Re-Facing and Lapping a Steam Locomotive Throttle Valve

[Music] hello keith rucker here finished machinery.org guys today i got a little interesting project i think you guys will enjoy seeing and we're going to be working on a throttle valve out of a steam locomotive now this is one that was actually sent in to me by a viewer who is wanting to be to help him on this the viewer's name is doug drake he lives up in the northeastern part of the u.s and he has a little steam locomotive that he's restoring and he told me that this is a uh unit that he bought it's actually a two foot narrow gauge steam locomotive an old one that came out from up in maine and if you know anything about narragage locomotives up in maine there was a bunch of two-foot gauge stuff going on up there look real small gauge uh by ref you know just as comparison we have narrow gauge at our museum here in tifton our little vulcan locomotive runs on a three foot narrow gauge and of course standard gauge is what four foot nine and three quarter inches that's probably not exactly right but much wider track so the narrow gauges use this nearer track and but there was quite a few of those two foot gauge steam locomotives up in that northeastern part of the united states back in the day now he bought the running gear off of this he said about 10 years ago from an estate sale up in maine it didn't have a bore on it but he was able to find a boiler made by porter porter is another big locomotive manufacturer from back in the day made industrial locomotives mostly and it was probably for a small narrow gauge locomotive very similar to this and he bought that boiler and was able to adapt it to the running gear that he has he says the bowler was in very good condition he's had it hydro test it has had it ultrasounded looks real good on the inside it's been all inspected everything but he's been having a problem with this throttle valve that was in that porter boiler and that the valve seats in here are just they become worn pitted and it's just not seating real good so he's wanted me to help him to basically clean these seats up on this and relap this in to get it where it will seal up now i've worked on a couple of throttle valves before off of steam locomotives our vulcan locomotive at the museum i did it may have done a video on that at some point in the past i can't remember if i did or not it's been a long time ago since we had that throttle valve out it looks very similar to this one a little bit larger than this one but very similar but what we need to do is i'll zoom in here in a minute show you this but this has got to have some work done to it and we're going to set it up on the lathe to do that and hopefully it's a challenging part to do and i'll explain why here in just a minute before we do that though he did send me a couple of pictures of his locomotive that he's working on i thought i'd share those with you guys real quick so you can kind of see where this thing's going all right so this is just some photos he sent and uh you can kind of see the running gear up underneath the bottom there this is the the boiler uh the locomotive boiler the throttle valve uh would be located up inside of this steam dome so in a boiler the steam dome is the highest point in the boiler with their steam and this is where the steam is basically taken out to go and do things you want to have your steam taken out at a higher point because the higher you get it from the water the drier the steam gets when it gets down close to the water it's very saturated steam as it gets higher in that steam dome it's uh it's just going to be drier steam so this is the throttle right here and it goes through through the boiler there's a rod that goes through there that goes to a connector in the bottom that basically pivots uh the motion coming in and out to up and down and that's what opens um this throttle valve the throttle valve will basically push up inside the the throttle valve the valve would and it would allow the steam to enter into that valve and then basically it goes back down into the boiler through a pipe a steam pipe that goes through the boulder up through out the front of the smoke box and then that would then split and the seam would go to the steam engines on either side which would drive the drivers so anyway that's just a little bit about what's where it's at and what it does and these are just some photos of his uh restoration this looks like it's coming along very nicely i'll just show these real quickly here's another view of the of the boiler from the front end uh you can see the steam engines down here in the bottom basically he doesn't have a i don't think it's opened up here in the smoke box but inside the smoke box that pipe would come out and there's the the two dry pipes that go down basically into this casting and then the uh steam goes into the steam chest which the steam chest is right here on the top that's where the valve is it slides back and forth that lets the steam go into the engines that drives the locomotive so just a few more pictures here we'll show you real quick of the work in progress all right so here's the whole throttle valve assembly and uh you see you got some bolts here this this is actually the the pipe that goes where the steam goes to the uh front so it would probably be in the steam dome with this being the front of the locomotive this being the engineer side and uh like i said that pipe just goes down connects to a flange that feeds up to those engines this is the actual throttle valve there's a stem that comes up through this and when you crack the valve and the in the locomotive it basically