Vertical Mill Tutorial 1 : The Basics

hello internet my name is Quinton and this is blondie axe welcome to mill skills this is a new series on getting started with the vertical mill behind me there and if you're new to machining I'm gonna go ahead and recommend you start with my lathe skills series because I think the lathe is the best place to get started in machining but if you've been using your lathe for a while and you want to bust into the world of vertical milling well this is a series for you okay let's dive in now just like on the lathe the most important mill skill is safety and that means safety glasses at all times that means short hair short sleeves no jewelry no dangly bits no rings no watches this just like the lathe is actively trying to murder you at all times deny it any opportunity to pull any part of you in and for goodness sake keep your hands clear this whole area when that machine is in operation it really really wants to hurt you don't let it wait a minute you can't fool me that ain't no mill or is it well that was our special effects budget for the season so I hope it was good for you so what am I doing here well I'm trying to make a point my point is that machine tools are all fundamentally the same now we call the way the queen of machine tools because frankly it can do everything and that's still true so why would you ever need a mill well I think the thing to keep in mind is that the lathe can do everything but all other machine tools are more or less optimizations for common things that take a long time to set up on the lathe so yes in theory you can make large flat things and cut bevels and do all the other things that you might ever want to do on a lathe however many of those operations are giant pains in the ass and so we have Mills the lay that remains the most flexible and the most cleverly designed machine tool it achieves a maximum precision with the fewest moving parts and with the simplest cutting tools and for all of those reasons and more the lathe is still the most generally useful machine tool and it remains the one that you should start with when you are getting interested in machining however let me just get down off the ceiling here and I'll show you what the mill is really all about so there it is a very typical hobbyist bench top vertical mill and note that word vertical there are other types of mills there are boring mills and horizontal mills and and embrace things but generally speaking when we use the word mill we're talking about a vertical mill and the hobbyist ones are all going to be some variation of this form factor you might say it's run of the mill so fundamentally a vertical mill is so named because the spindle is vertical and it's just like the lathe in the sense that you've got a spindle that can be precisely aligned relative to the workpiece now in this case the workpiece remains stationary and the cutting tool is spinning which is different than the lathe and the reversal of that relationship between what's spinning and what's stationary makes those setups easier on the lathe that we were talking about so things like creating large flat surfaces or creating specific angled cuts cutting slots that type of thing is much easier if the tool is spinning and the work is stationary more or less I mean of course the table moves but you know what I'm saying vertical Mills come in two basic types and the differentiator is how they manage to move the spindle vertically relative to the work this is a column mill which is what you'll pretty much always find in hobbyist benchtop machines and this guy moves the entire spindle up and down on a column in the back hence the name now a larger floor-standing machines are typically knee mills and they work by moving the entire table assembly upwards to meet the spindle and that lower assembly that moves is called a knee and knee males are generally more rigid because there's more surface area back there and more triangulation in the front to maintain parallelism with the dovetails so you know obviously that's going to be a better choice if you have space but for these hobbyist bench type machines the advantage of a column mill is that while it can sit on a bench and the bench doesn't have to move now wait a minute you might be thinking hey that looks an awful lot like a drill press and have a drill press and it was a lot cheaper than a vertical mill all I gotta get is one of those fancy XY table things put down here and I don't gotta buy no mill I'm a genius nobody has ever thought of this well here's the thing there are two key and therefore expensive differences between a vertical mill and a drill press first and foremost is the bearings drill presses are designed to apply cutting forces only downwards and what that means is that they use thrust bearings in here and they're not designed for any kind of side load and milling is really all about the side loads you're cutting sideways and so the bearings need to be designed to handle those types of loads and then the second reason is how the spindle is secured in here Mills and drill presses are similar in that they both use a taper to secure tooling in the spindle and in the case of a drill press it's typically a Morse taper but the key difference is that the drill press spindle is held in there only with a taper so tapers are very good at resisting forces along their length the harder you push on them the tighter they seat but they are not designed for sideways loads any kind of sideways load will actually just pop that taper right out of there so if you have ever tried to