Thread: Metal lathe.

Originally Posted by rodweb

C'mon guys we went metric way back in the 70's and there is only two countries in the world who still officially measure stuff in inches so why bother?

Hi Rod,
hmmmm, now where do I start with that one
Everything I do is in imperial Rod, but I guess i'm just lucky
If I hadn't learnt imperial I would certainly be dead in the water or at the least very restricted in what I could do.

Phil

I really would hope never to have to cut a imperial thread, and I don't really plan to cut that many threads but when is a lathe used for what you intend it for?

That is a very very good point!
You may need to fix something, add to something, match something......It is better if you have the option than not. What Andre (Welder) signs off with is very correct, better to have tools and not need them than need something and not have it.....

Cheers
Ew

Hi, I have a question for all those that have a Al-250g, it is an expensive lathe for the size so is it worth the extra money? The Cl-6 is about the same size as the Al-250g so why such a big difference?

Originally Posted by Alaks McGREGORE

Hi, I have a question for all those that have a Al-250g, it is an expensive lathe for the size so is it worth the extra money? The Cl-6 is about the same size as the Al-250g so why such a big difference?

Same size, but two very different lathes:
The AL-260 is a geared head lathe, and has a quick change gearbox for threading and automatic feed, and has power cross feed too.
The Sieg C-6 (AL-60) has a belt drive headstock, simple change wheels for threading and automatic feed, and no power cross feed.

The AL250 has a 25mm spindle bore, power cross feed, MT3 in the tailstock and MT5 in the spindle. The AL250 also has 80mm tailstock travel and I think you'll find it also has more travel in the cross and compound slides, all in all it is a bigger machine. However, the C6 looks to be a well made machine, the 250 not so much. If not for the power crossfeed and 25mm spindle bore I probably would have considered the C6. As for hoping to never cut an imperial thread - you will: Despite metric measurements coming in years ago, many things still have imperial threads, just look at the bolt selection in any hardware store.

I see that Seig now have introduced the C8 model which actually has a quick change gearbox - first ever.

It's also got some other nice goodies but is well out of this price range.

Unfortunately it comes with an M2 tailstock, which seems odd when an M3 could easily be fitted, in line with other machines of this size.

It's dear for what it is, but looks to be a nice machine.

Rob

The AL-250 also has a reverse gear for the leadscrew, I don't think the C6 has that either. I saw an ad for the C8 lathe on ebay, but like nearnexus said, it is dear. At $2800 it is horrendously dear, particularly when it doesn't have a reverse gear leadscrew, power crossfeed or geared headstock. Some others to consider: BV250, 280 x 700G, TL250V, some of these and many others are on machines4u.com.

Originally Posted by th62

The AL-250 also has a reverse gear for the leadscrew, I don't think the C6 has that either.

The C6 does have a reverse gear for the lead screw for LH threading/longitudinal feed.
The C6 is also quiet in operation compared to geared head lathes, and comes with several change gears to allow a wide range of imperial and metric theads to be cut. (See attached spreadsheet for change gear/thread cutting combinations on the C6).
The only issue with this setup is it may take a minute to change speeds and a few minutes to set up the correct gear train for threading, but for a non-production workshop I don't see this as a big issue.

Andrew
lathe thread calculator.xlsxlathe thread calculator.pdf

Originally Posted by rodweb

I am occasional visitor to this forum. Back to the original question about the AL250G. I reckon this would be a great choice for a starting lathe.

At your age not being able to cut imperial threads should not be an issue as even at my age (54) who has got into this stuff over the last couple of years, I try very hard to stick to metric in everything I do and even hate using a tape measure with inches on it! By the time you really need to cut an imperial thread, you will be ready to upgrade your lathe I reckon! C'mon guys we went metric way back in the 70's and there is only two countries in the world who still officially measure stuff in inches so why bother?

i looked hard at this lathe in January when I upgraded and decided to buy the next model up (AL320G) which means I can cut imperial threads God forbid. I would have loved the next one above it the AL336 but it would not fit in my shed.

I have to muck around with change wheels to do it when you have a gearbox to do that for you. With a 250G you get a 25mm spindle which is a good size but you don't get a 4 jaw chuck as standard but one is available. You can use 16mm tooling and mine is 12mm. I know some will disagree but I find Hare and Forbes to be good to deal with and they always give me a discount off their list price for tooling and stuff but can't do that on some of the Aussie lines they sell.

Go for it I say. If you ever outgrow it, you will get good money for it and skip to a serious lathe say the AL336 with coolant, spindle brake, Camlock chucks and DRO options and your tooling will still work on it.

