Beginner Lathe for Loco building

[Mike FreemanParticipant @mikefreeman95253]

Hi

I am a complete novice in terms of machining and am coming from a 3D printing & 3D design background.

I'd like to learn some machining skills and have been looking at lathes with a view to building some steam engine kits and eventually getting into steam loco building.

I don't have a large budget and was looking at old Myfords on ebay but then started looking at the Chinese offerings and found the Sieg SC3 on Arceuro.

I have no issue with Chinese machines and know from 3D printing that you can get some capable machines and the fettling and upgrading is all part of the fun.

I don't however want to buy a machine that just isn't capable of doing what I want or have to buy twice so my question is, would the Sieg SC3 be capable of machining things like the Stuart models engine kits and then also be able to do the machining required for something like a 5" loco?

Regards

Mike

[Mike FreemanParticipant @mikefreeman95253]

[Martin KyteParticipant @martinkyte99762]

You need to identify the largest component on the loco or Stuart engine which generally is the driving wheels or flywheel. If you can swing that it the large you are looking good to go. You need to be able to bore cylinders either on the faceplate or boring table (cross slide in Myford terms).
regards Martin

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Mike, welcome to the forum. As Martin has said, you need to know the biggest diameter of the engine you wish to build is, for instance, some loco wheels in 5" can be 7-1/2" or bigger diameter castings, which you won't be able to do on a C3, and depending on any lathe such wheels being either loco or flywheels, you will need to make sure you can get the tool close enough to do the work, this may mean you will have to clear the lathe saddle as well as the bed, and the cross slide will also need to be able to be retracted out far enough.

Regards Nick.

Edited By Nicholas Farr on 11/11/2022 14:17:23

[Mike FreemanParticipant @mikefreeman95253]

Thanks for the replies.

I'm currently trying to decide on a loco to eventually build but it will be something suitable for a beginner. I was thinking of a small tank loco such as the Boxhill or Simplex which both have 4 3/8 wheels.

Other than the size of the parts would this machine be man enough to do the job?

Regards

Mike

[Clive Brown 1Participant @clivebrown1]

Hi Mike, welcome. The SC3 will machine almost all of the Stuart engine range, and also most 5" locos, the exceptions being designs based on large, main line prototypes and, say, single wheelers such as the Stirling. I'd go for the longer lathe bed length as the 300mm version sounds a bit short to me for comfortable working. An issue that I'd see with the small, far-eastern offering is the fairly high bottom speed, over 100rpm in many cases. This is on the high side for machining large diameter castings although the Simplex isn't too bad at 4.375". My Boxford has a low speed of <40 rpm and that can be useful.

Be aware that any 5" loco is a major undertaking in terms of cash and perseverance, don't under-estimate this.

Another essential will be a basic milling capability, these days usually by a milling machine, but a vertical slide for the lathe will suffice. I've built a Simplex using one.

Best of luck.

[Nick Clarke 3Participant @nickclarke3]

I bought the sc3 a few years ago and can recommend it as a first lathe. The only drawback is supposed to be power at low speed as it has no back gear – but it has never proved to be a problem for me.

Basically I felt the advantages of buying new with a guarantee far outweighed the suggestion to buy a second hand unknown quantity that I would not only not know if was any good and would not know how to rectify if it wasn't.

The only issue with asking this question is that there are people like me who own a mini lathe (although I have used many different types over the years) and those who have bought second hand lathes – not many of us do both.

[Nick Clarke 3Participant @nickclarke3]

As you are intending to build a loco are you going to join a club with a track to run it on? If so many clubs have workshops where jobs too large to do at home could be machined.

Possibly an indication of your location (but definitely NOT your address) might bring forward some club suggestions

Edited By Nick Clarke 3 on 11/11/2022 15:10:42

[not done it yetParticipant @notdoneityet]

Good myfords (and some, err, less good ones) seem to fetch high prices.

I have neither a myford, nor a chinese lathe. The attraction of a new lathe, for a beginner, might well outweigh the urge to buy second hand. Arceuro are a respected supplier and are well-recommended on the forum. I’ve never bought a main machine from them, but most of my other requirements are sourced from there.

[SillyOldDufferModerator @sillyoldduffer]

All lathes have pros and cons.

