Machining a Model Steam Engine Cylinder - Part 1

a very generous supporter of this channel dropped this model kit off to me this week i was not expecting it but i'm looking forward to building it i'll squeeze it in as time permits there's a lot of pieces here and it's one of those where do you start i just figured i'll just dig in and start with the scariest piece and once you look at the blueprints you'll find out that is this guy right here it's the cylinder oh when it's done it looks like this there's an awful lot of steps to get there so let's get started my first step i'm going to press this against the sander and i'm going to flatten out the bottom of this part i will try to press it evenly as to clean up from the center out i don't want to clean up one side completely or the other side i want to start right in the middle and get this sanding line to go completely across realizing that this pocket right here is called out specific depth where is it there you go 438 and it does have a finished spec on it a sliding valve rolls back and forth in this pocket and that cast surface right there it says not going to cut it so we're going to remove enough material so i can go back in there with an end mill and clean that up and make it suitable for an articulate surface sanding first here we go all right we have a nice clean surface here i'm going to put this on a surface plate and see if it rocks if i can trust it i know that is a fresh belt and this should be nice and flat if it is that is my registration surface for starting to work on the overall length let's check it all right once you know feel that it's flat once you trust it and that is really nice i like that you can tell if you spin it and it keeps on spinning chances are it's high in the center if it's just dead well it might be low in the center but once you have a nice little ring like that nice little float to it you can trust it i like it let's put it in the middle get serious let's clean up the end with one end of the cylinder machine square and flat you can flip it over use a parallel tap it down against that parallel snug it up get ready for the second side now that i have a finished surface on each end of the cylinder i can squeeze it in the vise and reposition it to do the pocket on the bottom lay a tool bit across the opening sweep it zero it tighten it up it is always a good idea to take some rough measurements on the casting that you're working on to just find out where you are this is a 438 deep pocket and the rough casting itself is around 425 it's pretty close and without a hard dimension on the print you really don't know exactly how much you can get away with taking off of this surface now there is a there is a trick and there is a way to do it to make sure everything lines up as intended and all the mating parts go on like they're supposed to but i'm going to save that save that trick for a little bit i like to go around the outside with the cutter cutting in and the inside with the cutter cutting out that way any chips or any burrs any fractures of the casting does not result in a chipped edge drop down in the center i'm going to sweep it back and forth looking for about 435 and right now all i am doing is looking for the extents of travel how far i can go back and forth on the x and y i'm gonna write that right on the top of my vice right there i am now staring directly at the digital not even looking at the part i just know these numbers have to be hit keep me away from the wall there's nothing that says to clean up those walls so if you hit them i don't think it'll hurt but it's not necessary dialing into the final depth of the 438 and we're going to finish the pocket next step we're going to change over to a smaller cutter and take the corners out that this left behind one eighth end mill i'm using a quarter inch tool bit sliding it on the face of the casting until there's just a little bit of resistance underneath that carbide do not drop the end mill down on the tool you'll chip it zero out the table bring the table up the thickness of the tool bit and now the cutter can go down into the pocket to try to blend the 438 surface that the previous end mill left behind if i were to be able to stick a camera down inside this pocket you'd see four very distinct 3 16 radiuses a radii one in each corner i'm going to sweep back and forth on the x-axis until i just detect a little bit of debris coming off the cutter that is my zero spot same thing on the y and i'm writing these values on top of the vise just like i did with the 3 8 cutter if anything you want this perimeter cut to be exactly or a little bit lower than the 438 call out there's a valve that slides in and out of that area right there and it'll still work with the edges cut slightly lower i think it'll work better and we're going to walk all the way around any debris that you see coming up is just inconsistencies in the casting or irregular shape of the pocket itself with the table moved up to the final 438 439 depth i'm going to make one more pass a little bit lighter load on the cutter that way it's nice and straight and let's get ready for the next operation this is a 3 16 diameter cutter i believe this slot is 312 deep 5 16 and ideally you want this slot in line with that elevated boss on the side of the casting i'm going to take a couple of plunge passes here with the cutter so using a center cutting end mill is definitely preferred and clear the debris out as you go cast iron pack up around that cutter it might not end very well and once i hit my final depth i will sweep back and forth and here we go up and back it's an easy feature 3 16 by 3 8 symmetrical slot and this is the slot that will intersect with the air coming in through this port right here so when we drill a hole in that port it will come across and intersect that hole and as the valve slides back and forth it will release air into the chambers or