Tools/metallathe/induction
Harrison M300 Metal Lathe Inductions and Workshops
Some of the tools at the Hackspace are potentially hazardous to use, for these tools members are required to have an induction before they can use them. Inductions provide the most basic information on how to safely and effectively use the simpler functions of the tools, we appreciate that some members may have professional experience on some of these tools and in this case please tell your induction provider and the induction may be very reduced and just cover any risks or procedures specific to rLab. Some tools have multiple levels of induction in order to cover more advanced uses of that tool without making the basic induction take too long, higher induction levels will introduce some of the more advanced features of the tools but as with all inductions are only intended to provide basic information on the capabilities of the tools and how to use them safely. Some members of rLab may be willing to offer more detailed tuition beyond basic induction level or offer guided practice sessions in exchange for beer money or assistance on their own projects.
For all tools you are only required to take level-1 induction before use, after that you may perform any task that you feel confident you can do safely, higher levels of induction may be useful to you in performing more advanced operations but are not required before doing tasks covered in them so long as you're confident of your ability to handle those tasks without risk to yourself, others, or the tool.
PLEASE NOTE : All induction providers are volunteers who are providing inductions to the best of their ability but are NOT qualified instructors. Inductions are provided on a best-effort basis but you and you alone are responsible for your safety while using the tools and for satisfying yourself that you can operate the tools safely. There are professional training courses available from various providers in Reading and the surrounding area if you feel they are appropriate for the level of work you intend to undertake. Reading these notes is NOT a substitute for an in-person induction.
Note for wiki editors : Please do not edit induction pages unless you are one of of the people that gives that induction
Level-1 induction[edit]
This is the most basic induction and provides only the absolute essentials.
Topic | Detailed contents | Rationale | ||||
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Proper Clothing |
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Obvious Safety issues, don't want to get pulled in! | ||||
PPE |
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Basic safety information | ||||
Nomenclature | The proper names for all the various parts of the Lathe | Got to have common language to communicate effectively | ||||
Start-up/Shutdown |
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Stopping and starting! Turning off when unattended in case someone brushes power lever | ||||
Oil System | Location of the 3 sight glasses, what they should show, who to contact if they don't, using automatic one-shot oiler | Don't want people running the machine when dry | ||||
Materials Selection | Which materials can the Lathe operate on, types of metals and their properties, plastics that can be turned and modifications needed to do so, materials that cannot be used on the lathe.
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People need to be able to choose the right material for their project, other materials to be covered in Level 2+ Inductions | ||||
Mounting the tools |
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Cover only the basic steel roughing tool, leave the rest for level 2 inductions | ||||
Tailstock mounting | Fitting the drill or the live centre, aligning the tang, keeping the tapers clean and dry, ejecting the tool | Need to know this to set tool height | ||||
Setting tool height |
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We'll get a lot of broken tools if this isn't done right | ||||
Mounting Workpeices |
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Holding the work securely but only on a basic level for induction. | ||||
The 3 slides |
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How to move the tool around! | ||||
The Lamp |
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Getting a clear view, and not being fooled by strobe effect | ||||
Selecting suitable speeds | Using the chart above the Lathe. It's OK to start out going slower than the chart suggests to give yourself more time to react as you learn and work up to the full speeds listed | Just the chart, calculations and modifications for various operations are for level 2 inductions | ||||
Make sure feeds are off |
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Don't cover using the powerfeeds for induction level 1 since that will require also covering how to select suitable feedrates or we risk someone just using whatever the machine is currently set for with possibly harmful results. | ||||
Facing off |
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Covering the very basics of Facing off | ||||
Parallel Turning |
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Basics of Parallel turning | ||||
Drilling |
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Using a drill safely and to the target depth | ||||
Parting off |
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Ideally people should be able to do this to use the lathe properly but induction level-1 shouldn't cover grooving or use of carbide | ||||
Cleaning |
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Keeping the Lathe clean! |
Level 2 Induction[edit]
This one is to cover people who intend to seriously use the lathe in an upcoming project but who don't need to handle complex or detailed work so quite a bit of what was previously level-1 induction will now appear here. Level-2 induction requires people have completed level-1 induction first and and is broken into 2 modules of 2 hours each.
