Micro-lathe suitable as multi-function system for small workshop?

Hi folks,

Lurker here who could use some advice on choice of lathe, on two points: is the Taig Micro Lathe II capable enough for building small stationary steam engines, say bar stock or a kit of the size of PM Research #3; and, is it worth considering the 5C headstock from the get-go?

I last touched a lathe or mill 20 years ago, but recently much enjoyed assembling a machined Chiltern vertical engine. I'd be interested in tinkering with it, making parts and fittings, and eventually maybe a full engine from castings. My workspace is space-constrained, however, and my one workbench is shared with other tasks and hobbies, so I need a small bench-top machine, preferably moveable. Any machine would have to serve as both lathe and mill (I otherwise have only hand tools and a vise), so the adaptability of the Taig is appealing, and I get the impression it's capable despite its small size. Is that accurate, or should I really consider a mini lathe instead of a micro?

Assuming I'm not overestimating the Taig, and setting aside cost for a minute, is there any reason not to invest in a 5C-based model? Seems like it's a general upgrade in terms of precision, with the only downside being cost.

5c would be a bad choice IMHO. Collets are expensive and only take one size, and the only way to fit a 3 jaw or 4 jaw chuck would be on a tapered arbor to fit the collet taper. That would result in more overhang than desirable for rigidity. A better choice would be ER collet spindle though they only do an ER16 which limits you to 10mm diameter stock or cutters. Still a problem fitting conventional chucks though a backplate to fit the 22 x 1.5mm thread should be possible. ER collets take a 1mm size range so more versatile.

People do nice work on the Taig but whether it's up to what you want to do I don't know - is there a Taig user forum? Milling on a lathe is very limiting, more so on a small lathe. They look rather expensive, you might get a mini lathe and a mini mill for not much more.

Also look at Sherline, who have a good reputation.

https://groups.io/g/taigtools

You could of coarse put a 5C to ER32 adaptor into the spindle if you had odd size work to hold as I do sometimes, cost is only about 50p a collet difference so I don't think that really comes into it.

I also have a parallel shank adaptor that takes my small 3 and 4 jaw chucks which work fine for small items if I can't be bothered to change the 5C chuck over to a larger one for one part.

Having said that the threaded spindle that will take 3 & 4 jaw chucks as well as a faceplate would be the most versatile for the type of work you are thinking about

Starting out I looked closely at Taig and Sherline and decided they were too small for what I wanted, and biased to small precision work rather than the clunkier general-purpose turning I do. I bought a mini-lathe instead, learned a lot from it, and decided it was too small as well!

Small precision work like clock making and OO gauge railway modelling is well served by high minimum RPM, table-top machines fitted with collets, but general-purpose machining is easier with larger machines with a low minimum RPM and a chuck.

Looking at the PM #3 on their website for difficulties, I see a few:

1. The kit is castings based, and they have to be held firmly on the lathe.
2. The diameter of the flywheel is 2¼" . I'd hold that in a chuck or faceplate: 5C collets are unsuitable, though it might be done with a stub mandrel. The Taig appears to have enough 'swing' to make the flywheel.
3. The piston cylinder needs to have the ends skimmed square and the interior bored to size and well-finished. I'd hold the casting in a chuck. Taig should be big enough to hold the job.
4. The valve is drilled, so a tailstock and drill-chuck are needed (both extras). Looks as if the valve cylinder is part of the piston casting, so some way of holding the casting off-set to centre the valve cylinder is needed. A 4-jaw chuck would do it, but needs to have enough jaw movement: I don't know if the Taig 4-jaw has enough capacity. Otherwise mount on a faceplate, or clamp to the saddle and drill with the spindle.
5. Not shown in PMs photo are the eccentric and other valve gear details hidden behind the flywheel. Should be OK, I doubt any of them are beyond the Taig's capabilities.
6. My biggest concern is machining the main casting. It's 6" long and might be too big or awkward to hold on a small lathe. But it might be possible to do most of the work by hand - skimming the base flat could be done with a file. Even big lathes aren't ideal for odd shapes like the base, which is why we all buy milling machines if we can.

Mostly guesswork on my part: I've never built a PM#3 or used a Taig in anger. The best answer will come from a Taig owner who builds engines!

As an aside, don't get hung up on precision unless it's specifically needed. Most Model Engineering is done ±0.02mm ( ±0.001" ) and any lathe in reasonable condition will do that. Engines like the PM#3 actually work better when built a bit loose - they jamb when made to close tolerances! High precision and accuracy seem highly desirable, but in practice they're rarely needed in a home workshop where parts are tweaked to fit together rather than guaranteed interchangeable straight off the machine. We don't need jigs, fixtures, gauges or anything else made to tool-room standards unless something special is afoot.

