Homemade - Boring Head

ah did you see that Adam Adam you paying attention let me show you that again parking attachment now what's guns like these hey welcome back oppa chair I thought I'd build a bit more compact version of one of these classic boring heads then maybe more suited to the size of work that I do and the size of the machine that I have and perhaps of all goes well a little bit higher quality now I'll be honest I've never really had any problems with these import boring heads the real problems really come in with the boring bars themselves and I thought I'd get into these boring bars a little bit specifically these import sets that you see back there I'm sure we've all got a set tucked away somewhere if you've tried to use these as is right out of the box depending on how lucky or unlucky you got you may already be aware of how frustrating they are to get a good cut and good finish but as fate would have it I stumbled across a video by a fellow named Locke cracker let me write this down for you who basically beat me to it you may have won this round Locke cracker but I think he did a really good job on explaining some of the issues one runs into with these types of boring bars these quality of boring bars I'll put a link to that video down in the description so this video will probably mostly be a build video building a boring head making some decisions probably making some of our own tools and just all-in-all goofing around in the garage so there are a couple things I'd like to do different first I'd like to make this as I mentioned much more compact there's a lot of wasted space in here so there's probably an inch and inch and a half of space in here I can recover which gets me back some Z height in the milling machine which is always welcomed while we're looking at this side I'd also like to make a larger dial this is to hundreds of a millimeter per division I think if I make this dial twice as large I could get more divisions on there and hopefully a finer resolution hopefully twice that 1/100 it will be a metric boring head the mill is metric but it doesn't really matter let me sketch out I think what have in mind here more or less something like that I don't have exact dimensions just yet I think I'll just sort of make them up as I go along see what looks right and more or less spit ball it for now on second thought you know what forget about the sketches you know might be easier to just show you what the new boring head looked like side by side with the old one so give me just a moment I'm going to time travel about two weeks in the future and bring back the new boring head this is one of those operations you really don't want to screw up tapers tapping thumbscrews tin time-travel really be careful not to time-travel in metric fifteen hundred years is just one tumblr position away from two weeks make sure we're going in the right direction alright I found it and a snack this thing was rotten in the future and here it's good as new alright man I'll never get used to that I'm a little surprised with myself it looks like it turns out a little bit better than I expected I think those engravings could use some work though I'm looking forward to seeing how I actually did that anyway it's smaller it's much shorter I get about an inch and a quarter maybe back in overall clearance in the mill body diameter is smaller and alright there's a lot more divisions on there and there they actually look legible that chicken scratch at the top I think is meant to say 0.01 millimeters you know I'm not sure if this move is legal but since I've got this I think I'm just going to break it down and take the dimensions off of it that way I'm not spitballing and hopefully the show goes smoother forty millimeter body and millimeter tools m4s on the locking screws 20 millimeter dial eight millimeter thread four millimeter Gib screws that's curious I was going to make those three millimeters alright sweet I think I got what I need I best get this back to the future before I cause some problems so have some more chromoly here looks like I'll need a 40 millimeter piece and then about a hundred and ten should do it that'll be 44 moving head and 110 for the body I know you folks get a kick out of all the metal cutting shenanigans but uh I don't know if I have it in me this time I'm just gonna walk this over to the saw and cut it off like a normal person what are the odds so just like every other great story in history ours is going to start off at the lathe I've got the hundred ten millimeter blank this is going to be sort of the body of the boring head with the integrated Arbor if you watched my mill tooling video that the first steps here will be essentially the same dimensions at this point aren't super critical and that we can sort of to some extent make them up as we go along but concentricity is going to be a big one here you wouldn't want your boring head all off-center wait that didn't come out right last time I came across this chromoly I had some trouble with chip control so I'm going to give it a go with a positive rake insert this I think is a dnm G like six or an eight size millimeter like quarter-inch it'll be spinning at 1,200 rpms and I'll mess with the feed rate and see what effect that has on the chips so the chips look a lot better than before I mean they're not long and stringy but I think that insert is under sized for the depth of cut I'd like to take and it sounds terrible when I push it pretty deep back to the Trigon I'm probably have to deal with some strings I just don't want this to take all day all right so it's about a foul over finished dimension that's still pretty hot though my money's on it coming right into size once it's cooled down so this side now is the actual body of the boring head I don't have too much take off this side so I'm back to the smaller positive rake insert I'll turn the body size down leaving a bit of a flange for the eye so taper and I'll probably leave at 1/10 hour so for a finished cut that I'll do last when I have the fixed part and the sliding part of the boring head put together by the way if you don't have a lathe file I strongly suggest you try one out you have a look at the difference between this and sort of your standard file this is my beater lathe file I don't know if you can see the pattern on there hold on a minute I hope you can see the difference now