pushes this valve up and um depending on how far you open it up is how high this raises and that'll basically allows you to control the amount of steam that goes up to those engines up in the front it's an adjustable valve now the interesting thing about this is is there's actually two valve seats in here there's one in the bottom and one on the top and if you look inside of this you can kind of see you got a valve seat here and a valve seat in the bottom so when you do open that again you've got steam coming in two different places that just allows that steam to come in really well and uh that's the way pretty much all throttle valves that i've dealt with locomotive throttle valves work so here's the challenge we've got the two seats in here now the seats inside the the throttle valve itself don't appear to be in too bad of shape i mean they seem like i don't feel any big gouges or big ridges or anything like that in there i think these are pretty much going to be okay and that's good because it's really difficult to machine these the problem we've got is with the actual valve and i don't know how well you can see this in fact let me zoom in a little bit closer on that valve so there's a really a really big ridge up here at the top of this and and what happens is this the seat will wear but it's only going to wear in the area that comes in contact so this if you were to lay a straight edge across this it's higher in the top and the bottom than it is in the middle and it's basically just worn to the point to where it's not sealing up anymore and that's happening on the top and the bottom so what needs to happen is is we need to come in here and basically freshen up these uh the surfaces on the lathe and get them where we got a nice flat surface from the top to the bottom that's gonna allow cause this valve to seat down just a little bit deeper than what it is right now but we've got some extra material i don't think it's going to be an issue at all to do that but that should go a long way toward helping us seal this up once we get these uh surfaces freshened up we'll have to re-lap it into uh the the seats in here so that everything works real good now here's the challenge on most valves you just have a single valve seat you just go in and you freshen it up everything's good but with this one you've got two valve seats that are a certain distance apart and we've got the matching valve seats inside the the casting back here the problem is is that when i freshen these up on the lathe these seats have to be exactly the right distance apart to mate with the the piece over here in the casting and it's really not adjustable it's a certain size and it's it's extremely really the only way to measure it is through trial and error and getting it where both seats fit just perfectly so i've done these before and it's just like i said it's just a certain amount of trial and error involved i'm sure that when this was made new in the factory they probably had some jigs and fixtures and so forth to help with that but doing uh fixing an old one like this the only way we can do this is again through trial and error so my game plan is is we're going to make a fixture to hold this over on the lathe we'll come in here we'll freshen this up and then we'll probably use some lapping compound and we'll also use some something to mark in here to see where it's cutting and make sure that we're actually lapping both surfaces at the same time and we may have to make some adjustments on either the top or the bottom valve to get it where it matches uh what's going on inside the actual throttle body there so anyway there you go um fun little project let's get over to lathe let's start working on our fixture to hold this and see if we can get this knocked out so i just got a piece of metal here we're gonna make this uh little fixture to hold it on and i'm going to start by facing that side and then we'll put a center in it so that we can support it a little bit deeper still just a little bit more here we go this ought to do it okay just put a center in the end and that should support it all right so we've got a piece of stock that's about one inch in diameter um and we've got a hole through our valve here that's about 625 thousandths 5 8. just a little over that we'll uh kind of make it where it fits it slides up on there and what i want to do is i'll have a shoulder back here that this will go up against and then we'll turn a place for a nut to go up on this end that will tighten this in place and hold it in place and we can turn that on that mandrel so uh let's see we want to yeah we want to take it back to about right in here really kind of arbitrary as to where it needs to go to but that'll be a good point i'll just make a little point there and we'll just start turning filling this thing down it's gonna be a little over 5 8 we just kind of have to find a fit that it fits on um that hole that's through that casting probably isn't perfectly round and perfectly true i just want to get it where we got a good good snug fit up on there and we'll work off of that but uh we're this is about 750 thousands we're going to about 625 630 so a few more passes and we should be there all right we've been turning over here and just having to take a little bit of time but i've got a nice fit up on there i mean it just fits almost perfectly and that's exactly what i want that will give me a manual to turn this on so now what i want to do is uh i'm going to turn this down to half inch and we're going to thread that to be able to turn a nut up on the end and we'll just basically tighten and tighten it up in there and the friction