The cross-feed dial is always zeroed after each pass, so you have less to remember, such as whether the last pass was at 0.030 " or 0.050 ". My lathe was once owned by an educational establishment and the top slide shows much evidence of chuck-crashing!!! I can never remember which line on the threading dial to use with which thread pitch. You might expect the triangle which forms an M10 nut to have a pointed peak, but is heavily flattened by 1/4 of the triangle height. I have always enjoyed cutting threads on the manual lathe and have learned a few tricks over the years. I don't take the stud bolts off the banjo, just undo the screws on the studs and slide off the studs. Maybe even a small grubscrew and brass pad to bear on the thread, if space allows? On the last pass, feed straight in with the cross-feed at a light 0.001 " spring cut. on Step 5. The calculated depth is more of a reference for about how far you need to go. I think the offset of 29.5 degrees forces you to cut on one side of the thread only??? The backgear idler shaft nut is loosened and brought into engagement with the bull wheel and bronze gear - then tightened again, The pulley is lubricated via its oil nipple (note this is OIL not grease). Post Not quite sure how this happened! The Instructable gives details about making a pair of internal/external metric threads in 1" (25mm) diameter aluminium tube/bar. This Instructable shows my first effort at thread cutting. It can be done with a conventional HSS bit or if you use insert tooling and don't need ctr support then the internal threading tool makes it easy to reach around the back without having to move the topslide rearwards. When left to their own devices, machinists tend to cut threads tighter than necessary. Another good idea. As seen in his videos, I also find it much less stressful and have not had any issues with breaking carbide. I first bored out the tube to the correct dimension using the boring bar, then used it to 'relieve' the starting 3mm and also produce an internal groove between 15mm and 20mm inside. I hope that comments from other people, will highlight these so I can correct them. The mystery was that the bolt was good and tight, and there was no way to get something like Vise-Grips on it. On the ML 10, this is 38 divisions on the dial). After posting that and reading the rest of the instructable, I can see that you can rotate the toolholder. Thread files actually work. Just general ideas not sure of your resources and or friends. 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Process of both external (e.g., thread milling) and internal (e.g., tapping, thread milling) cutting, turning and rolling of threads into particular material. I learned how to thread on the lathe using the compound infeed method. Apart from that, I think I understand it fully! For a better experience, please enable JavaScript in your browser before proceeding. Try it. (The additions/subtractions are done twice because the diameter is made up of threads on BOTH sides of the tube/bar) Finally. To make this happen, the following steps are done: TESTING Switching on the lathe will produce a different sound from normal. Thanks for your interest. If I want a nicer look, I switch to a radius tool. All CNCzone.com Content - Copyright 2019 - All Rights Reserved Leave a nice finish - it will form the 'flats' at the top of the thread. I did this for so many years. Skip the rest of this step if you are bored by the maths - the next step does just the same, without any theory! This is usually not a problem on external threads, but it can be on internal threads that end against a shoulder. I was thinking of doing this in order to use my existing quick change tooling. The point is small; in the first couple of passes, the area of the tool tip engagement is also small. Edited By not done it yet on 21/12/2018 14:43:00, What ideas do the team have to lock the chuck onto the spindle nose when cutting in reverse or rear tool post parting off. It is a flat-topped triangle where the triangle has been chopped off by 1/8 of its height. Click THIS LINK for full contact details. At times, I used to run my ML7 in reverse, having made sure that the chuck was firmly in place (not so firmly that it could not be removed without undue force) . I must produce a bigger platform for the grinder! No doubt there are websites, which would do the maths for you. The shape seemed ideal, with a skew which meant that I could set the tool post at the perfect angle to cut close to the chuck (see "Cutting the external thread" step). Andrew, if you happen to know any people like that. Nope, don't personally know anyone like that. JMO from my experience. Typically on a Boxford with screw on chuck. Typically on a Boxford with screw on chuck. However, my hardened cutting tool was pretty black and I was not sure how to make it shiny! Enco was the Harbor Freight of machine tools. The engine lathe consists of a headstock and spindle, tailstock, bed, carriage (complete with apron) and cross