Case Steam Engine Clutch Rebuild: Turning and Installing Bronze Bushings

[Music] hello keith rucker here finished machinery.org guys today back to working on this clutch arm that goes on a 75 horsepower steam traction engine that belongs to the florida flywheelers down in florida and uh if you remember we actually worked on boring this out in a previous video went up to brian block shop up in kentucky and we use this big monarch lathe to do this job on need to get this thing finished up they're going to be coming back through here in another week or two to pick this up and i need to have it ready for them so to finish this up i need to put some bronze bushings in here we had to bore this out oversized so basically the way this clutch works is this whole arm fits up on a the main uh shaft that comes out of the steam engine the crankshaft and depending on whether the clutch is engaged or disengaged when it's disengaged it's just the the shaft is rotating but the clutch arm is not then whenever you engage the clutch all of a sudden this will go to turning with the shaft and it's a way to turn the power on and off uh where the steam engine is running constantly so it's a clutch but over the years the when that thing was just free spinning it wore the cast iron or the bushings inside this down excessively and we had to actually come in here and bore it out over size and the plan is we're going to install some bronze bushings in here to get it back to size they also had to weld up the actual shaft where it had worn down they've got it machined back down to a nominal size i've got that dimension written down over here i don't have that part to compare it to but i know what we need to bore the inside these bushings to so to do this i've got the bronze bushings they actually provided me one piece of bronze that we're going to use that will do one side the other side i had to purchase a piece of bronze this came from mcmaster carr and uh yeah a chunk of bronze that size was rather expensive but that's what we had to have so that's what we're gonna do but i will turn this down both the inside and outside diameters uh to fit in here so start with we're going to take this over to the lathe we're going to bore the inside to size we want to have a little bit of clearance between the shaft and these bushings so that it can free spin and we have room for oil in there and he's told me what he wants me to bore this to i've got that number written down the outside diameter then needs to be turned concentric to the inside diameter for a press fit in these and when i say press fit the diameter the outside diameter of the bushings will be a couple of thousandths larger than the bore this is going to go into and i've looked it up i got in my machinery's handbook i think i need about three to four thousands of interference so in other words these need to be about three to four thousandths larger diameter than what's in here and we'll use the old heat trick we'll actually heat this up expand it make it a larger diameter i'll probably also throw these in the freezer which will shrink them down a little bit and uh so we won't be actually pressing that full 3 thousandths interference or 4000th interference whatever we end up with it'll go in a lot easier hopefully just drop right in and then whenever it cools down and normalizes it'll be shrunk together and fit just right that's the game plan before i get going turning i want to get some really good measurements uh of the the the bore we have here on both sides and kind of so i know what i'm going to be turning to and then we're going to start boring these out to the right size so we're going to start again by getting some measurements here and i'm just going to quickly measure this with the calipers to get a rough idea where we're at and we're roughly three inches and three and three quarter inches and that's a rough measurement that's not what i'm going by here but that tells me which bore mic i need to grab let me go get it now so to measure this i'm going to be using one of these bore micrometers this is a little three-sided micrometer they're really handy uh for checking bores they're accurate to within about a half a thousandth of an inch and this is much more accurate than using a snap gauge or something like that now i do want to check the calibration on it before i go just to make sure because i'm going to be measuring the inside with one instrument measuring the outside with another a lot of times if i'm using a snap gauge or something like that i'm going to be measuring with the same micrometer i'm not really worried if that that micrometer is perfectly calibrated because i'm going to be getting the same measurement i'm using the same instrument but because i'm going to be using different ones i want to make sure that we're good so i actually have a ring gauge here and this ring gauge is four inches in diameter this uh particular uh 4 micrometer measures between 3.6 and 4 inches so i'm just going to put it down in here and this is just a known standard and i'm just going to check that and we're going to see how it reads and here we go so it is pretty much dead nuts on this it's within actually this measurements in two ten thousandths of an inch increments and it's about two ten thousandths over so um with the interference fit that we're gonna do later on we're gonna have uh it's gonna need to be about three or four thousandths larger the bushing so two tenths isn't going to make a difference so we're good to go there so now i'm going to do is come over here and we're going to measure this bore so let me back that off get it down in there and that's just a perfect fit right there i'm going to read it while it's in there so let's see where we're at so it looks like it's measuring three inches 700 thousandths i'll write that down 3.749 so just a thousandth under three and three quarters of an inch now i want to have interference on