The SC3 is a mini-lathe like the one I started with, except mine had a fancy digital controller with an RPM display and a slightly more powerful brushed motor. However, RPM is only mildly useful and cheap point and shoot meters are easily had online. Also, the latest SC3 as sold by Arc has a brushless motor, efficient, no brushes or commutator to wear out, and markedly better slow speed torque.

Physically the machine is what the American's call a 7×12 lathe, meaning it can turn a maximum of 7" in diameter, and 12" in length. Both figures are optimistic, requiring the operator to jump through hoops as the maximum capacity is approached. For that reason, unless specifically doing small work, beginners are advised to buy the biggest lathe they can manage. It's because big lathes can do small work at a pinch, whilst small lathes are useless when the job won't fit. The diameter of the hole in the spindle is 20mm, which can be a problem turning long rods or pipes.

On the face of it a 7" (180mm) lathe should hold most of what's needed for a 5" gauge but I'm not a loco builder. I guesstimate the biggest part to be the driving wheels, about 100mm in diameter. These could be turned in a chuck with a stub-mandrel, or bolted to the faceplate. Which loco is it? Someone who has built one will know what the largest part is.

Mini-lathes don't take up much space, are quiet, and a one man lift provided you're in good health. (Too heavy for this retired office worker now!)

Disadvantages:

• The minimum speed is too fast for powered screw-cutting. Not a problem, you make a hand crank and turn the chuck manually. Bit slow, but hand cranking provides loads of torque and wonderful control – you won't wreck the machine by crashing the saddle into the headstock at high-speed!
• The change gears are fiddly to set up because they're cramped. Just takes longer to move gears about on a mini-lathe than most bigger machines.
• Being a small hobby machine the lathe isn't really rigid enough to take fast deep cuts. Cuts steel fine, but the operator has to work within the machine's limits. Again, it just takes longer to remove metal than a big lathe. They get the job done with light cuts rather than the heavy hacking preferred by a short-tempered gorilla in a tearing hurry!
• Although vertical slides for milling are sold for these machines, mine was very frustrating to use. Only light cuts are possible, takes an age to set up, only small objects will fit, etc, etc. A waste of money. Real milling machines are in a completely different league.
• The slide doesn't have any T-slots, which makes it difficult to fit a rear tool-post for trouble free parting off, and to mount work on the slide. The latter is handy for boring cylinders parallel. Some owners have milled slots or drilled and tapped the slide to hold work.

I learned a lot from my mini-lathe and only swapped up because it turned out to be too small for about 20% of what I wanted to do. Next step up hobby lathes also fix most of the disadvantages listed above. An SC4 is usefully bigger, and a WM250 bigger yet again. I run a WM280 which is rather bigger than a Myford 7, and the biggest machine I had space for!

Three other cutting machines are also extremely useful:

• A band-saw saves an enormous amount of tedious hack-sawing
• A milling machine does most of the metal cutting you can't do conveniently on a lathe, filing, drilling, slots, gears etc.
• A bench grinder, essential if you use HSS cutters rather than carbide inserts

Dave

Edited By SillyOldDuffer on 11/11/2022 15:46:31

Edited By SillyOldDuffer on 11/11/2022 15:47:39

[Nigel Graham 2Participant @nigelgraham2]

Nick –

Re retracting the cross-slide enough for large diameters (wheels).

I've sometimes overcome that problem by using a left-hand tool mounted to project "sideways" from the outer side of the top-slide. Rather than the conventional pointing inwards set-up.

Nevertheless the biggest lathe you can sensibly manage to buy and install is the real answer!

[BufferParticipant @buffer]

It would be worth buying the book a beginners guide to model loco building by Tim coles. He explains all this stuff for you.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Nigel, I have done similar on my Boxford, but it's not always the best idea and at times when the diameter is on absolute maximum, there is more overhang than I wish for, as the saddle won't go close enough, so you have to be aware that your cuts can't be too heavy, and if you have a larger diameter in front of where you need to machine, it makes even more overhang as the tool post itself maybe in the way. Not something a beginner needs to try doing.

Regards Nick.

