Good morning, good afternoon,Synchronized machining,Is it possible to do something more than that? We're gonna look a bit about what the monster machine needs to have, some power skiving,we're gonna look at some optional features also. So let's see what we can bring this half an hour 40 minutes. I'm Thomas Waberg,work as a product solution specialist for Europe ,and for my help I have my excellent... And my name is Ivar Sigstedt,I work here in the center,and I'll be the machine operator today. Yes, but I think we need to start with something more important. I hope you are used to the drills about safety and all the emergency exits. I'm not gonna talk so much more about that. But the psychological safety,I will push a bit extra on. In this kind of meetings and webinars,you have two different options in the Teams channel. Either chat or Q&A. But please use the Q&A. Ask your questions. Hopefully we'll have some time in the end to answer all the questions. So, let's start to see some foundation of the skiving. How is it really working? And what is it? Yeah, we have a tool. We have a component. And to be able to cut some chips at all or having a cutting process ,we need to have a cross axis angle. From that ,we put the speed on the component and the tool in a fixed ratio. And by that RPM and the cross axis angle,we got the summary of a cutting speed. So, we push this in set direction over the phase width of the gear. And repeat this. And how many times we repeat this? That's depending on the module we have. So, if we look a bit on a machine then. So, some things to keep in mind here. And the most critical one I would say is that not every machine is capable of power skiving. Just because you have a multitask machine and synchronization in it doesn't mean you are able to do skiving. We are talking about a higher resolution here of synchronization. The RPM. Very common. Very important to have in mind. Especially on smaller diameters on the tool. We need to have some kind of cutting speed here. So, I mean with a tool of only 15-20 millimeters, you need a lot of RPM. And the RPM here in combination with the synchronization. Maybe you have a maximum tool on the tooling spindle of say 6000. But maybe, probably not it's suitable for full synchronization of that maximum RPM. Perhaps it's only 80% of it. And also the main spindle need to really sync with the tool spindle. Why travel distance? Yeah. In many multiple task machines or in other machining centers, you have some kind of limitations in the Y. And this is important when you are doing external skiving. I mean you have a workpiece diameter. Additional to that you have a tooling diameter. And you need to have a certain amount of Y travel distance. The spindle interface. You need to have a tool that you have to do with. I prefer CAPTA overall. Especially when you are working with two or more tools in the same gear. Because there are some gaps in the keyway for HSK. And with the really tight tolerances on the component. Yeah. It's easy that you fall outside the tolerances on the component. C6 on smaller components. Yeah. Up to module three, module four. That's capable of C6. And then we have a lathe with a driven unit. Very common that you have a lathe. You would like to use the driven unit to do the skiving. And yeah, it's possible. If they can sync with each other. And if you don't have too high tolerances. And then we have the repetition again of the synchronization. And the fixed RPM. And vertical machining is preferable. When it comes to ship evacuation. Of course, you can work in a horizontal machine also. And very important. Robust and rigid machine design. It doesn't matter how good synchronization. You have a good setup of the component. If the machine is not stable enough. If we look at the increments then. We used to say that it's really important to have this full synchronization. And what do I mean with that? I mean a multitask machine with synchronization. Normal standard. Maybe have some about three to five million increments per revolution. But that is not enough for skiving. For hobbing it's enough. That's no problem. But for skiving we are talking about 10 million increments per revolution. And a tolerance around. Plus minus maximum 100,000. It's not preferable to have a typical old kind of machine. Where you have this gearbox. We are talking here about direct drive spindles. That's needed to have this in control. And also have the control over the different spindles. In a kind of a closed loop. That what you are measuring and coming back to the in a closed loop. So you have totally control over it. If we look a bit on the ship form and behavior. I mean the worst thing for skiving overall. Is the ship. To re-cut the ship. That will destroy the tool. And of course there are some problems here. If you are producing internal. In a hole. And you don't have a through hole. It's a bottom hole. You need to get rid of the ship in some way. Here coolant is really needed. The coolant itself. When it comes to normal material. If we stay outside