do any kind of side loading milling type operation on a drill press you learn this the hard way because your Chuck fell out so the key difference with a mill is that it has a drawbar so the drawbar and the bearings are the two things that make of a mill different than a drill press and also expensive I mean I'm oversimplifying their you know mills are also built much more rigid than a drill press and they have precise dovetails and table slides and things for moving the work in repeatable ways relative to the spindle and yadda yadda yadda but yeah those are the two Biggie's that's that separate drill press from a mill the bearings in a drawbar and I'm just throwing that word drawbar around like everybody knows what that is well let me explain this is a drawbar every mill is going to have something along this line and it might be manually operated one like this or big Mills might have a pneumatic or electrically operated drawbar but they all do the same thing grab our is a threaded rod that runs all the way through the spindle and it serves two main purposes first and foremost it threads into whatever Kaulitz or other tooling that you're using in your spindle and slide that guy up in there and then as you tighten the drawbar it pulls that guy in and when you tighten it all the way up what it does is it seats that taper in the spindle so that's job one and then job two is when you come to remove the tool it will actually also push down on that taper to pop it loose because if you've been using that tool in there for a while these guys can get pretty wedged in there and so the drawbar will also push it back out again so that drawbar keeps the taper from breaking loose under side loads and that's why you can mail on a melon you can only drill on a drill press now for a manual drawbar you'll need some sort of tool for tightening and loosening this guy and if yours is a typical hobby mill like this it probably came with a tool something like this guy now proper technique with this tool is very important step one and then make up something like this in this case this is a ten millimeter square drive so I have a 10 millimeter pipe plug socket on here on a socket wrench that lives on the bench next to the mill and life is very good wait a minute you can't fool me I've seen this guy on mills and that looks just like my drill press ergo still just a drill press well not quite so this is the quill and it's another way to move the spindle vertically it relative to the work and so you might be wondering well why is there a quill and also a column or an e for moving up and down what's the difference why does there two ways to do it fundamentally the quill is a trade-off between rigidity and machinist laziness or should I say convenience as you can see it's a very quick way to get lots of spindle travel but the trade-off is that the quill is much less rigid than the rest of the system so when it's extended like this your whole setup is less rigid so if you're doing aggressive cuts or types of milling operations where you need the most rigidity you want to keep this quill all the way up keep the coil locked and use your column or your knee to get your vertical travel so what good is the quill well there are lots of operations that you might do that don't require maximum rigidity so if you're taking light passes or if you're milling aluminum or for example drilling just like on the drill press the quill is great for all of those and the fact of the matter is moving the knee or the column for all of your vertical travel is a ton more work so typically you're going to use the coil as much as you feel like you can get away with now a key difference though on the quill from a drill press is that there will typically be a course feed and then also a fine feed of some sort in this case there's a warm drive here on the front and this is very important for getting accurate depths of cut and in this case there's a Dro on this coil so you can see exactly what kind of depth you're getting and then typically the fine feed will be some sort of warm drive so it has zero or minimal backlash in it which is also very helpful so people new to the vertical mill often wonder a wall okay what's the right mix then of quill and column or knee usage how do I use each one and when well for most milling operations generally what you want to do is get your column or your knee kind of in the ballpark of where your cut is going to be you know maybe give yourself enough room to get the cutter in and out and do your cutting generally with the quill mostly retracted and then as you do each pass you know you're going to drop it down 20 30 40 50 thousand so whatever that depth change that you're doing on your different passes you can do that with the quill and if you're milling just to make sure to lock the quill with each pass just to get the most rigidity out of it that you can but even with the quill the most precious resource on any vertical mill is your vertical real estate there never seems to be quite enough space in here and so the quill will give you you know two or three inches of wiggle room on your travel but like it or not you're going to end up moving the column or the knee up and down quite a bit and on a hobbyist column mill that means you're gonna be reaching back here for this column crank quite a bit your right shoulder is going to get buff so just get used to that so the mill itself just has a spindle and the service it provides is to spin that spindle at whatever your desired rpm is with good rigidity against lateral loads everything below here is