Module 2A[edit]
Topic | Detailed contents | Rationale | ||||||||||||||||||||||||||||||||
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Use of cutting fluids and other lubricants |
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Proper cooling extends tool life, allows deeper faster cuts and helps keep machine clean | ||||||||||||||||||||||||||||||||
Materials selection |
More advanced materials and how to work with them, all materials allowed at level-1 plus
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Next step up on materials | ||||||||||||||||||||||||||||||||
Advanced work-holding using 3-jaw |
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Not covering gripping large/thin-walled/long things that will require steadys until intermediate | ||||||||||||||||||||||||||||||||
Switching between 3-jaw and collet chucks and when to use each |
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These 2 cover everything that's needed for beginner training | ||||||||||||||||||||||||||||||||
Using the collet chuck |
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Just general use like the 3-jaw | ||||||||||||||||||||||||||||||||
Using the Tailstock |
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Expands the range of objects that can be worked | ||||||||||||||||||||||||||||||||
The 3 tool types |
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Need to know the proper tool for each job | ||||||||||||||||||||||||||||||||
Tool Inspection |
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Bad tools will give bad results! | ||||||||||||||||||||||||||||||||
Changing carbide inserts |
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At this level we can expect people to change an insert, but not to grind their own tooling | ||||||||||||||||||||||||||||||||
Tool shapes for various operations |
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At this level people should be shown how to do a wider range of operations and the tools they require. | ||||||||||||||||||||||||||||||||
Differences between roughing and finishing |
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Covering the 2 basic types of cut and when to use them | ||||||||||||||||||||||||||||||||
Using the slide locks |
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Accurate surfacing | ||||||||||||||||||||||||||||||||
Selecting Feeds and Depth-of-Cut |
These tables are under development and will be expanded in time, till then, use your best judgement
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Cutting efficiently without breaking tools! | ||||||||||||||||||||||||||||||||
Using the power feeds |
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Using the powerfeeds for larger cuts is almost essential but proper settings must be chosen to avoid breaking tools |
Module 2B[edit]
Topic | Detailed contents | Rationale |
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Taper Turning on top-slide |
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Putting tapers on work |
Using taps and Dies |
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Tapping and threading are pretty common operations but with the brittleness of the tools there's quite a few gotchas people need to be warned about, so it's neither level-1 nor level-3 |
Boring |
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The need to produce holes of odd or very large sizes |
Breaking corners |
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Important safety and aesthetic technique |
Parting off |
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Parting neatly is needed for work at this level |
Turning using indicator dials |
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Basic use of the dials will have been covered in level-1 induction but a deeper understanding will be needed here for boring and flood cooling. |
Polishing using emery cloth/paper and files |
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People are going to do this, so we might as well make it as safe as possible |
General oiling |
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The more people helping with this the better |
Refilling apron oil | Checking the sight glass for level, where the fill and drain plugs are, using the proper grade of oil (ISO 68) and when to fill it up, how much to use | With the one-shot in use this will need to be done often |
Level 3 Induction[edit]
Requires Level 2 induction to be completed first as there's a lot of material to cover on this one so don't want to be going over basics again. People don't have to do the entire level 3 course, and in fact we don't recommend it as covering all of this would take several days and your brain would be about ready to melt by the end of it! Individual topics can be done as needed, the content of this course isn't finalized yet so we're not ready to run it as a full course but if you're specifically interested in one topic then contact a induction provides who offers level 3 to plan out and arrange a short session on that topic.
Level 3[edit]
- Internal and external thread-cutting with insert tools including multi-start and worm gears
- Theory of thread-cutting
- Thread forms and how they change with size
- Which bits are critical and which aren't
- Extra reliefs needed for worm gears to mesh nicely
- Helix angles and how numbers starts alters this
- Relief angles needed
- Problems of setting suitable speeds
- What wrong speed or insufficient rigidity looks like
- Thread forms and how they change with size
- What tools are available
- Semi-profile, full profile, and why neither will work well for multi-start
- The option of grinding your own
- Setup for thread cutting
- Creating gullies
- Creating external gullies using parting tool if you have to but effects of stress risers
- Using the thread tool to make internal gullies
- What to do if there's not room for a gully
- You probably shouldn't be thread-turning, look at specialist taps/dies
- Using reverse-side thread-cutting
