Some geometry basics and cutting Tangent radii

hey guys chill pie here advanced innovations welcome back to my shop you know this demonstration is going to be about rounds and angles as they apply to both the lane and the mill so whatever your passion is hang around because I'm going to bounce back and forth between the applications for both of these but this is something to be about this is going to be about geometric construction standards that will take a lot of guesswork out of the work that you do things that you should just lock away and say this is the way it's going to be forever and my life is going to be easier because I know this so my life will be easier if I can find my heart rate there we go all right here we go let's start with the lathe part and I'm only gonna draw just a basic profile of this and there's a reason for it so hang in there you got a turn diameter to a specific length right just what the engineer wants right there and 45-degree angle but that's pretty close to 45 and now now after he does his finite element analysis on this he's going to say can't have a sharp corner right there because it's a crack point so let's put a giant radius on that and he just says let's just change the reeds add the radius I'm gonna go with my fancy wooden protractor now you got a radius on your partner wish it was that easy but in fact it is not that there's now in this changes it's no longer a matter of just moving the carriage specific distance locking the carriage and then using your compound that single point that out or form tool that out now everything has changed now the carriage actually from the time that you've faced this part off here zero this is how far the characters move before you can start sweeping that angle so how far is that you were what's going on here and how do we know how to calculate how far everything has moved or needs to move well the one thing that will remain constant forever and this is this is the lesson here you look at the angle that you have here the angle given on the print it's going to be on the print 45 degrees when you have an arc that blends a conical to a flared surface it will always be perpendicular to each surface at the tangent point here's your Center 90 degrees 90 degrees all day long now as the pieces start to fall out of the drawing you start to get little fragments of information that you can actually use okay what do we know well you know the radius of the tool because it's called out on the print it's probably on the insert that you're using on the form to let you just round so where's the radius here radius was right here radius here are you just here cool we're getting there let's go with the theoretical projected point here there's your theoretical sharp corner that they wiped off the print before this angle right here will always be this angle right here they will always be the same great here's the kicker this point right here the theoretical previous theoretical sharp corner will always cut that angle right down the middle so now this angle is equal to this angle everything is starting to fall out of here piece of cake now the angle the triangle that you now have looks exactly like this this is 45 each one of these is twenty two point five twenty two degrees 30 minutes 4.5 but thirty minutes and the base leg is the radius and once you have this information here you take the radius if you multiply the radius times the tangent of the angle now the angle is going to be 1/2 of whatever's on your print okay 45 is the total when you split it you're only looking for this leg right here so when you split whatever angle this is in half that's the value that's reflected right here 22 degrees 30 minutes it's half of 45 so now you can see you have all the information necessary to find the buck or the face off and the move before you start to shift dimension on the print - the leg that you've just found will view this distance here plus the radius there's your total shift radius times the tangent of the angle and I know okay and this little link right here appears in two places in this formula it's here and here since you have two identical triangles there you go let's go with two arcs exactly the same size centerline relationship between two arcs exactly the same size okay now you have two art senators that are touching what do we know about that well we know that they're tangent right that's about all you know you know what the radius is and as far as the radius is concerned one could be a little bit larger than the other this rule will still apply if you take the center of both of those circles for both of those round features and draw a straight line between them and you play the Centers of the arcs will always be on the same line Center center tangent points straight line forever construction 101 make let's draw a slowing on there prove it it doesn't matter what size the arc is senators will always be on the same line as the tangent or should I say the tangent will always be on the same line that's the center's okay another good one to lock away good for construction if you know how to break up these problems that you're having in two pieces all the pieces that are presented will allow you to solve whatever you're looking for now this is the core