Mini Lathe and Accessory Advice Please.

[Chris]

Stub Mandrel,

Very impressive machining there! The spokes on the loco's wheels must have taken a lot of time and patience.

Thanks for the link to your site, I'll spend a bit of time looking on there and see what I can learn

Yeah, I've now realised that I'm going to be limited in what I can achieve unless I cut through my obsy pier and use the 6x6' section of my obs as the workshop. If I decide to stick to the plan of a new mini lathe I will pick the Super C3 or Warco180 and just accept that I'll be taking small cuts and working on 2-3" workpieces. However I've now started to look on ebay a bit more also just in case one comes up local that I feel comfortable with.  

Thanks for the link regarding cutting metric threads on imerial lathes and the other way round, I've pretty much got the idea behind the 63 tooth gear now

[Ajohn]

Can't remember what the minimum speed was but I have screw cut on  Hobbymat. It's not too bad if the pitch isn't too coarse. The thread was whatever UNF size is used to attach electric drill chucks. Emco items tend to be a bit expensive when they can be found so I found a cheap morse taper reamer to fit the tailstock and parted off enough to make a morse taper arbour. Turned to the correct diameter and then screw cut it. This was up to a shoulder. That meant that I had to have a gap at the end of the thread to the shoulder that was big enough to allow the lathe to stop when it was turned off without the tool hitting the shoulder. Fortunately lathes stop pretty quickly when screw cutting is engaged. Easy to find out how much space is needed - just try it without taking a cut. Sometimes it's possible to turn a short section at the end of the thread that is below the root diameter of the thread being cut even just using the screw cutting tool. Saves having to wind the tool out when the lathe is being turned off. It can be useful when cutting internal threads as well because the sound from the lathe will change when the tool enters the recess.

I thought Myford Super 7 and ML7 lust might crop up. Most of their fame really is down to commercial interests - all of the things that have been designed to be made on them and the publicity that gives. In real terms they are budget lathes of their day with the attraction of being relatively light for their size. They can have all sorts of problems and can also be incredibly good in terms of surface finish especially the Super 7 but unfortunately some parts wear rather rapidly if they are used a lot and also as is often the case not that well maintained. The lathe bed is a very poor design really even of it's type, that causes a lot of the problems. ML7's need shims available under bearing caps so that they can be rescraped when needed. Adjusting a Super 7 headstock to achieve what they are capable of is very difficult and wear is likely to prevent that anyway. ML7's for some people are more popular as they can drill bigger holes than a typical Super 7 - the headstock on those really is tricky to set up.

I owned one of those 3 in 1's too. Mills and drills after a fashion, turns a good finish if adjusted correctly but the general alignment of things was awful. I spent some time trying to sort it out, got very annoyed with the suppliers, water off a ducks back and sold it on very honestly to a garage owner who wanted to impress his customers and the main requirement was shortening bolts. I still used the supplier when I had too and looked at a used Super 7 they had just got in. For some reason they decided to be honest with me this time - the previous owner made model aircraft engines on it so it MAY be ok. The chances are that the engines were sold on and the lathe had been used a lot. Could be it was time for another. He had obviously made a lot of them. I also came across a Boxford locally. Home turner who made a living doing batch work at home. Time to get another one due to wear even though the tolerance requirements on parts like that are pretty low as people who put that sort of work out generally don't expect much from a lathe. A lot of this sort of thing has gone on using cheaper semi pro machines for a long long time which is why they can be so bad generally. Home machinists are also seen as easy picking by some. There are all sorts of dealers about even some that look like they are model engineers. Some are. My 1st milling machine was a barely used Chinese. My 2nd was a Dore Westbury. Both owners thought that the machines were hopeless The 1st one just needed adjusting correctly. The next owner was very happy with it, I  phoned to check as forgot to give him the manual. The DW was risky, they are sort of home made but the work looked to be of a very high standard so I risked it. He demo'd it end milling with a slot drill, poorly adjusted and using a vice that just isn't up to milling. Interesting machines. I've come across a few people with them, all seem happy. Might be because anyone who took on actually making one would need to be pretty skilled to even try. I'd guess in my case a retired toolmaker.

