Roll-Forming Metal - Copper tube plates, boiler heads, etc! Model Boiler Build, Part 4

breast fits are one of my favorite things in machining you when you get that dimension just right and you put it in the press and it just slides all the way oh ah crab nuts hello internet my name is quinn and this is blondie hacks i'm back on the fire 2 boiler bill today i'm going to make the tube plates traditionally these are hammer formed out of copper sheet but i'm going to roll form them which is i think a cool process that you don't see a lot so let's go i've got my copper sheet here that i'm going to roll form for the boiler tube plates a quick sidebar on hammer forming because that's the traditional way to make two plates and boiler heads you make a form or a buck out of hard wood and you anneal the copper and you hammer it over the form and then you kneel it and you hammer some more and you kneel and you hammer some more this is basically the same process but the lathe is doing the work of the hammer you'll see what i mean here now this is roughly what we're gonna need this is a roll forming mandrel and i made this previously for the last four inch boiler that i made however mysteriously this mandrel is much too small for this four inch boiler and i don't really know how this happened because i definitely used this mandrel to make the last four inch boiler that i made yet somehow it's much too small so who knows that means we're gonna have to make another mandrel so back to this familiar fellow regular viewers will recognize this large slug of aluminum that's increasingly becoming just a slug of aluminum as i continue to make many many things with it so i dialed this up in the four jaw and wait a minute did you flip that around yes i did and then i dialed it in again and i didn't show you all that because it's not good video this is the director's cut so i get to tell you all these little details that normally i might gloss over in a video boy let me tell you this day this was the 10th take on this day and best boy grip called in sick and nobody knew how to plug anything in and sorry let's get back to the video with that nicely faced off as a tradition i can start making the discs that i'm going to need for my roll forming mandrel we need two ones the base and one is the cover plate so i'm going to get some tail support in here first because we're going to be doing some heavy turning the last time i made a large disc from this material i did it with tripanning so if you're interested in that go check out my trapanning video this time i'm going to go in and turn it down because i want to try out this new aluminum grade insert that i've been using for other things besides aluminum i wanted to see if it would do a better job breaking chips and so far not so good however i experimented a lot with speeds and feeds what i found worked really well was large depths of cut with very slow feed and you can get it to create these very thin ribbons that come off of the cutter very very well behaved the chips don't break but they're very nicely controllable it's very sensitive to feed rate though you got to get that feed just right i'm feeding by hand here there's no power feed setting that would make results this nice note at this stage i'm actually leaving the disc oversize a little bit and that'll make sense here in a moment but no matter how you do it turning aluminum is a giant mess nobody's happy with this except maybe swarfy the duck now we're going to need a shaft on the back of this mandrel just like on the demo that i showed you i'm going to drill this out in a couple of sizes going up to pretty close to the size that i need and then i'll finish it up with the boring bar to final dimension this dimension needs to be quite precise because i'm going to be pressing the shaft into this hole i'll check this with the telescoping bore gauge or as i sometimes call it the snap gauge when i want to generate negative i mean engagement and now the finishing pass on that i'm looking for a one thou interference on the shaft that we're going to make so right now i'm just worried about getting a known dimension because i can turn the shoulder on the shaft to whatever i end up with here so i just want something appropriate and then i'll chamfer that now i decided to try parting this off previously i've not had good luck parting off material this large in diameter on this lathe but i thought i'd give it a shot and uh well yeah i i blew a fuse and by that i mean three fuses so i took the hint and took it over to the bandsaw and cut that material off there and then i put it back in the four jaw and dialed it in again so that i can make the cover plate so i'll face off that giant mess right there i did my best to do the drilling of the center hole in the previous part in such a way that it wouldn't mangle this piece too much because i don't really want to have to face this all the way down to get rid of that drill cone entirely that would be a lot of facing so i can live with some of it there now i'll turn this down a little bit further to dimension the cover plate needs to be a little smaller than the other disc was the cover plate needs a reference hole in the middle of it and it needs to be precise but we've got that weird drill cone left in there so i came in with a two flute center cutting end mill and made a little flat spot in there so that it won't interfere with the center drill and then i center drilled pilot drilled drilled under size and reamed that hole to final dimension and then i snuck the center back in there so i can try parting this off again now i learned my lesson in the last time so i just made a starting groove there and then took it over to the band saw and then