bertiedog

Just had a talk with one of the suppliers whilst ordering some bits, and there are two reasons the other brand had failures, one....

• The screw was done up far too tight, it needs to be secure but people were adding leverage to the bolt head, and two....

• They were over extending the whole tool, one of the keys to parting is the minimum amount possible and no more should be extended to do the work,.... grip at the back, with an extended front and great force is applied to an already over stressed clamp down bolt and it can shear the body blade groove where the blade sits or even strip the bolt.

These are FE made and usually OK. The full clamp type do no suffer in the same way, but again only use as much blade as strictly needed.

It was not so much the small size, but inexperienced use that brought problems to light.

Stephen.

Unfortunately, that one looks A LOT like the one RDG tools withdrew from sale.

 

At least two others are still selling the same tool on e-bay, so I'm loathe to buy unless sure.......

Well I have used this type and they work, but they may have had makers troubles, but there is the g/tee... or going for a more expensive Glanz insert type in 6 mm size..

There are also the 6mm full clamp, where the holding force is provided by the clamping screws, should work fine, there is nothing to go wrong !!!

Stephen

I hope this is clearer, and explains why B and C are in fact the same, as it is just a mirror image and still results in a down force to act on the saddle, albeit with the pivot point moved...indeed A and D are mirror as well.

So front mounted in reverse will work the same as back the right way round.....to a degree, and less force than B.......phew!

Stephen.

And by the way the Sieg is quite good at parting off, the troubles reported would apply to many smaller lathes, it's the method, not the lathe.

A saddle lock is vital for a decent parting off experience, and the Sieg does not have one at all, only the gib adjustment. A saddle lock can be added in an afternoon, there are kits or home brewed versions.

To part on any lathe the tips are:- ........ a firmly mounted tool, a locked saddle, and a slow speed, and the tool tip must be below the centre line by a few thou.

The appears to leave a pip, but one side of the tool tip face can be set to leave no pip, but the bulk of the face should be shy of the centre line. On, or above the centre line, causes or risks judder as the tip alternatively skates and then digs in.

For most cut off work the rake should be near zero, or slight for steel in small lathes. With normal rakes the tool digs and then relieves and again judder sets in.

For amateur home machinist the other golden rule is that the parting off is not the finishing cut, many pros take pride in production work to use it as the finishing cut, but do not aim for this at first, part off and then face the work with a round nose tool, much better finish, and no pip.

Also with smaller lathes, do not expect to part plain mild steel easily, it needs lubricant like Rocal, and some steel is really quite rough and tough. You would find silver steel or stainless actually easier.

With Aluminium, the parting should be easy at low speed, but aluminium swarth has a tendency to weld itself to the tip at higher speeds, so use paraffin to act as cutting oil.

Brass should part off dry, and cleanly, the speed can be a bit higher.

Stephen.

He is right about the upside down and reverse as the object is to throw the cutting force down on the saddle when the rearpost is used and the reversed front does the same in a more limited way. (It does not seem to logically, but the bed/slide acts as a fulcrum/lever).

I have used this on the small Ward turret lathes where the saddle was full of tools both front and rear all set on stops and motion regimes to do a sequence of pre-set cuts on complex items, and the parting worked better in reverse.

The Myford, despite its renown, has the design flaw of a "loose saddle", you cannot adjust it tight enough to part off, without locking all the gibs tight, but you can leave them unlocked if the rear post is used, or the front in reverse, to apply down force to the saddle, preventing lift and judder.

A further web search shows the Emco 8 and 5 share the mounting system and it is like the Hobbymat, three or four nuts secure the chuck to the nose on studs. These are not the bolts at the front of the chuck, they are behind the flange which remains on the lathe.

Yes just checked the Emco has a standard number two Morse Taper mount in the head stock, how the chuck is held on it does not say, but the three bolts seem to hold the chuck to a backplate screwed to the flange surrounding the morse taper, so I assume the whole chuck is unscrewed, the retaining bolts are not meant to be removed.

The other way they mount chucks on lathes is the other way round, the flange remains with the nose and the chuck has three studs out of the back to do the retaining with nuts in the way of Hobbymat. With the nuts removed the chuck comes away and you can get at the morse taper, leaving the surrounding flange in place.

So it seems that the collet on the mill will fit easily, it should be number two morse, if it is number one, then a sleeve converter will be needed, ( easily sourced). Should the collet chuck have number three morse, then you are out of luck, unless the number three removes from the back of the chuck.