cutting with a lathe file is just an absolute dream relatively speaking the angle of these teeth are cut result in a much more smooth shearing action compared to somewhat of a bulldozing action you know these teeth are almost perpendicular to the length of the file lathe files also tend to hold up a lot longer you can see how you know the grooves that I've sort of permanently cut into this this lathe file also happens to have two safe edges meaning there's no teeth here compare that to here or the other side so there's less of a risk of you know marring or scuffing up already finished surfaces there's one thing to take away from this video I'd say it'd be to buy good quality files well I guess two things hold on time travel is dangerous and buy good quality files you want to get a good file and a few file cards just to keep around keep them nice and clean I keep my file card in my wallet I used to be a big Nicholson fan but I'm not quite sure what happened to their files I know three four or five years ago not what they used to be so they look for older Nicholson files this one happens to be a Heller there are a few things as frustrating as trying to do file work with a bad file may be slow internet all right there's the blank they go over to the mill first thing I'd like to do here is cut in the dovetail something a little bit like that maybe a little bit straighter problem is I don't have a dovetail cutter small enough to really get in there so I think what I'm going to do is sacrifice one of these import boring bars now I know some of you might be thinking that's a heavy price to pay now the angle this dovetail isn't important because I'm making both the male and the female side as long as they match that should be fine now since the boring head is a little bit on the small side I prefer a larger dovetail angle I mean probably almost like 70 degrees or so but again it's not important I'm just going to let sort of the material here dictate how far I can get somewhere between the 60 to 70 range should be fine this rest was made for I think a three quarter inch wheel the wheel is one-inch so I'm gonna have to close this chasm otherwise it might suck the tool right down into it not sure if you can see that it's about 65 degrees should be fine for what I'm doing now that was more or less the easy part the trick now is actually making this thing cut maybe I can show you over on the service plate I'll just set this on a V block and we'll take sort of a dead-on view I'm just going to use my surface gauge here to kind of square up the top of that carbide now you're not going to see it but I'm going to pick up the OD of the tool and then drop down half the diameter bring that back up front you can see how much higher the carbide is from the centerline of the tool I mean the rake on a tool like this I mean have a look at that it's so far past negative it's defeatist now I'm not going to get into the details here like I mentioned earlier lock cracker did a great video on it but basically what we need to do to this tool is grind at the top of that hole insert down until we're on center line basically cut off everything from the tip of that surface gage up and that would give us essentially like a neutral rake tool actually give it a shot at cutting what I like to do though since that seems like a lot of carbide to take off is just roll the tool so the tip is about where we want it and take all the carbide from that tip on back so sort of cut off that wedge shape this poor geometry is the reason why so many people recommend against these boring bars so the tool looks like it's starting to come in pretty good last step is to just sort of hone these edges a bit now you could give this a few licks with a diamond lap a diamond hone but I've got one of these Cup wheels on a bench grinder and it seems like it does a pretty good job I polished all three surfaces that sort of make up the cutting edges while I was there I also took a opportunity to knock a very small round on that corner the top faces at or slightly below center line and the other two faces have a bit of rake we're sent to scale this thing is ten millimeters about 3/8 of an inch and what I usually do is take my best guess like this start to make some cuts within it if I don't like it just sort of tweak some of those angles a bit so I've already centered the work in X&Y I'm just about to set the Z height I'm just using a slip of paper here this is about 4000 meter this dovetails going to be about five millimeters deep and sort of that the top is going to be 14 millimeters I think the exact size here isn't really written in stone any deviation notice I didn't say mistakes any deviation from the dovetail size I want in this part I can just make up for in the mating part anyway it's a 10 millimeter to flue 10 mil about 3/8 and be cutting two millimeters deep 600 rpm I'll do that in two passes and it'll leave me a little bit of material at the bottom for the dovetail cutter to clean up well here goes nothing with the dovetail cutter now I just want to really clean up this top surface this top surface is essentially the bearing surface between the moving part and the fixed part when the dovetails are locked they'll sort of pull that moving part down and lock it against the surface will be clearance inside of the dovetail itself now I think it's best if this top surface is smooth as possible just so the adjustments are nice and fluid that said I don't believe it's necessary to do it on the surface grinder in fact I think I'm taking some risk having moved it from the mill from the mill vise to the surface grinder but I think I trust the mill vise and this mag Chuck enough to feel confident that this will work out alright this could have been maybe fly cut on the milling machine or chucked back in the lathe and just faced off with a very fine feed or heck I mean it's not very much material at all it could be stoned by hand the way the clamp is set up it's biasing it back into the corner and I've got the collar here that acts as a vertical stop all right so it's 175 and 23 198 I'm going to call that five millimeters and good enough I'm starting to get the feeling that this video is going to be a long one button the famous words of Benjamin Franklin never put off till part two that would she crammed into part one you know I floundered a bit as to what to do next there's still