Metal Lathe Tutorial 1 : Theory

hello Internet my name is Quinn and this is blondie axe this is lathe skills a series of quick videos on getting started in machining this is episode number one theory if you like this content please subscribe to me on patreon I post exclusive video to that feed of all of my projects and we would really appreciate your support alright let's dive in we're gonna start with the most important thing in the shop and that's safety rule number one safety glasses don't set foot in the shop without them rule number two no dangly bits that means short sleeves short hair no gloves no jewelry machine tools are actively trying to murder you at all times deny them the ability to grab you and pull you in they'll mangle you so fast you won't know what happened in rule number three is Chuck keep discipline this Chuck key should only ever live in two places in your hand in the chucks or in its home it's home might be a holder on the machine in my case in my apron what you don't ever do is you leave it in this Chuck this Chuck key sitting in the check is now a missile and when you least expect it it will embed it in the far wall of your shop by passing through your face don't want that to happen so habit develop Chuck key discipline make it a habit that you put that Chuck key away after every single time you use it you don't ever set it on a bench you know put it over here sometimes it's in your hand or it's in its helm here's our work envelope now the core principle of a lathe of course is that it spins a material and the cutting tools remain stationary and the value of that is that it minimizes the amount of motion that's required of the tool relative to the part to give you flexibility in within the work envelope now what a what a machine tools job is essentially to do is to hold the work square relative to the tool and allow you to move that tool square so the ways here and the Chuck and the cross slide are all square to each other so that when you make cuts in this piece you know that they are square and it's a simple concept but it's it's the magic that makes that makes machining possible so lathes are what's known as a single point cutting tool which means that the cutting is actually done by tiny little point on the end of the cutting tool and so in order to make cuts of surface to reduce the diameter of a part or to flatten the end of something this this part has to move all the way across because it's only cutting in a tiny little area at a time and the value of that is that it minimizes tool pressure because there's only a tiny little area that's being cut at a time the machine has a lot less work to do and so you can get very precise and rapid machining with a relatively small and light machine so the other core principle of a machine tool is rigidity everything is a spring and that's especially true in machining when when the tool is acting on our material you know imagine this material material is spinning this material wants to drive down the end of this cutting tool it's trying to push it down and the cutting tool is trying to resist and the tool post is trying to resist the motion of that cutting tool and the cross slide is trying to resist the motion of that of that tool post and in the ways is trying to resist the twisting of this carriage all these parts are all Springs and they're all resisting that that motion and so the more mass and the more precisely made all these parts are the more rigid the whole system is and the more precise your cuts will be and thus the easier it will be to hit dimensions the more aggressive cuts you can take and of course the finer your surface finishes will be so a machine tool is very much about mass and so that's why the larger machine you have the better the more cast-iron that's in it the better and last but not least we'll take a look at the controls this is pretty standard for what's typically a standard metal lathe now it's sort of often technically referred to as an engine lathe or used to be called a screw cutting lathe screw cutting lathe basically meaning that there's a lead screw that is synchronized to the drive in the lathe which means that it can advance the carriage in time with the turning of the part for cutting threads and then an engine lathe typically means that the carriage can be automatically advanced a power feed so you're always going to have your carriage hand wheel here and you're going to have a cross light hand wheel here and then this here is your compound and the compound can be adjusted to different angles for taper cuts or threading operations things like that and then of course the tool post up here in addition to that you may have your power feed here it's the power feed clutch this slave has longitudinal and cross power feeds so it's got a different set of positions here for that and then this over here is your half nut which is a rigid engagement of the carriage to the lead screw which is used for threading operations and then you can't quite see it in the picture here but there's the threading dial over here as well which is also used for thread cutting some usually the basic controls you're gonna have on every lathe larger more complicated machines will have other bells and whistles but using the basics and these are what we're going to use and then the last thing you're likely to encounter is something along these lines this is a quick-change gearbox many machines have some variation on this but the general idea is that it's a transmission that allows you to change the speed relationship between the drive and the lead screw so in normal turning operations this allows you to change the power feed rate and when your screw cutting this is often involved in setting the thread pitch and then this here is a feed direction change which not all lathes have but this allows you to power feed in both directions or then there's also a neutral position for disabling the power feed and of course here's the speed control often older lathes or less expensive lathes will have only what are called change gears for the speed in which case there's a set of gears behind a cover and you manually swap up the gears out to change the feed of the power of the power feed which is a lot more tedious but it certainly can be done and often older lathes will have a cone pulley with a belt system for changing the speeds this machine is a brushless DC motor with a digital speed controller so it's got a very handy speed control knob here with a an RPM display there that'll do it for lesson number one the theory of the lathe so tune in next time and we will talk about using the machine and we'll start looking at maybe making some chips thanks for watching and please do subscribe and support us on patreon for exclusive behind-the-scenes video content of blondie annex projects you

Channel: Blondihacks

Views: 132,931

Rating: 4.9554291 out of 5

Keywords: blondihacks, machining, machinist, steam, electronics, making, maker, hacking, hacker, lathe, mill, woodworking, workshop, shop, model engineering, engineer, engineering, live steam, machine shop

Id: H6Dnmd3lDzA

Length: 7min 22sec (442 seconds)

Published: Sat Sep 29 2018