Any adaptors can be made on the lathe and miller.

Stephen.

Thanks for that, Bertie, I'll look into Chronos for a parting tool then.

 

The collet chuck that came with the mill was different to the one for the lathe, which fits to the spindle with three bolts, like the chucks do. The mill one fit on a taper. Probably a Morse?

 

If the lathe has no morse, (unlikely), the nose which has the three bolts should come off and a morse will be there in the headstock, if there is none an adaptor can be added on the nose and use the bolts to secure in place, but would be bulky due to the existing morse on the back of the collet being out side the head stock.

It may be possible to remove the morse tang or change it to one which will fit the Emco morse ( I am sure there is one there).

Stephen.

Thanks for that, Bertie, I'll look into Chronos for a parting tool then.

 

The collet chuck that came with the mill was different to the one for the lathe, which fits to the spindle with three bolts, like the chucks do. The mill one fit on a taper. Probably a Morse?

 

Sorry, double post. Can't find which one of those you mean, they go from £14 to £8..........

Stephen.

Meanwhile ----->here is a real luck of the draw

 

Based on that single photo, I wouldn't be bidding at all.....

There's also an Alan Gibson kit of a GWR county 4.4.2 loco that appears to have parts of a pannier added to it and 060 wheels .......

http://cgi.ebay.co.uk/OO-GWR-4-4-2T-COUNTY-TANK-LOCO-BRASS-NICKEL-SILVER-KIT-/380245569129?cmd=ViewItem&pt=UK_Trains_Railway_Models&hash=item

Stephen

A collet chuck fitted to the mill was mentioned, by Alcazar, and of course this should be able to be fitted to the lathe as well, just needs an adaptor plate, no loss of accuracy, the adaptor is machined in place on the lathe.

If the mill is Emco brand,(or a clone), the whole collet may already fit the lathe anyway, just needs a bit of inspection to find out what's there.

Stephen.

Bertie: my lathe is an Emco Compact 5. The only tools I have for it, apart from metric drills, are a set of 1/4" tool-steel ground tools, l/h, r/h and end, made for me by a friend I used to work with, (ie: ground to shape).

 

They work, but need to be shimmed up to centre height.

 

I'll try and take measurements off the lathe, like what size tool will fit, and the clearances you mentioned on the drawing, tonight, once the loft has cooled down a bit.

 

I'll also try and further identify the milling machine, but I do know it has a co-ordinate table with it. I have a collet chuck and full set of 25mm collets, but no LATHE collet chuck although there is one on e-bay at £56 at the moment. I could also do with a fine feed attachment for the milling machine, it has just a lever at the moment, like a pillar drill, which it greatly resembles. It also has a decent 0-10mm keyed chuck for drilling etc.

Thanks.

What you need is done by Chronos the small parting holder on

http://www.chronos.l...g_Tools_82.html

Half way down, the about ten pounds type, 8mm shank mounting, this is perfect for the Emco 5. There are Glanz types as well, but far more costly.

The 8mm type will fit direct to the lathe as standard, it will not fit the accessory four way tool post which would need the 6mm version.

The shimming that you are using means the tools are 6mm and really the lathe takes 8mm, but of course you can use the 6mm as well. The 6mm also fit the four way post and adjustable insert toolposts.

Hope this helps.

Stephen.

Also mentioned is the three jaw chuck and it's accuracy, especially against collet chucks, and collect chucks bet any other chuck hands down.

But the poor old three jaws gets a bad press from a lot of users and it dates from the fact that they are so used in a factory that they get worn out.

Any modern scroll 3 jaw is basically accurate to hold round items, and do not forget you are holding the blank not the work, so the accuracy of the chuck barely matters.

Better three jaws exist, like the grip true type, adjustable to get accuracy, but do not let the stories of the basic types being rubbish take grip.

Some older UK made type also had "ramped" scrolls, these gripped tight , but the jaws move in and out dependant on the diameter, and once worn are all over the place.

When working with any chuck it holds the scrap part, and all the accurate work is parted away, so the fact it might be out of true is neither here nor there.

A collet is a tight fitting bored hole, and just fits the one size( unless a special type), and holds with supreme accuracy so can grip part turned items and maintain accuracy.

Stephen.

Boring heads are mentioned and these do not go in the toolpost, (they can but unusual), they are a tool holder that fits the morse taper and can move the tool tip on a calibrated slide as required, to bore a particular diameter in work held in the chuck etc..