your problem okay so speaking of milling cutters though how do we actually hold them in here all we've got is an empty taper now I know this seems reasonable but it doesn't actually work as well you think so any tooling you put in here needs to have a taper on it that matches your mill so a very common way to put stuff in there is gonna be a collet alright so holding our milling cutter in a collet is very simple that call it in there and tighten down the drawbar if you wondered why fancy Mills always have pneumatic and or electric draw bars this is why because you spend a lot of time doing this and then once your call it is kind of all the way in there you'll feel it kind of seat on the tape or a little bit and then you can go ahead and insert your milling cutter and then tighten that guy down like so and then give it the final snug with your spanner and you're ready to mill now different mills have different tapers in their spindles but there are a couple of very common ones the most common is the r8 like this guy and you'll find this on the vast majority of mills but some larger machines or like horizontal mills will use a 40 taper or 50 taper so there there are other common ones as well but something like an r8 is is going to serve you really well and of course you have to make sure you're getting Kaulitz that match your spindle taper and they have to have a drawbar in the back now the drawbar threads themselves are standardized to the taper dimensions you don't have to worry about that matching but the key difference with spindle call it's like this guy is that they have a place for the drawbar there's there's no through-hole compared to like a 5c collet for example which has a hole all the way through and can hold stock so don't confuse your mill spindle collets with general work holding collets now there are other options for holding milling cutters one of them is an end mill holder which will have a taper that goes in there and will make use of this flat spot on the end mill for a set screw and that will give you a more secure hold for you know very large end mills but on a small hobbyist machine like this you're really never gonna need that and mill holders are expensive and I've never had any trouble using I call it so call it through your friend for the hobbyist shop now other types of tooling might use Ann Arbor such as this Big Shell mill you'll also see this with face mills and another larger tooling and as this guy will have the taper built into it like this and it have a place for your drawbar to thread in and then your cutter or whatever will thread onto the end of the arbor so this whole assembly slides into your spindle and find that key again and then once again tighten that up and away you go and once again to get this guy out you are likely going to have to push down with the drawbar to pop that taper and then there's our old friend the Jacobs Chuck which is as useful in the mill as it is in the drill press and similar to the arbor it's got its own shaft here with the matching taper and a place for that drawbar to thread in and that guy slides in there just like the arbor did find the key and then tighten that guy up and the Jacobs Chuck is where you really start to feel that vertical real estate so you can imagine trying to get your workpiece in here and also a room for a drill and we're running out of space pretty darn quick so with the Jacobs Chuck I'm a small hobbyist mill you're generally gonna have to crank this guy up as high as it'll go and then that leaves you room with your quill to do your drilling operations and what-have-you so yeah vertical real estate very precious now at this point you might be thinking hey I don't need all that fancy tooling for holding end mills this here Jacobs Chuck is designed to hold these guys and these look an awful lot like these guys so what if I just grabbed machine is no cookie okay so what's the straight dope on putting an end mill in a Jacob's Chuck why can't you do it there's a bunch of reasons first is hardness now while these guys are both high speed steel assuming this is a quality drill the the end mill actually is much much harder than the drill and Jacobs Chuck jaws are also very very hard so it's kind of like two pieces of glass trying to grip against each other you're gonna get a very poor grip on the shank of an end mill with Jacobs Chuck jaws second reason is lateral loads Jacobs chucks are designed for drills and so they're only designed for upward forces on them lateral loads on these little jaws would make them very sad you know what said Jacobs Chuck jaws and even if all that wasn't reason enough the other is frankly just rigidity Jacobs chucks are not as rigid as other types of tool holding and look at all this length it's adding to the end of your spindle imagine this end mill way down here and lateral loads down here you're losing a ton of rigidity so you would never want a side loaded cutter this far from your spindle in any case old machinists tell tales of the greatest machinist who ever lived and she was so because she had three hands there are many operations in machining that really seemed to require them and removing your milling cutter is one of those here's the problem if I go ahead and loosen the drawbar right now I've got one hand on the drawbar wrench I've got one hand on my spanner wrench and well what's gonna happen the milling cutter is just going to fall right out of there it's gonna damage the work it's gonna chip the cutter chaos ensues cats and dogs living together so when you're first starting out just go ahead and put