Making Your Own Springs On The Lathe!

foreign ternet my name is Quinn and this is bloody hacks today I'm going to show you a really cool thing that you can do with your lathe and that's making your own Springs now of course Springs aren't that expensive and you can buy them in probably every shape and size so this is maybe the most practical thing to do but making your own Springs is really fun it's really neat to see that you can do it yourself and who knows someday you might have an application where you can't buy the exact thing you need so I'll show you how to make them right now another certain project that I'm working on requires some custom Springs that look very much like this so I thought I'd show you the process of how I went about making them and hopefully you can learn from this for your own custom Springs first step is to choose your wire the two basic choices are music wire which is a high carbon steel that has springiness to it or you can use stainless steel spring wire which is a very stiff form of stainless wire obviously the stainless is stainless but music wire is going to be cheaper and easier to get if you don't need it to be stainless next you have to choose the diameter of wire obviously the thicker the wire the more compression force or tension force the spring can handle and thus the more energy it can store now look let's be straight here this is an enormously complex topic entire semesters in mechanical engineering school are devoted to the math around Springs that would be the spring semester so this is not something you're likely to calculate yourself if you really want to do it there is a large section of machinery's handbook devoted to Spring design but for the average hobbyist it's probably easier to just look at a bunch of Springs in your life take apart some ballpoint pens and some door latches and other spring-loaded mechanisms and measure the diameter of the wire used in those Springs and you can develop kind of an intuitive mental map for how thick the wire you probably need is I'm using 39 thou wire here which is definitely the high end of what a hobbyist would ever need these Springs are going to be pretty stiff because their suspension springs for a small vehicle that is going to take a fair amount of weight now we need to make some tools to enable us to make the springs on the lathe start with some steel round bar I'm using 1144 here something fairly strong is a good idea there's going to be quite a bit of force on this mandrel that we're about to make tool steel would not be a terrible idea but it doesn't have to be hardened or anything like that I'm going to put a center drill in the end of this thing because we're going to need lots and lots of tail support in addition to turning a long length the final mandrel is going to need a lot of tail support for the forces that are going to be on it while we make the Springs so tail support not optional this piece of scrap that I'm using happens to have some old diameters and threads and stuff on it that I'm turning off you want to turn this mandrel down to the arbor size for the spring diameter that you want to make which is not one to one as you've no doubt surmised we're going to be wrapping the spring wire around this mandrel to form the spring however funny thing about spring wire it's springy so the mandrel that you wrap it around has to be smaller than the final spring you want because it's going to expand once you take the tension off of it after you're done making the spring so then the question is how much smaller should the mandrel be again that's actually pretty complicated to calculate but luckily machinery's handbook has our back here there's actually a big chart in that book that explains exactly how big your mandrel should be for a given wire diameter and desired final spring diameter so that's nice give yourself about double the length of your final Springs on that wire wrapping area you're going to need more room than you think as you'll see I'm also turning down the larger far end of the mandrel I'm going to keep that area open for turning other diameters for future spring making and also it's helpful to have extra room down there as well for the tools that we're going to be using next you want to put a nice taper between these two diameters this looks nice but is actually important to the function of the wrapping of the spring as you'll see that's it for the lathe work on this mandrel so I can part this off and we're going to be ready for the next step and fake Yahtzee one more detail required for this mandrel is a cross hole and that's going to hold the wire to start the wrapping process this is easiest to do on the mill I'm going to stick it in a collet block for this purpose you could also do this with a cross drilling fixture or holding it in a v-block in the Vise plenty of ways to drill a Cross Hole to get centered up this is a good excuse to use a fun old school tool that I've had in my drawer for a while but haven't used and that's this center finder this thing goes in your spindle and then the movable v-shaped piece rides on the round stock that you're trying to Center the way this works is you apply light pressure with the quill and then you move the y-axis back and forth on the mill until the tick mark on the movable jaw lines up