There's basically no easy route to home machining that doesn't have it's risks. I'd have saved some money if I had listened to my father. Metal removal was his expertise. He asked me what lathes they had at school. I had used one of them and noted the make next time I went into the metal work shop. Boxford, comment those aren't bad they are based on an American Southbend. His idea of a good small lathe was a fully equipped CVA. If only, the head is probably 1/2 the length of a Myford but they are short for this sort of thing. Equipment would be a problem too. He was also looking for several lathes to fit into vans to go to various motor racing meetings and the people who went asked if they could have Myfords so he went there for a demo. He was very impressed with the finish they obtained on a super 7. As this sort of thing was his business he took a look at the headstock bearing arrangement and told me that it was down to the huge cone bearing they used at the front. And then added I'll bet they adjusted it just before I arrived and also had run it for some time. I'll add that Myford may have had a source of good quality free cutting mild steel in black bar as well. If it can be found it is way better than bright bar. He bought Chipmasters instead 2 reason, bearings and also that the people who would be using them would break several things on Myfords especially the T slots if they use them. Wish I new what millers he had put in them. Probably too big for me anyway.

Are Boxfords great - no but my feeling is that lathes that use a headstock with rolling type bearings in it and a fairly sensible bed design have fewer problems than others. I could tell other hard factual tales about Myfords but it wouldn't serve any useful purpose. There can be problems what ever any one buys and lightly used machines are not that easy to find.

John

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[Chris]

Ajohn, wow, this thread is turning into quite a resource! Thanks for your very detailed posts and your explanation about metric machines and threads, I read through it last night and will probably refer to it again just to make sure I've got the full jist. So from what I can gather so far you have to stop the machine with each pass on a metric lathe due to the lack of a screw cutting indicator, but its still doable if not as quick perhaps. 

[Chris]

My other hobby is model engineering, here is my experience for what it is worth.

I cannot recommend a Chinese lathe. I bought  a new 3 - in -1 a few years ago which I completely stripped down and rebuilt before use. I cleaned an egg cup of sand out off the headstock, I replaced all of the red grease, much of which had dried out. I had to hand finished all of the castings and machined parts before I dare reassemble and set it up. Even after all that, it just did not come up to a standard I could recommend. In the end I used it largely for roughing out, and later sold it.

I have had a Unimat  SL, 3, and 4. They are ok but only for very small work. Unless you are a complete novice (in which case they are excellent to learn on because you are less likely to injure yourself) their limitations will soon frustrate, and they can work out dearer than a larger machine by the time they are fully accessorized.

I still have several Austrian made Emco 5 machines, bought second hand, which are very good and easily work to "tool room" standards. I use them to make narrow gauge steam engines in "16mm" scale on 32mm gauge (SM32). However little steam engines don't require screw cutting, and like most small machines, it runs too fast for screw cutting. If necessary, I would hand turn by making a winding handle to fit on the rear of the spindle.

I regularly use a friends Myford Super 7, which is a superb "tool room" machine with low speeds for screw cutting. It is undoubtedly the most popular and versatile model engineering lathe but it comes at a price, expect to pay four times the price of an Emco 5. It is also twice the size.

A machine I have often admired, and were my Emco's ever to wear out (extremely unlikely), I would most likely buy a new Proxxon PD 400.

Do remember that the lathe is only part of the cost. You will also need a lot of  other bits and pieces, if you don't already have them.

Hi and thanks

I've started looking at some second hand lathes also, and I've decided to sell my ES100 degree eyepieces to help buy the extras needed, I'm pretty happy with my Luminos EP's anyway so I think I can just about bear to part with them.

