New lathe arrived today : The ongoing saga

Looking at the photo of the chuck key I would suggest changing your foot wear

Okay, thank you everybody. I will try another tool tomorrow with less overhang.

Malc : thank you for the explanation about the jaws. I think I eventually did something like that to get it to work !

Yes, I have those RH and LH tools and I will use them tomorrow. Does the direction of the lathe chuck make a difference to the finish ?

Footwear ? The only heavy thing is the lathe and that is not about to fall off the bench. I am working in the living room.

Edited By Brian John on 26/08/2015 09:30:03

Too much overhang on your tool, wrong geometry, stick to HSS tools for aluminium, I suggest getting the Eccentric Engineering diamond tool ( usual disclaimer ), initially expensive, but will do most of your machining requirements without too much hassle, this tool will also give you the best top rake for Aluminium when ground using the guide provided.

Internal / external jaw alignment... I'm sure you are well aware of ... both sets of jaws should be numbered 1,2,3, to match numbers in the chuck, rotate the scroll to appear just in the #1 slot, place #1 jaw in the slot, back off the key a tad then rotate the chuck key until the scroll engages #1 jaw, rotate key just enough until scroll appears at #2, fit jaw, & same at #3 this should bring all jaws to meet in the centre irrespective of which set you use.

Rpm for aluminium, dependant on OD; if your flywheel is about 2" then you should be in the region of 800 rpm+ again also dependant on it's composition, it could be hard /soft aluminium which affects it's cutting ability, plus the cutting tool being used, there are a lot of variables to consider. I'm sure others will offer there own advice / suggestions, possibly with more detail.

George.

Yes it does - Anti clockwise looking at the chuck.

Did you check that the tool tip is on or very little below centre ?

If you are using the automatic feed it needs to move the tool along slowly.

Sometimes aluminium melts onto the tool and sticks to it and that will wreck the finish. It can be prized off and the speed reduced to prevent it happening again.

Overhang causing that - personally I have my doubts but lots of it wont help especially if the slides are too loose. They should be adjusted so that you can feel a little bit of resistance at the handle, just a little. Oil is also needed. Slideway oil is best ( ebay ) but even cycle oil will help. WD40 - waste of time.

Rake ? In practice a huge range will work better than that but aluminium benefits from rather a lot of it. A polished finish also helps prevent it sticking to the tool.

John

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Edited By John W1 on 26/08/2015 10:15:27

Your question about which way the chuck should turn and the finish it would give, As far as you are concerned now the chuck should turn towards you as you face towards it. The finish, if it is turning away from you will be obviously a bit Naff.

Not sure what you are saying here, the chuck should be rotating in a clockwise direction viewing the lathe from the headstock end.....for most normal turning, milling, drilling operations...

one more thing that could influence finish is tool height.... Make sure that the tool tip is on centre height of the machine, check with a centre in the tail stock.......

Mmm! Speaking as someone with two black great toes, one permanent, I'd say Eric is right but hey ho!

For an explanation of the angles people are talking about for the tool you might like to look here.

Russell.

I think a lot of your troubles can be ironed out or at least understood in one step:

I found it helped to understand what is happening between the cutting tool and the work piece - because almost everything else about a lathe and tool geometry is built around that basic principal. When people talk of rake and clearance angles etc. if you understand what they are there for then all should become clear, including which way you turn the chuck and why!

I found this website very useful when I was more of a beginner than am I now. I also had an image which was basically a section through a round piece of bar with a lathe tool next to it, touching it and the appropriate centre height and you could really see how the clearance angles worked, and it showed a chips curling off the top rake and point where it sheared away from the workpiece. I cannot find this - perhaps try to image it, if you understand the principals then you should be able to sketch it out, consider that a bit of homework

**LINK**

also worth checking out his general "tips" page, although I have not read it, it may be useful.

http://www.steves-workshop.co.uk/tips/tipsindex.htm

Looking quickly in to the "initial lathe setup" page, I don't think this is entirely required at the stage your at.

That said you should certainly be cleaning and adjusting all slides before you start any precision work and if you have any tolerance fits of holes and shafts (that you machine or bore rather than drill or buy the right size already) your going to need to check your lathe turns parallel (minus a nats towards the tailstock if anything)

(Centre drill, should be used to spot only, 2/3rds of the way up its conical section is about the right depth)

Edited By Russ B on 26/08/2015 11:08:16

Edited By Russ B on 26/08/2015 11:11:41

Brian,

Welcome.

