Making Spindles for a RACE CAR! || INHERITANCE MACHINING

many years before I inherited this machine shop from my grandfather I did get to dip my toes into the world of Machining and by dip I mean full-on dive I joined my college as Formula SAE student race car team our job was not only to design but also to build and raise a quarter scale Formula One style race car and a global competition I remember many long hours in the campus machine shop working on everything from weldments to carbon fiber and of course many many machine components now eight years later I find myself with a machine shop a little bit more knowledge and some excess production time so what better way to leverage that than to help my old team out and make some race car parts [Music] thank you [Music] first off I have to clear something up this is not a sponsorship in fact it's the exact opposite I mentioned before that formula Kentucky not only designs builds and competes but they also have to raise all their funds materials Parts everything I remembered what a struggle this was during my time on the team so I reached out to see if they had anything I could help with and sure enough they did they gave me many options to choose from but I was especially drawn to the front wheel spindles you know because of all the Glorious lathe work they would involve their design is simple and that they are made as a single piece but also complicated in that they have a ton going on so I'm excited for the challenge of figuring out the best way to make these being a wheel spindle which would come as no surprise that there's a wheel hub on one end it has a Four Hole bolt pattern that will accept some pressed in wheel studs and the majority of the flange between the studs is scalloped to reduce weight there's an additional six hole flange for mounting a floating brake rotor they aren't actually holes in the traditional sense but rather have holes either way order of operations is going to be critical to making these features successfully the rest of the spindle is where the bearings go included is a Straight Shaft for the tapered roller bearings to mount on and the end has an m55x2 thread for the bearing preload nut I went ahead and ordered one of these just to be sure the fit comes out perfect continuing the theme of reducing as much weight as possible a significant amount of the internal diameter also gets bored out and both spindles will be made from lightweight 6061 T6 aluminum this massive slug is actually a pretty cool part of this story entirely independent of talking with the team a very generous subscriber named Craig offered to donate some raw materials to the channel turns out Craig owns a high-end CNC shop called machine time in Nicholasville Kentucky just a stone's throw away from the University of Kentucky small world anyway machine time was a very impressive facility to visit and Craig was more than happy to donate such a large blank knowing it was also supporting the student race team he even gave me enough to make three spindles you know just in case with one blank cut to length it's time to get started because there are features on both ends I'll have to flip this at some point but if ever there's a chance to screw something up I like to do it early I'm going to start with a threaded side since that seems like the riskiest feature on this part naturally the first cause they're just to clean up the saw marks on the end then I'll also skim the OD to give myself a nice starting point for everything else out of all the operations boring typically gives me the most trouble it can be super finicky to eliminate vibration sometimes one thing I know that will help with this though is the bore when the part is the largest and has the most Mass to resist those vibrations the second thing that helps is to use the largest boring bar possible I happen to have this honking one inch boring bar and it's also long enough to do the whole spindle at once I'll mount it in this heavy duty boring bar holder designed for just this purpose but I can't quite go to town with this just yet I still need a hole to start with I'll center drill my starting point then jump right to the largest Morse taper drill I have in the shop at one inch this thing really likes to make some Hefty chips the problem I soon ran into though was that the tail stock quill doesn't have quite enough travel to reach the back of the park so I had to switch to a method of moving the whole tail stock in and out of the board to clear the chips honestly this is a heck of a lot faster than Wheeling the quill back and forth that whole distance each time I'll need to remember this next time on to the boring the starting diameter of this one inch boring bar is still quite a bit larger than the one inch hole I made so this first pass is going to be a bit chunky The Limited room also means I have to manually clear the chips after every half inch of travel or so not ideal but once I get that first pass through I can finish up with continuous Cuts using the power feed [Music] well that doesn't sound very good it seems the larger the board gets the louder the chatter is I tried adjusting several things to help compensate for this including different speeds and feeds and Tool Heights but the only scenario that didn't result in this thing screaming its head off was a super light cut around five thou deep which at least is promising for getting a nice finish on the last pass it just means that I either have to take something like 100 passes to get there or just listen to this thing yell at me for a bit while I take it to diameter I'll take the quick option that didn't go exactly to plan but in the end the Finish looks really good next is the outside this gets turned down to accept the tapered roller bearings