of this particular video when you have a big radius that has to go tangent into a smaller radius and that's what I'm going to cut on a rotary table and a lot of you would early on early on would look at it and go you have to move that fork 37 times in order to get that to do that but you'd be surprised how easy it is seriously the part part is square and for some reason there's like huge radius on this corner kind of ugly but there's an eternity cyclone and there's a smaller radius on this corner this is what you want to do maybe you're making a cam I mean this looks exactly like it can right nice long slope and rise and drop but I really like to improve on that guy so just bear with me for something that kind of defeats the purpose if it's like the close enough all right here's the center of the large radius and lo and behold here it comes the center of the small radius is on this hip centerline Falls right back to that tangent arc thing the tangi point is in line with the Centers of those pieces so when you set your part up on the rotary table to cut this outside arc when you go to make your move you don't move the entire set up you only slide the part you migrate the part here's the center of the rotary table you need to pull the part down so that this Center is now over the center of the rotary table and then you continue your arm so knowing that this construction will hold true forever really does help downstream when you make your setup put a rail off put a stop on register both sides of the park something that you can move without losing your mind and moving the whole table and starting over from scratch it's a lot easier to go from one to the other when you know how that applies those radiuses are on the same centerline this way what you need to do a slide apart and you can adjust the size of those raises if you slide it in a precision manner of course and well well that's what that little alignment tool does that we sell works out quite well let's go through milk grab a pan grab a vise grab a piece of material clamp it down let's cut some rounds and guys before I get into the demonstration on the setup of this rotary table got to show you this new little gadget that I got this is a multi-axis stop from edge technologies and the thing that I am most impressed with aside from the absolute quality of the production here is the adjustability in the range of motion you can get out of this with all the surfaces rounded like this everything on a swivel this can stand vertically and be quite high or you can literally put the tip of this stylus right down on the table for plate work or whatever but I use it a lot I use it all the time for my vice and when I don't want it inside the jaws or around the Vice I've just mounted it to the outside of the table here so it's here when I need it and it's worked out quite well for holding my air hose too so I leave my air hose dangling from it and one of the things that I've seen in the past at a lot of shops and that I've just got a cringe when I see it there's all the little bullet marks and dents and stuff you're going to get on your table from guys throwing their air hose onto the table and the air hose coming in contact with the casting just don't do that so there you go if you're not using it as a material stop use it as an air gun holder because it works like a charm so thank you to the guys at edge technologies first class job if you're looking for one look them up nice peace well let's start this demonstration naturally you want to align the center of your spindle on your machine with the center of the rotary table and that is most commonly achieved by mounting some type of device to the spindle and rotating the spindle with an indicator on it now this is an Endicott let's see if we can make this just stand out ultimately something's going to get in the way here guys and I try to keep my fingers out of the way zero coming around let's move back on this side zero zero in the back this is what you call trustworthy right now what you want to do when you have an indicator that doesn't move and you think you're saying hey this is awesome grab the indicator body and just bump it back and forth when you're done just to make sure there is some range of motion on either side of that zero and you are not pinned so to speak rotate it all as well now this being the recognised way to indicate a rotary table spindle or align it with your mill I'm going to show you a second way and this way is arguably more accurate than what I just showed you since you are not technically rotating the mass of this rotary table about that hole there is other mechanism below this table that this top table registers on that is your axis so that's what really should be checked if you can trust it with that hole if you've proven it to be true to that hole then continue to indicate that hole but just for safety purposes just for sake of accuracy we're going to mount a different indicator on here we're gonna check it to the spindle and we're going to compare the readings without moving anything except the table as the table moves when you use it and that setup looks like this I've mounted my indicator to the face of the rotary table it's a magnetic base and for those of you that are going