You will soon change your mind about footwear the first time a piece of hot swarf lands on one of them toes.

You may not be generating such swarf now, BUT you will very soon as you gain experience and start pushing your new toy to its limit.

Hot swarf make one shout the accepted Anglo-Saxon when it hits bare skin.

Geoff - Not to mention melting plastic footwear as well.

Edited By OuBallie on 26/08/2015 11:09:49

HA!

Two Russell's giving the same link.....

Great minds think alike!

That is a decent link but really it needs more explanation as to why and what effects the angles have. This is something the OP should bear in mind for later but I went through the basics here and wont be typing that lot out again.

**LINK**

I did it because rather than slavishly following some fashion it's better to understand why because there can be a number of reasons for departing from any one's tables of rake angles - who ever they are. There are lots of them about. The problem is that they are based on factors that largely relate to tool life of various tool materials and the material being cut. Not load on the lathe, tearing effects on the metal being cut or the power and general rigidity of the lathe

If the OP was grinding his own tools I would suggest a bar turning tool as shown in the links with 12 aprox degrees on all faces tending to more rather than less. Not too much side rake. For the flywheel on this lathe I would also add 12 degrees of back rake. That's not a bad idea on other turning jobs but in this case it's needed to cut as he appears to be doing it. It will work well on all of the materials mentioned apart maybe none free cutting stainless. That is tricky stuff in other ways.

The link also mentions using a stone to add a rad. As it needs to be several times the feed rather than large it's difficult to do on a grinder. I use a slip stone. Of late these are being sold in aluminium oxide for clearing diamond wheels. I would also polish up the faces of the tool with the same stone being careful not to radius the edges. I would also use the same stone to sharpen the tool while it's in the lathe from time to time. That gets round angles being used to make the cutting edge last longer.

The jig he shows leaves a rad on the surfaces - this helps polishing because it's only really needed for a short distance from the cutting edges. I wonder if he realises that the height of the tool on the wheel also alters the angle. It's equal to the angle of the chord at the top of the tool bit plus any the jig adds. Usually the chord angle at 1/2 the tool bit height is used and the tool fed square on to the wheel. When polished evenly top and bottom the correct angle will be obtained Jigs help because it takes a lot of practice to feel that the tool bit is at the same angular contact with the wheel when it's removed to look at or cool. Wheel wobble makes that even more difficult.

I'm mentioning grinding because any one with a rather small lathe will find they need to grind tools for specific bits of turning at some point unless they stick to small things. Really though the initial answers to this thread should have asked about the very very basics first. If they aren't correct buying something else wont help at all.

John

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A. The tool tip is in line with the tip of the dead centre of the tail stock ; it was the first thing I did when setting up the lathe.

B. So clockwise direction looking from the headstock from the headstock. That is ''R'' on my lathe. The opposite direction is marked ''L". I think I was using both directions today !

C. I am not using a centre drill. This is a spotting drill which a different thing altogether. I was led to believe that the centre drills are only used to make a shaped hole in the end of the work piece for the tailstock to sit in. Correct me if I am wrong ?

D. I was not using any lubricant as I thought it would not be necessary with aluminium.

E. I am not using the automatic feed as I want to get used to using the hand wheels and get to know which direction things move in.  I also need to be very careful about staying away from the chuck jaws when machining the outside of the pulley/flywheel. This is a good reason to make a faceplate or a mandrel so I do not have this worry ! Note that Arceuro said their mandrels are not suitable for this purpose as they may break.

F. Too much overhang...noted for tomorrow.

G. I will keep in mind what has been said about footwear. I do not usually wear shoes in the house but I may have to change that policy.

H. I do not want to grind my own tools at this stage. Unless I know exactly what I am doing then I would only be introducing more errors.

Edited By Brian John on 26/08/2015 13:35:28

Edited By Brian John on 26/08/2015 13:54:46

The centre drill is also used before an ordinary drill. The reason is that even if the tailstock is slightly off centre it's stiff enough to form a hole that will be on centre. That will pull the drill in even if there are slight alignment errors. Otherwise it can skid around and make a right mess even breaking finer drills in the extreme.