with the tick mark on the stem you can kind of Intuit how this is working just by seeing what it does this is obviously not as accurate as Edge finding or other methods of finding center of a round part but it's pretty good and it's very very quick this would be an easy tool to make also if you wanted to do a beginner project of some sort then drill that through a little bit larger than the wire that you're using you want it to be easy to slide the wire into the hole but not easy for it to pop out again on its own it's important that the Cross Hole be through the larger diameter of the mandrel not the spring wrap diameter you'll see why in a moment that's tool number one for spring making tool number two requires a rectangular piece so for that I'll go back to the scrap bin and something like either of these would work fine it needs to be something that will fit in the tool holder on your tool post to that end I'm going to Blue it up and I'm going to install it in my tool post to Mark out some Dimensions you want the piece to be able to stick out past the front edge of your tool post as you see here I'm going to scribe a line here because we need to make this into an L shape so I want to leave just enough material on the inside for the tool holder to hold it and then I'll square it off at the end so that I can have an L-shaped piece that sticks out past the front of the tool holder like so and I'll cut that chunk out that's a pretty big chunk to remove so rather than turning it into chips and wasting it I will rough cut it on the bandsaw and then the remaining chunk can go back in the bin and I'll use it for something else in the future just leave a lot of cutter wire as well and I'll put this in the middle and clean up that saw cut there's no Dimensions or anything on this part I'm absolutely just eyeballing everything something that looked about right on the tool post as you saw and I'm cleaning up the edges so that they look nice and really nothing else matters once I've cleaned up that surface I leave the End Mill locked at that same height and I do a couple of side Milling passes on the short extension to clean up that surface and make a nice sharp inside 90 corner finally I side milled the end of the piece which were also rough saw cuts from whatever previous life this piece of scrap had this is probably a waste of time but you know if you're going to make your own tools you might as well make them look nice especially if you're going to keep them and use them over time as I do plan to do with all of these tools setup is kind of a funny looking one I need to stand the piece on end at a 10 degree angle I've got an angle block for that and I'm gripping the piece by the end now obviously this is not a rigid setup but we only need to drill a very tiny hole so this will be fine for that I start by putting the drill that I'm going to use in the Chuck and I make sure that the position I want for the hole is going to come through in a good place on both sides and then I Center it up roughly on the L-shaped extension with a scale I'm going to center drill this because we have a 10 degree angle and I don't want the drill to wander off because this is just a 10 degree angle we can get away with just a center drill dimple if the angle was much more than this you'd really need to make a flat spot with an End Mill first and for that you'd need a much more rigid setup than I have here but because I'm just doing a slight angle and I'm using a tiny tiny drill I can get away with a center drill dimple and this crazy not at all rigid setup this hole is the same diameter as the one in the mandrel this is a very high aspect ratio hole it's quite deep relative to the diameter of the drill so lots and lots of PEC drilling is the secret otherwise you're going to jam up the drill and break it I chose a location that puts that hole near the top on the front and kind of roughly in the middle on the back here's how the wire feeds through so sitting in the lathe like this so you can see that that hole feeds the wire through at an upward angle of 10 degrees that's important for how it's going to relate to the mandrel the purpose of this block is to allow us to control and steer the wire with the tool post as we're doing the winding it's crucial that the movement of the wire be carefully controlled by the tool post and not by hand you can't do this by hand it's never going to work so now I can put the mandrel in there three jaw Chuck is fine concentricity is not super important here and now I'll feed the wire in and we want to set up the relationship of that new guide block tool that we just made with the mandrel I'm going to adjust the height of the tool post until the wire is feeding just over the top of the wire wrap section of the mandrel you can see how that 10 degree angle feeds it up nicely over the top of the small diameter that's what you want okay it's time for wire you really want to cut a section of wire to work with resist the urge to use the entire coil in this fixture it'll never work those coils are very difficult to manage and if it sprungs on you you're going to be having a very very bad day to cut this stuff you need to use grinding tools don't try to use Nippers or any other bladed tool like a saw spring wire is very very hard and you'll damage those