to say gee what is that this is a US general model 387 it is simple it's just a bunch of laminated plates with some magnets and a few adjusting screws this is a discontinued item from about 40 years ago believe it or not I'm almost ashamed to say that but what we need to do now is spin the table and watch the indicator because it's the movement of the table against the spindle that you want to see this particular table has a release mechanism on it and this knob right here if we unlock this if we unloosen this there we go this entire dial mechanism not just the dial to the graduations but the entire dial mechanism will move up and out of the way and when that happens you can spin this by hand go so about by rotating this around the spindle there's movement there's absolutely movement let's go around the back and check it a little closer in the back so the y-axis is a little bit better than the X the digital has not moved from the primary set up Phil about four out come back around I'm going to be looking for my zero to come back around just so I know I completed one continuous rotation here and I should be back on zero which I am so the bearing the rotational mechanism that controls this table is not true to that for now I have to imagine that the manufacturer of this table probably wants to allow you to cut that bore if you wanted to so there's an undercut in this top ring so you don't have to bring your tool your cutter down and hit this Morse taper ring that's on the inside you can stay clear of it so by doing this I know that when I set up my rotary table I can indicate the bore close as close can be and then put the indicator on the spindle and move the entire table so I'm gonna bump this in till it's true there's no sense in doing that because I just demonstrated what's going on and when it's true we're gonna set the vise up with the rail that I have mounted true to the x-axis travel so let me indicate this will put the place on okay the initial placement of the vise will be determined by the alignment pin once I stick the vise up on there I'll put this back in I'll demonstrate two ways to actually three ways to use it this time and let's put the pin in I've repositioned the camera around the operator view so this is looking straight at the front of the machine and the pin that we're going to use as a zero face on center and one that's 500 off-center just to demonstrate the utility of the 500 off-center face when I put this up in the collet it's a 3/4 collet I'm going to work with the 500th face let's see how that goes [Applause] lock it in take the machine out of gear [Applause] I'm gonna bring the pin down within the range of the jaw visually line it up in my y-axis so that I'm about centered on the pin that's what I want to do let's go handheld for a second so I can show you I'm talking about I'm gonna try to keep the pin in the middle of the vise okay Digital is still on zero the machine is still aligned with the rotary table you 350 gauge pin excuse me 350 kg block I'm going to take that and stick that right in here and pinch it now by higher mathematics at the center of this block connected to the alignment pin is on Center at the rotary on the center of the table excuse me on the center of the machine spindle then this back job right now is 850 back 500 on the pin 350 on the gauge block so let's pinch it and keep it pinched this is strictly a tool bit it means nothing the sizes arbitrary all right we have a nice solid stack the spindle is unlocked we can still rotate freely I'm going to put an adjustable parallel on the backside of this vise to align the vise true to the table true to the fence that I have mounted to the rotary table let's reposition the camera so you can see how that adjustable parallel works I did show this in a previous video but if you didn't have a chance to see that one it's a good idea to review it okay let's say the vise is no longer parallel with that back surface and it's only because it's being restricted with the slot in the vise to the bolt to the slot in the table so the range of motion is relatively restricted I'm gonna take the adjustable parallel if you've never seen these they're pretty cool as you squeeze them one end to the other they get higher or lower and in a pinch they can come in real handy especially for something like this we're gonna stick that in there and in line with the pin in line with the parallels we're just gonna squeeze it and watch the vise come around I'm not even going to touch the vise see the movement you want to give it a slight little jiggle when you think that you've got what you're hoping you got and this is where I'm going to tighten down my plant you will not have to move the vice for the duration of this tangent arc setup so don't be afraid to lock her down and I will put two clamps on this one it's not gonna be a big cut but I will position the camera straight up for front so you can see the next step in line but I've got to put a clamp on the backside in the meantime now that we have the centerline of the table on the x-axis exactly 852 the rear jaw we want to go on the y-axis 850 out as well these centres excuse me these surfaces on either side of this pin are 500 from Center so we're going to do exactly the same thing that