Let's Build A Model Steam Engine : Flywheel!

[Music] hello internet my name is quinn and this is blondiax we're back on the pm research steam engine today and we're going to make an iconic part on any steam engine that's the flywheel this is one of those parts that i thought was going to be straightforward turned out to be pretty unusually interesting so stay tuned for that and by the way if you're wondering how to watch all the videos in this series check out my playlists or there's a link to the playlist for this entire build at the end of every video okay let's go for months now you've seen this casting sitting on the back of my workbench well finally it's moment to shine a quick inspection here and no disrespect to this kit it's a great kit but this casting is pretty rough you can see that it's actually flash rusted unlike all the other castings because of the roughness and it looks like it's going to be tough to machine let's compare to a more traditional model steam engine casting it looks like this you'd hold it on the outside you drill and bore the center of the hub there and then you'd mount it on something like this which is a tapered mandrel that has centers in the ends and flats so you can mount it between centers drive it with a dog and then you mount the flywheel on that mandrel turn the od everything is concentric bob's your uncle however i don't think that's going to work here because this is a very large diameter flywheel with a very small hub so the flywheel has a lot of leverage on that hub and we're asking then those delicate spokes to take all of the machining forces so i really don't think that's going to work well instead i am going to bring in something completely different the face plate now this is not something you've seen me use much or possibly at all on the blondie hacks youtube channel this is a very rare thing for me to use but i busted it out for this occasion because i think it'll be just the thing check if it's running okay since i've i think only used it once or twice on this lathe and it looks like it's running within a few tenths there on the face and well that's good news so it's at least in decent shape now there's some surface roughness there that you can see in the needle so i decided to take my precision ground of flat stones and just debur this thing so my goal is to mount it on the faceplate like this and then the faceplate is going to be taking all the machining forces and the spindly casting isn't going to be doing any heavy lifting here now the question is how do i mount it on there i need some way to mount it such that i have access to the od the face and all of the hub area so really just the spokes and the inner rim there are up for grabs so i might be able to do some kind of through bolting scheme like this so i decided to try my hand at that first i got some scrap here and i whipped up a set of little pins that are threaded in the center have a shoulder on them and some wrench flats on the outside as such nice thing about the faceplate is that it's easy to remove and set on the bench for fixturing so i'm not fighting gravity here while i try to figure out how to do this so i've got some blocks here that'll act as supports for a strap clamping style action here now we have some small bolts and big slots here to deal with and well like any half-baked fixturing idea the solution is stacks and stacks of washers it's exactly where i wanted those i've got some little pieces of copper here to protect the casting from the steel pins and the idea is that the pins will go through there clamp between the casting and the blocks there and then i can tighten into the threads from the back using the stack of ridiculous washers so multiply that by four and here is the setup i'll start by dialing in the od although that's not actually what matters as you'll see here in a moment but i'm just tapping this in as best i can and this seems like it should be pretty straightforward i made good progress here and i got it to within about 15 thou but here's the important lesson about machining flywheels the concentricity of the od and the hub don't actually matter nearly as much as you think obviously they need to be machine concentric so that the mass is balanced when it spins but visually it will look like it's running out no matter how concentric all of your machining is unless the cast details in the center are running as visually true as you can get them within the imperfections of a casting of course so this is the real trick to getting a nice looking flywheel if you don't indicate in the cast details that won't be machined then the flywheel will look like it's wobbling when it's running even if everything is machined perfectly concentric so with it roughly dialed in on the od i switched to the id and i'm now indicating on that fill it in the casting there on the inside rim which is a little tricky but can be done now this was going fine until right about here where i was tapping tapping tapping nothing was moving anymore i had about ten thou i needed and i couldn't get it and here's the problem the pins are bottoming out on the slots in the face plate there and because of the slope of the casting here there's nowhere for that copper to go so i've run out of room to move the casting and it's not yet concentric now i tried 20 different arrangements of the pins in different positions on the