The same work can be done with a tool post mounted boring bar, but the tailstock mounted type saves the space on the toolpost for other set-up.

Most of this refers to production methods to save time in a factory set-up and can be disregarded for home machinist work.

Boring heads are also used to bore holes in work mounted on the cross slide, and the boring head fits the headstock morse, and the whole thing rotates as it works in to the workpiece, which is stationary.

Stephen.

Can I add on rear parting, apart from suiting Myford etc., also allows a parting tool to be left as part of the set up on a bigger lathe, all the work is done by the front toolpost, and then the upside down tool is drawn towards you by the tool slide and parts the work.

Smaller lathes can't always take rear toolpost due to the practical lack of space,(or mounting slot), and there is no option but to use the front tool post.

Stephen.

Ozzyo, with Reference to and continuance of.....

To give a little light to newcomers to mills, and too leave out too many complexities, the two types of end mills commonly used are slot and end mills, and the end mill will not drill down as the cutting faces do not cross the centre.

• The reason is a centre hole is left to allow the grinding between centres in manufacture, this allows great accuracy in grind and re-grinding to sharpen the mill.
• The four teeth can be arranged to sweep over the centre though, and this type will drill down in material.
• The same applies to slot drills, but two blade with a centre are now rarely encountered in the workshop.

These days both slot and end mills are centreless ground and equally accurate for our home machinist purposes. However a centre ground mill from say Staul will be more accurate than a slot drill, so keep in mind there are exceptions.

For home use four of more blades are better for other reasons, the cuts are smoother as slot drills are prone to vibration in light mills, and are noisier than a mill cutter with more blades. Most home mills are not able to handle big slot cutters or even ripper grade mills. I was trained on a 6ton Brown and Sharp, and that was not going to vibrate......ever!

To ease into home milling, keep the cutters small, and multi tooth, but use slot drill mills as well, especially in small sizes under 10mm. A newcomer may not realise that even a small endmill can surface massive surfaces, it just takes longer, unacceptable in factory conditions, but perfectly all right at home.

In a factory you could gash cut in one go a trench of 6 inch deep and 2inches wide in one pass on the B&S,

you would not do this at home!!!! At home with milling it has to be "Small Nibbles", in stages to achieve the same bigger cuts.........

At first, with all lighter machines, steer clear of flycutters for large surfaces, they cause out of balance vibrations on large diameters, and must be used with light cuts and great care. A fly cutter is a blade on an arm that swings around as a single cutting point only, at saw 4 inch diameter, used to create large smooth surfaces. Once you are used to ordinary milling , then move on to fly cutting and single point tools.

A modification of fly cutting is used for gear cutting, (along with form tools), and as I said before a rotary table is needed, and these days all normal types available to home user come with the full set of division plates required to do cutting like this.

Yes, it is quite possible to get small tables without fixed, (but adjustable), divisions, and with these for gear cutting then division plate sets are made or the changewheels of the lathe can be pressed into use to do the divisions.

Stephen.

Right, here's a question.

At the moment, I don't even have a parting-off tool. (I use a hacksaw blade held on the rotating piece with enough pressure to cut it, then face it off if necessary..........and yes, I know it's dangerous

 

I've oredered one off e-bay wityh an inserted blade, only to have the seller cancel as he's stopping selling them after having too much trouble with faulty items.

 

I've found others and e-mailed the seller to see if it will fit my lathe, but don't understand his reply.

 

Here's the item: http://cgi.ebay.co.u...e=STRK:MEWAX:IT

The easy answer is exactly what is your lathe, maker and model or photograph, as the seller is advertising it as Myford fit, and his implies a Myford Seven size, and therefore to take it, the tool holder capacity and height must match within reason.

The means it should be a 7 inch capacity and able to take 3/8 inch tools, in other words, a medium to large lathe. If it is a mini lathe, (smaller than the Myford, like a Hobbymat or Sieg, or Cowells, then a smaller mounting type will be needed usually 8 mm or less.

If the dimensions are needed, they are the clearance over the tool slide, and the nominal distance from the tool holding slot to the centre line. (x and y) and the tool thickness for the lathe

However the quickest way is identify the lathe, and what size tools are normally in use, and we can find the right type.

Stephen.