a board or something down there to protect it just in case the cutter does fall out of there but there is a technique to avoid needing a third hand here just put your spanner wrench on there just kind of put a finger on that milling cutter keep it from falling and then loosen up your drawbar and then when you just break that drawbar loose the milling cutter won't actually fall the collet is still holding it so then what you can do is just grab the milling cutter and the spindle with your hands and then loosen it all the way the rest of the way and in fact you can see it still doesn't actually want to fall because they call it hasn't been popped off of that taper yet so there's going to be a point right here where it pops the taper and now you can take the cutter out so this technique takes a little bit of practice but it'll save you a ton of time and you won't drop milling cutters on your work and of course I can't leave you without talking about the table much like the lathe there's a stack of slides here and in this case they move the work relative to the spindle instead of the lathe where you're moving the tool bit relative to the work but it works much the same way there's gibs and locks on each slide for those times when you need extra precision or extra rigidity and there are markings on the crank for measuring your travel and then there's also a moveable caller so you can zero these guys out now also like the lathe is some bad news and that's of course backlash any mechanical system has backlash in it and the mill table is no different and like the lathe this is not a sign of poor quality this is just physics now unlike the lathe however backlash is a real pain in the butt on the mill because on the lathe it doesn't really affect you that much you know you're only generally moving in one direction during a and it's very easy to simply get into the habit of winding out wanting back in before you start a new cut it's really not that big a deal it's just a little bit of muscle memory the mill however you are often doing cutting operations in multiple directions and every time you change direction of course now you're into backlash town population you and all of your markings are now meaningless so if you're gonna go old school I applaud you but you will have to get very comfortable with backlash and understand how to compensate for it especially when milling things like squares or when you're milling back and forth but wait there's a better way it's called the digital readout or Dro now these guys are a real luxury item for a lathe but I honestly believe that for the mill these guys should not be considered optional equipment and the old-timers are gonna laugh at me for needing a dro but honestly these guys are transformative for your quality of life on the mill now fundamentally it's just like having hand wheels with no backlash in them and that's great and that's frankly enough value on its own but it also gives you all kinds of other powers that lets you find centers and you can make bolt circles and you have multiple coordinate systems for different fixtures and for measuring travel without losing the origin of your part you know all these sorts of things I would honestly consider the Dro required equipment on a vertical mill and you know with these Asian import Dr OHS they're really quite inexpensive and it is absolutely worth your money plus if like me you're working on English as a second language the manuals for these things are great exercise for example to clear 200 sets STM datum in ABS mode to continuously press the key ten times will cause to clear all the damn for 200 sets STM I understand thanks manual and while we're on the subject of spending more money than you want to the other area that I think is worth splurging on is the vise everything you do on this machine is only as precise as this vise and buying a high-quality vise is really going to make your enjoyment of the machine a whole lot greater and so yeah it's it's really worth spending as much as you feel comfortable on this guy but when choosing a vise do be mindful of this vertical real estate once again for example don't be like me and get seduced by these swivel bases on vices this thing seemed really great I'll be able to do angles and you know not have to reset my advice all the time but yeah this thing lasted about a year before I got rid of it and it was one of the best things I did because this extra couple of inches of height that it takes up makes all the difference with longer drills and some of those other operations when you you just need another little bit of extra space so yeah I think twice about this guy and finally if there's any way to fit it into your budget do definitely also consider a power feed you will spend a lot of time cranking that x-axis back and forth and this guy especially a model that has Rapids will save you a whole lot of tiresome cranking but this is also something you can typically buy later and add it once you get tired of cranking in my case I think I lasted about two months before I splurged on the power feed so those are the basics of the vertical mill now of course there's a ton more to learn about we're holding fixed during different types of cutters and so on but we will be getting into all of that in later videos in the mill skills series so thank you very much for watching and we will see you next time you

Channel: Blondihacks

Views: 152,091

Rating: 4.9541469 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

Id: FyuG-B95PQs

Length: 21min 18sec (1278 seconds)

Published: Sat Jul 06 2019