[JasonBModerator @jasonb]

SC3 is a 7 x 16 not 7×12

Just use carbide tools and you won't have to worry about needing a slow speed for larger diameters. In fact using a higher speed than the lowest setting is an advantage in getting more performance out of the motor.

SC3 can be run backwards without fear of the chuck unscrewing so no need for a LH boring bar, just mount a standard RH one upside down and hold in the side of the toolpost closest to you.

Likewise if you screwcut away from the chuck you don't need a slow speed to allow for reaction time

[HOWARDTParticipant @howardt]

I have an SC3 and have most of the frame, cylinders and all wheels, in other words the working elements of both a 5” Super Simplex and 3 1/2” 9f made and roughly assembled. All parts were turned and milled from solid bar, no castings. A little ingenuity is needed at times but most of the 9f milling was done on an SX2. Yes the SC2 does have its limits but one of the things I did was use the mill as a vertical lathe to turn the rims of some of the wheels, more out of curiosity than need.

[BazyleParticipant @bazyle]

Just looked at the prices. I'd go for the Myford on the for sale links on the right of this page although I'm not normally a fan of them and know little about the post war ones. However I believe that Keith Wilson who wrote extensively in ME years ago and also made locos professionally used one even for 7 1/4 in Kings.

[Mike FreemanParticipant @mikefreeman95253]

Thanks for all the replies, some great advice here.

I would rather buy a new machine if possible. I just don't know enough about it to check what I'm buying and whether it's set up and working properly.

I live in Ashford Kent so will join one of the local clubs at some point. There is one in Romney Marsh and also Canterbury.

The main aim really is to learn machining skills. Ending up with a loco will be a bonus as I've always been interested in railways but there is no rush to get it built. The whole thing is a learning exercise as much as anything.

[HollowpointParticipant @hollowpoint]

I'm not a big fan of the Chinese mini lathes. If it was my money I'd be looking for a good Myford ML10.

[Howard LewisParticipant @howardlewis46836]

As a beginner in machining, may I caution you to learn your trade BEFORE machining expensive parts for a loco.

Better to make your mistakes, and learn from them, on a piece of relatively cheap mild steel, rather than a costly casting.

It may better to,learn the basics by starting with High Speed Steel tooling.

Find a local Model Engineering Society and join. You will be among like mined inviduals, who can advise, guide and SHOW you how to do things.

Buy one or more books; there is quite a list.

Dave Clark, David Fenner and Neil Wyatt have all written books on the mini lathe.

Stan Bray, Harold Hall and L H Sparey have all written books on lathe work,in more general terms

Any one of these will provide useful information and advice.(Which will answer a question almost before you have formed it, and solve a lot of puzzles )

Do buy a set of Zeus Charts. I till regularly use the one bought bin 1958!

Where are you located? There may well be one nearby.

You can learn how the various clearance angles affect the way in which a tool cuts. (Carbide will cut harder materials, but moulded tips are not as sharp as well ground HSS tools. Ground tips are good, but don't take kindly to being banged.

As a beginner, you will have collisions, in all probability, One of the mistakes that we all have made, even if we won't admit to them!

HSS will stand a lot of abuse.

Basic projects enable you to learn, gain experience, and confidence, and a tool which can be used for years to come.

My suggestion for a first, would be a Centre Height Gauge. making this will give experience of Facing, possibly straightforward turning, Drilling, using a Tap and a Die.

Once made and set tools can easily be set to Centre Height, so that they cut properly. (If not at Centre Height, they won't, and will leave a pip around the real centre point of the work ).

If you want to, you can make one or more Tap Wrenches, or a sliding Tailstock Die Holder, maybe even a sliding Tailstock Tap Holder (A protege is making these currently!)

HTH

Howard

[SillyOldDufferModerator @sillyoldduffer]

Posted by Hollowpoint on 11/11/2022 20:38:58:

I'm not a big fan of the Chinese mini lathes. If it was my money I'd be looking for a good Myford ML10.

Tread carefully though. Because many overvalue the brand in my opinion, prices tend to be high, even if the machines are worn or damaged. ML10s used to be a good buy, but prices have shot up even though they're distinctly inferior to other Myfords.

Perhaps I'm jaded because second-hand lathes are rare where I live whilst everyone else is surrounded by bargain machine tools in tip top condition! For me it was much safer and considerably less fuss to buy a mini-lathe. Didn't regret it.

