Gear Cutting on a Horizontal Mill using a Dividing Head

[Music] hello Keith Rutger vintage machinery org well guys we're back on making our gears and we're about ready to attach to get over here and get the milling machine set up to start cutting some gear teeth and I've already gotten my dividing head mounted up here on the mill and we're gonna go over basically how to get the milling machine set up to do gear cutting and then go through the practice of cutting two gears on the horizontal mill let's get going what we're gonna use to actually make the divisions to make these cuts on this horizontal mill is this dividing head and this dividing head does just that it divides something up into certain number of divisions that you won't hear and there's a couple of different flavors of dividing heads out there they basically filed into two camps so they all do basically the same thing but what's different from one to another is the ratio so if you look here I got this this handle and when I turned this handle you see that the Chuck is turning here this particular dividing head has a ratio of 40 to 1 so I have to crank this handle 40 times to make the Chuck here boot revolve one time now some dividing heads have a five to one ratio the 40 to one seems to be more common but both of those are out there and what you have to do is you have to figure out how many turns you need to do for your dividing head now there's some charts online that you can look these up on if you have the instructions for your dividing head it should have a chart so if you wanted to cut a 12 tooth gear as we're gonna be doing you can look on there and it will tell you which plates you use which uh bolt holes are which whole circle you need to use and how many divisions now they're these plates that go on here that are multiple places K&T has six different plates with different hole arrangements in it this one here obviously we got a 15 - 16 17 18 19 20 so that's the number of holes in that division are in there and I know from looking on my chart that I'm in the 18 ring and to do 12 divisions what I have to do is I have to do 3 1 2 3 full revolutions and them 6 holes on that 18 ring so I have this little sector in here set to help me so that I can really quickly find that that 6 hole 1 2 3 and then go over here to your next hole now one thing I will caution here is there is a little bit of backlash there's not much you should always go into this thing moving forward if for some reason you go past your hole come back out and then come back into it don't just go straight into it because you could have just a little bit of backlash in your dividing head but anyway that's basically what we're going to be doing here today is using this dividing head to make these divisions now as for my part this dividing head has a Chuck on them some of them have a center in it where you can do it between centers I actually prefer that method but I don't really have a good Center in here except that I chuck up in the Chuck so instead of putting a sinner in the Chuck and that's the Chuck's out a little bit my Center will be Val I'm just gonna chuck the part directly in here and we'll just go ahead and tighten that down let me pull my part there around where I can tighten that up get that up on the top side [Applause] and another thing I like here you know if you're doing between centers you're automatically going to be pushing against the center and really it can't go any farther past that in this case I've got a little shoulder here I'm going to put that up against the the Chuck so that as this is cutting it's going to be cutting in this direction so it's impossible for it to push into the Chuck we do that and then I got my little foot stock here and we'll pull that up in there and have it running between I'll Center on this end just to give us some more support so now my parts in here I know my divisions I got my plate set here and this is ready to go and I've already actually come in here and I've done the the whole cycle around I count the number of dots on there just to double-check to make sure I'm getting 12 divisions and I am so now we need to get our cutter set up to make the cut now the cutter that I'm going to use is going to fit on to a horizontal shaft here it's going to be true horizontal milling so I've got a Arbor here this is a one inch Arbor so basically it will take a one-inch diameter inside diameter cutter let's just start by wiping out my 50 taper wiping out the spindle that goes on here and we'll go ahead and install the shaft in here and I will tighten it up on the backside the arbor here has bushings on it we're just basically this little spacers that fit up on here to position your cutter where you won't also have a keyway in here and that's gonna drive my cutter and I'm pretty much to the point here where I'm ready to put my cutter on and it's real important when you're cutting gears to make sure you have the right cutter and there's a couple of things need to look at number one is what diametral pitch are you doing I know from testing these this is a fourteen diametral pitch so I have a fourteen a DP 14 cutter okay I'll see you know my pressure angle I know that we're doing 40 and a half on these so I have a a cutter that is a 14 and a half pressure angle the other common size is 20 degree pressure angle although 14 and a half seems to be generally the most common type and for each pitch and for eat a for each pitch and pressure angle so for 14 deep diametral pitch 14 1/2 pressure angle there are 8 different cutters that you can potentially use on the involute series depending on the number of teeth that you're cutting and again you need to go look at a chart it's usually on very often it's on the the cutter here how many teeth you can cut on that particular one sometimes it just