Dave

Thank you all for the comments and thoughts! Helps me to focus on what the important considerations are.

Fair points about precision vs versatility. I like the idea of collets but I imagine that with irregular work I'll mostly be using the chucks. Makes sense to get the machine set up for that use case.

It sounds like what I'm imagining doing would be possible in a Taig lathe only (or Sherline, which is of a similar scale if I've understood correctly). However, the same argument about versatility applies - with such a small lathe, and without a mill, I'm really limiting myself in what I can do. Figuring out how to do an operation of some sort on such a lathe could be an interesting puzzle, but it might also become a point of frustration...

So, I've got two questions to consider: do I save much space by going with a micro vs a mini lathe, and can I really not fit a mill.

[This posting has been removed]

Thanks, will take another look. I was skimming those yesterday but must have missed that one.

Edit: will look at Cowell and Sieg as well. It's a question of space, but it's good to hear that they may be moveable if required.

Edited By Jan-willem De Bleser on 07/03/2022 16:32:49

Jan, you could mount a small lathe and milling machine on a suitably constructed cabinet with castors which could aid shortage of space. If drawers and shelves are incorporated this helps provide storage for tooling.

Robert Butler

I have a Taig lathe, but don't build engines so I can't help with the detail of the build. In my view Taigs are very capable and very reasonably priced, but they are the basis for creating what you want rather than ready to run out of the box. A Sherline or a Chinese mini lathe would be better out of the box.

Look at John Bentley's  modelengines.info  website to see what can be done on a Taig

The Taig Lathe and Milling Machine (cartertools.com) has lots of information on how people use and modify the Taig.

I opted for the ER16 collet spindle and am very glad I did. As John says 5C has the disadvantage that the collets are expensive and only hold one size while ER collets hold a 1mm range of sizes. (You can actually get 11 and 12mm ER16 collets from Gloster Tooling). I have a 12mm one and it works well.

Taig supply 3 & 4 jaw chucks which screw directly onto the M22 x 1.5 ER spindle nose so no need for a backplate. The sherline 3 jaw M22 x 1.5 threaded chuck also fits ( but is considerably more expensive than the Taig soft jaw version). I have swung 4" diameter on the lathe (nominally it will turn 4.5", and they also do a riser block that adds another 1" of clearance to the bed (albeit with some loss of rigidity) so up to 6.5" is possible.

As Francis says the recommended induction motor is very heavy, bulky and in my view very limited as the minimum spindle speed is about 450rpm which is a bit fast for turning cast iron. A variable speed DC motor is a much better choice. Mine is currently fitted with a BLDC 220W DC motor on a home made mount. which gives me 75-10,000 rpm at the spindle.

I bought the vertical slide and milling vice with the Taig. I have successfully used it to do small scale milling, but the setup is such a faff that I eventually bought a Sieg SX1LP mill.

Mine like Francis' and all standard Taigs doesn't have a leadscrew. I don't find the rack feed much of an issue. It is quick to move, but does provide accurate positioning. I plan to add a motor driven leadscrew and power feed when I get round to it.

Typos!

Edited By Peter Cook 6 on 07/03/2022 17:48:46

With the Taig system, I made my own headstock, as at the time, as Taig did not offer such a thing. Mine has two different spindles, a 5c spindle and an ER40 spindle. I use the ER40 spindle the most, but I don't think the ER40 is available. The advantages of the 5c, is the range of collets that are available, and that with emergency collets, can cut what ever shaper you want or turn them to suite. The 5c gives you the option of a large bore in a small frame machine, up to about 28mm I think I made mine. I put a 3phase motor on mine and a VFD, to get the lower RPM that I needed. It is a great machine. The other change is I added the Myford Dickson quick change tooling system for holding the same tools as I use in my Myford S7.

Neil

Noted about a cabinet on wheels: I'll likely have to do something along those lines so that it can be stowed when not in use.

Taig does currently offer a model with lead screw and power feed (L1015 vs L1017), which I've seen used in some youtube videos. Maybe that's a new offering?

I saw John Bentley's site and was impressed - his work is one reason I thought the Taig might be enough machine. Of course, he also has another lathe, mill, bandsaw, etc, which suggests a different question: in the process of building up a small workshop, assuming I'll likely eventually give in and find room for a mill as others have, would a Taig make a suitable first acquisition (more in the sense of "I have no other tools" than of "I've never used a lathe before" )? I define suitability based on how quickly I'll encounter the machine's limits.

Tools that allow one to tinker with them are interesting, but the downside is you end up spending more time building more tooling than building devices, something I've already experienced with electronics hardware 🙃

Edited By Jan-willem De Bleser on 07/03/2022 19:46:28

Edited By Frances IoM on 07/03/2022 20:41:54

Jan-Willem;

I was amazed by following the build of a 3-1/2" (1:16) Shay geared locomotive. On Sherline equipment.