- But if you REALLY have to.... using back-out strategies and the foot brake
- Reading the tables to set gear suitably
- Using the change-gears for really coarse threads
- Setting up the threading dial for metric threads
- Why it won't work on imperial threads
- Tool mounting and angle
- Choice of top-slide angle and setting feed angle on the top-slide
- Picking speeds that will work
- Using threading dial or using back-and-forth patterns
- Choosing infeed amount and using trig to calculate theoretical depth
- Using wire thread gauges to check depth
- Test fitting if possible
- Deburring when done
- Creating gullies
- Theory of thread-cutting
- Blind turning on the indicator dials
- Grooving Internal and External
- Grinding tools/Profile turning
- Decoding carbide insert type codes
- Knurling (calculating diameters for an even knurl)
- discontinuous turning
- Altering the change-gears and speed limits (540)
- Very large workpeices, faceplates and speed limits
- Using fixed and travelling steadies for very long workpeices
- Why to use steadies
- How the 2 types grip and stabilise your work
- When to use Fixed Steady
- Choosing location, have to make a flat to rest on
- Installing
- Tightening and lubricating
- Keeping chips out with shields
- When to use travelling steady
- Positioning
- Ahead - Stable but risk of transferring out-of-roundness and wearing brass blocks
- Co-incident - Strongest but hard to do and risk of chips getting dragged in
- Trailing - Roundness is stable but risk of longitudinal oscillations forming
- Positioning
- Burning in the brass blocks
- It's going to happen anyway, might as well make it happen when and where you choose
- Using the dial indicator to maintain position on complex cuts
- Calculating feeds&speeds for other materials not on the standard table
- Cutting standard module worm gears
- Pressure-plate turning of plastics
- Offset work mounting
- Mounting the large toolpost and setting it up
- non-round work
- Cleaning and oiling the lathe including oiling points
- Changing oil for the lathe
- Advanced materials - Titanium/Magnesium alloys/HSS (We don't keep the necessary materials in stock, but if inductee provides it these modules can run)
- Titanium
- Grades of titanium available, unless otherwise specified Ti6Al4V is the most common
- Properties of titanium and how they affect turning
- Poor thermal conductivity - Rapid heat buildup and critical need for coolant
- Heat goes into material, NOT chips - Even worse heat build up
- Thermal hardening, if you let heat build it'll harden and become un-turnable
- High toughness, Steel tooling is possible if razor sharp but carbide is preferred, brazed carbide can be very effective
- Flammability, swarf is a serious danger
- High toughness and tendency to hardening means low tool speeds are required, 15m/min is a common choice
- Excellent set-up rigidity is vital, use centers or steadies wherever possible, be very aware of work and tool stick-out and tool position relative to the slides
- Normal cutting depths, 0.5mm for roughing, 0.3mm for finishing, DON'T try to take skim cuts if you can help it
- Spring passes are to be avoided unless vital, and if they are vital be aware you'll only get to make one spring pass before the work is too hardened to turn any further
- Feed rates, 0.1mm/rev is a good starting point, but experiment and watch your chips closely
- Chips probably won't break no matter what you do, aim for tight curls, beware of birds-nesting as it's a serious fire risk
- Avoid discontinuous cuts if you possibly can, they're very damaging to tools
- Cuts must be decisive, you must not dwell with tool in contact with work, rubbing causes rapid hardening
- Cuts should be done using power feed whenever possible as it's hard to achieve proper evenness manually
- Cuts should enter at full speed, no gentle lead-ins
- Once cut completes then the tool must be backed away from the work immediately, it cannot rest at the end position, not even for a second
- After every cut, remove the swarf to a safe location where it can't be ignited from the work, and inspect the tool
- Drilling Titanium
- Uncoated HSS are often ineffective
- TiN/TiAN coated drills are OK
- Cobalt or Carbide drills are best
- Peck drilling is essential as it's impossible to cool the drill tip effectively
- Pecks must be small (2.5mm or 0.5 x drill diameter, whichever is less)
- Drill must be fully withdrawn between pecks to be cooled by the flood coolant
- Check for work heating every peck
- Watch your chips carefully and re-sharpen the drill the moment there's any sign of degradation.
- Parting off is possible with carbide tools, but only if the center is drilled, full-depth parting is difficult
- If the part-off is deep it may be necessary to change spindle speed during the operation.
- Magnesium
- HSS/Hardened materials
- Hard-turning can be used to produce hard items at a precise final dimension without having to allow for distortion during heat treating
- Some reduction of surface hardness will occur, the faster the turning the less pronounced this will be
- Checking the workpeice hardness using the ultrasonic tester
- Hard material turning is normally done without coolant
- Swarf will come off HOT, depending on circumstances maybe up to red-hot
- Rigidity of set-up it vital, pay special attention to stick-out and tool position relative to the slides
- Lock any slides you're not using
- Examine the toolholder carefully when fitting a hard-turning insert, all parts must be in excellent condition or be replaced.
- Hard turning requires relatively high spindle powers, be sure not to overload and stall the lathe
- Tool destruction is certain if it's allowed to stop in contact with the work
- Tool chipping is certain if it's bumped into the work during setup
- Inspect tool after every pass
- Moderately hard steels can be turned with higher grade carbides
- Suitable hardnesses range up to around 45-55HRC
- Swarf will come off very hot and may spark - take suitable safety precautions!
