Turning small diameters

I wasn't wound up by it at all. It makes sense to reply at the bottom. It's just us email types who have got into the habit of reading everything upside down, which is, after all, daft. Dave, ignore him, I am grateful for any advice.

Chas

Harry,

Maybe. There's also another one, who also does Amadeal or something, who says he has a relationship with Big Dog who supply the Real Bull clone. I am watching an Arc C3 auction that still has a couple of days to go with interest just to see how high it goes.

Or Arc or Chester or Axminster who do the Sieg C3. Or Warco or Clarke who do the C2. Honestly, I'm not much hooked on any particular supplier, and for the sums involved probably wouldn't pick the cheapest of all the clones. Maybe I'll pick based on colour, red is nice but green has a bit more of the authentic machineshop about it ;). Just kidding. Really I'd go for the one with the most accessories, it's not going to be a problem to spend as much again on bits of metal to screw onto it if i'm not careful. It's like my bout of home colour developing in the 70's - spend weeks choosing the right enlarger/lens and then spend 3 times as much on tanks, thermostats, colour sensors and what have you. And at the end of that you find that though you have a dark room that looks like a laboratory, you are actually practising an art not a science. Suspect something similar might happen with this.

I have joined that yahoo group and looked through the postings, though yahoo groups have a terrible search system, and much of the folklore on these machines goes back at least 10 years. But I'll persist putting in the key words and seeing if anything useful pops out. And most web forums are dominated by Americans, some of whom get obsessive about rubbishing any non-American manufacured goods, which makes it hard work decoding the truth sometimes.

My real bible is the Frank Hoosier minilathe.com site which I think is brilliant and by itself is a factor in whether to buy a Chinese 7x. Plus his example has encouraged others, so there's piles of stuff out there, by both good and novice machinists.

Chas

Dave, I guess this is getting a bit off the small diameter topic, but I don't mind if you don't mind being my unpaid tutor.

The graduated lead screw stuff: So I assume you are making the general point that being able to accurately position the lead screw and hence the feed position is a good thing, rather than something specifically to do with small diameter turning - yes? So, I was being dumb and thinking about the saddle feed handwheel. I see the point. And I see that many other lathes do have a leadscrew handle, and it is graduated.

Thanks for the pointer. The Harrison looks really nice, at a glance, but it's just too big.

Yes, that seems to be a consensus, both in this thread and elsewhere on the web. Now that I am clear that there's no issue with small diameters and a somewhat larger machine, I am sure I will plump for a bigger one.

Well, that comes into the same category as manual exposure on a camera. It's hard to say exactly when you will want it, but it seems like the sort of thing you ought to be able to do. So I would count this as a criterion. I have no idea whether I want imperial or metric.I suppose I would go for metric, aren't most threads metric now in the UK? This site suggests metric is most sensible

largely based on better availability of stock. But I must admit, if you tell me that I need an M6 nut, I do a quick conversion into imperial so I can visualise what it means. Same with lengths, and weights. It's an age thing. I no longer convert new money to old money (but I can if you want - I was working on the counter in Boots on D-day as a holiday job as a lad and developed the knack of instantaneous conversion for all the old dears who were confused. I do sometimes bewilder shop girls by expostulating 'Fifteen and thruppence for a bar of chocolate - you must be joking'. Now there's a useless skill - and I could have been paying more attention in metal working classes).

As I see it, if I make both male and female threaded parts myself, I can pick whatever I want. If I have to match to someone elses thread, I have to know in advance whether it will be metric or imperial, and I have no idea, so I might as well just gamble, I suppose. It seems a bit gadget-conscious to insist that my lathe must be able to do both, when I don't really know how much threading I will ever do. But thanks for the pointer to the Warco, which seems to be the same lathe as the Chester DB7. It's probably just a bit heavy and a bit expensive.

Some machines seem to offer a metric to imperial conversion kit which includes a 100:127 gear. LittleMachineShop offer a kit for the 7x that has a new lead screw - but only metric, presumably the Americans all buy the imperial version of the lathe. Maybe at a pinch the equivalent imperial 'kit' could be made up from spares.

Chas

In article , Chas writes

That's a large part of what newsgroups are about.

Yes, and also to be able to get very fine control when turning up to a shoulder (without relying on the topslide). Best method, I find, is to remove most of the material stopping a few thou short of the required shoulder, then do a clean-up of the shoulder to the desired position, then take off the last thou or so on the diameter. Others may have a different approach.

I agree; my Myford is imperial, but my Harrison and milling machine are metric, and I would for preference always use metric. My milling machine has a DRO, so I can switch between the two in a second, but I suspect a DRO is much less useful on a lathe. Those DROs which are add-ons to the handles are IMO a con - they don't give an absolute measure of position, and still suffer from backlash problems - though to be fair I've never used one.

(BTW, and back to your original question, I think you would find a milling machine about as much use as a lathe for modelling work. Be sure to get one which retains position as you move the head or knee - many of the smaller oriental types have a round column with no register, so if you move the head you lose position.)

Screwcutting internal threads is something requiring a bit more expertise - it's the same job, but backwards and with your eyes shut (to paraphrase Ginger Rogers).

Very likely, though check the banjo has room for the changewheels required.

david

Dave, Many thanks for all that.

This thread is quite long, and since you have opened the topic of mills, I have started a new thread on that topic, where I refer to this point

Chas

In article , Chas writes

No problem; I injured myself somewhat a few days ago and am spending far more time than I would wish sitting on my bum at the computer.

David

In article , Chas writes

A|so consider a decent second-hand model - often better value if you know what you are buying. Saw this just now:

(No connection). The MD 65 was very well regarded - I think it may have gone out of production, but there is quite a lot of literature on mods and improvements.

David

Chas used his keyboard to write :

They all do seem to be accepting the 7x12 and its variants as a pretty good compromise between cost and build quality.

There are loads of private web sites offering information on the Chinese lathe I'm stilling finding them.

I think that one has gone already, the link doesn't bring anything up. But I assume it is a Hobbymat - there was one on ebay and I looked up what lathes.co.uk had to say, and they were complimentary - unusually they thought the combined milling attachment that came with it was very good for the money. Their general view seemed to be that the overall quality was much higher than than the price, because it was communist E Germany government subsidised.