the S material. Like Inconel in titanium. Is not needed. You can preferably. Run the skiving totally dry. If it's no issue for the ship. But to remove the ship. Coolant is needed. And it's applicable in all our tools. If we look at some. Normal cases then. What can be. What can happen when you see a component. It can look quite visually clear that. Okay. This shouldn't be any problem at all. To do skiving. But there are some difference. Changes here. We start at the left picture. Yeah. Yeah. You have a typical ring gear. You are going to make some gears. Or splines in it. You have a free hole. It's no bottom contour on it. But you have some limitations. But you have some limitations on the spindle top instead. What kind of contour do we have in front of the gear? If we look at the middle picture here. On the shaft. The shaft can be really clear. You have no contour in the way somewhere. But here we have some problem with the spindle head again. With the low cross axis angle. You will probably hit the spindle head somewhere. That means. Means you need to increase the cross axis angle. Maybe up to 40, 45 degrees. And with that big cross axis angle. You will eat more of the clearance. So it's a balance all the time here. To really see what's possible. And a shaft of course. Used to be long. That means. It's a bit unstable. You have a tailstock probably. In the end. So it's about roundness here. And stability of the setup. On the right picture. Yeah. We have. Probably some kind of clearance. Behind the splines or gears. And from that. We design the tools. And sometimes we don't get the best tool of it. And just by increasing the clearance. Maybe one, two millimeters. We get the more optimal tool. So by this. I would like to say. It's. In many cases needed. Over more deep analysis. If we look at the design. Typical component. This gear. In this case. A typical planet gear. On the left picture. We have a design. Previous design. Decided by the hobbing process. That means. That we need to have a certain distance. A clearance. On the right picture. Instead. We see. Yeah. With skiving. We can come. Reduce that clearance. Very much. We can work. More or less. In the same length. Of clearance. As in. Shaping. So by. Reducing the clearance. We can also reduce the design. Of the component here. And I mean. It's about having the productive area. Of the components. Not. Any. Area. Where we are not. Effective of anything. So in this case. Hopefully. We can reduce the length of it. We still have the same strength in it. So. Maybe it's time to see something in the machine. Also. We gonna. Run some. External skiving. Right now. A module. Four. With the Cormel 180. And 180. That means. We have inserts in it. We're gonna run in. 200 meters. It's a. Ovaco steel here. 520 M. And the feed rate. You see. Is 0.3 to 0.0.11. And that's because. We have different feeds. On different number of cuts. So in this. We have total. 10 cuts. 10 cuts. So. Ivar. I think we. Try this now. Well. gonna. And as you see here, we are not using any coolant. It's not needed in this typical application, because the ships are like a jet stream away. They are not coming back for some kind of collision or anything. And hopefully you hear the sound of the process. And it's a high frequency but stable. No disturbing sound during the process. And that means that we don't have any re-cutting of the ships here. And now you'll see after eight passes, we decrease our feed from 0.3 to 0.2. And then for the final finishing pass here, we're going to be feeding a 0.11. And why do we have different feeds? Yeah, that's because of disturbing the frequency we had before in the pattern of the flanks. And we're getting deeper and deeper down in the profile also. And which kind of feed should you have on the final pass? Yeah, that's depending on the demands on surface you have on the components. Great. Now we have made some external gears. Module 4. So let's go back to the presentation then. So now we're going to do some additional. We're going to make a chamfer on this, a deburring. I would like to show you the two difference we have when it comes to deburring here. We have either the full profile, flank and root area, or only the flank area. And why do we have this? Yeah, it's different customers have different demands. Not every customer needs to make a chamfering in the bottom area, because it's not in contact, that kind of area. It's not the most important. But we have some difference here when it comes to tools from San Vic Coromant. For the full profile, we can achieve from module 2.5 and then up to 12. But for flank deburring, we can go even smaller. Also on flank deburring, we can change the angle of the deburring between 35 and 60 degrees. But yeah, it looks simple on this animation or this picture. It's a red area, but how does it work? Yeah, it's like a toolpath, I would say. It's the sight of the module, the number of teeth, the tooth height, the tooth gap, and some prime numbers. So we are not taking the complete profile in one cut and then