so I'm looking at some serious material removal aluminum is typically an annoyingly stringy material to turn but that isn't the case when you take super aggressive Cuts Like This only downside of this is that these Lava Hot Chips start spewing all over the shop and myself but nothing a junk piece of cardboard can't deflect I'm getting kind of close to the final diameter so I'll start taking lighter passes and also clean up the back face then let this thing cool down for a bit before taking the final measurements the diameter has a relatively tight tolerance window of only a couple thou so I want to make absolutely sure I don't overshoot this and one final pass I'll take this to diameter and length at the same time and it measures right in the middle of that tolerance window perfect next is to prepare the area for the threads which seems simple enough except those dreaded vibrations have returned despite the noise I was able to turn down the diameter just fine but when it came to clearing the starting area of the threads this thin walled tube just wasn't having it I'm starting to think that boring this out first wasn't such a good idea I don't know that I would recommend this technique but by pressing a wooden dowel against the surface I was able to dampen out the vibrations completely while sketchy it did allow me to at least finish out that last small operations without the deafening Screech to cut the inboard thread relief I'll switch to this groove cutter I made on our previous project and weirdly enough not a hint of chatter this time don't get me wrong I'm not complaining just thoroughly surprised all right with that prepped I'm ready to move on to the threads to cut these I'll be using one of my new favorite techniques by flipping the threading tool upside down on the holder I could then run the lathe in Reverse to cut the thread this has the advantage of feeding the tool away from the work which can be a little less hectic especially when cutting metric threads like this the challenge with cutting metric threads on my Imperial lathe is that I more or less have to keep the thread feed engaged the entire time after taking a scratch pass and verifying the pitch is correct I can begin taking Cuts 5 at a time backing the cross slide out and reversing to the starting point and board of the spindle before setting up for the next cut technically I can disengage the feed I just have to pick it up in the exact same spot when I reverse Direction but with the vfd setup on my lathe it's easy enough to bring the tool back into position each time without crashing when I start to feel the spindle nut engaging I back the passes down to one thou at a time and work my way in until the nut just fits the threads perfect that takes care of all the risky stuff so I'm optimistic that the rest of this will go more smoothly the next job is to hog out the material between the wheel and rotor flanges there are some special fillets in here that I'll get to shortly but to remove the bulk of the material I'll start with this button insert cutter which of course requires me to boot one of my other tools out of a holder after making six more of these holders I really thought I was done with this game to guide this roughering operation I'll scribe lines on each side marking my boundary these aren't the final Dimensions but rather leave extra material to form the fillets I mentioned earlier alright here it goes man this thing really eats it up this is my first time using this tool and I'm pretty surprised how there's literally no chatter at all it just cuts through this aluminum like butter in almost no time at all I reached the final depth but of course I left a little extra on the diameter for a finishing pass later on now for those fillets I mentioned there are three one on the back of the wheel flange and one on either side of the rotor flange seems simple enough only trouble is I don't have a tool to do it I guess it's time for uh you know what a custom form tool should do the trick after scribing the radius on a high speed steel blank I Can Begin shaping this on the bench grinder this isn't a very aggressive process so nothing happens quickly but it does generate a lot of heat so to keep the steel cool I'll dunk it in some water every so often once I get to the point that my radius gauge fits just right on the profile I can move on to forming the rake angles which I can accomplish just by tilting the tool at different angles against the wheel I'm sure there's some preferred geometry to go for here but I'm just generally going for what feels right and my guts tell me are roughly 10 degrees side and back brake angle should do the trick the combination of these two should hopefully do well as I'll need both the side in front of this tool I'll sacrifice yet another tool holder for the job boohoo and to make sure I have good clearance I'll set the tool at a slight angle before locking it down the first fillet I'll cut will be on the back side of the rotor flange so I'll scribe my stopping diameter with a divider set my zero point on the end of the spindle then let this thing rip nice other than making a big annoying Rat's Nest this thing Cuts great it gets a little angry near the Middle where a large amount of the tool is engaging at once so I just try to go quickly through this area getting close to the final Dimensions I bring in the depth micrometer to check the distance to the flange and also check the diameter of the bearing loop with calipers before taking the finishing pass this noisy tool actually left slight chatter marks on the fillet so I'll cover the waves with the board and give these finished faces an emery cloth treatment thank goodness for sandpaper the back side of the wheel flange goes just about the same only slightly