[This Old Tony] teaches us how to make springs on a lathein this video done in the style of How It’s Made. Mixed in with snark, in his usual style, is a lot of useful information.
The Machinery’s Handbook certainly has all the information one would need to design the basic spring shapes, but it’s not always necessary. [Tony] points out that cheating is entirely acceptable. For example, if you need a spring that’s close to the dimensions of a standard spring, simply copy over the values from the standard spring. He explains all the terminology needed to decrypt the pages in your engineering tome of choice.
He shows the basics of winding a spring on a mandrel (or that round metal thing, if you want to use the industry term). First wind the inactive coils, then set your lathe to the desired spring pitch. Engage it as if threading, then disengage and wind the final inactive coils. A quick trip to the sander squares the ends of a standard coil spring. However, the tools can also be used to make torsion springs, or even exotic combination springs.
For a good… educational laugh, watch the whole video after the break.
some equipment is missing in this picture….
A safety tie?
There is always missing equipment in my mind, but what exactly did you mean?
It’s not an annealing/heat treatment oven, the wire he used is already treated.
This is great! I have been needing a spring to preload the spindle bearings on my CNC mill spindle project. Had zero luck finding one off the shelf.
FWIW, you should not use springs to preload bearings. Ground spacers or matched set preload bearings are usually the order of the day for spindles.
I’ve been using “wave washers” for spindle preloading. Seems to be fine IMO as long as one puts the spring on only one side, and with relatively high preload force. Though by “fine” I mean fine for typical hobbyist stuff like precise-but-low-load (PCB milling) and “high load but not so precise” situations.
Spring preload is actually very handy and effective in many cases.
It’s also much more resilient to “bad” designs, enlarged tolerances and thermal dilatations not taken in account.
They’re actually used in many a industrial application.
It’s just another way of applying a preload force.
I have never seen a commercial spindle use springs for preload. And I have seen a lot of spindles, I used to be a tech working on commercial CNC machines.
I use a spring preload on a motor bearing before. I slid the spring over the shaft inside the housing and pressed it against the bearing. I calculated out the force needed and put the spring in the right state inside a housing that would be stamped together. That way even if the housing was stamped a bit smaller or larger than it needed to be, the spring would still provide a pre-load within an acceptable range. It didn’t spin fast enough to worry about balance and springs are cheap:)
Spindles are a different story though.
Here is a purpose-made lathe spindle bearing with built-in spring preload.
https://simplybearings.co.uk/shop/p20036761/Gamet-74025/74052P-Super-Precision-Tapered-Roller-Bearing-Integral-Spring-Carrier-Cup-Type-25x52x19mm-Allow-7-10-Days/product_info.html
Just one more use of piano wire. Yeah!
You mean the original use.
Love the piss take of ‘how it’s made’ :-)
This has been the most informative video I’ve viewed all week! Fantastic videography and the bad puns were right on key for How It’s Made. The perfect ratio of jokes to information in my opinion. :)
The comments section answered the heat treatment question I had.
(Music wire is already treated.)
For me too! only watching it just one day later makes all the difference. It is Monday. Great start of the week. Keep it up Internet!
This was good. But it made me remember something I saw long ago. I googled “jam handy springs” and this link sprung forth — https://www.youtube.com/watch?v=Os7FV-LXgSo.
Imagine a world without springs.
just own up to your love of MST3K ;D
Better than a world without summers :-)
That reminds me of a Twilight Zone episode. ‘The Midnight Sun’
It is in my top ten list. I won’t spoil the ending for you.
https://vimeo.com/118400452
i came into comments to post that. +1 sir
Wonderful (if you have a lathe)! Sometimes you can get away with simpler stuff: Two days ago I made a missing spring for a weedwhacker head with a section of pipe, fence wire, vice and a hammer. Heat-treated in a bonfire and a jar of water. Never before was I so happy with a spring (otherwise I’d have to buy another head!)
Just an FYI. Fence wire will almost never (maybe never never?) contain much carbon in the metal it is made from, which it needs to contain for heat treating to change anything. Heat treating mild steel will only change the color and not make it any harder. The new color probably looked kind of nice though :)
Heat treating is done on alloys which have higher carbon content, not mild steel.
the surface can absorb carbon from the fire and become case hardened
Yup. Much better to anneal music wire, wind it, harden it, and then temper it.
Better still _not_ to anneal music wire and use it as it arrives. The cold-drawing process is what gives it its useful properties, annealing it removes those properties and no amount of heat treatment gets them back.
(I did a postdoctoral research project on optimising the heat treatment and cold-drawing of spring steels, this is slightly more than an internet opinion)
You can cold-work spring steel up to reasonable sizes but the forces get pretty high. Here is a brief video of me making saddle springs for a motorcycle out of 1/4″ wire. https://www.youtube.com/watch?v=thtDRjgbxRE
Above a certain size springs have to be hot-forged and then heat treated, but those use different steel alloys to music wire. This is partly because it isn’t really practical to cold-draw large springs to sufficient strain levels. A 1/2″ spring would need to start at 4″ diameter….
Today on How its made; springs !
Great video, Never thought about making my own springs. I think I will give this a try next time I need one.
I was hoping to see some hardening tech. Do you use electric kilns and quenching methods when you are producing any of your springs?
I had the same question. Check the YouTube comments; the morons haven’t found this video yet, so there is some good dialog going on. SPOILER ALERT:
Proper wire is already hardened, annealed, tempered, ect for this use. :)
How about those springs that they used to use in kids electronics kits, like those ‘Science Fair’ things that the Rat Shack used to sell.
If I use that accordion style air duct, by removing the wire, would that make a good spring?
I have loads and it never bends like copper, so I was saying it for an unknown future use.