here and i'm gonna go for three thousandths interference so we will want to turn our bushing to be 3752 thousandths of an inch and that should give it make it three thousandths larger i'm gonna make several measurements here and just verify that we gotta that's the measurement all the way up and down do that off camera but that's my my initial measurement we may adjust that after i do some more measuring i'll be back so the other side is a good bit larger diameter this side had a lot more wear on it uh than the other side so we had to take out a good bit more material there's also more metal in there to work with than there is on the smaller side even though the inside bore is going to be the same on these this bushing will be thicker now i'm going to have to go to a different bore mic this 4 mic is same principle but this one measures between four and five inches and i've already checked it with my standard again it's measuring this one measures to half thousandth increments the other one is measured to two tenths but it's within half a thou of being where it needs to be so again we're going to come in here now and let's uh get a measurement so we are at all right so it's measuring four inches 25 thousandths pretty much right on the money there within half a thousand that anyway uh we're gonna again make several measurements in here and just make sure we're getting a good measurement so we got our piece of brass or bronze here for the small side and again we're going to start by boring it but first i want to just face this end off we've got to actually reduce the length of this by a fair amount i don't remember exactly but it's a little bit oversized right now we'll get to that in a little bit but let's start by facing that here and touch off [Music] my little plastic face shield going here this uh bronze tends to want to spray everywhere when your machining with it so keep it out of my face there we go just get a rough idea of where we're at so we're about two eight fifty and i need to go to uh three four four five so we've got a good bit to take out of there at least fifty 60 thousandths or excuse me five six hundred thousandths so uh just gonna come in touch off i'm gonna do a pretty heavy cut here right at 100 000 total and just feed on in there [Applause] [Music] all right here we go with another pass take a little bit more uniform cut this time [Applause] all right i'm going to get a rough measurement here with my calipers so i can see where we're at and kind of be following it on my digital readout it looks like we're at two inches 982 thousandths i'm gonna put that in my digital readout all right we'll take another 100 thou here this will put us a little over three inches [Applause] come in here again with a bore micrometer it's 303.2 25 225 3.2 50. three point two seventy five so we're 3.2 75 85 86 3.2 84. i want to change my digital readiness within a couple thousandths 3.284 [Music] we just measured the first time with the calipers so this is going to be much more accurate measurement we are going to 3.445 so yeah we got almost 200 thou to take out of there still not quite we'll take another hundred thousandths pass and um that last measurement i want to let that cool down because it is getting some warmth to it okay we've let this cool down it's uh back at room temperature so um what i'm going to do now is we're going to come in here and i'm going to touch off on it again i'm just going to take a really light pass to clean it up right there i don't want to take much at all i just want to take a little bit out of there and that'll give us a good measurement to start from we're getting down really close to that final measurement that we're shooting for so i just want to make a good clean pass here after everything's cooled down so that i'm getting an accurate measurement and i might lay the set where i can dial off of it from there so let's get this pass done and we'll take another good measurement and see what we need to go to all right we're right on three four two five i'm gonna put that in my digital readout 3.425 we're going to 445 so i've only got 20 thou to come out of this so the 3.445 and we do have a little wiggle room on this inside bore we just basically are going for clearance so um actually if i'm within probably i don't want to be any less than that but if i'm five ten thousands over we're going to be fine but we're going to try to shoot for that 445. all right we're at about 347 which uh it's gonna be fine that's good uh we're gonna leave it just like it is i'm gonna come in here with my little noga tool and deburr that bore there since we're gonna leave that just like it is and this one needs to be three inches long and we're a good bit over that right now so i need to face off the other side i may um cut it on the band saw and then come back in here i think i'm going to debur that outside edge too just get that burr off of it we're going to turn the outside later but it'll just make it easier to handle so instead of facing off half three quarters of an inch whatever that is i'm going to saw it off using my new marble saw this is a new tool in my shop this is one of the first real jobs that i've used it on so i thought i'd show you real quickly this whole bandsaw head moves across it's kind of like what they call a rolling saw but this is a particular brand a marvel made by armstrong blum let's uh try her out here and we'll let her feed across there so all right back over here at the lathe i got my part turn around this is the side we just cut and we want that to be a little over three inches three inches 38 thousandths is what it uh measured we're about three inches 100 thousandths right now let's clean that up oh let's see if we can get that running a little bit truer than that running pretty true on the outside we got a little wobble on the cut but uh we're about to clean that up you can see it's making interrupted cut right there