Here are a couple of lathes I've been looking at on Ebay:

This one looks nice but as said is perhaps a bit light duty

http://www.ebay.co.uk/itm/Stunning-Elliott-Emco-Unimat-SL1000-Lathe-Austrian-made-English-Ash-Base-/201367562837?pt=LH_DefaultDomain_3&hash=item2ee2712a55

not sure about the size of this one

http://www.ebay.co.uk/itm/smart-brown-lathe-/111701275756?pt=LH_DefaultDomain_3&hash=item1a01ea346c

This one looks very good

http://www.ebay.co.uk/itm/EMCO-COMPACT-5-LATHE-MAIER-CO-WITH-LOADS-OF-EXTRAS-PLUS-THE-EMCO-MILLING-HEAD-/281732013966?pt=LH_DefaultDomain_3&hash=item4198895f8e 

[RLWP]

Ajohn, wow, this thread is turning into quite a resource! Thanks for your very detailed posts and your explanation about metric machines and threads, I read through it last night and will probably refer to it again just to make sure I've got the full jist. So from what I can gather so far you have to stop the machine with each pass on a metric lathe due to the lack of a screw cutting indicator, but its still doable if not as quick perhaps.

Do be careful now. This subject is just as complicated as 'what telescope should I buy?'. Eventually, you are going to have to go back to basics. What can you afford, what do you want to do with it, how often, where will you put it?

I have a fantasy machine tool shopping list with a BCA borer, a Schaublin lathe, a hob and drag attachment for my lathe, and lots of other esoteric things on it. In reality, I turn, face, bore and part off a lot. Occasionally I cut threads with taps and dies. I use the lathe for cleaning things quite a lot (valves for engines). Very infrequently I cut ordinary threads. Once in a blue moon I cut weird threads. I do spherical turning far more frequently than I screw cut.

Have a think about what you might do with the lathe. If you want a real dampener, work out what it would cost to get parts made instead of buying a lathe and all the tooling you will need

Helpful?

Richard

[Chris]

Do be careful now. This subject is just as complicated as 'what telescope should I buy?'. Eventually, you are going to have to go back to basics. What can you afford, what do you want to do with it, how often, where will you put it?

I have a fantasy machine tool shopping list with a BCA borer, a Schaublin lathe, a hob and drag attachment for my lathe, and lots of other esoteric things on it. In reality, I turn, face, bore and part off a lot. Occasionally I cut threads with taps and dies. I use the lathe for cleaning things quite a lot (valves for engines). Very infrequently I cut ordinary threads. Once in a blue moon I cut weird threads. I do spherical turning far more frequently than I screw cut.

Have a think about what you might do with the lathe. If you want a real dampener, work out what it would cost to get parts made instead of buying a lathe and all the tooling you will need

Helpful?

Richard

lol yes Richard that is a real dampener but it's good to get a reality check

I don't need need a lathe and could just get Moonraker to machine custom parts for me. I've not got quotes but I think it would very quickly add up to the cost of a mini lathe lathe. I also want to machine my own parts so I can say I 100% made it.

I would like to make a long focus refractor f12/13 ish, which is a real niche market now days. Moonraker and Skylight do these but at a premium price for their work and craftsmanship that goes into each scope. I would like to see if it's possible to build one but would need to machine a counter cell and focuser flange to go with any achromatic objective in a cell that I source.

If it's achievable to build an attractive 80-100mm long focus classic looking refractor for less than 600 pounds I would have saved myself 2000 pounds on getting the lovely machined Skylight 101.15 from Richard Day, or 1700 on the fantastic looking 4" f13 from Moonraker. Not that mine would be anywhere as good but I would have made it which would give me a buzz.

Other things I want to do:

- Turn an objective dust cap for the brass dew shield of my Skylight 60mm (currently has a plastic pot on the end ) 

- Posh 1.25 and 2" focuser plugs with a bore for fitting desiccant packets. 

- Agena astro have stopped making focuser flanges for the C100ED, so I want to turn one for my C100ED so I can get a better focuser without having to fork out for a Moonlite. 

Someone should really turn some better focuser knobs for PST's, that's another idea ( I would want a knurling bar for that)

ok the next ones a bit sad but ever since I sae Shawshank Redemption I've wanted to turn my own chess pieces

I'm fairly sure there are more things I can do with a lathe and it's jut nice to do it by yourself rather than getting someone else to do it. I have a chess set but not one I've made (not that I've got anyone to play against now days).