from the chambers accordingly let's put the small ones in three thirty seconds gonna be a little bit more delicate that is a feature that you've got to be real careful about we just did this one we're going to do these guys now and that is a 3 32 3 8 long just as long as this symmetrical quarter inch deep i'll do it exactly the same way i will plunge it like a drill and then i'll walk the slots both sides symmetrical about the center line piece of cake let's do it [Applause] next slot is considerably thinner but just as long and because of the proximity of the cut and the camera and the cranks it is going to be very difficult for me to film this but here's the settings that you're going to be looking for we're going to be 266 off center both ways in the y-axis and 141 off-center both ways in the x-axis so we're going to step up to the 266 on the y cut a slot lift out come back down to the 266 on the other side get the depth cut the slot i will peck at this in a series of holes i will try to capture it but i cannot guarantee the camera will be in my way this is ideal shot right here but i can't see anything except the monitor okay we are five plunges into the 332nd slot there's a very small scallop in between all the five holes the outer holes are at 141 and the center holes are just split the difference goes 70 70 141 and you're in i will walk that back and forth and it is pointless to shoot the second one the second slot will be done exactly the same way then we'll move on to the holes for the mounting cap in this orientation try to do everything that you can there you go step one slots are in take your time when you walk this little cutter and that is a little cutter 330 seconds 0.93 that's about two and a half millimeters for anyone looking for metric two and a half millimeters and it is about a quarter of an inch 240 6.3 millimeters deep take your time on that one if you can keep a vacuum on it keep a vacuum on it let's do the bolt pattern around the outside when we initially dusted this pocket up and back to establish the depth called out on the print from a clean face down that gave me the center point that center point has served me well throughout this entire side so now i can do the bolt pattern around the outside without ever having changed or touched the digital all right let's move on to the six hole pattern that is going to mount the cover to this particular cylinder and just like any casting spot everything first check out the symmetry make sure you have real estate for the feature you are trying to create once you are pleased with how everything looks like it's going to sit go ahead and do it fast forward through a bunch of this it's just simply tapping holes when i'm done with this there is an overall length that is referenced on the print and in this orientation i will put the end mill back in and shave one end so that when it goes vertical i have a starting place and i don't have to worry about picking up the inside features okay let's tap some holes one of the secrets to successfully tapping small holes is not to use a handle that absorbs all the feedback from the tap this is a tiny little handle if it's steel i use a small handle like this if it's aluminum or something softer brass plastic i'll use a knurled thumb wheel if you use a t-handle make sure that the t handle is running true the last thing you want to see is that tap going in if it looks like a mild tornado try to maintain as true a trajectory with your holes as you possibly can this is an electro lube coated 540 plug tap i will tap all of these in line as is then i will come back at a later date with a bottom tap and finish the 380 the quarter inch depth excuse me [Applause] with all the holes successfully tapped in this positioning right here we're going to evaluate this print and come up and establish the blind end distance i can't cut all the way down i mean it is referenced as a finished surface i can't cut all the way down but i am going to put a witness cut across here so that when the orientation changes i'll know exactly where to stop it will not be a problem okay we are looking for the 1 and 15 16 overall 31 30 seconds off the surface so i will check the boss and i will try to keep this symmetrical about the existing casting that does not get cut using a 375 end mill to establish this end face we're going to go 968 which is 31 30 seconds plus the radius of the cutter which is 187 the digital readout target is one inch 155 8 or one inch 156. we're going to leave a little cleanup mark right there take it off depth of the cutter is just below the face where the end cap will sit i want to keep a round face there so this is going to leave a small flat step on the end of this part let's do it as promised [Applause] now they do say for preference i believe you can use either one of these depending on how you orient this cylinder on your model but that is a finished surface that the far side face of the cylinder here on this end will be driven from that surface right there there's an overall that needs to be maintained and that's how we're going to do it it is safe to pull this part out there's nothing else that needs to be done in this orientation let's clean up take a look all right for no particular reason moving right ahead here we're going to put in the steam inlet and exhaust ports that's these guys right here the inlet side is the low side that goes into the chamber on the bottom and the exhaust side will intersect the large slot in the center in a perfect world so we're going to grab a 7 30 seconds drill and a quarter 40 tap that's a real fine tap and we're going to do these features standing up in the vise let's do it if everything has gone well up to this point all the features that you've put in should be symmetrical to the reference points on the forging or the casting excuse me when i do the inlet and exhaust ports they say line it up by eye i will put a