i clamped it up and faced off the saw cut once again you can see lots of run out here i didn't bother dialing this disc in because we're just facing the back of it now back over to the base disc and this still needs facing off from the bandsaw cut on to the shaft that is the base of this mandrel now i've got a scrap of aluminum here that's a little short but i think i can squeeze this part out of it so i clamped it in the edge of the four jaw there i dialed in one end and then i tapped in the other end to get it running pretty straight we're going to turn it down anyway but might as well start with it straight and then i'll center drill that end and then i can put my center in there and turn down the diameter the diameter this doesn't matter a whole lot although it's always a good idea to make your mandrel diameter something standard in case you ever want to put it in a collet or something that pays off more than you might expect so i cleaned up the surface there and then i'm turning down a shouldered area at the end here and this is extremely critical once again i'm aiming for a one thou press fit here on the main disc of the roll forming mandrel so i really want to nail this dimension now unfortunately i should have checked for taper in this area and i didn't my cross slide had actually slipped a little bit during that cut and i didn't notice it so that'll make some fun for us here on the next step and just because people get sad if i don't do it and yahtzee now the next step after parting off is to take it over to the press put some loctite on there it's the press fit loctite and try to press this thing in and it pressed about halfway in and then got extremely stuck yeah so there's that taper i was talking about i couldn't get it in any further but this is a fairly easy fix i can just bust out the torch and heat up this disc to expand it and that allowed me to press it in a little further so i heated it up some more and pressed it a little more and managed to work it all the way in i couldn't quite get it fully flush as you see there i made a rookie mistake i forgot to undercut that shoulder so it doesn't look beautiful but it'll still work just fine back to the lathe now and i'm dialing it in on the shaft because that's my reference i want the final outer disc there to be concentric with the shaft once that's dialed in i can face this down there's a little bit of extra thickness there and i'd like it to be flush with my press fit shaft and now i can bring in the center and turn the od down to the final desired diameter and this way everything will be concentric with that shaft now ultimate precision here is not actually that critical boiler tube plates are pretty low precision affairs but you know might as well practice good work though while we can the od of this disc is fairly important though it needs to be the inner diameter of the boiler shell minus the thickness of the two plate times two of course plus a few thou of clearance for silver solder so i'm checking this dimension carefully now the next step is to round the outer corner we need a bend radius for the two plate i've got an eighth inch radius gauge here which is what i want i don't have a form tool this size but i do have a corner rounding end mill in this size this is a trick that i think i learned from adam booth so i'm going to set this cutter up in the tool post and i'm using an adjustable parallel to line it up there the back side of these flutes are flat so you can get the cutter horizontal this way now a form tool this large on a four inch diameter part is asking a lot of this little lathe but just keep the rpm low to avoid chatter and a really really gentle feed and that just feeds straight in with one edge aligned with the od of my part until that curve is fully formed and then when i think i'm close i stop the lathe and i bring the cutter in and just see how it lines up with the other side of the flute there and needed a little bit more there just bring it in real slow until you've got a smooth transition on both faces that's looking really good and the radius gauge confirms that we are there it's a really nice result for quite low effort the base of the mandrel needs the same reference hole in it that we put in the cover plate so we'll use that center once again to start the pilot drill and then drill up in a couple sizes and ream this hole to the same dimension as before now this hole is actually the diameter of a fire tube and this will be important here in a moment but you can see now how i can stick a gauge pin in there and that gauge pin is going to be the reference for every other operation that we do on these two plates so cover plate goes on there and that is looking pretty good that cover plate's still a little oversized so i'll be trimming that down later but for now i can go over to the mill i'm going to use this backing plate that i made for the rotary table because it's also great for mounting the chuck directly on the mill table and it's going to make a great vertical setup here for the rest of the operations on this mandrel so clamp the two plates together and then i use the gauge pin to just feel and find the center there and then i'm using a long center drill to get around all of my clamps and stuff there to drill a four hole pattern here now this four hole pattern is going to be used throughout the roll forming operation and these locations are chosen such that they correspond with fire tube locations so these are areas that will be holes ultimately in the tube plates this is the key to this method is you have to be able to find four holes in your tube plates that you can use as fixture clamping holes in this setup in the earlier version of this that i showed