It would be cool to make a collimation cap maybe.

Maybe after lots of little turning projects the lathe and kit will eventually pay for itself?

oh yeah, maybe I can turn a nice steampunk style RDF/finder, that would be up my street.

[Chris]

Another turning job I'd forgot about, I could really do with a couple of slip rings for my eyepieces that don't have enough back focus for my Lunt 35. Another idea would be a little helical focuser for a finder but that would off course need screw cutting.

[Ajohn]

Ajohn, wow, this thread is turning into quite a resource! Thanks for your very detailed posts and your explanation about metric machines and threads, I read through it last night and will probably refer to it again just to make sure I've got the full jist. So from what I can gather so far you have to stop the machine with each pass on a metric lathe due to the lack of a screw cutting indicator, but its still doable if not as quick perhaps. 

Not precisely. When cutting metric threads some pitches mean never disengaging the screw cutting so when a thread cutting pass is at the end the lathe has to be turned off and then run back to the start by running the lathe in reverse. If there is no screw cutting indicator may as well say that this always has to be done and it's a very slow process. If there is one the ability to use it depends on how complex it is and the pitch of the thread that is being cut. Some will be ok with more pitches than others. I tried to explain why this happens.

Switch to an imperial screw cutting lathe with a screw cutting indicator and common pitches, a very wide range of them in other words can be cut by disengaging screw cutting and winding back to the start by hand and then re engaging using the indicator. Fit gears to cut metric threads and it will be the same as a metric lathe with no indicator but I explained how the indicator can help screw cut up to a shoulder. Also more recently how to screw cut with these when there is no indicator. That is the same on either style of lathe metric or imperial when there is no indicator.

There are more variations. Some fit a large handle on the end of the lead screw - they cut coarse pitches by turning it by hand or any pitch they feel uncomfortable with the speed the lathe is running at. This also helps to cut up to a shoulder. Some might even cut with the lathe and wind back with a handle.

There is one other area that makes me stick to imperial machines that may not apply to smaller ones and that's the graduations on the dials. It's back to King Henry's thumb again. By some fluke 1/1000 of it's width happens to be a very practical graduation for a machine. It's even possible to judge small fractions of them accurately. It just happens that this works out with lead screws that have a sensible pitch that wont wear out too quickly. The graduations on metric lathes are often a lot coarser due to the physical length of a mm. On small lathes they tend to use smaller pitched lead screws which will get round this aspect but often on larger stuff they don't.  I need the accuracy some times. Curiously the same thing applies to measuring instruments. A mic for instance can measure with some hope of giving a real reading down to 1/10,000 via a vernier scale. The answer on metric is to go digital and supposedly go to 0.001mm. 2 facts, measuring to that accuracy with simple gear isn't that simple and to try and do it the mic's get cumbersome to use. A metric mechanical mike can measure reliably via it's vernier if it has one but the units are odd.   I often feel this must all be anthropic - some round here will probably know what I mean. The other weird thing is that I can measure with an imperial engineers rule to better than 0.005in. Those have to be bought from the USA these days. There were some attempts to get round this area. I came across some metric Boxfords. The cross slide lead screws had a 1.5mm pitch. I suspect they may have been specials for schools.

I was around toolrooms and drawing offices when some were metricated. It caused an extra ordinary number of problems all over. This included fitting dual scale dials to machines. Real fun to use because there had to be gap in the metric scale.

Some how I suspect this whole area has led to a vast increase in the sale of digital readouts once these had been introduced.

Actually I am perfectly comfortable working with either system and true in some areas metric units make the sums especially a lot easier. I'm not convinced this is the case when machining so have stuck mostly to imperial. I have had metric lathes. Other than where I have mentioned it makes no difference really.

John

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[RLWP]

This included fitting dual scale dials to machines. Real fun to use because there had to be gap in the metric scale.