Have a look at:

Chris Rueby's Shay Build

(https://www.modelenginemaker.com/index.php/topic,3778.0.html)

He's a prolific builder, so look at any of Chris Rueby's photos on his more recent builds to see what he does with this limited (hah!) sized equipment.

I've now got some Sherline equipment. The metric version has a 6.3mm x 1 pitch feed screws (6.3 is 1/4 inch). My only complaint was the UNC (UNF??) screws, but a metric thread is almost equivalent; seemingly some metric screws will fit, and if too tight, a simple "run the metric tap through" will help. That was from Sherline's web page. (I purchased a bunch of cap screws that I keep separate from my metric standard - wish I had figured this out earlier) I won't put the equivalent metric thread here in case I get it wrong. (not near my workshop at the moment)

The lathe can have a vertical mill column attached in which case (like the Unimat) the headstock mounts vertically. Years ago I had a Unimat SL, and liked it, but the Sherline is 100 times the machine than my little SL was.

I'm impressed, and I put my money where my mouth is, so to speak, and have purchased a lathe and mill from them.

Edited By John Alexander Stewart on 07/03/2022 21:12:30

Which comes down to your motivation for starting. Do you principally want to build models, with the PM #3 as the next in the line - and want a lathe to facilitate that goal? Or do you want to make "stuff" on the lathe and the PM #3 is simply an interesting example?

Do you see the future as a "collector/maker of well engineered models", or a time where you "enjoyed your time making ...". If the former, then probably skip the Taig because you will end up spending more time building add-ons and tooling - although that will happen to some extent in either use case.

I wanted to fix clocks, and needed a lathe to do so, but I have migrated to the second position. I enjoy making/creating useful "stuff". So modifying and enhancing the lathe is as good an outcome as any other. The Taig is probably the best platform for that.

I like and understand the way you phrase the trade-offs involved. It's not a clear-cut A/B choice, as while I definitely enjoy the process I also want to build more than just tools, but this does give me a helpful way to think about these lathes.

I will take another look at other lathes, and more importantly see if I can't make room for a mill as well, rather than trying to buy tools piecemeal. Might still end up with a Taig of some sort, but either way this thread has given me a clearer idea of the use case of these tools, and some more ideas of what to look for.

(Will check out Chris's build photos as soon as MEM forum approves my account 🙂

One thing I would like to point out regarding chucks and collets. You can buy an ER collet holder on a parallel shank and hold it in a 4 jaw independent chuck. This will allow it to be set on centreline with a dial indicator and give the lathe the advantages of collets. You can also buy collet blocks for the larger ER collets and do the same thing. So I would say always consider that a 4 jaw independent chuck will give the best of both worlds where a collet based system may be limited.

Martin C

Another thing to consider is time. Although you may be able to physically fit the item onto a small lathe it will take a lot longer to machine as they will only be able to take shallow cuts. For example on the smaller machine you may only be able to take a 0.1mm depth of cut but on something larger a DOC of 1mm would not be a problem. So that means it will take you 10 times longer to machine a part on the small machine that a larger one.

I made my first steam engine casting kit, a Stuart 10V on a Unimat3 but it is slow going both in machining as well as setup time.

I collect micro lathes. My opinions:

1. Cowells. The best of the bunch. More rigid than the others and has features like power feed, screw cutting, taper turning as standard. Higher quality than the others but much more expensive. The biggest downside is the small spindle bore

2. Sherline. Good rigidity, Good size spindle bore, Good quality. The downside being parts and accessories can be hard to find in the UK. Not a problem if you are in the USA.

3. Taig. Kinda like the Sherline but not quite as nice quality imo. Parts and accessories are cheaper and easier to find. Good spindle bore size for a micro lathe. Inexpensive second hand.

4.Emco 3. Decent quality, decent rigidity, spindle bore is smaller than the Taig and Sherline. Parts and accessories are readily available. Middle of the road pricetag. One to consider.

5 Unimat SL. Nice to look at but less rigid and not as capable as the others. Quality is ok. Parts and accessories are readily available.

Now you also mentioned the mini lathe. They are more capable being much larger but Imo they aren't good quality at all. They usually come new out of the box with a whole range of problems. On top of that the electricals are extremely unreliable. You can negate these issues somewhat by buying from a reputable dealer. But I'm sure someone will be along shortly to tell you why my experiences and opinions are wrong. 🙄

Other options not yet mentioned is the handful of lathes that sit somewhere between the micro and mini lathes. A few examples being the Emco compact 5, Proxxon pd250, toyo ml210 and at a stretch the hobbymat md65. These have there own quirks both negative and positive but would have more capability than the micro lathes while still being small enough to be easily moveble and are generally better quality than a Chinese mini lathe.