you might have noticed four holes in kind of a strange trapezoidal pattern and that was where holes happen to be in the boiler heads that i made with that particular fixture both plates are drilled through tapping drill size then i drill clearance size just through the top plate using the depth stop on the quill and then i can pull the top plate off and tap the holes in the lower you can see that the clearance drilling of the upper plate nicely chamfered the lower plate holes i wish i could say that was intentional but yeah for youtube i'll say that it was okay mandrel done let's get back to the copper i'm going to blue up the relevant areas of one of the sheets here and i'm going to roughly find the center here with the cross corner method finding this precisely doesn't really matter because these sheets are oversized i just need a place to start so i'll center punch that and then i'll set my dividers to the diameter that i want for the plates and i'll scribe that out so this is basically the diameter of the tube plate plus the bends plus the flange depth that you want plus a bunch of extra for fudge as you'll see and just for fun i used a wiggler to find the center of that again precision not super critical here and then i can drill this out and i'm forming that reference center hole again you can see that i've got both two plates clamped here together i have to keep them clamped together until this reference hole is fully formed and then we can separate them after that final step is to apologize to my reamer for exposing it to plants it's okay woodworkers don't write me sad comments about how i make fun of you too much it's all in good fun i love all of you and that end result is a little looser than i wanted i think the reamer got into the mdf there a little bit and caused it to wander but that's okay this is close enough to work then using the dro i drilled the same four holes in both of these plates that were on the mandrel these are clearance holes for the clamping screws all right there's our two copper plates now i need to rough cut those circles and i briefly in a moment of comedy thought i could do that with tin snips but no so it's over to the band saw and for this a zero clearance table is your friend so just push a scrap of wood into the blade before you start clamp it down and then the bandsaw makes quick work of this copper actually bandsaws extremely easily and yes i know that blade guide is higher than it should be but that's as low as it goes this is a horizontal bandsaw with a cheesy vertical setting that you can use in a pinch it works just fine for things like this so please stop making me delete comments about that now using those center reference holes we can clamp these plates together into the fixture and get ready to turn them down to the final scribed circle there on the lathe that rough cutting on the band saw saved us about 28 000 hours of machining time machine tools are not like woodturning lathes where you can just take a square thing and make it round in five minutes you really want to start with something quite close to the final shape that you want or you'll be here all day you can see some run out in my fixture there i'm not actually sure where that's coming from maybe i was a little sloppy with my dialing in but i didn't bother to correct it because it really doesn't matter for what we're going to do from here out determining the size for these discs is a little tricky because you have to end up with a specific flange depth generally you want about two times the wall thickness of the boiler header tube plate as your flange width you don't want the flanges to be too wide or the silver solder won't penetrate all the way through so generally you just make them substantially oversized and then trim them down here later as you'll see that way you don't have to try and work out the bend radius of the copper and how much it's going to draw when we form it and all of that jazz with everything turned and deburred we can pull these plates out of the fixture because it's time to anneal them for roll forming but first i decided this cover plate is still a little bit too big it was fine for that turning operation but for roll forming we're going to need more clearance so i just bolted it back up and turned it down a little bit okay on to annealing so this is a process of just heating the copper up with a torch until it glows dull red and that softens it so that we can form it copper is generally hard when you receive it and it work hardens very very quickly as soon as you start to bend it a little bit it will work hard and you cannot bend it any further without cracking it or damaging it and once you're done annealing you can just plunge it in cold water to cool it off quickly and save yourself time you don't harden it by doing that copper alloys will not harden by heat treating the way that ferrous alloys do they only work harden and heating only softens them and quenching has no effect on hardness you may have noticed that the copper plate warped there when i quenched it that's not a problem for roll forming because the fixture is going to squish it flat again and then after the first operation there will be enough of a flange that it will stay rigid but if you wanted to avoid that like you were making some other type of part just don't quench it let it cool down naturally back in the fixture now and i'll set up the roller so this is my roll forming tool it's just a roller blade ball bearing and actually a worn out one you don't need a good one for this and it's mounted to the tool post using actually the bushing that comes with rollerblade bearings there and that allows me to put it on either side which will be helpful so you