quite a bit to do on the fixed side of boring head of course and there's no real critical order of operations at least that have dawned on me so far but since I started off with the dovetail I thought I might see that through I did decide to make another smaller blank for the movable part of the boring head the movable part isn't very tall but I figured it was probably worth taking the diameter down now instead of putting a lot of work into this and then having trouble holding on to it you you now I don't always measure dovetails but when I do so let's talk about actually having a shot at getting these dovetails to match as usual you'll need a couple of pins about the right size for your dovetails and again right size look something like that they'll want to make contact about halfway up that dovetail now I recommend you use a couple of pins with some light surface pitting if you use brand new pins and your dovetails turn out sloppy you'll have no one to blame but yourself drop the pins in make sure anythink nice and clean and try to do a good job taking that inside measurement and use a couple of gage blocks pick up that inside measurement this now gives us our baseline nominal to cut the male dovetail to then as you're cutting the matching key dovetail you can occasionally drop these pins over and take that measurement when you're measuring the outside like this you'll want to add two more pin diameters because you've moved from an inside measurement to an outside measurement but if you sketch it out on paper what you're trying to measure with the dowel pins and everything in there it'll become obvious now we can go back to the mill and start to build in sort of that hybrid Gib / dovetail now hold on just a minute pardon this interruption I wanted to show you something would you just look at that color match I mean you couldn't do that if you tried really Switzerland you I was a little concerned about the size of the m3 screws but they're doing a excellent job of locking his head down I've set them in firmly not excessive and that the head just isn't budging I'm really happy with that lock though to get that feel just right I did come in and cut a little bit more of a relief on the inside of that dovetail I undercut about another six teeth out millimeters and a half approximately I just thinned up that little area there without it I could get it to lock but I was little it seemed a little excessive the force I needed to put on this very small allen wrench it was sort of borderline will I strip the screw or will I strip the wrench but just that little bit of added relief seems to have made a world of difference I think I can now start adding some features to the moving part of the head I'll bore this and start taking the size you you I didn't go all the way through with those I wanted to leave a solid face on one end for a center my next step is to take an intermediate sort of finish pass the second to the last if you will so I can get both parts nice and concentric and set back up in the mill not really impressed with how this surface finish turned out but I think and clean that up these scallops I think are more or less cosmetic if you saw the clamp and you're wondering what that was about it was just to help the set screws keep that mobile piece in place the dovetail is very strong left to right and up and down but the only thing keeping it from sliding are the set screws so the clamp was just bridging this the dovetail gap just in case this setup had the funny idea of gone south all right so almost there you saw me drill the cross hole drill and tap the holes to lock the boring bar in it's 90 percent there it just needs a couple of features on the inside to interface with the adjustment screw but before I bore for that adjustment screw I'd like to make the final pass on the OD not that it's terribly critical all right that works for me you saw me indicate the dovetail vertical it's important that this the threaded adjustment hole is parallel to that otherwise you potentially risk binding in the screw I spot faced center drilled went in with a small drill bit all the way through then took it to size which in this case is 7 millimeters for an eight millimeter tap and now I need a 20 millimeter hole about halfway down halfway through the thickness of this head that's where the adjustment screw will travel I'm up to 14 millimeters now and I'm just about to break this wall I'd rather not risk this with a drill so I've switched over to you can just make it out in the frame here that's an 18 millimeter end mill it happens to be a rougher but it's not important in this case after the 18 I'm going to follow it with a 19 I want to get to 20 but I don't have a 20 millimeter diameter anything to finish this hole up with so we'll have to bore that out all right so far so good left 2:19 I need to get it to 20 now the boring head that I have isn't really the best boring head in the world especially in a situation like this from using a very small low-quality tool to get inside of a small bore and spinning it at you know relatively high speed adjustments aren't super smooth and again by the time I grind that down so that it actually cuts I guess it's just a little bit of a gamble on how well that finish will turn out on the inside I could sneak up on the size but I wouldn't expect it to be mirror finish in there and this is exactly why building the small drawing it it would be ideal here with a nice carbide inserted boring bar oh hey you know what I know just where to get one all right now we're talking all right well I don't know what you folks think but from where I'm standing that looks pretty nice all right I should probably hurry up and get this thing back oh boy that can't be good holy smokes that was a bear to tap that's an eight millimeter by one millimeter pitch tapped about an inch deep 25 millimeters is chromoly is some tough stuff all right well things are just getting out of control and I had to stop and deeper this thing if this thing nicked scratched or cut me just one more time I mean it passed out from the blood loss this dove tail just claimed another quarter pound of flesh out of my thumb sorry if I was disgusting but I just managed to stop crying like a little baby long enough to pick up this video again and there's absolutely no shame in crying you just think of the alternative do you really forever