all right i see where we're at on the length here still got just one little area there that it hasn't cut i want to make sure i'm measuring on where we have and all right we're at three inches one twenty put that in my readout 3.120 enter and we're going to take that down to about three see three inches 38 thousandths was the total depth i'll probably shoot for three inches 20 thousandths so we're just gonna work our way down that's exactly what i dialed in three inches 20 thousandths that gave me about 20 thousandths clearance 18 000 clearance at the end the hole and let's go ahead and break that outside edge there the machine down later but it just makes it easier to handle right now and we'll debur the inside of this hole using my noga deburring tool all right the inside diameter is done and this one just needs to be turned on the od and i need to get the other piece of bronze board out on the inside as well all right this is the piece of bronze that uh i got from mcmaster carr and honestly most of this piece of bronze is going to end up in my chip pan i really hated to buy a piece so big but it was the only option i had to get the inside and outside diameters where i needed them anyway we got a lot to bore out of there that inside diameter is two inches two and three eighths inches and we got to go to three point four four five so it's got over uh what is that that's uh that's an inch that's got to come out of that inside diameter and then i don't remember what the outside diameter is but there's a good bit we're going to turn off of it as well this is uh the initial cut will touch off his first cuts a little bit of not interrupted but that this is extruded material so that hole isn't perfectly round so it's taking more off of one side than the other i'm hoping we don't get that vibration as we continue on i wish i had a little bit larger diameter boring bar but uh and i do but it won't fit on this lathe with my current tool hutter holders if i continue to get a bunch of vibration i may have to do a little upgrade before i finish this out all right let's do another 100th owl still got a good bit of vibration in there yeah there's a lot of chatter tell you what let me uh i may have to order a new boring bar i can i think that's a one inch boring bar all right guys i've got a one inch boring bar in here right now and it's it's sticking out as far as it is we've got six inches sticking out there's just too much flex in this thing uh and we're getting some vibration in there now my holder here you can tell there's a bushing in here it'll take a boring bar that's an inch and a quarter in diameter the problem is is i don't have an inch and a quarter diameter boring bar i think what i'm going to do is just order me one i do have an inch and a half boring bar but it won't fit this block and i don't have anything on this lathe big enough that will hold it i may even see if i can get a boring bar holder that will hold an inch and a half and look at that option as well but regardless i really just need a bigger diameter boring bar for this particular job and i can order one have it here in a day or two so i think that's what i'm going to do we're just going to take a pause right now and see if we can get the right tooling to do this job right i'm sure that if this was a rush job i could slow down and uh you know maybe not take as deep of a cut and probably get by but i just want to get a better finish than that and it's going to be hard to do with this particular setup so anyway time to take a break we'll be back once we get some different tooling in the shop well as promised uh we have upgraded boring bars here so what i ended up doing first off this is the original boring bar that we were using one inch diameter this is a inch and a half diameter borne bar that i had and basically if you look here you know you got a hole through this there's a bushing in there the hole is inch and a quarter so i couldn't get my inch and a half in there but they make a different model boring bar block it holds an inch and a half and it has a bushing that will also let you use an inch and a quarter so i got me a bigger a large tool block holder here to hold the larger boring bar and uh that should go a long way toward helping to stiffen this up a little bit hopefully take some of the vibration out of this bar while it's turning now another issue i may run into is because of the stick out here only gripping it in a small area back here and having probably about four times as much sticking out as what i'm grabbing i may get a little vibration in the bushing itself if that happens i'll probably just turn back a little bit on the outside and put my steady rest in here which will dampen any vibrations but we're going to try it like this first so i've got everything back together just make sure yeah that's good and tight hey got a little uh run out in it face that front got a hundred thousands uh cut out in there let's roll through and see what it does all right sounded better see what it looks like yeah that's a nice uh nice finish in there that's what we're after and it looks like we're right on the money well we're about four tenths under the mark we were shooting for according to the the bore micrometer here uh and that's going to be perfectly fine we've actually got plenty of we're just trying to get some clearance on the inside that bore so four tenths isn't going to matter one bit i'm not going to try to run another pass through there or anything like that it's just not worth it so that bore is done so to turn the outside of this bushing concentric to the inside running on this exact same plane we're going to use this tapered mandrel or expanding mandrel to uh set it up on so the way this works you got a mandrel and then you got this piece here you see it's got all the cuts in it this will slide on this mandrel and as it slides down this gets bigger and bigger and bigger and you basically