we did to set up the stationary jaw we're gonna pinch a 350 gauge block or gauge block stack against this face and then move our stop up against that stack and lock the stop off that way at that point the center line of the machine is going to be exactly 850 into the corner of the park that we will ultimately load on here and I'm using my nifty little pointer describe the courtesy of Randy Richard in the shop if you haven't checked this channel out go click them out check them out alright here we go we're going to put the 350 stack against this side of the block because it's 500 from the center to the surface another 350 gives me the 850 radius I'm looking for just enough to hold them not enough to damage I'm thinking about shutting it down so check it still there alright guys don't forget if you're going to be doing any kind of profile milling on a part and you're going to be using the top of your jaw as a reference make sure that your stopper rod is below the jaw or when you come around with the end mil you're going to get a wake-up call that sounds like just really unpleasant so some parallels in there throw a part in there and show you exactly what we've just accomplished if anyone is having a little difficulty visualizing exactly what just happened we took the center of the spindle of the mill and position the vise on the rotary table so that is 850 from the stationary jaw on the vise to the center and 850 from the stop to the center there you go when I come down with my cutter I'm going to make an x-axis offset to the edge plus the radius of the cutter so I know the edge of the cutter is right on the edge of the part I'm gonna climb mill it around to the corner at which time the long line here will be positioned 90 degrees and sit on the x-axis I'll get the cutter up off the part reposition the part with the 200 block for the demonstration because that is the difference in the radius radii and now the part is perfectly in line for the next cut let's do it 850 radius goes first half-inch cutter 850 plus the 250 on the radius one point one 500 diameter cutter 250 radius 850 requirement on the part 850 plus the 250 is 1 inch 100 there's 10,000 this table for a clean up cut and that is what I'm going to do so we're gonna climb cut this a lot of people will tell you you know climb cuts they grab climb cuts do grab but do yourself a favor and leave a little bit of drag on whatever table access mechanism your you're using at the time and the drag will probably overcome the desire for that cutter to grab if there's enough drag let's make the cut reposition the part real quick and go for the 650 tangent radius do yourself a favor and figure out which way your tables going to turn before you make the cut I want to climb this cutter around this in a clockwise trajectory on the part but that means the part is turning counterclockwise don't get confused counterclockwise rotation of the part counter clockwise rotation of the dial this is how we want to do it that is a counterclockwise rotation of the rotary table dial okay counter clockwise very superficial cut strictly for demonstration purposes here we go [Music] [Applause] that was when you add the 200-day flock and if all the math is correct this arc should finish out on this side the tangent to both ends relativity you will have to remove the spindle as well so instead of 1.1 we're going to be looking for 0.9 on the x-axis [Applause] [Applause] there is a extremely small the spot in the center of this this is a sanded end guy so if there's a small flat right there that will be the reason why this is not a machine to end we have an 850 radius you saw the 200 shift on the fly by moving the gauge block into the stop 650 on the backside elliptical it's not really an illegal arc tangent arc two of them and that's how it's done let's just say that is one of many ways you can do it and I'll tell you if you've got one of these guys it certainly is a benefit for a rapid setup all right well it's really not all that scary if you have a decent setup and you just make some provisions a lot of the rotary table work that I have witnessed in the past there is no XY reference on the table so putting that rel on the table is a really good idea too to just assist you in your positioning of everything the pen is a great idea it's a nice little tool to have in your arsenal and a basic understanding of geometry also helps refer to some of the stuff in the body of this video to do the construction and cut a couple of hours off your job hope you enjoyed that I hope you got something out leave me a comment if you did as always thank you for watching thank you to everybody that has already purchased those pins I do appreciate it and that's all we got for this week thanks very much guys we'll probably best innovations Austin Texas you

Channel: Joe Pie

Views: 46,583

Keywords: Joe Pie, JoePieczynski, Advanced Innovations, advanced innovations llc, how to, machine shop, shop tricks, shop hacks, shop techniques, shop tutorials, rotary table, alignment pin, tangent radii, cutting a radius, Jimmy diresta, abom79, abom, turntable tricks, setting up a rotary table, setting up a turntable, beginner machinist

Id: QmgO2XyrtKc

Length: 34min 11sec (2051 seconds)

Published: Wed Aug 07 2019