gauge pin and a chuck i will center that gauge pin about that boss and we're going to call it a day right at that point i used a 1 2 3 block to re-reference the square and i have a shim that takes up the relief in the center of the cylinder so i am not actually clamping on the cylinder itself on the ends that's hard to see but i am actually applying pressure here against the back jaw so let's visually line that up i will take a dust cut on here it's not on the print there is nothing on the print that says to finish that surface and it is not required to finish that surface but for sake of cosmetics i would like a nice clean surface it's my model so hang in there in the drill chuck visually lined up all right guys a heads up here they called out a 7 30 seconds drill on here that is a 218. now if you follow the formula for a quarter 40 tap you're looking for a 225 drill and the closest you're going to get is a 221 this is a number two drill i am subbing out the seven thirty seconds 218 for a number two 221 drill see how that works out [Applause] okay take note on this particular boss you are going to drill across one of the holes that's going to secure the cap i paused this video to figure out exactly what that was i was feeling and seeing down inside the hole and in fact you're cutting across one of the screws that's going to hold the cap on so if you put this thing together and you have a pipe in there make sure that the pipe doesn't stop the screw from going in or the screws stop the pipe from going in so be very aware that this is an intersecting hole we're drilling the 221 drill is a favorable substitution do not be afraid to use it this is a bottom tap and normally i wouldn't go putting a bottom tap in a hole without a plug tap or a taper tap or some other starter tap but because the thread is so fine not to worry it'll work just fine flip it over and do the exact same thing to the other side there's one steam port down all right let's take a look at what we got mounting holes are complete bottom surface is complete the inlet is complete you can see the shadow in the hole now i'm not sure if that's the let's see what we're going to call that one that's the exhaust port the tall one is the exhaust port so when we do the ends here there's going to be a pair of oblique holes that go down at a 20 degree angle and intersect these little slots so for anybody wondering what's the deal why did you start with the slots i like having a termination point for any holes that intersect it's a nice even load on the end mill and when you put your oblique features in or your intersecting features you'll know that you are there when it breaks through so as far as sequence is concerned i would start with the slots all day long ports are complete you can see the 40 threads per inch in there real fine thread on this one i did clean up both of the surfaces here that is not called out on the print but i think it just looks better so i'm going to do it if you wanted to you could go deeper with the 540 pilot drill it's not going to hurt anything there's a whole lot of meat here and it's there's nothing that's going to intersect except this one right here you'll see that there's a you can see the intersecting hole maybe the light will tell you there you go there it is okay that hole does intersect the thread and that's probably why they keep the threads very shallow they call out an eighth of an inch deep on that so let's establish the overall length start having some fun part now sits in the vise in a vertical format since the ends are parallel i have a spacer block underneath the far side of the cylinder and it's tapped down against that square against the back jaw and a finished face and the cutter is currently ten thousands above the area that i side milled when i had it in the drilling position so i'm going to take this end of the cylinder down ten thousands above that and we'll see what we have at that point alrighty for anybody that may be wondering exactly why i cut it like that castings can be brittle i did not want to chip any of the edges off i wanted a nice clean edge so the rotation of the cutter was always into the material it's the only reason backside's complete now standing vertical in the vise going for the one inch 937 or 1 and 15 16 only on the cylinder side not on the gland port okay you can see how it still sticks out that is very important and that is dimensioned right there one inch 332 from the center of the side hole out this is the one we're shooting for right now only the cylinder if everything went well 110th hour away off we go let's find out now if you wanted to at this moment you could calculate the height difference based on the print from the surface you just formed to the call out under ideal conditions now remember that the hole that they are dimensioning this particular elevation from that little gland port right there they told you to line it up by eye off the casting right there center of boss there's really no decimal dimension for where that hole is located and that is the driving hole both of them as a matter of fact we're center of the boss right there that is the driving hole for the outside of that edge so we're going to do a little bit of math we're going to figure out what the calculated height difference is between that face and that face right there and that's what we're going to do i'll let you know what it is calculated height of the end boss is exactly 125 above the cylinder end face 125 up now we're going to cut this off and then i'm probably going to cut to a part 2 on this video because we have some relation between what's inside the base of this under here inside in the center line of that hole since we only have rough castings to work with we're going to have to get creative to figure out how to align those two so that they function as intended i'm going to deck this off at 125 call it a day all right the next feature