Metal Lathe Tutorial 11 : How To Buy And Use Indicators

hello Internet mmm my name is Quintin and this is blondie hacks this is late skills a series of quick videos on getting started in machining this is episode 11 indicators this is a topic that's often confusing for beginners there's a lot of terminology that overlaps so I hope I can clear that up for you in ten minutes if you like my content please consider supporting me on patreon where I post exclusive project videos and 3d models engineering drawings lots of cool stuff okay let's dive in dial indicators come in a lot of different forms but they fall into two major categories and this is often confusing for beginners because the names are very similar these guys are dial indicators and these guys are dial test indicators these guys are typically for measuring larger distances and I'll test indicators are for doing very fine work measuring surface finishes alignment of vices things like that however they both work the same way they are a clockwork mechanism internally but with no escapement so the linear motion of the plunger is translated into rotary motion of the needles at different scales by a complex series of gears internally so starting with them more commonly used dial indicator these guys measure fairly large distances by machinists standards woodworkers can turn away now so this is a standard one-inch plunger and you can see that it's measuring on two dials there's the large hand and a small hand much like a clock so the large hand is measuring the finest increments which on this guy are thousands and this is going to be indicated right there on the dial so you know what these divisions are and then the larger scale is going to be measured with the smaller hand much like a clock again and since this is a one inch travel you can see our one inch it's broken down into tenths there so you can see how those guys will count all the way up to an inch now much like the hand wheels on machine tool the indicator is giving you relative distance but they all have this dial on here that you can move and that allows you to set a zero anywhere you want so whatever you are measuring you can push this plunger up against at some arbitrary amount which we call the preload and from there you can set your zero and now suddenly you have an absolute measurement okay great so we have a really precise way to measure one inch of distance well what use is that really it turns out quite a lot you can use it to for example measure concentricity you can use it to measure squareness on a surface plate you can use it to cancel out cosine error and your compound one signal point single-point threading you can use it to calibrate other measuring instruments you can use it as a stop one turn into a shoulder on the lathe so there are infinite uses frankly for a dial indicator and you know you really can't do precision work without them in fact the more you get into machining the more you will find you never have enough of them now your dial test indicator is a slightly different beast they typically measure horizontally with a pivoting arm rather than a plunger and they are typically much much higher precision the large numbers are still thousands but the tick marks each of those ticks is a half thousandth as indicated right there so you'll use this guy in really high precision applications like finding surface imperfections or measuring squareness on a surface plate or indicating an advice on a mill those types of things okay so let's look at how we actually use an indicator much like machining with indicators setup is half the battle so whatever you're doing with your indicators you're going to need a way to hold it in some very specific usually inconvenient position to get the reading that you need so to that end you typically are going to use an indicator armed with an indicator and there these come in a lot of types but typically they have a magnetic base and this is the much-beloved Nova arm which is has a single knob and so you can position this arm in any position and then simply tighten that knob down it's hard to overstate how convenient these guys are and I would honestly consider a mag based Nova arm to be a required piece of equipment for any beginning machinist the mag base itself deserves a little extra attention because they're pretty wonderful as you can see it's a magnet that you can turn on and off and it's a permanent magnet there's no power so how does it do that you might think oh well it's just moving the magnet further away from the surface so it can release not what's happening there's actually a specially shaped block of aluminum inside the space and in special shapes aluminum can cancel out magnetic fields and that's really important because you would think magnets are useful in machining because there's a lot of iron steel everywhere but in fact magnets are the bane of the machinist because they collect chips and once you get chip stuck on things you'll never get them clean again so this guy allows it to be magnetic in the machining environment without attracting any chips because once this is in the off position this has no magnetic field in any direction so this that's why the meg base is kind of the only place that you really see magnets in use and this design is really really remarkable dial indicators typically have a lot of ways to attach them to things there's often a log on the back for a bolt and there's often in these little dovetails which for example fit into this Nova arm and that's a very convenient way often to quickly attach them and remove them and on the style test indicator we've also got a long dovetail here we've got another one up here and there's also a precision ground shaft on