less noisy as the material is a lot better supported here now for the final fillet on the front side of the rotor flange this is opposite handed from the other two meaning that my special cutter will not work but rather than make an entirely new tool for one operation I'll just flip this one upside down in this hole holder now I can run the lathe in reverse and cut the feature not ideal from a machine rigidity standpoint but it seems to go okay for the most part anyway as the flange got thinner and thinner the vibrations only got worse and worse and again I'm sure boring that ID first only exacerbated this but luckily I was able to finish out this last operation before it put up too much resistance after some Emery clothing and Scotch briding this thing is looking super sharp and ready for some milk work the drill and cut the rotor mounting features I'll make use of one of my favorite tools the rotary table I'll get this set up on the mill and mount my Infamous Chuck adapter on here then bring the Chuck and spindle over from the lathe damn I was worried this is going to be an issue with the table lowered as far as it will go there's just not enough clearance to get all the tooling I'll need in here this does present somewhat of a problem but fortunately in Machining there's usually more than one way to skin a cat it just may not always be the most elegant solution I'll have to make do by mounting the Chuck right to the mill table itself using some one two three blocks to elevate the chalk I can clear the studs at the bottom and then use some toe clamps to hold it all down not elegant but it'll work all of the coming features are dimensioned from the center axis of this spindle so I'll use the coaxial indicator to find that center before zeroing the dro now because I can no longer rotate the part to draw all the holes the polar coordinates for each of these are not going to be very useful so I first have to do a little bit of trig to convert all these locations to X and Y coordinates then I can get the center drill set up and spot drill for each of these 12 locations six of these are for the rotor mounting themselves and come with a specified Tolerance on the diameter so to ensure I stay within that window I'll ring these holes to dimension first of course I have to drill each of the holes with an undersized drill leaving about 15 000 the diameter then I can bring the reamer in and finish these off the last six holes are for the weight reducing cutouts and even with the extra diameter I've left on the flange I can't drill these right to size without breaking through the edge and causing chaos so I'll drill these out with the largest diameter I can before moving on to some more specialty tooling to finish these off I'm hoping to make use of the boring head but I do have a small reach issue to contend with since the head has to stay up above the end of the spindle now my grandfather had a tendency to buy the right tool for every job unfortunately that desire of his comes to the rescue with this extra long boring cutter it's literally the perfect length for what I need so let's see if this is actually going to work foreign yep that will do nicely from here I can start working my way around to each hole in sequence opening them up a little bit at a time and adjusting the boring head between each round because of the interrupted Cuts though the quill feed ends up bouncing all over the place but I quickly learned that snugging the coil lock slightly gives just enough resistance to keep the feet nice and smooth when I get close to the final diameter I take a couple spring passes through one of the cutouts before measuring looks like 31 thou left to go I'll dial this offset in on the head then work my way around one last time taking two spring passes on each cutout to get them to the final diameter perfect that went pretty smoothly actually I do have one more operation on the flange before moving on though and that is turning down the diameter on the lathe after verifying there's no run out on the part from dismounting and remounting the Chuck I can move on the whittling away the flange surprisingly enough the chatter I experienced before while turning this flange doesn't seem to be an issue now it might just be a result of the direction I'm cutting but I also realize that the cuts are super interrupted by the holes in the flange which I suppose could also be interrupting the resonance before it gets too crazy whatever the case it's running smooth now and in no time the flange is at its final diameter before dismounting though I'll give this a look with Emery cloth to debur the edges and also slightly file the areas the emery cloth didn't reach then that's it for this end I'll need to remount this in the lathe to finish off the other side which means switching to the four jaw Chuck and to protect the already finished surfaces I'll drop my aluminum jaw guards on here before clamping onto the bearing area from here I can begin the meticulous process of centering the part in the Chuck checking the alignment both near the Chuck jaws and further away at the end the rest of the operations are pretty straightforward I'll first face the end of length then turn down the outside diameter the tolerances on these features are pretty forgiving but it still brings a smile to my face whenever I get it spot on the last bit of turning work is to form the wheel locating Hub at the center of the flange the combination of this feature and the four wheel studs are what keep the wheel centered and carrying the load of the car and finally I get to put an actual chamfer on something for the first time in this build that was really eating at me the wheel flange gets cuts and scallops on it as well so it's back over to the mill only this