- Depths of cut and feed rates should be low, ideally <0.2mm
- Surface speeds around 30-50 m/min
- Very hard materials can be turned using CBN inserts
- CBN Inserts are expensive and delicate, they must be treated with extreme care
- Maximum hardness ranges up to about 65HRC but values above 55HRC will cause rapid tool wear
- Swarf will come off up to 450C - take suitable safety precautions, consider how you're going to stop the machine if burning-hot swarf is spraying over the controls
- Breaking a chip is unlikely, expect birds-nesting
- Depths of cut and feed rates should be low, ideally <0.1mm
- Surface speeds around 50-75 m/min, the harder the material the slower the cut but go as fast as possible for any given job, CNC machines can run faster than this but our set-up won't allow it.
- Diamond tooling exists for use in hard non-ferrous materials and highly abrasive materials
- Diamond tooling comes in PolyCrystaline Diamond (PCD) which is very expensive - more so than CBN, and MonoCrystaline Diamond (MCD) which is eye-wateringly expensive.
- PCD is very, very hard, MCD is the hardest tooling material known to exist.
- Diamond tooling cannot be used on ferrous metals as the carbon from the diamond will dissolve into the iron
- Diamond can be used to turn exotic materials such as aluminium superalloys, nickle superalloys, precious metals, tungsten carbide and carbon fiber
- Maximum work hardness for diamond tools can go as high as 70HRC although wear increases above 60HRC
- Cutting speeds can range up as high as 1000m/min or as low as 10m/min depending on the hardness of the work
- Depths of cut and feed rates should be low, ideally <0.1mm, however the very high surface speeds used with PCD tooling will still result in rapid material removal rates
- Titanium
- Workholding using all chuck types and recovering concentricity
- Using reamers
- Turning between centres
- Why you might do it
- Improved concentrically and repeatability
- Holding awkward shapes
- Reusing centers on existing parts or that someone else cut
- Recutting a center if you need to (toolpost support trick)
- Setting up a center and a catch plate
- Installing a center in the headstock
- Installing the catch plate
- Picking a suitable dog size, setting it up so it won't slap
- Caution about over or undertightening
- Alternatively making a center on stock held in a 3/4 jaw chuck
- Live or Dead center at the tailstock?
- Might require the use of steadies if the part is long
- Turning between centers
- The dog and catch plate will cause imbalance so watch speed
- Parts may be very long so watch out for flex
- Use support if needed
- Take shallow cuts
- Tailstock offset turning
- Regular centers only for the smallest of offsets
- Part distortion if used too much
- Using ball-bearing centers for larger offsets
- Resetting the tailstock alignment when done, high precision required
- Regular centers only for the smallest of offsets
- Why you might do it
- Making and shaping brazed carbide cutters
Maintenance[edit]
Doesn't cover actually using the lathe at all, covers all the maintenance jobs that lathe might need apart from stuff that requires specialist tooling we don't have or factory assistance
Topic | Detailed contents |
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"Maintenance in progress" sign | Putting the sign on the lathe if you need to leave mid-maintenance |
Cleaning | General clean-down, all the surfaces that must be done including hidden ones and inside the change-gear case. Use of solvent to clean and possibly at some point if we get some then use of touch-up paint. |
Checking tightness | Checking the tightness of the various exposed bolts and fasteners including the changegear mountings |
Surface oiling | Wiping down all surfaces with a thin skim of ISO-68 oil after cleaning, oiling the leadscrews |
Checking oil tanks and draining/refilling | Location of the sight-glasses, fill point and drain points for all 3 oil tanks, which grade of oil goes in which and how much. Main tank takes 1L of ISO68, screwcutting gearbox takes 0.5L of ISO220, Apron takes 0.3L of ISO68. Disposal of used oil ( How do we handle this? ) |
Oiling points | Applying oil using the high pressure oil can to all the oiling points listed in the manual, including the ones under the changegear case |
Oiling the changegears | Opening the case, oiling them, do not bypass safety to run the gears while oiling |
Checking and adjusting play in mainslide | Measuring the play with the dial-indicator at the 3 relevant positions, how to unlock and adjust the grip clamps, how little they need to be rotated, rechecking with dial gauge, what proper adjustment feels like |
Checking and adjusting play in cross-slide | Proper points for checking the play, how to release and adjust the wear strips |
Checking and adjusting Backlash in cross-slide | How to measure the backlash, and how to release and adjust |
Checking and adjusting play in topslide | Measuring the play, which grubs screws adjust the wear strips |
Checking play in spindle | Check only, adjustment is a back-to-factory job! |
Cleaning and re-lubing the chucks | How to disassemble and clean the 3 and 4 jaw chucks and which parts must and must not be lubricated |
Keyless drill chuck | Disassemble and clean the keyless Chuck, which parts to oil and which parts must be kept dry |
Flood cooling system | How to check the fluid, clean and change if needed |
Update Wiki | Make entry indicating you've performed maintenance, update status if there's a change |