gives a number I know that we're doing 12 teeth on this and looking in my Machinery's handbook I know I need cutter number 8 and this one says number 8 sometimes it will actually actually it says right here it is for 12 or 13 teeth so the number 8 is only used for 12 teeth and 13 teeth so I got the right cutter the cutter is going to be turning in this direction cutting in toward the dividing head so I make sure our position on there correctly and we will go ahead and put that on there and we'll build the rest of this out just putting spacers on here to get us out toward the end here a little bit farther and and then I'm gonna put my bushing on here this is basically just a bearing that's gonna there's going to be a over arm support that goes up on there and this larger one here it will be that the bearing surface and the nut and I will I'm not going to tighten the nut down right now you always want to tighten the nut when you have it supported because if you come out here right now and put a big crescent wrench on this ain't gonna yanking on it with it sticking out you can very easily Bend this Arbor we wanted this Arbor to run true so we'll wait till we get the over arm support on and with that I'm gonna go grab the over arm support and I will get it fit on here we've got them over arm support here sitting on the end of table and I've already come in here and just taking a rag and cleaned up all the bearing surfaces on the inside this has been sitting for a while and it's gotten kind of gritty and greasy next thing I'm gonna do is I'm going to extend my over arms Forks out here and there's just a little hand wheel on the end I'm going to go all the way out pass the end of the the Arbor I find it easier when I'm putting this thing on instead of trying to line it up on all three bearing surfaces at one time just get it on the arm first so we'll just slide it up here on the arm we grab a wrench and tighten that down okay that is locked down now on the over arms and now what I'll do is I'll use my little lever back there and we'll pull it up over and onto the the bushing I just find it that makes a line that go a lot easier it just goes right up on there and there we go to you I'm gonna push that this a touch yeah that's fine right about there and then the next thing I'm going to do is there's a couple of bolts on the top and that's going to lock these over arms so they can't move in and out so we'll go ahead and tighten these down as well I got you assumed in here because I want to show you how I'm gonna get this cutter now centered up onto the shaft here and I don't know if it's going to show up in the video or not very well but basically what I did was I just eyeball the center on this when I lowered or raised the table I guess up into the cutter here until it was just barely touching the top and when I did that I then move the tables side-to-side just swept across it and what that does is it marks clearly across the top there the the center basically the the lowest point of the cutter is hitting the highest point of the part I moved side-to-side across that swept it and it left a little mark right there in the very center of this shaft and now some people don't like the way I do this but this is what I this is where I was taught this is what's always worked for me from there I can easily go in here and just look down this thing and line the center of the cutter up with that mark and it's that simple no measurements no nothing your eye is actually a very good measuring device use it to your advantage and in this situation like this I'm gonna have that plenty good enough on center for this gear so anyway that's how I did it that's how a lot of old-timers do and that's the way that I'm gonna do it here so the other thing that this is done now is I've marked on zero on my height here so I know that that's a zero and we'll back off of that now and we'll know how far we need to raise a table up in there to make our cuts to get all this to the proper depth so I'm going to show you this little sheet that I created I actually create a little Excel spreadsheet that will do a lot of my calculations for me when I'm doing gear cutting and I know I've had some people in the past asked if I would share this spreadsheet and I'm not against doing that but right now the spreadsheet is not really exactly finished yet basically I'm having to go in and manually put some some factors in here basically going information out the Machinery's handbook to do this and I'm trying to get this where it's completely automated where you don't have to go look anything up and there's no manual input we're basically all you'll have to do is put in your diametral pitch your number of your teeth and your pressure angle and it will calculate everything for you and if I forget that done I'll be glad to share this but right now it's too much user input to be useful to the general public but anyway I've got this and this tells me all my critical measurements everything I need to know to come over here and cut these teeth and it also tells me how to what I'm doing checking it using either measuring over pins which is a good way to and that's one method will do or using a gear caliper I usually use both to to double check my work but right now what I'm looking at here again I'm diametral pitch is 14 number teeth is 12 it's a 14 1/2 degree pressure angle it tells me I need to use cutter number eight that's set it tells me it automatically calculates the outside diameter of what that gears should be which is one-inch we already knew that a lot of other stuff in here that's really not super important unless you're really a lot of measurements the big thing I want to do is look at here depth of cut to obtain backlash and backlash is something that you have to factor in these gears they mean you can make