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The nicest I came across was a lathe fitted with a direct and a geared dial coaxially on the cross and topslide. It would therefore always give both readings continuously

I am also reasonably bi-lingual, except I struggle to work out small clearances in MM. A couple of thou makes more sense

Richard

[RLWP]

Chris - that 100mm long focus refractor. Can you buy the lenses for £600? Playing fantasy telescopes, I don't think that is anywhere near enough.

Otherwise, most of what you want to do should be in the capability of smaller lathes. It's mostly turning, boring, facing and perhaps parting off. you may be screwcutting, although I can imagine careful design could eliminate a lot of threads. Any you do make you will probably be creating matching male and female threads so you can choose a pitch that is convenient to use with the lathe you have.

And, have you managed to find any plans for a classic refractor? I've searched the internet without success so far as Newtonians are simpler to make. I'm surprised there wasn't a design in the Model Engineer magazine from the early 1900's

Richard

Oh yes - chess sets. Sixteen identical pawns is bad enough, you'll die of boredom. Setting up for the rest to make four of each is a pain. Rather you than me

[Stub Mandrel]

Chris, that Smart & Brown is old but nice. It has a 9" swing. The little unimat would both fit on its bed, and is very basic (you really need screwcutting for astronomy accessories!) the Compact 5 is very similar to a mini-lathe in capacity, and well made..

The fact you are looking at lathes that are so totally different from each other (The three lathes you highlighted are like comparing a 12" Dob, a 2 1/2" refractor and a 5" mak).

I suggest you decide exactly what sort of work you fancy doing and that will allow others to advise how big, how accurate, & what capabilities you need.

That said, plenty of people buyt a lathe and fit their hobby to its capabilities (although they usually get stretched beyond what the manufacturer anticipated).

> just accept that I'll be taking small cuts and working on 2-3" workpieces

I never have. I have happily taken over 1/8"" cuts in steel at small diameters and turned 6" diameter laser cut flywheels (smaller cuts!") in rather tough steel on my mini-lathe.

Neil

[Ajohn]

Do be careful now. This subject is just as complicated as 'what telescope should I buy?'. Eventually, you are going to have to go back to basics. What can you afford, what do you want to do with it, how often, where will you put it?

I have a fantasy machine tool shopping list with a BCA borer, a Schaublin lathe, a hob and drag attachment for my lathe, and lots of other esoteric things on it. In reality, I turn, face, bore and part off a lot. Occasionally I cut threads with taps and dies. I use the lathe for cleaning things quite a lot (valves for engines). Very infrequently I cut ordinary threads. Once in a blue moon I cut weird threads. I do spherical turning far more frequently than I screw cut.

Have a think about what you might do with the lathe. If you want a real dampener, work out what it would cost to get parts made instead of buying a lathe and all the tooling you will need

Helpful?

Richard

 LOL if you obtained your dream machines you could well be disappointed. I did have a Schaublin for a while to resurrect. Proved to be too problematic so sold in bits. In order to get some information on it I joined the schaublin group who were very helpful. Most had larger ones that use more complex rolling bearing arrangements. This was the group that suggested I tried the tips I posted earlier when this sort of thing was discussed. All of them do excellent work but several of them were impressed with the finish I could get on silver steel on my Boxford. Some had excellent machines with no wear, virtually new. Totally different animal and the bearings for them are very very expensive so there is a need to have rather a lot of cash about if that needs fixing.  The problem with lathes is that people buy them to use and bearing wear far more than people might think if they are used daily for long periods. Beds too.

I wondered about a BCA borer too - such a name that silly money comes out just like it does on worn Schaublins. It would be nice to have the fancy bit that goes on the bed of some of these borers - I could stick it on my miller.

Lathes linked to

Early Unimat - think clock making on the cheap. That needs a lot of generally expensive bits and pieces if you fancy doing it.

Smart and Brown - that's a collet lathe and a very old one. Don't know what type of head stock bearing it will use. Collets are wonderful for some things but chucks are far more useful and may be a problem to find or fit on that one. That sort of lathe at that age could well have been used daily for 5 1/2 days a week some where.