spokes and loosening and tightening things and there was just no position that i could find where i could tap it in concentric so that's usually a sign that something's wrong with your fixture if you're fighting it that much and you can't get it to work it's probably the wrong fixture so i switched to this approach instead two brass bars clamped on the spokes much simpler not as secure mind you as you'll see here later but this was quite easy to dial in using the same method and i had little difficulty the caveat here is that the spokes are tapered in all three dimensions so as you're tapping in the part the clamping bars can get looser or tighter depending on where they land on those tapers so you got to keep a close eye on those bolts and tighten them as needed or if you can't get it to move loosen them a little bit and then tighten it again and work your way up until you've got it concentric and all the bolts are tight so this is where i landed we'll spin it up here see how it looks and i feel pretty good about this the key is to focus your eye on the innermost circumference of the outer rim of the wheel because that's what we're trying to dial in the hub and the od and everything else is going to run out and it's going to look bad it's easy to think that the thing isn't concentric again this is a rough casting so there's no position where all of those different surfaces are all going to be concentric the only one we care about is that circumference on the inner portion of the outer rim because everything else is getting machined the next interesting challenge with this flywheel is access because it's such a large diameter for my little lathe so one trick i'm using a lot on this is rotating the compound around so i'm using it at 90 degrees and i'm even using it pointing towards the operator all sorts of different positions to get extra reach here on the cross slide so now i can come in and start machining the scale now you can see as soon as i start doing this the wheel has shifted to where it's running out again and this is because that hard scale is banging into the tool and it's causing the wheel to shift and that's okay we just need to get through this scale and then we can dial it in again so as i go i'm kind of checking here and if it's moved too terribly off then i tap it in again but again before the finishing pass i'll make sure that it's very dialed in taking light cuts on this scale is very hard on the tool and it's slow going but there really isn't a lot of option you know the conventional wisdom on machine castings is your first cut should be deep enough to go under the scale but there isn't enough rigidity in the setup or the part to do that nor do i have enough material to remove to where i have that luxury you know we're trying to basically just remove the scale and not really go any deeper than that so we don't have a lot of choice except to chisel our way through it the hard way i'm using high speed steel here because a carbide tool is just going to immediately chip and it's just setting five dollar bills on fire so i've resigned myself to resharpening the tool as we go here and i did resharpen all these tools about twice during this machining quick sidebar on steam engine flywheel geometry now traditionally the flywheel is also the drive pulley for whatever work you want the steam engine to do and so you would want to machine a two or three degree crown on this surface so that a flat belt can run on it and it will track in the center of the pulley without sliding off now this flywheel however is very narrow and very very large diameter for this engine much too large to actually do any useful work for the horsepower of this engine so if i want to drive something and i will be driving things with this engine just you wait it will need a separate power takeoff pulley elsewhere on the crankshaft that's smaller diameter and that will have a crown machined on it for a flat belt if i were to do this again i might just take a dremel and sand most of the scale off the od before machining this thing eh live and learn but a little perseverance and we do get through it and now i can machine the front face here the front face is not quite as bad scale wise as the od the od was really bad it was like this casting was just wrapped in glass it was so hard i don't know if it was chilled or what but the od on this thing was really tough i was mighty glad for power cross feed on this step though because the rpm is fairly low because of the large diameter and so you want to be feeding very very slowly and so the power cross feed takes a lot of the tdm out of this in addition to all the scale the od on this thing had a lot of inclusions and other roughness so i kind of had to decide how deep do i want to go which inclusions am i just going to have to leave there which ones am i going to try to machine out a lot of judgment calls here but i got to where the surface looked pretty good and now i squared up my tool post and come in with the chamfering tool and put a delicate chamfer on that edge there just kind of clean it up and make it feel nice to the touch [Music] with that chamfer on there it's really starting to look like a flywheel now it's looking pretty good now the next little secret here is i'm going to chamfer the inside edge here where the fillet of the casting meets the machined face by cleaning up the roughness