a year that is perfectly meshed but you you want to have this a little bit of play in there so that things don't bind up and the spreadsheet actually calculates what the backlash should be for an average situation 3000's backlash in this particular case and then it tells me my depth of cut that I need to make to put that backlash factor in there that's the number of Michigan right now 157 thousands deep is what I want to go I think what I'm gonna do is we're gonna do this in two passes I'm gonna do a one hundred thousandth deep cut and then we're gonna go in here we'll measure everything over the pins that will give me a more accurate measurement to dial into for the next cut and then we'll check it again and if necessary make a third usually two cuts that's all I need to do I can dial it in but 157 I'm gonna go a hundred right now okay what I'm gonna go 125 I'll still give me enough to clean up on the last pass and my machine will easily take it under 25 someone dial in that 125 now to do that I'm using a dial indicator to tell me how far I've moved we're on zero right now I'm gonna bring my table up 125 actually my back off of that just a little bit because I'm gonna light my table and when I do it usually all right brings that measurement up just a little bit there we go 125 I've gotten my Heights locked I've got my table lock going in this direction the only way it can move now it's going in and out we're gonna take 125 thousands off of each side and that should leave us about twenty seven thousand so it will have to come in and clean up on the next pass we're ready to make our first cut now I think a little bit about feeds and speeds I've got the machine set up right now we're cutting 119 revolutions per minute and as far as speeds go I maybe play around with my feeds right now we're on 2 and 1/8 inches for a minute a little cutting oil in here and we'll start feeding our table then see how she sounds you hear that kind of bum bump bump sound that's pretty typical on a horizontal mill these cutters rarely run perfectly true but as is cutting one tooth is probably cutting a little bit more than others but it's getting the full the full depth all right we're through cutting pulled my cutter back out if I'll loosen my lock on the dividing head remember we're doing three turns and then six indexes go one two three over here we'll lock it back down and now we're ready for our second pass all in here our second pass we've got our first pass done here the gear is looking great you can tell us not to depth yet and would like we did we said we wanted to cut it a little bit shallow and then come back in and clean it up on another pass so now I need to measure this to see exactly how much we need to take out and the way we're going to do that is I'm gonna pull my little cheat sheet back up here again and we're going to use some method called measuring over pins so if you look here you can see there's a pin there and a pin there 180 degrees apart from one another and we're gonna basically measure across those pins now my little calculator spreadsheet that I've got here it will tell you what size pin you need to do use in this case for this gear pitch you need to use when it's 120,000 in diameter so I actually have cut 14 pitch gears before so I purchased some time back to gauge pins that are 120,000 so I got to perfectly 120,000 sched pins I'm gonna put them across from one another and we're gonna measure across that distance and down here it tells me what that measurement should be so just normally it should be one inch 13,000 but when you calculate in the backlash again we want to have 3000 SPAC Lash in there it needs to measure one inch one thousand one thousand over niche so let me get in here and measure it and see where we're at and then we'll know how deep we need to go so here are my two gauge pins and I know you can't see that but I can see 120,000 for both of those what I'm going to do is we will put these on here directly across from one another they will I measure like that instead of going straight up and down this is when you need a third hand sometimes that I want to come in here with my micrometer now and we'll get a good measurement right across those pins [Applause] all right so we are at 50 plus 21 would be 71 thousandths so we're one inch 71 thousands okay we need to be at one inch 1000 so I'll subtract 1000 from that so that gives me 70 thousands over and remember that's on both sides so I need to bring in half of that amount on the each side so we need to come in 35 thousands more in depth and that should get us right on the money so I'm just going to go ahead we'll dial in another 35 thousands and we should be finished with this so now when arrays are up our table I've got it zeroed now I'm going to release the lock and it's going to probably move just a little bit that's fine we're going to go off with the lock position to raise it up so there's 30 [Applause] I think that's gonna be good enough right there 35 thousandths maybe off by tenth or two but it's not gonna matter we're good let's go ahead we'll make another pass through here get the rest those teeth send them away okay I've got my pins back out here we're gonna go in again measure across both of those we're shooting for one inch one thousandth and I don't love you can see that or not see [Music] right there 1,000 silver one-inch dead on the money so that gear should be just right so we're ready to press this together now so I've got my piece I need to put my little key way in here this will take a little hammer [Applause] tap that in there and we're gonna press this in but before I do you know just to be on the safe side I'm gonna put a little Loctite on this just to make sure it doesn't come through this oppress fit so it should be fine I'm just gonna a little light layer all