Emco - that sort of milling arrangement can be useful but usually a small miller is a better option. Lathe - pass depends on a lot of things such as wear and tear. It probably uses standard sized bearings in the headstock so they could be replaced. It might not. The only way to tell really what is what with them is to use them and to be really sure take some tools, a mic and some steel with you.  Much the same with any machine. For some reason it's missing it's 4 jaw - unusual. A lathe of this make might have had a fairly easy life. There are tools  with it which may have been made on it. Some possibility that this is a good sign.

If you post a link to a lathe I don't think anyone will say buy it.

John

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[Chris]

Chris - that 100mm long focus refractor. Can you buy the lenses for £600? Playing fantasy telescopes, I don't think that is anywhere near enough.

It's just like anything you can pay a little or a lot for a 80-100mm long focus achromat objective.

Cheapest way = find a vintage Towa or Kenko 80mm f/15 refractor on ebay for 100 quid. I nearly had my hands on one from ABS but the deal fell through so I'm still keeping my eyes peeled. These lenses are the ones used by Moonraker.

New quality lenses in cells your best bet are Istar where you could get a 6" f15 !! for 600 plus shipping, or a 4" f12 for about 330:

http://www.istartelescopes.co.uk/page_2414078.html

Budget wise here for 109 pounds 4" f12:

http://www.astrophoto.co.uk/surplusobjectives.php

A very rare 4" f15 lens crafted by one of the best at a premium of 600 pounds (too steep for me)

He does have some budget 83mm f12's for about 160 pounds and will ship for free if you're in an astro society

http://www.irpoyser.co.uk/index.php?page=120

As I said I plan on making a budget classic long focus refractor with a budget of 600 pounds, which bit of this is fantasy?

Thanks for your help on the lathe front

Yes it would probably be boring making the chess set, but we all have quarky things like that on our bucket lists don't we?

[Chris]

Chris, that Smart & Brown is old but nice. It has a 9" swing. The little unimat would both fit on its bed, and is very basic (you really need screwcutting for astronomy accessories!) the Compact 5 is very similar to a mini-lathe in capacity, and well made..

The fact you are looking at lathes that are so totally different from each other (The three lathes you highlighted are like comparing a 12" Dob, a 2 1/2" refractor and a 5" mak).

I suggest you decide exactly what sort of work you fancy doing and that will allow others to advise how big, how accurate, & what capabilities you need.

That said, plenty of people buyt a lathe and fit their hobby to its capabilities (although they usually get stretched beyond what the manufacturer anticipated).

> just accept that I'll be taking small cuts and working on 2-3" workpieces

I never have. I have happily taken over 1/8"" cuts in steel at small diameters and turned 6" diameter laser cut flywheels (smaller cuts!") in rather tough steel on my mini-lathe.

Neil

Hi Neil, they were kind of selected by geography which I realise isn't the best way to choose a lathe lol.

The first lathe looked too big to me but it was tricky to tell with there being no measurement. I was wondering if you could use a chuck with it and from reading Johns later post I'm not so sure. It is very close and cheap so I thought I would link it to get your guys opinions. Pretty much not for me by the sounds of it as I'll be mainly making small astro bits and bobs with the odd slightly larger ali job.

The second one had a postage option and didn't look too big, I didn't realise quite how small and basic it is so again not for me.

The third one I chose because someone mentioned they liked Enco, it looks about the right size at a guess but is a little on the far side.

I think this illustrates that I don't really know what I'm doing on the second hand market, so I'll probably get one of the Chinese 'kit' mini lathe, either the C3 or Warco 180. For the price of them I can't really complain too much if they are not 100%.

It's good to hear you're able to use these mini lathes in anger at least, you must have got a good one!

[RLWP]

I never have. I have happily taken over 1/8"" cuts in steel at small diameters and turned 6" diameter laser cut flywheels (smaller cuts!") in rather tough steel on my mini-lathe.