tools for the same reason if you need to deburr it use a stone and not a file so cut off a piece of it a lot longer than you think you're going to need the springs that I'm making here don't look like much but they actually have almost 11 inches of wire in them so cut off a bigger piece than you think you need okay we're ready for the magic taking a look at a spring you notice how the wire forms a helix guess what machine in your shop is really good at making helixes the lathe that's right we're going to set our lathe to cut threads that are the same pitch as the coils in this spring so in this case I've got six coils spaced a hundred thou apart so we're going to need to set the lathe to 10 threads per inch or whatever a bunch of metric numbers are that match that I'm doing this with change gears but of course if you have a gear cutting transmission on your lathe then you can set some knobs and levers for whatever thread pitch you need the other thing to note of course is that being a helix the wire has to feed at an angle so I'm going to set my tool post angle over a little bit again just eyeballing this is fine if it's sort of in the ballpark then it'll work then I'll feed the wire through and we can feed it into the mandrel you want to feed it in about halfway through the mandrel not too far or it would be very difficult to remove later and not too little or it'll pop out while you're winding the spring which is super annoying next I wrap the wire around the mandrel just turning the Chuck by hand and let that taper feed the wire down onto the wrapping mandrel you can see now why that taper is important now it's time for some tension I find it easiest to do this with smooth drop pliers do not try to do this with your hand you won't be able to hold it tight enough and if you're going to be doing this under power that's a really good way to lose a finger with tension on I'm going to wind the Chuck by hand and put a couple of wraps of closed coil at the end you want a couple of wraps of closed coil at each end of a compression spring or if you're doing a tension spring then all the coils are closed as I'm doing these I'm also moving the carriage forward a little bit by hand just to keep the closed coils from piling up on each other you want a couple of extra wraps at the Leading Edge of the spring because that end gets distorted when you pull it off the mandrel okay magic time now it's time to engage the half nut then we keep applying wraps the next couple wraps are still going to be closed because the half nut has to take up the backlash in the carriage but then you're going to see the coils start to open up once this happens Mark the Chuck maybe with some tape or a Sharpie and start counting your turns then keep turning and count the number of turns of the Chuck for the number of open coils that you want in the middle of your spring now you could do this part under power if you really want to honestly unless you're making very long Springs I wouldn't you're going to create a lot of drama and danger for really no value but if you do want to do it do it at very low RPM and make sure the lathe is running in Reverse once I have the right number of open coils then I disconnect the half nut and I do a couple more wraps and that creates another one and a half to two closed coils at the far end this end won't get distorted but we do need some room to work with as you'll see now it's time to extract the wire from the tool post so I wind the carriage back but I hold the wire with pliers and let it go slowly this is the moment where it's gonna spring you do not want that free end to hit you in the hand because holy dinette does that hurt for the leading end I have to pry it out of the mandrel this is why you don't want to stick the wire too far in this is also why the Cross Hole is in the larger diameter because it's way way easier to get the wire out if that Cross Hole had been in a small diameter it's very difficult to extract it without destroying the spring this might look like a hot mess but if you use your imagination there's actually a perfect little spring in the middle of this hot mess let's go clean that up now for the next step it helps to take a look at a commercial spring the ends of a compression spring need to be square and this can be done in two ways most cheap commercial Springs like this one are what's called open end they fake a square End by having the final wrap flatten out and do one half turn ending touching the coil below it this works okay at small wire diameters for faking a square seat but it's kind of chintzy larger Springs or higher quality Springs will actually taper the final coil into the coil below to create a truly square and flat seat all the way around you'll see this a lot on high quality car springs for example part of the reason you shouldn't cut down your car springs if you want to lower your car not to mention you're borking up the spring rate when you do that don't be a buster just buy shorter Springs to make proper Square Ground seats we're going to need a third and final tool it has to attach to your bench grinder tool rest I happen to have a miter slot on my shop made tool rests so I'm measuring that I'm going to use that to secure the fixture and keep it square I went back to the scrap bin and I found this piece