The lathes which I considered to be beyond it were victims of very poor casting technique, blowholes being the main culprits. In one case a sliding surface was machined over an approx 60% blowhole in a casting. QC seemingly was non existent.

 

The point I was trying to make, and as I seem to have to labour it I am going to leave it after this post, is this: I am not a trained lathe turner or milling machine operator, or indeed engineer. However I have been a model engineer and full size locomotive restorer for in total over thirty years, owning and using machine tools for that length of time. During this time it has been my experience that a good used quality machine tool such as a Myford will give more satisfaction, especially for a beginner who needs instant accuracy from his machine than any seemingly cheap far eastern machine which we both agree will possibly need a good setting up before they can give satisfactory results.

 

This is simply beyond the ability of most first time machine tool owners without enlisting the help of capable assistants.

Well we agree then, but I should mention that the Chinese are the casters of both Euro and UK makers lathe beds, and it is merely a matter of checking the purchase, which if it comes from the well known UK suppliers is checked over in the UK and is fully under G/tee.

I am not defending blow holes in the casting, I do not know the size of what you mentioned, but minor bed blow holes and marks do not actually affect a lathe, it is the average of the point of contact on any touching surface that matters, this is why nicks and marks can be removed safely from lathe beds, and why a worn lathe can still work fine.

As you mention experience I am a trained machinist, and a published author in the ME magazine, I do try to post with as much information as I think the readers can take, qualifying everything to cover what has been said in previous postings would hardly be practical.

Stephen.

On milling in general, the cutters are a bit of a mystery to a newcomer, it needs surprisingly few of them to get started. Don't forget a small cutter can cut big channels in a miller, and you could start with one of say 5mm and do lots of work with just that single cutter.

If you had say 2mm, 4mm and 6mm this would cover most work. As others said two point HSS slot drills are a good option, they drill as well as side cut, but there is the option of a four blade cutter with cross point that will do the same. These reduce vibration and give a finer surface finish.

A true mill cutter will not drill a hole, it can trim a channel in bites, and move sideways and with smaller mills the four blades make the operation smoother than a two blade slot drill.

Most cutters in the small sizes can be fitted into a plain arbour blank holder, no chuck or special retainer is needed, a bolt bears on the shank, with an added ground flat spot for security.

These fit the Morse tapers in all sizes, and can take the milling machine drawbar to hold them firmly. They can easily have a sleeve fitted, made in the lathe to take odd diameter mills. This system suits smaller mills where Autolock chucks may not fit, or waste a lot of space over the milling table, reducing what can be machined.

Any alternative I use, that suits small precision work is to use 3mm shank carbide"burr" mills, they cut anything except diamond, and work without vibration unlike slot drills.

A 3mm can cut 12mm deep and any width, so covers a lot of model work like frames etc. A holder can be made in the lathe to fit a morse blank arbour. Burr mills will not drill properly, they do not cut at centre axis, which slot and cross point mills do. They are fragile to heavy blows, but cheap to replace if they break.

So with just a very few milling cutters you are up and in action, the main use would be frames as described in the other postings here, along with block frames, footplates, toolboxes, square buffer shanks, motor mounts, and potentially gear cutting, which would require a rotary table and tail post added to the milling table.

If the miller is bigger the jobs it does is limited only by size, and bigger cutters can be used for single cuts, and surfacing by fly cutting.

In general the attachment columns for the lathes are a bit limited due to the cross slide, and frankly using the lathe as a horizontal miller would be better, all you need is a few cutters, they can be gripped by the three jaw or an arbour, and a milling slide to suit the lathe. Working sideways does not affect what can be done much, and al jobs for smaller scale locomotives could be done on a lathe used as a miller.

The next step up is the FE sourced millers, and then the bigger Bridgeport types and copies, price governs the capacity rather than just the quality. There are some dedicated CNC home user millers on the market, Chester do small ones, and a lot of makes can be converted if you want to go down this route.

A final point is be wary of any mill with a round column, they may not have a vertical register that works during movement or register at both ends of the column. The better designs of round, like the MD65 have a continuous gib stripped guide rail, like Bridgeport and Brown and Sharp, but some lathe conversion columns do not have this feature.

Thankfully there are now lots of smaller mills with square or box columns where this problem is reduced and the full capacity of the miller is available with full movement. Sieg do a selection, Chester, and Warco do them as well.

Stephen,

It would be interesting to know what has made these lathes "beyond it", do you mean really unusable?...I have set up about 7 of these if a "3 in one" is included, and none failed. What was wrong to stop using them? Last year I used one regularly and it never gave any trouble of any kind.