The reasons for the rings on your work are probably down to hand feeding. It is a good idea to get to grips with that. What happens is that things bend slightly when a cut is being taken. If the feed rate falters it changes the pressure that is causing things to bend so rings form. It can be surprising just how visible rings even a few microns deep can be. It's not the easiest thing to do but needs 2 hands to maintain the same feed rate so that the other hand's fingers can be repositioned to maintain the same speed. Cock eyed explanation but you should realise what I mean. With practice you will do it even when the hand wheels on the lathe are rather small.

On thing I didn't mention on the photo you posted earlier is that you might get better results with the tool more angled into the work. It might also be worth trying to work away from the chuck at the angle it's at rather than towards it but you will probably only be able to take rather shallow cuts and might get chattering as the tool is fed in a little. Tightening the slides as I suggest can help with that. You might also like to try locking up the top compound slide when you your not using it.

The oil was for the slides - not the work.

John

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A. The tool tip is in line with the tip of the dead centre of the tail stock ; it was the first thing I did when setting up the lathe.

that should be OK

B. So clockwise direction looking from the headstock from the headstock. That is ''R'' on my lathe. The opposite direction is marked ''L". I think I was using both directions today !

The tools you have are designed to be used at the front of the lathe with the metal being pushed down onto them.

C. I am not using a centre drill. This is a spotting drill which a different thing altogether. I was led to believe that the centre drills are only used to make a shaped hole in the end of the work piece for the tailstock to sit in. Correct me if I am wrong ?

Spotting drills are better then centre drills for starting holes, but you can use centre drills.

D. I was not using any lubricant as I thought it would not be necessary with aluminium.

Not necessary, but you can use a cutting fluid.

E. I am not using the automatic feed as I want to get used to using the hand wheels and get to know which direction things move in. I also need to be very careful about staying away from the chuck jaws when machining the outside of the pulley/flywheel.

Wise decision, gives you a better feel for the lathe, too.

> This is a good reason to make a faceplate or a mandrel so I do not have this worry ! Note that Arceuro said their mandrels are not suitable for this purpose as they may break.

Don't worry - most people use chucks as they are much more convenient

F. Too much overhang...noted for tomorrow.

Definitely

G. I will keep in mind what has been said about footwear. I do not usually wear shoes in the house but I may have to change that policy.

Metal splinters in the foot are 'orrible.

H. I do not want to grind my own tools at this stage. Unless I know exactly what I am doing then I would only be introducing more errors.

Google each of the tools you have and read up on how to use them. Bear in mind the knife tools in y picture above cut on the SIDE of the tip.

Edited By Neil Wyatt on 26/08/2015 17:49:59

I used the spotting drill to drill the hole all the way through the wheel. Is this normal practice or is the spotting drill only used to get things started then complete the hole with a jobbing drill ?

Very few model engineers even have a spotting drill and therefore normally start with a centre drill. As the name suggests, and the price emphasises, you move to a regular drill asap. Centre drills are used for starting holes more often than making centres, and then not using the coned part of it. Then you move to a small drill and work up in stages depending on how big your lathe is and whether the drill slips in the chuck or taper.
You will sometimes see people saying how they shove a 2 inch drill straight into hardened steel same as they take half inch deep cuts at 2000rpm but it's just that they want to boast in a follow up post that when they were in industry (and they were always a 'toolmaker' their lathe had a 50 HP motor.

A lot of spotting drills have shorter flutes than yours so would get clogged if you tried to drill all the way through. I use spotting drills 99% of the time for starting holes and only use ctr drills when I need to place a ctr in the hole. They are far more robust than the end of a ctr drill which can snap off in the work. Once you have a dimple you can change to a regular drill.

Try a little parafin - kerosene applied with a small brush

Use both hands on teh handwheels to keep a constant pressure, if just using the handle there is a risk that the up/down movement will move the tool slightly and give an uneven surface finish

I've always thought that lathe manufacturers should not fit the single sticking out thingies on handles as it would encourage people to use them properly when taking cuts but they are really there for fast traverses of what ever part needs moving. If these are used for taking a cut the slides have to be so loose that there are likely to be other problems as well.

I was serious about locking the compound slide when it's not being used. I have 2 baby lathe cross slides I bought for something else expecting to be able to use them - useless was the word that springs to mind. Even the lead screw location they use is very poor due to the use of rolled threads and minimising machining elsewhere.

John

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