that we're going to do is the receiver features for the little flange that goes right here and this is a some type of a guide flange for the valve assembly inside you're going to have to know the depth of this pocket right here because of the way this is dimensioned and chances are when you hold it to establish that hole you're not going to be able to register anything in here i suppose you could if you wanted to but we're going to hold it against the vice this way so that gives us the center line side to side we can sit it on a parallel but i'm not going to for a very specific reason to orient the part this way now the next problem is how to find the center line of that pocket when that pocket is pressed up against the vise jaw and that's really not all that hard to do and here's the trick grab a couple of pins that fit the pilot holes for those threads and when you sit it back in the machine register on those pins that will give you two things that will give you a rotational reference and you could always double check across the face here but it will give you a tracking area where you can sweep the outsides of the pins or put a indicator edge finder across the insides of the pins but it will allow you to find the center of that particular feature always double check it because it's a casting you never know how it's going to look when it's done but the slider look the little valve that goes in here is not as wide as this pocket so there is some room for play don't be afraid of that in keeping with my own philosophy on machining when it is in this setup to do this feature here the through hole the two threaded holes on the side i should at least track a diameter through this part to establish the center of where the piston is going to ride and put in the whole pattern now there are two oblique holes right here that shoot through here let me pull one of these and we'll just do one of these things right here they will shoot through here at an angle and end up in these ports they come in from both sides and anytime like i just said anytime you start to reorient the part you're going to have a problem with that well there's an easy solution to that one as well when we get to those holes i'm going to show you that so stick around let's finish this let's pop some holes here and remove some material here's the feature that we will be machining this morning and this is a receiver feature for this part right here you would think it's going to sit right on there like that but in fact it's not it's going to be inverted and go down into the recess and i believe there's a seal underneath here as well a seal in the recess and this just traps it on the print it calls for a very specific thickness of this flange on this part but it does not tell you to turn this diameter down it tells you what size the diameter will end up at but it does not have a finish mark on it so if it doesn't have one of these little there we go that mark right there if it doesn't have one of those on the very specific dimension then check the piece that's with the model kit that number that little symbol right there is missing off the 245 diameter they tell you to turn this down too knowing the depth of the pocket is really important you can get the 188 in there it is uh they're suggesting plus or minus five either way the valve probably has enough slop that if you can't hit that that would be alright here's the setup i'll use an edge finder on the back move over for the center and i will sweep the pins actually i'm going to move this guy out just a hair there you go and i will use the inside of the pins as a sweep point for the indicator and we'll get after this using my edge finder and my digital readout i'm going to establish the zero surface against the back jaw this is my y0 and as soon as it kicks out we'll zero out the digital and a double check i always double check with an edge finder get the edge finder off the surface make your offset it's a 200 000 diameter edge finder i'll move it in 100 i know that i'm right where i need to be if i know the distance i'm ultimately going to move i may just add the 100 to the dimension so that i do not have to zero out my dro twice you start doing that you could stack errors if you need to zero it out three or four times for whatever purpose i come back go between the pins make sure i'm not grinding against the top of the vise but i want to make sure that i hit the full diameter of the pin on the x-axis now first time it kicks out i will zero out the digital there it is zero on the digital double check it there it is again number's good move it to the other side and when it jumps out i'm going to hit the centerline x function on the digital readout and now as we return the digital to zero we are right where we need to be let's drill it this is a very straightforward feature on the end should not take any time at all to knock it out we're going to start this process with a center drill this is 3 16 diameter center drill with a i believe it's an 070 lead on it you really want to see these holes in line with that boss that's a definitely a good thing this is a tap drill for the 256 visually aligned with the top i use a jeweler's loop double checking the setting make sure the drill didn't move make sure the table is set correctly second hole changing over to a 1 8 drill right now eighth inch drill goes through that looks a lot bigger than the eighth inch that's a that's a very small hole right there 1 8 goes through this is a 250 end mill and through the power of editing this is in a collet this is not in the drill chuck although you could probably get away with it we'll bring it down till we get a little witness mark on the top of the part make sure the quill stop is set double check everything move the table up the eighth inch depth that it requires plunge cut i am going to use the spring-loaded tap guide and a 256 tap to tap both of those holes i am