And I did take the comment quote carefully read , the continuing comment was just an expansion, for other readers, who as I said would be put off by such a lathes size. This was not a comment on your lathe, but as I said and carefully expanded on, a large lathe is not a popular domestic addition!..and especially for railway modellers who already have a large layout in occupation of the house.

Stephen.

I'm very much in two minds whether to recommend far eastern lathes to a beginner - all well and good if you get a good one, but it's definitely a lottery. The more experienced engineers amongst us would be ready, willing and able to sort them out, however it would be immensely frustrating and discouraging for a novice if the first thing he has to do is to try and get his pride and joy to turn properly.

 

I'm a big fan of the 'second hand good lathe' route. My example was bought from a university oceanography department. When I got it it had only ever turned plastics and non ferrous metals. Every conceivable extra such as 2 x 4 jaw, 2 x 3 jaw, 4 3 way toolpost (can't count), steadies etc.etc. It is a three phase example but they threw in a phase converter as well. An absolute bargain for the £600 I paid for it - yes, I was in the right place at the right time but the bargains are out there. I know this example is a bit large for a couple of O gauge models, but I'm illustrating the principle here.

 

Since I've had it it's done a lot of work, a lot of locos on the MHR are running round with bits made on this lathe nailed on to them.

 

I have the feeling most Railway Modellers would be plain frightened of such a lathe, (not me, I could use it at once), and would be a bit put off with lack of instant spares or even instruction books!!

For small models it does not need a small lathe, but a large lathe needs space and a sound floor, my house was purchased because a ground floor room had a sound level concrete floor, for a dedicated workshop. I needs concrete, the main lathe is 1/4 ton, and there are five smaller lathes and mill as well.

This is not going to suit a model enthusiast who just does relatively smaller work. The machine does not need to be new, the Grindturn featured earlier in the thread would suit any ones space.

I found the old Unimat One to be wonderful, the tiny machine could manage jobs far beyond basic work, and it a pity it's not still made. It could be put away in a drawer, with it tooling and needed no dedicated position to work with it.....and it turned into a very good milling machine....saw table, ....surface grinder....thread cutter, and a tiny wood lathe as well. The whole thing was " Domestically acceptable"........

This is part why the small Sieg is so good, all right it's too heavy to carry, but it can be moved, and fitted to a small bench is no worst than a domestic sewing machine table. It requires no special floor or mount, any floor will take the weight, even a shed or loft. .....but the same applies to any other small lathe rival.

Stephen.

Now I'm well and truly retired, I have also been considering the purchase of a lathe/milling attachment. I've had a good experience with Proxxon tools and am tempted by the PD230E lathe as a starting point. The thing that is holding me back is the cost which is almost twice as much as say the Clarke CLM330M.

 

I'm experienced enough to know you get what you pay for, but am curious to know what the quality differences are between similar function machines. Is it worth paying the extra now or is this just the high cost of the € that is inflating the price?

I am assuming the comparison is between the "Clarke 7x10 (Chester conquest), the basic Sieg", and Proxxon, and on the face of it the Proxxon is very good although more expensive and should be.

A small but subtle difference though, (and it applies to Unimat, Hobbymat(Saupe), is the size of the morse tapers, which on the Proxxon are Number One Morse.

Sieg are much more generous, with number two Morse on the tailstock, and number three morse in the head stock, bigger sizes associated with larger lathes. It makes it easier to buy accessories, they are a Myford size, and gives a generous through clearance in the headstock bearing tube, vital if long work is done.

It does not mean that the Proxxon does not take a range of number one accessories but they are more expensive, not so strong, and some things like turrets are not made in number one morse.

Number two live centres are cheaper, turrets are made, tailstock die holders etc all in the accepted No2 size.

To a newcomer this size issue will seem obscure, but it deeply matters on a good lathe. The small Unimat 3 was crippled a bit by being non standard,(no morse at all), and you were forced to buy Unimat accessories.

This does not apply to bigger Unimats, but the morse sizes are all smaller compared to the Sieg equivalent model.

Generally I would say do milling in the lathe or buy a dedicated mill. The add on column type work, but the crosslide gives limited movement on all designs compared to a table mill.

Stephen.