slides. I never have to tighten the rear saddle clap screws when parting off with HSS.. One little trick if you don't like running the tool towards the chuck and would rather run away from it. My Boxford can easily part off in the conventional manner when using it. Badlands - this is stupid. With all this geometry we know exactly how deep to cut our threads, which is useful for moving the tool in/out by the correct amount. There was a hole, but the hex had never been broached. Here is the maths: 1/8 of 0.866 = 0.108mm 5/8 of 0.866 = 0.541mm 7/8 of 0.866 = 0.758mm Tube deepest cut (bottom of the triangle) = 23.6 + 0.108 + 0.108 = 23.82mm Tube internal diameter (to the flat top) = 23.6 - 0.541 - 0.541 = 22.52mm Bar biggest diameter (to the flat top) = 23.60mm Bar smallest diameter (to the bottom of the triangle) = 23.6 - 0.758 - 0.758 = 22.08mm The above are the sizes needed for preparing the bar and tube for threading. hi guys I am doing my level 1 apprentice as a toolmaker so I want to know how can I make M12 can you guys help me with all the calculations and preparation. Reply This means that the best strength-to-fit ratio is around 75%. No, I put my 4-way toolpost in the 4-jaw chuck and took a carefully calculated amount off the bottom of it. They did fill a need, though. I think this would probably be the best set up though. You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. May also be fitted to the machine table to hold a workpiece. Mathematics - deciding on the thread size and exactly how to move the cutting tools, etc. This is from the "Myford ML10 and Speed 10 Lathes notes on Installation Operation Maintenance" (Booklet number 743L). If you buy a really cheap, plastic cooking spoon from a discount store, you end up with 30cm of polythene rod which is over 1cm in diameter. by Harold_V Wed Dec 16, 2009 4:34 pm, Post At the end of the pass, you can disengage the half-nuts and wind the carriage back by hand. Cleaning and oiling the threads then left a silky-smooth fit on the threads. Matt. bioflex Fabricating and installing a 300 mm riser block. It saves a tool change and looks OK. Comes in a variety of forms, ranging from manual to semiautomatic to fully automatic, with major types being engine lathes, turning and contouring lathes, turret lathes and numerical-control lathes. Surely a LH insert may not have the correct clearances? May be actuated manually, pneumatically, hydraulically or electrically. To do subsequent passes, you can engage the half-nuts at any EVEN line on the thread indicator dial. Also, don't forget to use some sort of cutting oil (way oil, synthetic, etc) during the cutting process. I took the bottom of the toolpost down to about 3.5mm thick. I have not seen a 'Machinists Handbook', perhaps they have tables for virtually every diameter? **The reason a 10mm bolt must have a smaller major diameter is because of Thread Class Engagement. This means that the head of the cutting tool is now the first thing which would hit the chuck - ie I can work the cutting tool right up to the chuck and not worry that the tool post (or the top slide) might foul the chuck. As long as your threads fit they are fine. First fitting of the threaded bar into the tube did not work! The only difference is you will be cutting on both sides of the thread instead of one side. View our privacy policy at www.mortons.co.uk/privacy. If the numerator has a value of "1" then that pitch is super-easy because you can engage the leadscrew at any time without worrying about the thread indicator at all. hinged 16g captive septum hoop clicker Still have a set of gauge blocks ($20) I use for less demanding work, hardened 1-2-3 blocks (reground by me), and a few other items. I often turned in reverse, machine cut better that way. Special lathe types include through-the-spindle, camshaft and crankshaft, brake drum and rotor, spinning and gun-barrel machines. The Boxford had this as a standard accessory to protect the school lathes from careless children. I purchased a parting tool from JB cutting tools at the midlands show this year. nose stud gold rose plated bend disc tulsabodyjewelry disk The column labelled "Numerator" is the key to this. Keep cutting until 15mm has been reached - disengage the half nuts, Wind the cross slide in to make sure the cutting tool clears the workpiece. It may not display this or other websites correctly. Carbide for a cutting tool is best ground with a diamond wheel. Finally, the whole arrangement is tested by hand rotation, to make sure everything is right, before switching on. Anybody else had this happen?? I don't know what a typical number of honing strokes people use (1, 5, 10, 20???). This will help "cut" the threads instead of smashing/ forming them (like in a zero rake tool), especially in aluminum. It looks like most barrel journals are in the 1"-2" range? Hence I think your thoughts are probably spot on! A precision instrument with a spindle moved by a finely threaded screw that is used for measuring thickness and short lengths. 