just slide your bushing into it and as it gets bigger and bigger it will just by friction capture everything in there so let's uh kind of get it down here all right it's starting to touch about right there all right that is sandwiched in there everything's good and tight and i can now put this mandrel on my lathe running between centers and the outside should be running perfectly concentric to the inside so i'll put a drive dog on this end i need to get a center in the headstock in and start turning let me get set up and i got the first bushing mounted on the expanding mandrel the mandrel is running between centers so basically we have a center up here which is just coming out to a point it's been i turned this on the lathe so it's running perfectly true to my spindle in the three jaw chuck i've got a live center on this end this is a dead center but it's spinning with the truck chuck and we also got this drive dog the drive dog just clamps to the mandrel and basically a little tab comes out here as the chuck turns it rotates this mandrel because it's between centers it could just spin on it so uh and let's see as you can see it's it appears to be running very true so we should be good to go uh we'll come out here and start by i'm just going to touch off about where we were before and finish turning that out i just turned a clean shot all the way across there i want to get a good measurement and we're at four inches 398 thousandths and that's what i got in my dro so that looks good we're going to four inches and 28 thousandths so we've got quite a bit to come off of there let's go ahead and crank it all out all right this is 200 000 total cut we're going to hog some metal off well we've let this cool down completely in fact i went and grabbed some supper and came back out here to the shop been gone about an hour or so and we've lost right at a thousandth of an inch in diameter just by that thing cooling down so it's exactly what i kind of expected so we're at uh four inches and forty nine and a half thou so what i think i'm gonna do we're going to four inch twenty five thou so let me get the lathe going what i'm going to do i'm just going to do about 10 thou let's let that pass go across so that gives us a new measurement to work with after it cooled down and we made a cut as a reference so i'm going to put this number in my digital readout whatever it comes out to be and we're at 25 plus 17 4.042 all right i'm just going to dial it in right there this should be the final pass and because i don't really want to make a mistake here i'm going to stop right there and let's just make sure that we're not messing up here right on the money 28. okay let's double check our work here we are right on the money exactly not even a tenth off so that's good just what we want so let me take this cutter out i'm going to put in my chamfering cutter just get rid of that sharp burr on the edge and we'll come to the front up here and i'm going to chamfer this one a little bit heavier this is going to be the side that i feed that i press in from and that just kind of helped me get it started all right this bronze bushing is all finished i'm gonna go ahead and knock this one off i'll put the other one on here i'll get it turned down on the outside not gonna show that one and these will be ready to press in we got both of our bronze bushings turned now inside and outside the again the outside is going to be a press fit about three to four thousandths interference if i remember right anywhere in that ballpark we looked the number up in machinery's handbook and these all pretty much are right on the money the inside bore uh they're all also pretty much right on the money but we've got about 10 to 15 thousands of clearance on the shaft that's going to be on there because this basically just needs to spin so um let's just see here this is the bushing that goes in this end and you can see it kind of starts but doesn't go in and that's exactly what we want what i'm going to do is we're going to go out to the museum and use the hydraulic press to press these in but before we do we're going to cheat a little bit uh we're going to we're going to make the dimensions where they'll fit better and the way i'm going to do that is number one i'm going to take these bronze bushings i'm going to put them in the freezer and let them just soak for several hours and the temperature by cooling it will cause it to shrink in fact we'll get a measurement uh before and after just to see how much it shrinks probably just a towel or two it's not going to be a lot and the same thing on the the arm here when we get out to the museum i'm gonna use the torch we're gonna just heat it up to a couple hundred degrees not like super hot that will make it larger and more than likely these bushings will just fall right in if not we can use the press to press them in lightly but then when the temperature equalizes it's going to shrink around uh these these bushings and everything will be super tight and everything should be good that's the game plan um yeah let's let's uh just double check our measurements actually i got them written down but i'll double check them and then we'll compare those after they come out of the freezer just to see what kind of difference we get so we are just about ready to go ahead and press these bushings in but i want to just cover a couple things real quickly so first off as promised i took those bronze bushings and i measured them uh before i put them in the freezer they've been in the freezer overnight they've had time to cool down and really get you know completely saturated to that temperature and equalized and i'm not going to show it because i don't want to take them out and it just takes time and as it warms up it's going to start growing but both of the bronze bushings that i made they both shrunk almost exactly 3 000 of an inch which ironically is also the exact amount that i made