I've had my Unimat 3 since new 20 odd years or so, common sence how its used, I wear hat and full face mask as it can chuck swarf and chippings around. thing to remember with the Unimat 3 is the motor, 10 min's on and 20 min's off to allow for cooling, not sure about the newer motors ?

 

mr B .. modelling Nethertown

Newer Unimat motors are better, the Unimat was odd in having an under rated motor on both the Unimat 1 and 3. I got round it on the one with an Elliot replacement, still in use 40 years later. I never found the Uni 3 burnt out, it just had a poor rating for long term use. You can of course put larger motors on the Unimat, a large motor on a board behind the lathe and a long round belt pulley.

Also it should be noted that the current Unimat's are made entirely by Sieg in China!! and Sieg supply other makers with the basic Unimat base castings for their own versions.

Stephen.

I have just looked up the current Cowells price for the 90ME and should mention it is £1899.00 and this does not include the selection of accessories that Sieg do as standard for under £450.

It can be looked at two ways, the Sieg is cheap and nasty, or the Cowells overpriced. If I was expecting to use the lathe professionally then the Cowells is far better., but the Sieg is far from nasty.

But for the "Home Machinist" the Sieg does all the Cowell can, and maybe more! It does it in an un sophisticated way, it is less well finished , but has the basic accuracy in the parts. I was trained in testing lathes, and the Siegs I have set up are totally accurate for normal uses.

The bed is flat, the parts line up with test bars and indicators, and I could write a test certificate for them easily for precision uses.

I found a slightly slack main bearing on one, detectable with a lever multiplied dial gauge, It was adjusted in seconds, and was not easily detectable on a simple dial gauge. It did not affect the work in any way. To improve the bearing Arc Euro do a de-luxe roller bearing, but most users will not need this alternative for normal uses.

The Chinese chucks are accurate, very accurate, run out was barely detectable, under half a thou, and the jaws are hard and the body induction hardened, so should retain accuracy for years

My Warco 1324 has a Taiwan Chuck, now 20 years old and it is still accurate, these were sourced from Sieg.....

I do know what accuracy is and the Lorch has it, but you can't buy such lathes these days except from Shaublin in Switzerland ......and we are in the area of £20000.......

Remember, with all lathes it is the operator, not the lathe that does the work, and the standard produced is down to the machinist. In no way will you have to "fight the machine" with the Sieg.... the better machines just make life a bit better than having to put in a bit more thought with the cheaper machines, when they are pressed to their limits.

But frankly, model railways is not going to press any small lathe to it's limits, an interest in IC engines might however!!

It's really your chose on a lathe, the more expensive ones are better made and finished, and I should make it clear I have 5 lathes of different sizes, including a tool room small Lorch, but it has given me the experience to see issues with all the lathes.

The Emco series are all accurate and well made, as are Proxxon etc., but if starting from scratch these days my first choice would be a Myford, but this is because of an interest in 5 inch gauge locos.

It simply does not need a lathe that size for model railways, and smaller types like the C3 are handy size, they can be moved and operate without bolt down if needed.

The rivals to the C3 7x10 often use Sieg made chassis blocks any way, they supply Taiwan and Japanese run Korean lathe producers......and some so called European made lathes have Sieg castings in them, even in the UK.

With other makes in the main price range of smaller makes service and spares may be the biggest issue, and you should look into how unique the design is and how serviceable without an importer( they do go out of business).

The advantage any Sieg has is spares from all "makers" fit all, and nothing is non standard, for instance the makers main bearings are industry standard, and can be replaced in a couple of hours.

It is a mechanics lathe, one to do work on, and maintain, fit with extras and generally bring up to standard, but then what standard?

It can rival any lathe with attention to details, converted to collets it would rival the Cowells, and the bed and accuracy is the same, but Cowells offer far more in specialist equipment for very precision work, and it has to be said, at a higher price.

As you move up from the basic C3 each supplier offers other Sieg models, or their own design, and first look through the range from the supplier, like Warco or Chester, determine what the largest work you expect to do, and decide on a matching machine.

I would advise buying from established importers like Chester etc, they have back up and experience.

At the other extreme is Myford, very expensive, huge range of accessories and reliable, Cowells are similar, but specialise in clock and watchmakers machines.

The other main suppliers in the mid range are the German makes, and these are these days a "combination product", using Chinese made castings , and basic machining and supplying and assembling them in Europe.

So it boils down to what you can afford, and the 7x10 variants offer the best value, and being so established now , look like being there for the foreseable future