there now this guy can also attach to the Noga arm there but because it's a precision ground shaft we can put this in kaulitz on the mill or all sorts of other precision fixtures so this shaft here is often the most used form of attachment for the dial test indicator when you're first starting out you can do everything you need with one of these adjustable Nova arms however as you get deeper into machine and you're going to want to start optimizing your processes to get more efficient and that means customizing indicator mounts for specific situations and one of your best friends in that regard is the 3d printer but you can also make these types of fixtures in various other ways you can make them out of wood even you could make them on a mill however you like but the idea is that these are quick to install for a very specific task that you do a lot so this guy for example fits on a quick-change tool post and I will link this on my patreon so that you can print your own if you like and then this is a ways melted clamp so this guy clamps onto the ways and allows you to measure travel and set stops for the carriage when you're for example turning into a shoulder and you saw me use this guy in my turning to a shoulder video now here's the surface plate because I want to show you a little bit of technique with dial indicators the number one thing to be aware of when using them is cosine error so they are accurate when you are activating the plunger perpendicular to its length as you might imagine but if you start measuring things at an angle if you have your plunger let's say at a 45 degree angle now you're actually measuring the hypotenuse of a triangle not the distance from for example where the indicator is mounted to the surface so the more of an angle you have on your indicator relative to the thing you're trying to measure the more so called cosine error you will have so try to make sure that your indicators are always perpendicular to the thing you want to measure a cosine error is actually most insidious on dial test indicators because as we said they have this horizontal arm and this arm is designed to be adjustable so you can move it to get a convenient angle for what you're trying to measure because often this guy's mounted you know on your spindle or in some awkward position and sometimes you need a little bit of clearance for the body of the indicator you know to move it along a surface something like that but the more of an angle you have on this little arm again the more cosine error you are actually introducing so when using these guys try to keep this arm as straight as you can and still get the measurement that you need and sometimes you'll see dial indicators incorporated into other tools and fixtures so for example this guy here is a flatness gauge it's got three dial indicators arranged in a triangle with a machined surface and registration pins and as you can see these are just standard dial indicators that have been reused for this fixture now these guys are among the most high-precision things you will own so treat them with respect don't drop them don't get them dirty treat them like a fine watch because in fact that's exactly what they are and to that end they are expensive and when you're first getting started in a machining you know you're looking for areas to save money on tooling don't skimp on these guys get high quality indicators and in fact you can get them secondhand often for very reasonable money all the ones that you see here eBay in several cases refurbished much like fine watches quality indicators can be taken apart and serviced refurbished and you can do that yourself as I've done here or you can send them away and off and save money that way so don't skimp on these guys get high quality indicators and take good care of them but I thought it'd be fun to do a little dial test indicator demo here so let's check out the quality of these cheap one to three blocks that I got off Amazon so I've set up my dial test indicator here on the service plate with a small amount of preload and much like with the plunger style the importance of the preload is to get the indicator into its range for what you're trying to measure you don't want the arm of the indicator to ever come off of the surface or to bottom out the needle during your measurement because those will of course invalidate your measurement and potentially even damage the indicator so I've got a little bit of preload on there and I'm going to use the fine adjust on my Noga arm to get this guy zeroed out because these guys are so touchy it can be hard to use the zeroing ring on them sometimes so we'll just zero that guy out there and then we'll just move this guy back and forth and see how good the surface is so as long as I don't fall off the edge and as you can see this guy is actually surprisingly well ground so this guy is very flat and no detectable imperfections now let's do the real test though how repeatable are these blocks here is a second block same manufacturer same package and surprisingly it is also the same height it's a little bit shorter I don't know if you can see that on camera but it's maybe a hundredth of a thow then the other one is at least in this dimension so this has been dial indicators in a nutshell I hope you found this useful please do consider supporting me on patreon there's a link down there in the description we'll see you next time thanks for watching you

Channel: Blondihacks

Views: 65,321

Rating: 4.9817419 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, metal lathe, vertical mill, metalworking, metal shop, jewlery making, diy, home improvement, resin casting

Id: 9XNm4zF6CJM

Length: 11min 19sec (679 seconds)

Published: Sun Feb 17 2019