here and getting it as concentric as we can without cutting too deep it really again helps the flywheel look like it isn't wobbling when it runs what i like about this setup is that i can machine almost every surface on this flywheel in one setup so onto the hub now i don't know who cb is but apologies i'm about to machine off your maker's mark now i talked about how rough and hard the casting was on the outside of this thing the inside the hub is a completely different story in here it was beautiful very little scale very easy to machine just cut like butter so clearly the outside of this casting had some difficulty like it was chilled or didn't feel very well something like that with the hub faced i'm going to machine the side of the hub which is not strictly called for in the drawing but i think it's going to look a lot better so i'm going to give it a shot here so i'm going to bring my boring bar in here i'm going to make sure that it clears my fixture here it's pretty tight in there and i'm going to figure out how deep to go just sort of to where i'm just touching all the spokes and then the key here is i got to run the lathe backwards unless you have a left-handed boring bar or you'd have to grind a special tool to do this operation on the other side of the hub here and just like the face the sides of the hub machined beautifully no trouble here at all even with the skinny boring bar sticking way out to clear my daredevil fixturing there you can see here how the more surfaces get machined the less wobbling there appears to be in the flywheel so to just get better as we go here more compound shenanigans now to get the reach in there to get to the side of the hub with my chamfer tool and one of the reasons i'm using the compound so much is that the carriage is going to hit the face plate if i don't there's not a lot of clearance under there and that's something you really gotta watch because if you're used to using a chuck the carriage can't hit that at least not on this lathe so you might not be in the mindset of thinking about where the front of your carriage is it's very easy to hit the face plate and not think about it onto the board now this is as close to the spindle as my tail stock has ever been i'll start by center drilling this and again we don't have to worry about concentricity with the outer rim because nothing's moved since the od was turned so everything's going to be concentric all one set up that's the secret here so i'm drilling this up in a couple of stages and then i'm going to come in with a reamer you could also bore this if you wanted it to be super super concentric but this is going to be just fine i think and then a little champer deburring action there some inclusions there in the hub as you can see this casting is definitely uh one of the more challenging ones do a little test fit here with the crankshaft which is where this is ultimately going to live and that's a good fit there and happy with that before i take this down i'm going to measure the hub diameter so i can match it on the other side the actual dimension doesn't matter i just want it to be symmetrical and i measure the depth as well now i can pull the fixture bars off here clean up the face plates covered in cast iron grit flip the flywheel over and now with those machined surfaces on the face plate we can machine all the features on the other side and we'll know that they will be parallel now i'm going to dial in the od which is quite easy now that it's machined i've got it within a few tenths there and i want to check the hub as well i don't have a gauge pin this size but i do have an end mill that's the right size for that so i'll indicate on that and actually the hub is even better than the od so that's down to surface finish i imagine the hub there is pretty much dead nuts hard to complain about that okay so now i have to machine the outer edge here a little bit again because obviously i didn't machine the od all the way into the faceplate before because i would have hit the faceplate so i was stopping tenth house short and then i just had to clean up that edge and of course as soon as i hit that crust it shifted again and i had to dial it back in again and once the crust was gone i could do one very light cut all the way across and because the backside is chamfered as long as the chamfer is bigger than the nose radius on this tool i can go all the way across without touching the face plate and then more compound shenanigans to get the chamfer tool in there champ for this edge same as the other side and i also chamfered the inside cast rim there as well just like before so that's starting to look like a flywheel now looking good i wasn't super crazy about the finish on the od so i got some memory paper tape to a block of wood and i just polished up the od a little bit and the block of wood just helps keep the hot dogs out of the blender and then as before the hub on this side just needs facing and then a little bit of chamfer and then i did the od with the boring bar and i matched the od of the hub with the other side with that measurement that i took and again i set the depth of this to where we're just touching the cast spokes there that should be it for this setup so i can take it down bring it back over to the bench and i know some of you were worried about whether or not there were ridiculous piles of washers involved