repeat that. It's a lot of small cuts. And that means we will have some kind of scallop shape here. But that we can set in the program. So yeah, maybe we should look at this also. How it looks in real. We are having this M670 tool. We are going to run it on 60 meters. On the external gears. And with a field of 0.01. So let's see in reality how it looks, Ivar. So for this, we do it in four increments. We are going to do one flank and the roots on the top. Then the same flank and the roots on the bottom. And we'll reverse the gear. And we will do the opposite flank. Good. And here maybe it's a problem to hear the sound because we are not cutting so much. It's even problem out here in the machine to hear something. But I can see the ships are removed. And isn't it incredible? On these RPM, 1000 RPM, we are moving the insert along the flank. So it's not only rotated and just chamfering. It's moving along the flank at the same time. Really nice. That was chamfering. Deburring. In a controlled way. In the same setup. So should we go back to the presentation again and see some more slide. Yes. Now we're going to try to make some internal spline here. We are going to use a cylindrical tool. Cylindrical is the half of the tool on the right side where you can see. The conical is on the left. We're going to try to explain a bit more about the difference between those. But here we are going to run a cylindrical tool. A braced version. On 60 meters. We have different feeds here. And we have also some kappa angle added on this. To be able to even cut it. Cross access angle around 14 degrees. So. Should we run it? And now when we are internal. We need to add on some water. And you can see. The coolant is coming out very smooth here. From the coolant cap. It's not about having the coolant just through the tool. Because that will not help the ship removal so much. It's about forcing the ships away. Still the same kind of pattern in sound. As the external gear. No disturbing cracks or ship yamming crashing sound. Sounds very good so far. And now we begin the finishing passes. For this process we're doing two finishing passes at a speed of 0.04. Good. You can directly see how much slower it goes right now on the finishing pass. And it's all demanding on which kind of surface you need to have on the flanks here. Go. And now we're entering the Lost Pass. And should we say something about the face width we are using internal here on the component? Is it around 20 millimeters or the length of the spine? It's a module 1.8 at least. Yeah. I think it's around 20-25 millimeter long here. So, we have completed external gear module 4. We have made a chamfer on it. Now we have made some internal splines. And what we have in total, cycle time for the machining. Is it approximately 8, 9, 10 minutes? Yeah, something along those lines. We have a couple of pulses in here. Exactly. It's not optimized in the productivity way here. But just to compare it. Okay, for some in the audience maybe think, okay, that's quite a long time for making one component like this. But I mean, compare it to, of course, if you do it in a hobbing machine for the external, yeah, maybe it goes faster. Broaching for the internal splines absolutely faster. Then you need the additional chamfering machine also. Here we are about collecting the component and the features in the same setup. And by that we can reduce the tolerances also. Keep them smaller. We have better control over the position of everything. So that was a demo. Yeah. And we still have some slides left, I guess. So. So what about the cylindrical tool then? Why should I have that instead of a conical? Yeah, there are some benefits, of course. A cylindrical tool have this parallel shape here. That means we don't have any conical. It's totally straight. That means we have the same profile over the complete distance. On a conical tool, when you resharpen it, you get more outside the profile. A normal case, we used to say around two, three millimeter is possible to resharp on a conical tool. On the cylindrical times two, three instead. We're talking, depending on the phase width of the tool, of course, but around seven, eight millimeters. And you have the same profile all the time and the same diameter on the tool. And that makes it more easy also in the handling. But does it put an extra demand on the machine then? Yeah. We are not using the same cycle here as a conical tool. A conical tool is working on the center line. Either it's nine o'clock or three o'clock. But here we are outside the center. We need to add a kappa angle because we don't have any relief on the tool. That's the major difference here. So what you win in handling the tool maybe could be more critical and more tricky to work with in the machine setup instead. So it's always plus and minus and everything. Unfortunately, I can't show you the pointing process in the machine right now. It's not fully optimized, but I would like to mention it at least and show you what it is. Pointing is very common in transmission parts like