the way around this [Music] [Music] some nice press-fit it's not too tight but it's tight enough that it shouldn't come apart and the gear is now set on there so we're set up now to do the 40-tooth gear i've got this set up in the dividing here we just flip it around so that it's chucked up on the small end and we got the big gear exposed here I don't have to worry about centering it on the shaft because we did that previously the setup hasn't changed centerline is still exactly the same and I've already touched off on the top here to get my zero on my depth and now we'll go ahead and move the table to make that first cut I've zeroed my indicator and just like before I want to move up for this first cut at 125 thousand so just go ahead and dial it in there we'll go 100 right there and then up 25 which is right there and I'm not gonna get too fidgety with this because we're going to be making a measurement and May coming back and making a final cut you know we're within probably 3/10 but hey again I'm worried about that on the second pass this is just a rough cut and we are ready now to start cutting so as far as the dividing head goes this is a 40-tooth gear and with the 40-tooth gear and this being a 40 to 1 ratio dividing here this is about as easy of a gear that you can cut because basically every time I turn this knob around 40 to 1 it's going to be 140th that's the ratio we're looking for so we're just going to be going back to the same pin doing one revolution back into the same 10h each time really really easy I've got my sector over here basically we wrap we can come around to that and it will tell me which one to go into we won't be using the other side of the sector on this one so now we are definitely ready to start cutting Plus let's make a pass and see how it goes my feeds and speeds and the last one worked out pretty good so I think we're just going to stick with that and I tried on this gear as well so we'll come in here and [Music] let's see how she sounds we're cutting cast iron this time I'm probably not going to use any lubrication people ask me about that all the time and the fine powder that you get off the cast iron it just makes for an abrasive when it gets mixed with all and cast iron has graphite in it it's kind of self lubricating I typically don't use a lot of lubrication when I'm cutting cast iron [Music] all right [Music] make a Rev here 140th mokhtar dividing head [Applause] [Music] and maybe next pass [Music] so we got our first pass on the gear done looks great one thing I want to mention because I forgot to mention this while ago when I was we've started cutting this butt and I thought about it halfway through the job but we did change the the cutter for this a book on the first pass we were using a number 8 cutter for this 40 tooth we needed to use a number 3 cutter so even though it's the same diametral pitch the geometry of the cutter is a little bit different because of the angles on the on the the gear itself so anyway we use the number 3 which is the correct one to do that and now we're going to come in here and once again measure across pins I'll put a pin on the very top and we want to get straight across from it and we'll come in here with my micrometer and get a good measurement across these all right that feels good right there so pull that out and we're basically on I see that's 16 plus 50 so that'd be 66 so that'd be 3 inches and oh six six three point oh six six we're shooting according to our spreadsheet three point zero zero six so I'm gonna subtract two three or excuse me the six from that that gives me sixty thousand total depth that I need to go down and again we need to do half of that so we'll do thirty so I need to move pull my bill down 30 thousandths and we'll make another pass on this and we should be dead on alright ready for second pass here I've just Martin my first tooth here so that when I come back around I know when I've finished it's a little bit harder to tell when you're doing these cleanup passes so anyway we'll feed-in and take our first pass out of there [Music] [Music] [Applause] last one we should have this gear cut [Applause] [Applause] our target was uh three inches and six thousandths if you look on my scale there I'm about a half a cow over six so we're gonna call that good enough but the backlash allow it that was put into this that should be that half thousandth isn't going to matter for anything in the world so anyway we're good we go ahead and take this out here we go our finished gear set I'll look right to me hopefully this will fit right in and it's the right tool use it looks good I'm happy with more well there you go one more project knocked out so we got this little gear set all made up for laddie and we're gonna get this back in the mail to them so you can get it reinstalled back in his reprinted slave and hopefully get that machine saved from the scrap yards and back into action so anyway I always enjoyed doing these gear jobs it's just fun to do and it's just really neat to be able to start with a couple pieces around metal and come out with a fairly intricate precision machined piece such as this anyway lots of fun I hope you enjoyed it as well and if you did please leave me a thumbs up leave me some comments if you haven't already please subscribe to the channel you'll get to see some more content coming your way with machine shop workshop related stuff and with that will sign off thanks as always for watching we'll talk to you later [Applause] you

Channel: Keith Rucker - VintageMachinery.org

Views: 129,418

Keywords: Machine Shop, Machinist, Milling Machine, Restoration, Vintage Machinery, Metalworking, how to run a mill, Keith Rucker, VintageMachinery.org, Kearney & Trecker, Model H

Id: u33rAbtL82Y

Length: 35min 32sec (2132 seconds)

Published: Fri Sep 08 2017