in this second setup and rest assured there were next up we need a set screw at a 15 degree angle in the hub something like an angle adjustable fixture plate would be perfect for this guess what i don't own instead i'm resting my 90 degree plate on a 1 2 3 block setting it at 15 degrees clamping it in at a ridiculous angle with a bunch of washers as is tradition presto 15 degree angle fixture now obviously this isn't very precise but it doesn't need to be the 15 degree angle it's really just there to give you clearance on the quill which i still don't have i need a longer drill here so i'm measuring about how much longer i need this drill to be you can get very long drills sometimes called aircraft drills for this purpose but i don't have any so i'm going to do something else i've got a piece of drill rod here nope nope nope nope there it is i need to keep the back of this from flopping around i don't have one of those fancy spindle spiders what i do have however is a shop rag and guess what this works just fine i'm facing off the end here now what i'm doing is just making a simple drill extender it's going to hold the drill go in the spindle drill gets longer after center drilling i drill it out with one size smaller than the drill i want to hold in this because drills tend to cut a little over size and i don't have a reamer the size of a number 38 drill so drill it a little under size and then it ends up a perfect fit and then i'm just going to lock tight the drill in place loctite is amazing for quick and dirty fixturing and holding jobs like this a little bit of that on there let that set up for 20 minutes and it's good to go while that cures i'll finish fixturing the flywheel here now i need to center drill it and luckily i do have a very long center drill this is actually a donation to the channel by viewer and i would not have guessed how useful very long center drills are just the thing here the center drill is important here because we're drilling at a slight angle and on top of a convex surface so the drill would wander off if we didn't center drill it first if this angle was much steeper than 15 degrees you'd want to mill or file a flat spot first but we can get away with this here now i don't have a way to get an edge finder or anything in there so i'm using this trick of just pinning something straight with the drill and then you move back and forth until it looks level and that'll be precise enough for this okay drill extender should be ready to go and it's an inch too long when does that ever happen well easy fix just gotta cut an inch off of it and well i don't need both hands for that so i'll take a coffee break with the other challenges of a small mill i had nowhere to go but down on the column so that had to be shorter now i've got some run out in the drill there but it looks like it's going to be okay as long as it finds the center drill there that we made it's going to be just fine and that is drilling very well okay out with the chuck and in with the spring-loaded tap follower to tap this thing i've got the tommy bar on the tap wrench all the way over because i thought i was going to need to move it back and forth because i also don't have pulley taps which are very long taps but luckily there actually was enough room here so i didn't have to do any of that i did however have to come in with a bottoming tap because my bolt that's going through the hub there didn't leave enough clearance for the taper tap to do the job and a little test fit with the set screw perfect it's exactly where i wanted that wrench now i can take it down and we should be basically done here here's another look at that set screw so you can see the 15 degree angle in action there and you could put that in straight if you had long enough tools but i don't now the drill extender has done its job so a little heat breaks the 603 out of there of course the drilling and tapping left a burr on the inside of the bore there so i just run the reamer through by hand to clean that up and now let's do a test fit on the crankshaft it's very exciting really starting to look like an engine now slides on there very nice tighten up that set screw and let's take this thing for a spin hey look at that it's flywheeling now did i achieve the goal of a flywheel that doesn't look like it's wobbling when it runs well i'm not going to sit here and claim there's zero visible run out in that but i am pretty happy with that considering how challenging this casting was to work with i think it's going to look really great especially once it's all painted up so that's all for this part thank you very much for watching if you like what i'm doing maybe throw me some love on patreon and i will see you next time you

Channel: Blondihacks

Views: 71,201

Rating: 4.9733992 out of 5

Keywords: blondihacks, machining, machinist, abom79, this old tony, vintage machinery, steam, electronics, making, maker, hacking, hacker, lathe, mill, woodworking, workshop, shop, model engineering, engineer, engineering, live steam, machine shop, metal lathe, vertical mill, metalworking, metal shop, jewlery making, diy, home improvement, resin casting, how to, do it yourself, do it yourself (hobby), ASMR, mini mill, mini lathe, tutorial, flywheel, steam engine flywheel, machining a flywheel, fly wheel

Id: 0s0GuKfbFBo

Length: 19min 35sec (1175 seconds)

Published: Sat Jan 09 2021