sliding sleeves, synchronizer ring, speed gear, ring gear. And the pointing function is that it's about connect and disconnect between different parts. And this is not a new way. Not a new process in some way. It's already done in dedicated machines, but they can only do the pointing. What we would like to do is to make the pointing in the same machine as we do the skiving and deburring. So that's possible. The pointing process itself is synchronized machining and comes from the skiving cycle. We are doing it in the same way. And as you see in the animation right now, it's about hunting. We are not meeting the teeth. We are hunting it. So same direction of revolution on both tool and component. Then we can have enough clearance for the insert to come into the gap and create the form we should have on the teeth. Should it be straight in some area? Should it be totally round? Here it's really important. The diameter of the tool, of course. It puts a lot of demands on the engineering part here to design the tools. If we look in reality, how does it look in the machine then when we run this? So we have the tool come into a certain position. We come with the data for the position of the tool and which kind of angle it should have. So we started with the left flank. Change the tool. Come into the position. And do the right flank. And it's quite incredible. Also here. For a normal eye, it just looks like it's a lot of RPM on everything. But it's really fully synchronization we are talking about here. And in this kind of application, it's not enough to only have HSK spindle with a high tolerances on the component, which it's used to be on the pointing. It's not enough. So by that, that was it. And hopefully we have some questions. Let's see. Where is the start here? Are we on the top? Is it roughing and finishing in one process? Yeah, in this demo it is. And sometimes when you are on a high volume producer, maybe you have the separation instead of making a typical 180 tool with insert as a roughing tool. And then you bring in a solid carbide tool as a finishing tool just to take the last passes. By that we can keep the tolerances on the gear during a longer time. Exactly as you have in turning, for example. You are having rough turning first and then you come with the finishing insert. So it's a matter of how you set up the process, how big the volumes are. But that's that's totally possible. Is the programming done on the machine or using external cam program? The skiving is done directly in the machine. Yeah, exactly. You get data from. The data comes on the tool set, the tool sheet from us on the tool drawing. On the tool drawing, you have the component data and then you have the tool data also. So and all that data is enough to put in in a typical parametric boxes dialogue. So it's it's rather easy, I must say. When it comes to the the chamfering and the burring here, then we have a dedicated tool path. I can't answer if it's possible to do that in camera, but I don't think so since it's connected to the synchronization fully synchronization. Yeah, and I believe this one is hand program. Yeah, the one we're running at least. Yeah, good questions. What do we have more? Come on. Let's say I use skiving with conical tool today. Can I just convert to a cylindrical tool instead? The easy answer is no. Not just because you can do skiving in a machine doesn't mean you can use a cylindrical tool. You need to have certain options in the machine and absolutely in the control system here. If you don't have the possibility to take in the box for a cylindrical tool, then it's not possible because you need to add on the kappa angle here. So check up what kind of capabilities you have in the machine. Have we something more? Will the presentation be available after the session? Yes. If everything in the technique have worked out well here, it should be recorded. So let's see in the shot here also if we have something. Hi, do you use only custom inserts or also standard insert like V for roughing operation? As of today, we are not using any V insert. It's only. How say special inserts dedicated for skiving or gear machining. No process sound. Which cross angle range is the most economically? Oh, tricky one. I would say between 20 and 25. Because if you have a cross axis angle like 40, 45 degrees, yeah, you get a lot of ship removal and quite high productivity, but you have a longer distance to walk instead. So I mean that the phase with over 20 millimeters maybe are up in 25, 27 by having 20 or 25 degree cross axis angle. You reduce this. So what you win in cross axis angle, you lose in distance. So around 20, 25, I would say. So. Now I think it's empty on questions. Cool. You don't see anymore. Good. Then. Thanks a lot for attending and the interesting question also. And if you have further thoughts, questions, feedback, take contact to your closest Coromant contact and he will forward it to some specialists for gear machining. So we say thank you here from Sanvika. Thank you. Thank you and have a nice day.