line it up at a 10 degree angle off the surface of the copper spin up the lathe run it nice and slow and then just push the bearing into the copper you can use the compound or the carriage feed whichever is convenient just push it in until the copper is flush with the bearing now it didn't look like much happened there and it won't look like that at first but you have to stop now after you've had a couple of laps around the roller you have to stop because it's work hardened now you got to take it over and anneal it again and then bring it back and you can do a little more so here's what it looks like after two passes don't get greedy with angle or with how much you push if you do you'll dig in and create lines you can see me getting a little bit hasty there so i got some lines if the lines aren't too deep they'll come out later as you'll see between each of these clips i'm annealing again i ended up doing somewhere between 7 and 10 annealings total you can get away with less because the area that you're working with the roller work hardens but adjacent areas don't so you can do two or three passes on each annealing if you're clever about how you arrange it but as you can see i'm changing the angle of the roller each time and just working my way gradually around and the longer you go the faster this gets because the annealing goes quicker as you have a dish shape to catch the heat and as you're over the hump on the corner as it were each trip around the roller has much more of an effect here's another look at the annealing and lower lights you can get a sense of the glowing dull red that you're going for it's much much easier to do this in low light so i do recommend turning down your shop lights as you're annealing because it's much easier to see the color if you do this in a well-lit area then you're going to end up overheating it because you can't see the red color forming and it won't necessarily hurt it but you're just wasting a bunch of time and torch fuel here i'm doing multiple places at once on a single annealing resist the urge to move the tool post with the roller in contact however that's just going to cause the roller to dig in and damage the works you just want to apply inward pressure at a couple of different spots when i think i'm close i start checking with a square and that'll show you where any high spots are and i had a couple so i annealed it one more time and flattened those out and that's looking good now the final dimension is likely to be a little larger than you thought it would be based on the diameter of the mandrel and that's because as the roller is forming that flange from the flat sheet we're actually shrinking it into a smaller area than it was in before and so the material kind of piles up on itself and ends up being thicker than it was we're also drawing material in from the center to some degree and in any case the solution is the same we just turn it down and there is one roll formed tube plate no wrinkles no creases no nothing just one perfect little dish of copper so i cleaned up the outside of that on the scotch brite wheel the inside is a little bit trickier so i'm using these little mini scotch brite wheels that you can get on amazon they're cheap like borscht and they work great in the dremel so we can clean up all of the residue from the torch it'll come off the torch looking terrible every time but don't worry about it because you can easily clean it up as you see here so i made two of those to this point there's my upper and lower tube plates ready for the next step now the flanges are still quite a bit too deep as i mentioned so i go back to my mandrel and i bolt them on the other way got some copper washers in there to protect the copper from the bolts and i just face this down to the final flange depth that we need which as i said you want it to be somewhere around two times the thickness of the material and this is a 64 thou copper plate so i'm looking for somewhere around 128 thou of flange depth there and copper makes these really nasty burrs but you can often just tear off the worst of it with pliers and then come at it with the file now it's time to make all the holes for the fire tubes so it's back to the mill but let me stop and show you the drawing effect here that i talked about earlier you see how this hole isn't round anymore it's pulled out to one side that's what happens when you hammer form or roll form copper it's pulling the material from somewhere when you stretch it so this is why you want your pilot holes or your fixture holes to be smaller than the ultimate fire tube holes will be because they will become a weird shape before you're done next i bolt the top plate down on top of it so the plates are back to back and i turned these bolt heads on the lathe just to give me some kind of low precision machinist buttons just to roughly align those two positions with the y-axis of the mill this doesn't have to be that perfect it's just to get it in the ballpark within a couple of thousands here is fine the goal is not really to have the holes be in the exact perfect place what matters is that the holes are in the same place on both tube plates so that the tubes will be straight and properly aligned the tubes are arranged in a series of radial hole patterns so i'm using the bolt circle function on my dro for this so these were all center drilled and then i'm about to center drill the center ring but the center ring has nine holes in it which is an unusual pattern and that does not have the same radial axes of symmetry as the other patterns so i want to make sure that i have it correctly aligned here so i'm just comparing it with my drawings and i did a dry run there with sharpie as you can see just