will hold it on this mandrel to turn so let me get a marker and we'll mark that and turn that in down to half inch and thread it there we go take that off i want to turn that just a little past that point about right in there we're going to go to half inch we'll just turn a little bit off until we get there turned his shoulder back here in the back make sure it's uh nice and square all the way down and i'm gonna cut into it just a little bit that just make sure there's not a radius in that corner where my part won't go up tight against that shoulder i also want to just going to come in here and touch off [Music] come out there just a little bit it just looked like there was a little burr on it all right i'm all set up for threading and we'll thread that for half inch uh 13. we got our blade slowed down here i'm just going to put a leading chamfer on the front here at the same angle as our threads just makes for a nicer lead in there and zero my dial out here barely cut and i'm going to do a scratch fast here first i'm going to speed my lathe up a little bit just run a little bit too slow i'll then number come around and [Applause] and let's check that make sure we're on 13 threads per inch which we are and we should be ready to roll [Music] a little oil on there i've done a lot of videos on threading so i'm not going into the details here on how to single point thread on a lathe if you're interested in that i encourage you to go look at some of my older videos you can search them and there's multiple videos where i go over how to do this and i will say like i'll often say what i'm doing single point threading i know this looks hard it's really not you just have to practice and if you are scared to do it i would just encourage you to get out there get on your lathe put a couple of pieces of scrap metal in there and start threading and after you do a few of them and are successful it really becomes easy we're just taking a little bit at a time cutting those threads on out and what i'm looking for is kind of to where i get a sharp point at the top of the thread and then that tells me it's time to start measuring with a nut for a fit in another pass or two and we should be about where we need to be but we're going to check it after this pass right here so uh we'll pull that out and i've just got a uh nut here and it's a little bit tight so uh i'm gonna take a little bit more you know another alternative if you want to when you get down close like that you can just run a die up on there i find it a lot easier to just thread it out first and then finish it with a die if you're going to do that but i'll just single point it on the rest of the way out it'll be faster to do this than to go set a die up take a little light pass there i think i'm going to do just a few more thousandths and uh test fit it again let's try that again and that's starting up on there i think that's gonna be fine it's a little bit tight but i can tighten it up and no problem we're good all right i'm going to champ for a couple of corners there he's coming here with a little 45 tool i just want to break that corner make a nice uh make sure i have no something sharp there same thing here [Applause] all right and i think our mandrel is done all right so we are ready to assemble this we'll put our valve up on the mandrel i'm just going to put a washer on here to kind of where it'll press on the bottom that washer's a little bit big but we'll just cut it out with the lathe and make it where it's the right size tighten that up and now the friction we're just sandwiching this together we'll turn it it'll turn on that center stem and hopefully with any luck it's going to be running fairly true to those valve seats we're about to find out so let's uh get our tail stock and support in here so it looks like it's pretty good got a little bit of run out but some of that's just the wear in it no big deal like i said our washer is running out but we're gonna cut that down to size in fact let's just go ahead and get that out of the way [Applause] that's better just uh cutting it down to size so these angles are at 45 degrees i'm gonna go ahead and set my compound on the blade the 45 degrees get a tool in here and we'll see we can start cleaning those up all right guys i think we're ready to start working on these uh resurfacing these two valve faces and uh before i do i i can't remember i think i might have said what this angle was before if i did i probably said it was 45 degrees that's wrong it's it's a 30 degree angle i think a 60 degree included angle but anyway i i i had 45 in my brain for some reason but once i got over here and started setting it up i realized that i had measured in this it's a 30 degree angle or 60 degree included angle so uh regardless i think we're ready to go what i've got is i have my compound set here to where we're going to be doing a 30 degree angle and i think what i'm going to do is actually start on this top one and you can see that that follows that angle pretty well in there and i'm starting up here because this one appears to be the most worn and what i want to do is i'm going to touch off on this um top edge here and i'm going to zero out my my everything and measure how far in i have to go to get it to clean up and then we'll come down to the bottom and kind of touch off on this outer ring the reason i'm doing that is that's that appears to be an original unworn surface so uh with any luck if i go in the same amount on both of those everything will match up once we we get everything cleaned up at least that's the game plan so um probably what i'll do is actually get this one cleaned up first