Neil

Indeed

What's you shunter based on? It reminds me of the one that was stood at the brickyard on the Stoney Stanton road, Coventry

Richard

[RLWP]

I think this illustrates that I don't really know what I'm doing on the second hand market, so I'll probably get one of the Chinese 'kit' mini lathe, either the C3 or Warco 180. For the price of them I can't really complain too much if they are not 100%.

I would strongly disagree with this. You'll get a better deal with an older lathe. If it has come out of a factory or toolroom, it's probably going to be quite tired. If it has come from a home workshop, chances are it's had very little use. I'd be surprised if you bought an irredeemable dog that way. 

On the other hand, you are immediately giving away the VAT on a new lathe, equivalent to quite a bit of tooling and measuring kit, and will be more likely to be buying something with some quality to it.

Richard

[GraemeC]

If you get a chance, go and have a look at the type of machines you are considering. I did just that, I visted a new chinese lathe warehouse in the NW a while ago. Lathes and other machines from mini lathes to major engineering equipment. It kind of confirmed my view that, for me, the build of the Chinese machines wasn't good enough until you started spending more serious money. So my money will be saved for a used Boxford AUD, it's a compromise between size, capability, not too fashionable to be expensive but with a reasonable pedigree. My workshop is on my list of things-to-do right after my roll-off roof observatory graeme

[Ajohn]

Talking refracting telescopes and tubes I had reasons for mentioning getting nice square ends on drain pipe on a Peatol / Taig. The limitation is how large a diameter can go through the fixed steady and when metal fingers are used on those it's not a bad idea to modify them slightly by adding a small ball race to the ends of them.

The tube is best gripped with the outsides of the usual 3 jaw chuck jaws or the 4 jaw if it's to be set central. It might distort the tube depending on thickness. Have enough spare past the chuck to prevent that being a problem. There will be no tailstock on the lathe so the tube can be as long as required but at some point a support could be added - say a V in some piece of wood. The inside of the tube can't be bored. The outside can be turned within the length between the chuck and fixed steady. The whole tube can be polished but the steady may need moving along at some point. The outside of the tube can be screw cut if needed. When finished just part the wanted piece off leaving some on the chuck. The travelling steady can be used too which depending on design will prevent the tube from tipping when it is parted off if a bit of pressure is applied to hold it in it while the fixed steady supports it. Some sort of lathe external support could be used as well.

When it's parted off the outer cut will be square and clean. The inside may have some fraise easily removed with a deburring tool.

When I did some drain pipe I just supported it with my hand and the fixed steady - smooth dia etc well away from the parting tool and nothing to catch fingers on.

There are other ways of holding the tube. Turn up something to be a firm fit in the bore of the tube. A slight taper can help. Tap the tube onto it, square the end with a parting tool, do what ever to the tube and when finished tap it out.  This is the sort of thing that might be done on to a morse taper arbour if some one wanted to make a lot.

Fixed steadies are very useful. They can also be used to do work on each end of pieces of bar the can't be fitted on the lathe but parting off gets more tricky. The bar will need additional support.

John

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[Chris]

John, thanks for clarifying the benefit of an imperial lathe for screw cutting, it does sound like a better option all things considered. I can always stick a little conversion chart on the front of the lathe until I get my brain used to tenths of thou etc  

[Chris]

I would strongly disagree with this. You'll get a better deal with an older lathe. If it has come out of a factory or toolroom, it's probably going to be quite tired. If it has come from a home workshop, chances are it's had very little use. I'd be surprised if you bought an irredeemable dog that way. 

On the other hand, you are immediately giving away the VAT on a new lathe, equivalent to quite a bit of tooling and measuring kit, and will be more likely to be buying something with some quality to it.

Richard

I'm learning that buying a telescope is much more straightforward than buying a lathe.

Maybe a cheap Chinese mini lathe is like a Synta achromats, whilst the older second hand lathes are like Vixen or Tal achromats.

Well it might be like that if it wasn't for all the moving parts of a lathe! 