Dave

[Robert Atkinson 2Participant @robertatkinson2]

Speaking as a Myford owner and a ARC Eurotrade customer (mill and tooling), I suggest you purchase the SC3. It will do most of what you want, their service is excellent and If you do decide to get something bigger later it won't have lost much value unless you abuse it.
Buying a decades old lathe is a risk especially if you have nothing to compare it to. Yes they can be great projects and even a early ML7 is very capable if it's in good condition. But most are not and parts are expensive. Even the bolts are old sizes so you will have to get at least a couple of BSF spanners etc. If you have not used a lathe before it will be hard to know what is right and my blame yourself for issues caused by the lathe and vice-versa.

Remove some variables, don't learn about outdated systems (single phase motors that need a clutch for example) Get the SC3-300 HiTorq

Robert G8RPI.

[JasonBModerator @jasonb]

Just to set the record straight again

SC-3-400 is 400 between ctrs (16" )

SC2-300 is 300 between ctrs (12" )

The extra 100mm of the SC3 makes it the better option. Both come with the Hi Torque Brushless direct drive motor (no gears to mash)

[HollowpointParticipant @hollowpoint]

Posted by SillyOldDuffer on 11/11/2022 22:17:46:

Posted by Hollowpoint on 11/11/2022 20:38:58:

I'm not a big fan of the Chinese mini lathes. If it was my money I'd be looking for a good Myford ML10.

Tread carefully though. Because many overvalue the brand in my opinion, prices tend to be high, even if the machines are worn or damaged. ML10s used to be a good buy, but prices have shot up even though they're distinctly inferior to other Myfords.

Perhaps I'm jaded because second-hand lathes are rare where I live whilst everyone else is surrounded by bargain machine tools in tip top condition! For me it was much safer and considerably less fuss to buy a mini-lathe. Didn't regret it.

Dave

I agree the Myford brand in general is overvalued and some models in particular have a cult like following. I also agree that the ML10 isn't as good as the ML7 and super 7. BUT, in my opinion the ML10 is generally found in good condition since it was aimed at the hobby market, even so it is still a much higher quality machine than a mini lathe.

I have a SC2 mini lathe and it is literally riddled with problems, inaccurately ground bed and dovetails, tailstock alignment problems, faulty electrics, gear train misalignment, etc etc. They were never built to a high standard from the get go and so these problems aren't easily fixed. In my opinion it better to have the basics right. What's the point in having a powerful brushless motor for example if the cross slide has zero rigidity? My brand new out of the box SC2 felt like it had already been used for 50 years. Unfortunately I have found this to be true across several Chinese made lathes. My C0 and C1 lathes had similar poor build quality.

The ML10 on the other hand may not have all the bells and whistles but at least it was built properly in the first place! it's better to start with a good solid base and bring it up to date with a VFD and DRO's later.

[HopperParticipant @hopper]

Myford prices seem to have come down a bit since the great Covid slump. ML7s can still be found at reasonable prices, and nothing wrong with an ML10 in good shape either. Super 7s seem to have gone crazy and don't really offer a lot more than an ML7, other than some "very nice to have but not essential" features.

Other British lathes such as Boxford and Raglan tend to offer better value for money. They are slightly bigger, better built lathes that cost more than a Myford when new but now seem to sell for less as they don't have the cult status.

But buying a used lathe is like buying a used car: all right if you know what you are looking at. A minefield if you don't.

The other alternative is the SC4 Seig lathe. That bit bigger and more solid than the SC3. Worth looking at.

[Mike FreemanParticipant @mikefreeman95253]

I am bidding on a ML10 on ebay, it's from a model loco engineer so hopefully in good shape. Not sure how high to go but if it gets anywhere near the price of the SC3 I'll give up.

I know people say to get the biggest you can but space is at a premium in my workshop and a smaller SC3 or ML10 would fit nicely on the bench. I don't want to make myself short of space for the sake of a few things I could get done on someone else's bigger lathe.

I think I have settles on a Don Young 4F as my first model but will be working on general bits to learn some skills before I work on that. I'll be 'building' it in CAD first so I know exactly how it goes together.

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