time the setup isn't quite as simple the drawing calls out that the bolt patterns of the wheel and rotor flanges need to be aligned so I can't just plop this down and start drilling I'll need to position the part somehow using the rotor flange features underneath and I think I have an idea but I'm going to need some special Hardware to make it happen all right you might be picking up where I'm going with this but in either case let me show you I can place each of these logs on the rotor Mount holes like so and the top pins give me something to rest a parallel bar against then I can whip an elastic strap onto each side to hold it all in place this gives me a straight reference Edge that I can tram against with a dial indicator pretty neat right after tightening everything down I can use the coax indicator to find the center once again then move on to Center drilling the four stud holes the drawing calls out a somewhat odd Dimension here at 0.496 plus or minus Thirty thou which seems like a huge tolerance window for a press Fit wheel stud my guess is that this is supposed to be more like plus or minus three thou and if that's the case I don't have a drill or a reamer that will get me in that window I'll have to make it another way I've never had the opportunity to use a small boring head but it looks like the perfect tool for this job first of course I'll draw out the four holes undersized then switch to the boring head and take a skin pass through one of the holes I'll measure the diameter make the appropriate adjustment on the head that will take me to the 0.496 diameter then work my way through all four holes taking both a roughing pass and a spring pass through each to cut the scallops I'll swap back to the big boring head but rather than leave this extra long cutter on here I'll switch to something a fair bit shorter no sense in making this setup less rigid than I need except that there's a problem the amount of offset I need in the boring head is causing so much vibration it's got the whole Mill shaking this isn't going to fly fortunately there are a lot of mounting options on this head so I can set this up in a much more balanced manner I'll have to do some fine adjustments on the diameter later but for now I can move the head to the center position of the scallop and adjust it relative to the center Board of the spindle then I can begin taking cuts because of the tool orientation I have to feed in from the side as opposed to up and down like you normally would with a boring head and I also can't go all the way in all at once because of the boring head clearance once I get to the center axis of the scallop I'll take one shallow cut just enough to measure with calipers my target is 0.64 inches so I still have 20 thou left on the radius or 40 thou on the diameter I'll dial this difference in on the boring head then continue cutting in from the side but stopping five thou short of Center leaving just enough material for one vertical finishing pass to take this to the final radius perfect now it's just a matter of working my way around all four sides and repeating the process though I have to point out the particular enjoyment I get from this pass in particular that's all the Machining complete but I do have one last operation the drawing calls out quarter inch rounds on the corners of the wheel flange seeing as this is a mostly aesthetic feature and the tolerance is somewhat forgiving I'm going to save myself a whole lot of setup and just file these by hand mounted in the lathe gives a perfect work holding fixture for such a task and with the radius gauge as a guide I'm able to get all eight Corners to size and the time it would have taken me to even think of a more elaborate setup all right that's one spindle down for the most part that went really well but there are a couple things I'll do differently the second time through firstly I think a lot of the vibration issues I ran into resulted from boring the spindle first so this time around I'll wait until all the threads and flanges are cut to size before tackling the ID the second thing I'm doing differently is with the boring operation itself rather than doing the whole depth at once I'll reel the boring bar in and cut half the depth from one side and half from the other this shorter stick out will reduce the vibrations in the bar significantly other than that the rest of the operations are pretty much the same as before and honestly it's just as fun the second time through it's truly an honor to be able to help out my old team again and on such a critical component of this year's car but in truth when it comes to race cars every component is critical there's nothing more than what is needed and also nothing less I'm so pleased that I can make all their hard work in planning a reality I don't ask for much but if you'd like the help to I'll leave a link in the description on how you can support formula Kentucky or if you have an alma mater yourself consider supporting that University's Formula SAE team as well it's because of programs and projects like this that I fell in love with design manufacturing and most of all Machining as always thanks for watching and see you next time [Music] [Music]

Channel: Inheritance Machining

Views: 451,389

Keywords: fsae, formula sae, society of automotive engineers, race cars, formula racing, formula student, michigan international speedway, autocross, floating rotors, wheel hub, brake rotors, 6061, 6061 aluminum, kentucky, form tools, boring bar, boring head, formula 1, engineering, inheritance machining, manual machine, machine shop, tolerance, aluminum, machining aluminum, university of kentucky, college engineering, precision machining

Id: sG14491vjDs

Length: 22min 0sec (1320 seconds)

Published: Fri Dec 23 2022