we won't go all the way in on this one uh we'll we'll keep track of where we're at but leave it a little bit high so that we can kind of close that gap up with some trial and error so anyway let's come in here i'm going to that's the zero i'm going to zero my digital readout like i said and we'll just uh come across that face and you see it's only hitting at the top right now so i'm going to go in about i don't know probably ten thou come back across again we're missing through most of that let's do another 10. [Applause] [Applause] do another [Applause] 10. all right we're starting to touch a little bit in there we've gone in a total of 30 thousandths now i'm gonna do another 10. [Applause] still skipping a little bit in there but making some contact now we're not touching at all and start picking up again on the bottom [Applause] this will take us to 50 000 total depth in see if this gets it starting to skip these valves had a lot of wear in them all right let's uh i'm just going to do about 5 000 this time i don't want to take any more off than i have to still skipping here but we're getting a lot closer to where we need to be [Applause] all right we're going to go to 60 000 total depth total in man we're close but not quite ever so slightly still got a little bit of a gap in there all right this is a lot more than i was thinking i was gonna have to take off we're at 85 thousandths i think this will get it i hope this gets it [Music] i think it got it yeah it got it all right that's 85 thousandths off the total off the top diameter uh we'll come down here [Applause] again come in and touch off on this one i'm gonna zero my digital read out again [Applause] [Music] [Applause] so we cleaned up there at about 30 thousandths [Music] we'll take a little bit more off of it [Applause] all right guys i think we've got this pretty close so i'm what i've been doing is i'm putting this valve in and even though i was real careful not to take as much off the bottom as i did the top when i put this thing in the first time it was it was touching in the top but not the bottom which means that i had to take some more off the top to get it back down i really took a little bit more off the bottom than i should have but no big deal we're going to make this thing fit what i've been doing is bringing this in it's been catching in the top and i've been able to take my finger and just kind of shake this thing in this valve in the bottom a little bit at a time until when i first did it there was a good bit of slop in there and it's i've gone back to the lathe i think three times now i'll take about taking about five to ten thousands off per pass on the top now i don't have any movement in there so i think we're really close probably where we can start lapping this thing in and until we get it where we got it seated well in both the top and the bottom that's the game plan so i think we're ready i think we're ready we'll get our lapping compound out and start lapping all right we're ready to start lapping and to do this i'm going to be using some lapping compound that's made by time saver is uh the company that does this i think i bought this kit off a mcmaster car and this is just one that's got a little small sampling of a bunch of different grits and if you look on the cover here you got the the green ones here are for hard metals this is going to be your cast irons and steels the yellow ones are for soft metals that's going to be for aluminum brass bronze etc and we got everywhere from course the very fine i'm going to use the the green stuff and we're going to start with the course because we want to cut some metal here and all this is it's a powder and you can see in here it's just it's exactly that it's a powder and what i'm going to do is we'll take some of this and put it in a cup let me get something to kind of stir it up with just use this brush and we'll just take some and put it down into this cup that should be plenty to start with and what you do is you mix this with some oil i've just got some some spindle oil here and we'll take that and you just want to create a slurry between these two products need a little bit more oil and you can kind of mix up however much you think you're going to need for whatever job you're doing so let's uh just do this we will i'm going to take my brush and i'm going to just kind of brush some of this compound down in that bottom seat and we'll do the same thing for the top seat here and then we will drop our valve down in here now the gentleman that i got this from he made a little adapter here he tried lapping this himself but it was just so far that he couldn't get it done without machining but he sent along this little jig that we're going to put in a drill and just let it roll and i'm going to pull it out and you can see what's going on and it looks like it is touching in the top and the bottom it looks like it's cutting in the top and the bottom not fully in the bottom it's only touching i'm looking down in here it's only touching in part of it in the bottom so the top looks like it's pretty well touching all the way around so it's going to take a little bit of work to to do this we're just going to apply a little bit more lapping compound down in there you want to just add some fresh from time to time and it's going to be back and forth back and forth back and forth until you get it where it has cut what you want to cut [Music] so i've kind of changed up here and gone from using that little [Music] hand drill to over here at the lathe to do my lapping i didn't really like the way that that uh little adapter he made wasn't running true i was getting a little