I am a bit younger than you and have cut way more imperial threads on my lathe than I have metric.
It's not often you get to pick metric/imperial it's what your working on that makes that decision.
If someone wanted a new table saw arbour it's more than likely imperial and these are still made today with imperial threads. If you go to the hardware store it's much cheaper buying imperial nuts for a job than it is metric as they usually come in blister packs with 10 or so in them.

With saying about out growing it and upgrading I totally agree, this is why I try to steer people strait to something like a AL336 size lathe. I stepped up from a Hercus and have had mine (Toolex brand) for 10 years and it's done everything a normal home shop would need in my opinion. I know you where short on space, but if you have the room nobody will look back with the slightly bigger lathe.
It's just seems a waist of money to buy a $2200 lathe (plus a $200 chuck on top) then to sell it at a loss latter to buy a $3000 lathe. It saves a lot of money just to buy the little bigger lathe to start with and you get all the extra features like you stated with the camlock spindle etc.

Dave

The C6 was very tempting when I was looking around, but the 20mm spindle bore and no auto cross feed turned me off a little. Can’t say as I’m overly enthusiastic with geared head lathes: noisy as, lots more things to break, if you overfill they bog down and you have to turn the chuck back and forth while you wiggle the lever into position - just as easy to move the belt from pulley to pulley and belts are a lot quieter. Unfortunately, most lathes with 250mm swing or more seem to have geared heads, certainly all Hafcos do. I do prefer the quick change gearboxes though, changing gears by hand all the time is very time consuming. Titan seem to have quite a few with variable speed, they seem reasonably price and well enough made, but they don‘t advertise their whereabouts … NSW?

> It's just seems a waist of money to buy a $2200 lathe (plus a $200 chuck on top) then to sell it at a loss latter to buy a $3000 lathe.

You say bigger is better, because that is what did work for you. It is not that easy though. Bigger is not necessarily better for everybody. Not everybody wants or needs to go larger over time. It definitely depends a lot of what one wants to do. And how one likes to do this. Recently somebody on another forum formulated a brilliant comparison between a well made light belt drive lathe, and a semi-industrial geared head lathe: it is like comparing driving a sports car with a battle tank. Sure, it is perfectly possible to build a small steam engine on an AL-320, but I do not think it is a particularly fun experience. It is more like working to make a living.

A well made gear head lathe with hardened and precision ground gears is universally desirable but invariably expensive. Too expensive for most home shops.

A not so well made gear head lathe may be affordable, but can be very noisy, may have excessive backlash, may leak oil, may vibrate, is almost guaranteed to produce inferior surface finish, may only have a limited design life, may be difficult to repair as parts may be unavailable after only few years, has a limited/low top rpm speed, may/will break if things go wrong...

A well made belt drive lathe can be superior to a not so well made gear head lathe. It may not have the same power, but it will run much quieter, produce some of the best surface finishes attainable with a lathe, is easy to fix when broken, is more forgiving as it can slip when things go wrong, can handle higher rpm (think of a VFD upgrade), may be used indoors...

Best suited: Industrial type heavy duty use, get a good well made geared head lathe. Hobby/home shop use, mostly large and coarse workpieces in mainly steel, get the best geared head lathe you can afford. Hobby/home shop use, mostly smaller but accurate workpieces in mixed brass/ally/steel/plastics/wood..., get a good belt drive lathe.

No fun to drive a minig truck to a mountain race - no fun to ruin a Porsche in a quarry. Chris

Originally Posted by th62

The C6 was very tempting when I was looking around, but the 20mm spindle bore and no auto cross feed turned me off a little. Can’t say as I’m overly enthusiastic with geared head lathes: noisy as, lots more things to break, if you overfill they bog down and you have to turn the chuck back and forth while you wiggle the lever into position - just as easy to move the belt from pulley to pulley and belts are a lot quieter. Unfortunately, most lathes with 250mm swing or more seem to have geared heads, certainly all Hafcos do. I do prefer the quick change gearboxes though, changing gears by hand all the time is very time consuming. Titan seem to have quite a few with variable speed, they seem reasonably price and well enough made, but they don‘t advertise their whereabouts … NSW?

They are in the central coast NSW. Just a storage shed full of machines but the service and price are decent. Average Chinese quality I'd say, some machines ok, others to be regarded as a kit really.
My mini lathe was crap. TM20 mill I got is decent

It's not so much the size it's the features like cam lock spindle, power feeds etc.

Dave