here which should work just fine any old piece of scrap will work I'm going to once again Square this up and make it reasonably presentable for the next step [Music] next I machine a key that's going to register in the miter slot that I measured this is going to help secure the piece on the grinder table and also keep it Square to the grinding wheel obviously this step would be different it's going to just depend on what your tool rest looks like you can just do this with a straight rectangular bar and simply clamp it to the tool rest as well you don't have to get all fancy but I have a miter slot and this only took a minute so what the heck by sneaking up on that Dimension and getting a really nice close fit on my miter slot that holds it really securely and keeps the piece Square so I think that's going to be a nice thing finally I'm going to clamp it the other way and drill a cross hole through this which is going to hold the spring because of the key shape I need to put a parallel in there to hold it securely you might ask yourself why didn't I drill the hole first so that I wouldn't need to do that little trick the answer is because shut up that's why this hole should be slightly larger than your Target Spring diameter and plus a little more because your Springs are not likely to be perfect diameters the location of this hole is not super critical but I'm leaving extra room around it for other holes later for different spring diameters here's how that piece clamps to the table you can see that we're going to be doing the grinding on the side of the wheel that's going to ensure nice Square Spring seats back to the hot mess then I can clean up the ends a bit before grinding as you can clearly see through my transparent finger I'm just using the corner of the grinding wheel to remove the excess wire and it doesn't hurt to do a little bit of deburring and make sure that the wire at the end isn't sticking out past the diameter of the spring you want to make sure that's not distorting because then it won't fit into the fixture for the next step with both ends cleaned up now I can stick them in the end of the fixture and square up the ends you can also remove extra coils this way or you can also use the corner of the wheel to chop off extra coils a half wind at a time if you've got a lot of extra closed coils at the end to remove the ideal compression spring has a half to one full closed coil at the end not much more than that just do this until the spring is down to the final length that you want I'm grinding one end and then the other depending on which end has excessive closed coils on it at the moment if you're making a tension spring of course you don't have to do this step just leave yourself one extra closed coil at each end Bend those closed coils outwards 90 degrees to create attachment points and you're done make sure to dunk in water frequently while you're doing this grinding because if you overheat the wire you can anneal it by accident and if you do that well it's no longer a spring now it's just a piece of wire arranged in a very highfalutin way here's roughly the result that you're aiming for I've got the number of open coils that I wanted which is six and then a half to one full turn of closed coil at each end and everything is ground flat so the closed coil tapers into the open coil below with some care and practice this process is also nice and repeatable so these eight Springs are all within five thousands of the same length and they all have the correct number of open coils and closed coils on them all these tools should be reusable as well I'm not going to tell you you have to 3D print a storage case for them but it doesn't hurt you may have to turn additional mandrels for other Springs or you may have room on that one to turn other diameters but if nothing else certainly the wire feeder and the seat grinder can be reused or all sorts of other Springs that you might need to make now I made all that look easy because I kept all the best takes so you can see what the process is supposed to look like but rest assured there is a learning curve here you will mangle lots of them before you get it right you'll make them too short you'll make lots of other mistakes but don't be discouraged after a few false starts you will get the hang of this and the feel for how the carriage is supposed to look and move while it's winding and so on so stick with it it's really not that difficult but it does take a little bit of practice well that's all the time I have for you this week thank you so much for watching and thanks to my patrons for making all of this content possible I hope you enjoyed this and I'll see you next time

Channel: Blondihacks

Views: 297,047

Keywords: blondihacks, machining, machinist, abom79, this old tony, vintage machinery, steam, electronics, making, maker, lathe, mill, woodworking, workshop, model engineering, engineer, engineering, live steam, machine shop, metal lathe, vertical mill, metalworking, metal shop, diy, home improvement, how to, do it yourself, do it yourself (hobby), mini mill, mini lathe, tutorial, model engineer, steam engine, springs, making springs, spring making, custom springs, compression, tension, springs on lathe

Id: nH9ucI-vt-I

Length: 19min 31sec (1171 seconds)

Published: Sat Jul 22 2023