want to be known as that guy they found dead in his garage wearing an apron I'm using mostly this little slip stone though these old very fine drifters are coming in handy for some of the tougher to reach areas like in this slot for example there's not really a lot of other ways to get in here carefully and these small curved files do a nice job I've got the boring head mounted in the small four jaw Chuck its centered and I'm happy with how its run the tops line is set up to cut that taper and my top slide power feed is charged and ready to go I've also turned down the end and tapped for the draw bar really the only thing left here is the taper I sure hope that's the only thing left at any rate once I cut this taper I really don't have any good way to hold on to this part anymore last up is that adjustment screw once I have that adjustment screw I think I can cut the key the slot in the mobile part of the boring head put it together and try it out so although the m3 set screws were doing just fine clamping the moving part of the head future me was right I don't have ball bearings small enough to fit in that m3 hole so m4 it is slight change of plans I think I'm going to go ahead and cut the slot in the moving side of the boring head first I think it'll be easier to match the screw that I've yet to make to whatever dimensions I end up with here rather than the other way around no real difference just a matter of preference I'm holding the moving part of the head in the vise with the two dowel pins are used to measure the dovetail that's in there pretty solid but just to play it safe I'm using the vise stop to just provide some backup I'll be cutting the slot with a wood roof cutter I made the wood roof cutter out of one of these old bolts just a couple of licks on the bench grinder and we're good to go back at the lead and I've started working on the adjustment screw I've chucked a piece of bronze up in the three jaw and gave it some tailstock support if you don't have a three jaw Chuck you just make one out of an old hydraulic jack give it a couple licks on the bench grinder keep from born the pants off anyone who might be watching this video wearing pants I've already roughed this piece of bronze down so that's eight millimeter blank to accept the threads on the left will be the dial face and in the center is the ring that will drive the movable part of the jaw the moveable head mates up right there so as you turn the screw it will drive the head off center now if only I could find my small thread cutting tool I cut this thread threads have fits just like chefs and bores do the reason I decided to thread cut this instead of chasing it out with a die is that I have a lot more control over the fit between the male and the female thread because I cut the thread in the boring head with a tap that's sort of you sort of get what whatever you get from the tap they're right here I have more control in the diameter to make sure I get the fit that I like in order to hold on to this now so I can work in basically the dial face I drilled and tapped a piece of just aluminum cut off for the same thread and then split it lengthwise with a hacksaw it just screws on and gives me something to clamp on to both here for finishing the face and then later on the CNC to do the engravings I'd like to slightly crown the face and although you could do this with just a hand file maybe a ball turner if you have one that can get in that close I happen to have a form tool that's 40 millimeters this will help me out on the CNC because I have now a known radius that I can engrave on to just hope this thing still cuts I plan to cut the hex socket on the CNC router before I do that I'd like to rough out as much that material as I can just because the bit that's going to be in there is so darn small this might give me a bit more of a fighting chance I'm going to drill out the six corners and then Center drill you know the inscribed circle of the hex which is four millimeters in this case my apologies for not getting a wider shot here but we're now on the CNC set up to engrave the divisions the plan is to do a hundred divisions on that 20 millimeter face I'm cutting a few millimeters above the surface and eyeballing the gap to check if it's consistent which it wasn't the engraving is so shallow that even a few thousand C and my surface would have ruined the whole show now I fought with this for a while and finally gave up and just milled the top surface in for a perfect match and the surface finish was much better than I expected I am also flattening it out a bit dropping the centre down I'd like to 3d chamfer the bore this fits in and a flatter dial I think will look much better and here's the money shot you know there's something special about CNC that reminds me of the simpler times I hit the start button and I'm magically transported into one of those black-and-white Laurel and Hardy movies where I'm in a car going way too fast down a hill in San Francisco and the steering wheel just comes right off in my hands anyway this is the first time I've done any engraving on the CNC and I'm pleasantly surprised with how well it's turned out the v-bit here is homemade and by the looks of it it could have been sharper it's pushing up a bit of a burr the last step here was to mill the hex came out right to size but the rounds in the corners are still a bit large for a proper key fit I'll have to approach those maybe well I suppose nothing left to do then put this together I really didn't want to cut down this nice little boring bar but I suppose if future me did it I don't have much of a choice do I all right well I think that's it this is usually the part where I show you how this thing works but technically I think I already have it board its own countersink for the adjustment screw anyway a bit of a long one but I hope you like that thanks for watching

Channel: This Old Tony

Views: 2,263,797

Keywords: boring, boring head, milling machine, boring on the milling machine, boring on the mill, dovetail cutter, diy dovetail cutter, cutting dovetails, lathe, cutting tapers

Id: 7ngNtK9tKME

Length: 35min 58sec (2158 seconds)

Published: Fri Jun 10 2016

Reddit Comments

[u/p2p_editor]

Nice work, and excellently done humorous touches to the video. I don't know why this guy doesn't have way more subscribers...

[u/sjhaakie]

man, i really like this guy