only going to show you tapping one hole because when i went to reposition the tap for the second hole the autofocus tuned in on the blue rag in the background and it was completely washed out so you're only going to get one all right i think you can see that correctly positioned and dimensionally driven all the features come out right where they should with the casting you can change the elevation of a particular boss but the center line of that feature is usually a very good reference point all right let's punch a big hole right there [Applause] there are no dimensions on this print dictating the center of this bore right here this is my tap guide i am set at 0 0 on the 250 counter bore i'm gonna walk up and i'm going to visually sweep left and right with this by eye and i'm going to look for when this is tangent to either side of the casting and come up with a number stick with me this will make sense in a second on the y-axis i am visually in the center of this circle but that's not necessarily where it's going to stay move the edge finder out or move the tap guide out until it's right even with this edge right here and take a look at the number on your dial or your digital this side is 651. that number will change based on what you're using but for me it's 651 off center this side is 664. so we have a 13 000 difference in the readings that's six and a half per side i'm going to add that six and a half thousands value to the low number and come up with a 657 center line that 657 will be drawn back from the top to put me in the center of this feature [Applause] i'm back at x0 online with the counterbore i'm going to move up till i like the edge zero out my y and move back 657 let's see where we go so a little backlit compensation going on here there we go i say it looks tight to this side but then again it's a casting anything can happen x looks good y is a little different let's try one more thing using the mating component that's going to go on one side of this cylinder i'm going to sit it on here and trap it with the spring-loaded center it is now free to move around i am visually going to see how that spring-loaded center sits in the center of this casting as this casting sits in the center of the cylinder based on what i have right now and i have to say when you put the mating part on there it feels a lot better than the rough hole i think i'm going to leave it right where it is 6 57 off the center line of that feature right there excuse me 657 from the edge in mathematically it is one inch 136 to center from that hole right there one inch 136. i'm going to adjust that to 1 inch 125 1 inch 125 from here out okay testing the spot face with a 960 that is a 960 diameter that i've plunged this with and i'm going to go through it with a four flute 960 end mill hopefully it doesn't grab and explode but i will keep a vacuum underneath of it so the sound's going to be off for this next segment but this should at least clean up the casting inside this bore keep the fingers crossed that everything went well but i've left myself 20 thousands on each wall to bore out all right i am into the boring passes now do be very careful when you introduce such a large cutter over a long length of engagement like that if it starts to chatter it could go bad really quick so if you hear any noise whatsoever get out [Applause] let's take a look at the tool i'm using a 90 degree corner 45 degree lead carbide tool 660 rpm and about a thousandth and a half on the automatic feed rate now this is a compression surface in here this is the inside of a cylinder i will bore this to the low side and probably put it in the chuck on the four jaw on the lathe and clean it up polish it to make sure that we get good compression of this of the cylinder and the rings so take a look at the finish that this gives this is a ten thou pass 660 rpm that is an extremely smooth almost acceptable right now that's got to be a 32 finish or better in there it's almost almost completely smooth and that can be attributed to a small radius on the tool all right make sure that the radius of the tool is not too much not too little and that that balances with the feed rate or you're going to get all kinds of scratches inside the cylinder i'm going to finish boring it then set up for the bolt pattern and you've seen one pass you've seen them all but i do have a gauge i'll show you the gauge momentarily [Applause] this is the little beauty i am going to be trusting my cylinder board to this is an indecal and it is incredibly versatile very adjustable and what we have set up right now is when the indicator reads zero this tip out here is reading one inch so let me squeeze it for you and just show you how that works i'm squeezing out here there you go as you squeeze it the indicator lifts up off the anvil and right now it's not making any contact whatsoever but as it expands down inside the bore as it comes around there you go zero is out here somewhere but this is just the safety if you want to know whether or not your indicator is maxed out lift on the needle if it continues to go then you're really not hurting it okay into cow if you don't have one get one this will save you a bunch of time great little tool the board successfully completed the next step is to put in the one inch 250 bolt circle six hole pattern 625 radius 540 threads here we go all right let's tap them you saw me do it several times no sense in filming it same thing spring plunger small handle on the tap we're just going to go around the corners show you what i'm done you

Channel: Joe Pieczynski

Views: 86,751

Rating: 4.9327235 out of 5

Keywords: Joe Pie, JoePieczynski, Advanced Innovations, advanced innovations llc, how to, machine shop, shop tricks, shop hacks, shop techniques, shop tutorials, pm research, stema engine build, models, cylinder machining

Id: uaV6Qr_Tqys

Length: 50min 57sec (3057 seconds)

Published: Sun Oct 04 2020