a brass pinch plate to hold tension on the spring that’s adjusted by a knob that threads into my dedicated QCTP holder. The back of the winder has a slot for mounting a roll of music wire, but in this case, I just cut off a length.
My spring winding attachment. Music wire feeds through the MIG tip, tension on the wire is controlled by the clamp knob at the back.
I wind springs on the lathe; no epiphany there. The music wire is wound around a mandrel, and no pun intended, the mandrel diameter is undersized because of spring back. I keep a photo of the Machinery’s Handbook page on my phone (OCD much?) with mandrel sizes; inputs are wire diameter and spring outside diameter. The book says a mandrel of 0.416” diameter for a 5/8” OD spring made from 0.041” music wire. My spring is 0.615”, so I targeted 0.406” for the mandrel. And “yes”, I measured the spring on our mixer while it was under a bit of light compression, so my OD could be off slightly.
My go to lathe is a Grizzly G0709 14”x40”, but the Clausing 5418 was used for this project. The spring has 4 coils per inch; the QCGB would be set to 4 threads per inch for winding. The Grizzly does 4 tpi, but it requires a quadrant gear swap to go to the coarse series of threads; I typically leave the lathe in the finer-pitch thread range. The Clausing has a quadrant gear with a handle for sliding gear “IN/OUT”; simple pull of the handle switches the lathe from finer threads to coarse threads.
Chucked up some ½” CRS and turned to 0.406”. Then over to the Bridgeport to spot and drill a cross hole for holding the music wire. I didn’t show it, but I drilled out a MIG welding tip to 1/16” for use with the 0.041” wire.
Turning the mandrel
Spot drilling and drilling a cross hole to secure the music wire on the mandrel
Back to the Clausing to do the winding. Fed the music wire through the winding tool, through the mandrel and bent the end over. This spring was only a couple of coils, so it was wound by manually rotating the collet chuck. Began with a couple of flat starter coils manually turning the chuck and moving the carriage. Then engaged the half-nuts to “thread” the wire at 4 tpi. After a few turns, disengaged the half-nuts and turned a number of flat coils. Then snip off the ends with side cutters.
Hand turning a couple of flat coils
Half nuts engage for the coils
Disengaged the half nuts and manually wound a few flat end coils
One other note, there’s some trial and error to get the correct number of finished coils. When the spring is wound, it’s tight to the mandrel. But when the tension is relieved, it springs back (pun intended. . .) reducing the number of coils. I ended up doing 3 coils during the winding to end up with 2+ coils on the finished spring. A smarter person could do some calculating for the spring back, but at $10 for a 200 ft. piece of 0.041” music wire, I went the dead-reckoning route.
Finished springs!
Thanks for looking, Bruce
Our KitchenAid; compression spring helps secure attachments
The stock spring was made from 0.041” stock, OD of ~0.615”, wound at 4 coils per inch, RH wind, 2+ complete coils and flat “starter coils” at either end. I don’t know the proper terminology, feel free to feed me the correct verbiage! I referred to the coil as a RH wind which is my description. I look at winding a spring like cutting a thread; this spring was wound like a RH thread, so a RH wind. Also, “starter coil” is properly not the correct name. Just my term for the start of the compression spring; “starter coil” is flat so the spring doesn’t side-load when compressed.
I posted a POTD a while back on my spring winder. It’s an aluminum round with a drilled/tapped hole at the end for a MIG welding tip. Music wire feeds through the aluminum rod/MIG tip as the mandrel is turned. There’s a brass pinch plate to hold tension on the spring that’s adjusted by a knob that threads into my dedicated QCTP holder. The back of the winder has a slot for mounting a roll of music wire, but in this case, I just cut off a length.
My spring winding attachment. Music wire feeds through the MIG tip, tension on the wire is controlled by the clamp knob at the back.
I wind springs on the lathe; no epiphany there. The music wire is wound around a mandrel, and no pun intended, the mandrel diameter is undersized because of spring back. I keep a photo of the Machinery’s Handbook page on my phone (OCD much?) with mandrel sizes; inputs are wire diameter and spring outside diameter. The book says a mandrel of 0.416” diameter for a 5/8” OD spring made from 0.041” music wire. My spring is 0.615”, so I targeted 0.406” for the mandrel. And “yes”, I measured the spring on our mixer while it was under a bit of light compression, so my OD could be off slightly.
My go to lathe is a Grizzly G0709 14”x40”, but the Clausing 5418 was used for this project. The spring has 4 coils per inch; the QCGB would be set to 4 threads per inch for winding. The Grizzly does 4 tpi, but it requires a quadrant gear swap to go to the coarse series of threads; I typically leave the lathe in the finer-pitch thread range. The Clausing has a quadrant gear with a handle for sliding gear “IN/OUT”; simple pull of the handle switches the lathe from finer threads to coarse threads.
Chucked up some ½” CRS and turned to 0.406”. Then over to the Bridgeport to spot and drill a cross hole for holding the music wire. I didn’t show it, but I drilled out a MIG welding tip to 1/16” for use with the 0.041” wire.
Turning the mandrel
Spot drilling and drilling a cross hole to secure the music wire on the mandrel
Back to the Clausing to do the winding. Fed the music wire through the winding tool, through the mandrel and bent the end over. This spring was only a couple of coils, so it was wound by manually rotating the collet chuck. Began with a couple of flat starter coils manually turning the chuck and moving the carriage. Then engaged the half-nuts to “thread” the wire at 4 tpi. After a few turns, disengaged the half-nuts and turned a number of flat coils. Then snip off the ends with side cutters.
Hand turning a couple of flat coils
Half nuts engage for the coils
Disengaged the half nuts and manually wound a few flat end coils
One other note, there’s some trial and error to get the correct number of finished coils. When the spring is wound, it’s tight to the mandrel. But when the tension is relieved, it springs back (pun intended. . .) reducing the number of coils. I ended up doing 3 coils during the winding to end up with 2+ coils on the finished spring. A smarter person could do some calculating for the spring back, but at $10 for a 200 ft. piece of 0.041” music wire, I went the dead-reckoning route.
Finished springs!
Thanks for looking, Bruce