[Chris]

If you get a chance, go and have a look at the type of machines you are considering. I did just that, I visted a new chinese lathe warehouse in the NW a while ago. Lathes and other machines from mini lathes to major engineering equipment. It kind of confirmed my view that, for me, the build of the Chinese machines wasn't good enough until you started spending more serious money. So my money will be saved for a used Boxford AUD, it's a compromise between size, capability, not too fashionable to be expensive but with a reasonable pedigree. My workshop is on my list of things-to-do right after my roll-off roof observatory graeme

Thanks, I'll Google it and see if there's anything similar local to me. 

were there any of the Chinese lathes that you thought were a good compromise at least?

[Ajohn]

I would strongly disagree with this. You'll get a better deal with an older lathe. If it has come out of a factory or toolroom, it's probably going to be quite tired. If it has come from a home workshop, chances are it's had very little use. I'd be surprised if you bought an irredeemable dog that way. 

On the other hand, you are immediately giving away the VAT on a new lathe, equivalent to quite a bit of tooling and measuring kit, and will be more likely to be buying something with some quality to it.

Richard

If you want to see what Stub does on small kit there is a thread on model-engineer.co.uk called don't do this at home. There is also a thread on tailstock errors on a seig c3. This also shows what Stub did to his. If the guy who is on about the tailstock error is correct it's not too bad at all really. If you read it you will notice I am not too happy with how he determined this and suggested how he should go about it. The truth is though for most work a 0.005in height error would give a slight increase in dia towards the tailstock - easily corrected by a slight but difficult adjustment of the tailstock off set. Not really worth worrying about for lots of work. The thread is called tailstock and stiff handle or something like that.

The problem is though that as often is the case certain things have been read on the web and he wont do what is needed to really see what the lathe is doing. Pity as that would give an idea just how good or bad these lathes are. As it is he is lapping the base of the tailstock and the outcome might be nothing like he expects. If the errors on the centres are minor there are much easier fixes. Seems some one has invented a new name for a DTI. I also came across a go to bar recently and assumed it was something virtual written in dartmouth basic. I feel some are trying to make machining less understandable by changing the names of things to something meaningless.

The model engineer site is some what commercial so there is always the chance that things aren't as they seem. However I asked how some stainless steel work had been finished as so and so gives great results. Where there were answers files and emery cloth. Any old lathe will do that. When considering lathes that aspect has to be remembered - filing rests have been very popular at times for producing parallel work. Wonder why they have been designed for Myfords.

It's hard to know what to advise some one who is considering buying a lathe to do other than don't rush and point out the problems. Perhaps the best answer is to buy and find out. Even a C3 has a 2nd hand value. There are still local model engineer groups about. That could help but there will still be people about who will sell any old thing without warnings. I don't think ebay is usually a good place to go for lathes especially cheap ones with little or no kit. To many people about who just must buy a lathe, Many who don't really know what they are doing. People might find themselves paying a couple of hundred quid for something that was found on a scrap heap.  I tried buying one like that once but set a limit of £50 and got it. Few would be interested in a plain lathe of it's size, a Boley with some rust. Not too difficult to get rid of that. And it did come of a scrap heap.

John

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[GraemeC]

Thanks, I'll Google it and see if there's anything similar local to me. 

were there any of the Chinese lathes that you thought were a good compromise at least?

From what I remember, I was looking at machines like the Chester DB10 and above. I was avoiding the 'model maker' categories and favouring the bottom end of the engineering machines.

[RLWP]

I'm learning that buying a telescope is much more straightforward than buying a lathe.

Oh yeah? None of a lathe is turning about more than one axis. This planet thing we are standing on though - well!

Your analogy is dead right. It has stuff about people's attitude to new or used equipment, brands, sizes, capabilities, features, etc, etc, etc...

What I think you will get from this thread is a bunch of things to think about that wouldn't be obvious working on your own. Ultimately, you are going to have to decide what lathe to buy, and then it will be the right decision for you

Richard

[RLWP]

 LOL if you obtained your dream machines you could well be disappointed.

John

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I should add in a cutter grinder, a Hotzapffel lathe, a rose engine...

Richard