Dialing in bore for threading and chamber? Rate of change of position of the tool as a whole, relative to the workpiece while cutting. it all just falls into place, the more you do it. #signup input ~ label.wrap {
The main disadvantage is your Z-axis position changes as you feed in. On the Boxford, there is a rear saddle clamp, and a front saddle/ bed lock, but its a fiddle trying to tighten the rear cap screws when they are inverted and out of sight. Did some internal threading the other day using the cross feed only and running in reverse . I was thinking the offset angle on the tool was to compensate for the 29.5 deg on the compound (didn't do the math to see that 10 != 29.5..) I guess my question is, why the angle offset on the tool? You will need left-hand threading tools, running the lathe in reverse. The more you do, the easier it gets. Somewhere I read that you should leave the last normal pass a thou or so short, then do a final plunge cut with the cross slide, to leave a nice finish. Yes, that makes sense. This is brilliant for playing with external thread cutting - you can't damage anything because the material is soft, but it holds a thread nicely. If I were to add anything to your instructable I would say that you should consider a Positive Rake Cutting tool. So the actual height of the metal thread in a properly formed nut is 5/8 of the full triangle height (1/8 'lost' due to the flat at the bottom of the thread and 1/4 'lost' due to the flat-top of the thread). HSS is less susceptible to edge chipping, and thermal fracture during grinding. I do however have a fairly tight lathe and use 29.5 degrees on the compound to infeed. The thread size comes in two dimensions, thread pitch and thread diameter. Now when cutting threads again, always check them with a hardware store nut/ bolt. The threads also looked to be without a flat top. Specifications such as thread height are critical in determining the strength of the threads. Every time I turn around I'm spending just another couple hundred on this dang hobbybetween lathe tooling and loading equipment I'm gonna go broke.
Dialing in bore for threading and chamber? Rate of change of position of the tool as a whole, relative to the workpiece while cutting. it all just falls into place, the more you do it. #signup input ~ label.wrap {
The main disadvantage is your Z-axis position changes as you feed in. On the Boxford, there is a rear saddle clamp, and a front saddle/ bed lock, but its a fiddle trying to tighten the rear cap screws when they are inverted and out of sight. Did some internal threading the other day using the cross feed only and running in reverse . I was thinking the offset angle on the tool was to compensate for the 29.5 deg on the compound (didn't do the math to see that 10 != 29.5..) I guess my question is, why the angle offset on the tool? You will need left-hand threading tools, running the lathe in reverse. The more you do, the easier it gets. Somewhere I read that you should leave the last normal pass a thou or so short, then do a final plunge cut with the cross slide, to leave a nice finish. Yes, that makes sense. This is brilliant for playing with external thread cutting - you can't damage anything because the material is soft, but it holds a thread nicely. If I were to add anything to your instructable I would say that you should consider a Positive Rake Cutting tool. So the actual height of the metal thread in a properly formed nut is 5/8 of the full triangle height (1/8 'lost' due to the flat at the bottom of the thread and 1/4 'lost' due to the flat-top of the thread). HSS is less susceptible to edge chipping, and thermal fracture during grinding. I do however have a fairly tight lathe and use 29.5 degrees on the compound to infeed. The thread size comes in two dimensions, thread pitch and thread diameter. Now when cutting threads again, always check them with a hardware store nut/ bolt. The threads also looked to be without a flat top. Specifications such as thread height are critical in determining the strength of the threads. Every time I turn around I'm spending just another couple hundred on this dang hobbybetween lathe tooling and loading equipment I'm gonna go broke.