to make sure that this is going to be correct after all of this work you really don't want to mess it up at this stage and then the outer hole pattern is done in the same way and i'm just skipping over where the bolts are and you can see that i'm skipping two places that are marked with an x there because the upper tube plate has two extra holes that are not in the lower two plate and those are for the safety valve and the steam output that goes to the engine so everything is pilot drilled but for the final holes i wanted to make sure i had a good approach here so i put a piece of scrap over off to the side and fixtured it and drilled it the same way and i wanted to make sure that if i say drill it the fire tube size is the clearance going to be right when i when i'm done or do i need to remit or what what i'm aiming for here is like a two or three thou clearance around the fire tube for silver solder so i tried it with the straight up drill and that was okay but a little snug i ran an oversized reamer through it and that felt about right so this tells me that i can at least go in with the drill and the holes won't be too big so i'll start with that and see how it goes so those were all drilled out for the outer ring i worked my way around and just pulled out the bolts one by one as needed to drill those holes next i carefully pulled off the top tube plate which is actually the lower tube plate in the boiler and then put the bolts back in so that i can drill those two extra holes that are in the upper tube plate once again those are for the steam output valve and the safety valve and we are done with the fire tube holes looking pretty cool so a bunch of deburring later and a test fit in the boiler the last thing we need is a way to fixture these plates in the boiler shell for silver soldering so i'm just lining them up visually i want the two output valves to be kind of square and equidistant from the gas vent on the bottom there so i'm just kind of eyeballing that to where i like it and then i'm marking a reference spot with a transfer punch there this is where i'll start the bolt pattern here now i'm lining that reference mark upwards on this fixture here so this is the same mandrel again but now set up vertically in the rotary table on the mill so i can drill the bolt pattern that's going to support these guys for silver soldering and then i put the other two plate on there back to back again and line up the two hole patterns correctly and bolt them together and once again the exact position of these support holes doesn't matter that much but it does matter very much that they're in the same place on both tube plates so i'm centering up the fixture here using the pin a flat thing to the round surface trick when that parallels horizontal then we know we're roughly in the center and then i center drilled and pilot drilled each of those holes this is a three-hole pattern around the outside of the flanges and then i decided to come in and tap these now in a previous video i said i was going to use rivets for this but i decided against that because rivets i was afraid would would clamp the plates too tightly in place and not leave silver solder clearance so instead i'm threading the holes and i'm going to make some little studs out of copper bar stock that i have here and these will make little studs that i can screw in through the shell through the holes that i made for the rivets and will allow me to just temporarily support the tube plates during silver soldering and these studs are likely to get silver soldered in place but that's okay when i'm done i'll just file the studs off and you'll never know they were there initially i used pliers to put them in but it turned out to be much easier to just cut slot in the backs of them with a hacksaw then i can use a screwdriver and the nice thing is these are easy to remove so i can take the two plates in and out a bunch of times while preparing for silver soldering so that's looking pretty good there's both two plates installed and the alignment on everything looks really good so i'm very happy with how that's turned out so far and this mandrel sure was the business as you can see it was absolutely essential for just about every single operation on these two plates so this was absolutely worth the effort to make there's the final two plates so was this faster than hammer forming the traditional way i don't honestly know because i've never hammer formed a tube plate but if you have experience doing it that way maybe you can watch this video and get a sense of whether this is faster or not i would say the mandrel took me a couple hours to make and then each tube plate took 30 or 45 minutes from there roll forming is certainly cool and the results are outstanding i think i would encourage you to give this a try if you're making boiler parts that are round and need flanges if you like these videos maybe consider throwing me a little support there on patreon if you can manage it that's what keeps these videos going thank you very much for watching and i will see you next time you

Channel: Blondihacks

Views: 133,008

Rating: 4.952096 out of 5

Keywords: blondihacks, machining, machinist, abom79, this old tony, vintage machinery, steam, making, maker, hacking, hacker, lathe, mill, woodworking, workshop, shop, model engineering, engineer, engineering, live steam, machine shop, metal lathe, vertical mill, metalworking, metal shop, diy, how to, do it yourself, do it yourself (hobby), mini mill, mini lathe, tutorial, keith appleton, boiler making, model steam boiler, model engineer, scale models, keith appleton steam, boiler making drawings

Id: HMc5UL8t1EY

Length: 26min 42sec (1602 seconds)

Published: Sat Jul 10 2021