them oversized for an interference fit i probably could come over here and press those things in right now without doing anything else but i'm going to put the odds in my favor and we're going to put some heat on this part which will make this diameter actually grow in size hopefully by thousands or two and when everything's said and done they should just drop right in may require a little bit of a press power which is why i'm over here at the arbor press i don't ever like to assume they're going to go in without any pressure i like to have the arbor press ready to go just in case and more than likely even with everything even with having a couple of thousandths difference between the two sizes with the temperature gradients um it's still probably going to take a little bit of pressure to get them in there it's my my bed so uh we're going to put some heat in here with the torch get it heated up to probably a couple hundred degrees nothing crazy and then i'll go grab the uh grab the bushings out of the freezer and we'll press them in so i'm gonna be doing that rather quickly when the time comes so uh i'm not gonna be talking a lot but i'll show you the process all right here we go it's going to take my time put some heat in here i know my gas pressure is getting down a little bit low on my tanks i hope i got enough to do this if not we'll have to stop and go down and get my bottles refilled which i need to do anyway but again we're just going to get this heated up a couple hundred degrees and that should be ready to go all right here we go i got my frozen piece let's just hope that falls right in place it's going nice and easy getting a little bit tough there at the end all right we're home [Applause] all right one of them is in let's let this temperature equalize just a few minutes and we'll flip it over and do the other side so we are ready to put our second fishing in i will say that uh i had to go refuel fill up my tanks that's what i wanted to do right there had to refill my tank uh my it just wasn't putting out a lot of heat yesterday so i went and got the tanks refilled last night or yesterday afternoon and uh i waited till this the next morning to do this job because i had laid my settling tank down flat to haul at home and uh i wanted to get it a chance to equalize everything you're not supposed to use that tank until it's been sitting back upright for a while but as you can see we put some heat in there and that expanded that out this was a 3 000th interference fit whenever the temperature equalizes that bushing will be in there and be in there well so we should be ready to go so i think we are done with this job we're gonna let this cool down uh i'll show you the bushings real good and we'll be ready to send this down to florida and get it put back on to that case steam engine all right here's a look this is the small bushing side uh that we pressed in first it's got a little frosting in there left over from that ice i think but it'll clean right out but that one looks good and we'll flip it over take a look at the other side and this is the larger bushing and it also looks good you can see where this little area here this is where it wore into the cast and we elected not to face it down past that but again i'm tickled with how that turned out i think everything looks good and that's going to be both of these bushings are in there plenty tight now that the temperature is equalized and they've gone back to their regular size uh should be a good time nice tight fit and there we go i think we got this job complete but before i wrap this up i have to make a confession and i didn't show this on video but very frustrating mr bozo did come to town on this project and messed me up and let me show you this i've got an extra bronze bushing here uh this was about a 300 mistake that i made and it's all on me but what happened is is when i measured the bore on the large size originally i misread my four micrometer by one whole turn one turn on that bore micrometer is 50 thousandths of an inch this bushing is exactly 50 000 too small i didn't show it i just went ahead and ordered a new piece of bronze and and made it it was the exact same process as before but anyway i wanted to show that yes i make mistakes every machinist that works in the shop is going to make a mistake from time to time unfortunately this one was a very expensive mistake for me and unfortunately that happens as well but uh i did just want to share that i'm not trying to hide anything i don't want you guys to think i'm perfect because i'm far from perfect it was an honest mistake it could have happened to anyone the rule of thumb is and my rule of thumb is always measure twice cut once and i didn't do that this one time and it caught me and if i had gone back and re-measured that bore before i went to the lathe and said just going off the numbers i had written down probably wouldn't have happened but it did and uh this piece of material like i said with the shipping and everything was about three hundred dollars and uh i'm gonna have to eat it but that's uh that's part of the game uh it happens to everyone from time to time um so anyway with that guys uh that's gonna be a wrap as always thanks for watching please subscribe the channel if you haven't already thumbs up and comments are appreciated and hit that bell icon to get notifications and when new videos are posted and with that we'll catch you on next video again thanks for watching [Music] you

Channel: Keith Rucker - VintageMachinery.org

Views: 79,255

Keywords: Machine Shop, Machinist, Lathe, Restoration, Vintage Machinery, Georgia Museum of Agriculture, Metalworking, How to run a lathe, Keith Rucker, VintageMachinery.org, case steam engine, traction engine, turning between centers, expanding mandrel, bronze bushing, bronze bushings, turning bronze bushings

Id: pcqRY1KB0kU

Length: 39min 16sec (2356 seconds)

Published: Fri Sep 17 2021