bit of an oscillation in there and i was just afraid that might affect the lap so i just mounted this back over here on this lathe spindle i had to cut that washer down a little bit to make it let it fit through the bottom but uh just turning my stem and i can come in here and just kind of push it up on there and this also allows me to kind of go in some steps here because what will happen is that will drag a little bit more of the lapping compound whenever i loosen up it kind of lapses it just brings that lapping compound in there and i can get a little bit more cycles out of this and i'll pull it off and we'll put a little bit more lapping compound down in here and i'm just making sure those uh valve faces are covered really good and go through another cycle [Music] rinse and repeat um there's no way to get in a hurry about this lap and it just takes time it cuts a little bit at a time and you get a nice uh valve seat all right i think we're gonna call this uh job done i've been lapping on this for probably about an hour now and i feel like i've got pretty good seats on the top and bottom it's definitely rubbing in both places simultaneously it may not be 100 across that seat but it's good enough that i'm going to go ahead and send it back up there to him and uh at the state that it is in now i think that if he wants to lap it further he can easily uh spend the time and do that i'm just sitting here spending a lot of time doing this when this is something that he could be doing up there and i know that he's tried lapping this to begin with without having to machine it but now that we've got things where they are it's really can be further lapped if he so thinks he needs to to do that it's probably good enough as it is but i'm real happy with how this turned out everything uh appears to be seating really good you know i was a little bit concerned that we may drop the top of this down past the top of below it you know we had to take a good bit of metal off to get it to clean up and i know that the bottom seat is probably hitting is the the top of this is probably a little bit below the top of the seat down there but we've still got plenty of material that it's seating against so i think we're in good shape here i think this is going to be just fine you know this is probably was the original seat in this boiler that's well over 100 years old and with fresh seats in here probably no more than that locomotive will be ran it'll last more than a lifetime i'm sure as it is as long as it's cared for so i'm gonna pack it up send it on back up well there we go one more project knocked out i'm going to send this back up to doug and like i said if he wants to lap on it further he can sure do that but i think it's probably good enough like it is one thing i'll mention on this time saver lapping compound is i was i was told a long time ago by someone i think richard king told me this but he said that this stuff was uh kind of invented back during world war ii by the navy because they were needing to lap a lot of stuff in for repairing ships and one of the concerns that they had with their lapping material they were using is they didn't get it perfectly clean that uh grit from this lapping stuff could get into the the machines and mechanisms on the ship and caused further damage so they came up with this product here that will break down pretty rapidly you have to kind of keep putting fresh stuff on it for it to continue to cut because it breaks down rather quickly so that if in the heat of battle repair uh they don't get something perfectly clean this this product is not going to damage things further or at least the damage will be extremely minimal compared to your more traditional lapping compounds so it breaks down over time fairly quickly so you have to keep a fresh coat on there for it to work but you know if there was a little bit of lapping compound left in here and i took this my parts washer and cleaned it really well but if there were and it got down into the the the cylinders on the engine the seam locomotive it probably wouldn't cause any damage at all or very little damage and not enough damage to matter it's not like it's going to sit in there and go back and forth and score big holes into the cylinders or what have you uh it would it would break down pretty quickly and all would be good so anyway i really like this stuff i use it all the time and it's been a good product for me again like i've saved me all the time these guys aren't sponsoring me or anything like that just a satisfied customer uh telling you guys what i like that works good in my shop and with that guys that will be a wrap as always thank you so much for watching please subscribe to my channel if you haven't already hit that thumbs up comment our thumbs up button down there if you like what you saw that helps out with my analytics a lot uh leave comments down below if you like as well that also helps out with my analytics and hit that bell icon if you want to get notifications of when new videos are posted to the channel and with that i'll catch you on the next video as always thanks for watching so [Music] you

Channel: Keith Rucker - VintageMachinery.org

Views: 45,922

Keywords: Machine Shop, Machinist, Lathe, Restoration, Vintage Machinery, Metalworking, How to run a lathe, how to run a mill, Keith Rucker, VintageMachinery.org, steam engine, boiler, throttle valve, steal locomotive, porter locomotive, porter steam locomotive, porter narrow gauge locomotives, valve facing, lapping, narrow gauge, maine steam locomotive, 2 ft gauge

Id: wHIyZrlPWrk

Length: 38min 33sec (2313 seconds)

Published: Fri Dec 03 2021