Sieg C2 Lathe

[hollywoodfoundry]

My trusty old Sherline lathe has just died in a manner that cannot easily be repaired, so I am looking around to see what I can get for a reasonable price. The Sieg C2 is one that attracted my attention. Does anyone out there have one who can comment on their experiences with same?

 

Geoff

[Rob Pulham]

My trusty old Sherline lathe has just died in a manner that cannot easily be repaired, so I am looking around to see what I can get for a reasonable price. The Sieg C2 is one that attracted my attention. Does anyone out there have one who can comment on their experiences with same?

 

Geoff

Geoff, I don't have one myself but Mick Nicholson of this parish did a review of one of the Seig models(the baby one) for one of the magazines that I downloaded as a PDF from a site as I was considering getting one. If you PM me your email address I will send you it.

[bertiedog]

Geoff,

(No commercial connection whatsoever with Sieg)

 

 

Picture courtesy of http://www.7xlathes.com/ and copyright

net ref http://www.mini-lathe.com/Default.htm also good site.

Also Yahoo user group http://groups.yahoo..../7x10minilathe/

Massive link list for mini lathe users http://www.mini-lath....htm#Home_Shops

I have not got one of the Sieg lathes personally, but I have set up three for friends in the Model Engineering world, and I will probably be getting one later this year myself. Very pleasant to use, a proper design in miniature, but still big enough for live steam locos.

 

I would rate it very highly, especially if you are adept at engineering and are prepared for a little work to set it up for really accurate working.

 

The basics are all there, it works from the box, and the back up on spares and parts is good, and hundreds of accessories fit the machine.

 

It's weak points were the standard of finish, and some of the design details, all of which have been addressed by the Chinese makers, or by the legions of enthusiastic owners groups and individuals around the world

 

It is the Worlds most widely sold small lathe, and comes in lots of ways to the buyer, each supplier specifies things differently, and the bed comes in two lengths. It is made by Sieg, who have a website, but is sold locally around the world under dozens of names.

 

In the UK it comes in a basic form from two suppliers and a more expensive better spec version with digital readouts etc., added. Most in the UK are the long bed version.

 

But the basic machine is quite all right without these extras. It will need a service on arrival, as it has thick grease in the gears and on the bed, a clean and attention to the jib strips is needed.

 

The grease can be changed and motor cycle chain grease is excellent. The motor should be run in with no load for at least an hour before any heavy work.

 

The gear on the spindle was considered suspect for long term wear, but it's very cheap to replace and a de-luxe steel replacement is made as well.

 

The electronics were considered suspect as well, but pressure on the Chinese has altered all of this and the electronic control is now OK. It uses a DC motor to achieve the control, and has a stepless range on each belt position.

 

The main advantages are the old ones, it does things in a traditional way, normal tapers, same as Myford, normal screw sizes, and standard tailstock fittings, nothing unique to the machine.

 

The bed is induction hardened on most supplied , but check with your local supplier.

 

Some Harbour model in the States have the old un-hardened bed to save money. They are however as accurate as each other.

 

The general standard of accuracy is fine, it would pass any normal test, except toolroom standard, and it could easily be adjusted to pass that higher standard should you want to.

 

My own issue is with the Jib strips, which are steel, and I prefer bronze or hard brass, and you can change the old ones with home made strips in an afternoon, improves the adjustment ease, and makes it smoother than standard. Some people change the handles to more convention ones to taste. They vary though with suppliers.

 

The one missing thing one the whole lathe is a lock for the saddle which if really a must for parting off etc.

Several independent makers offer kits of a handle and lock, and the net has several designs that can be made on the lathe itself, easy to do and very satisfying to add. Also the adjusting screws can be removed and replaced with Allen head screws of longer length, that make adjusting the jibs so much easier. De-luxe additions like ball ended bolts can be added instantly.

 

Mentioning the net, have a good look, there are lots of enthusiast and professional sites on the net for users of these very popular lathes, in the States there are clubs and conventions for users, it has that type of following.

 

Designs for extras are legion, there are few tasks that you cannot undertake on the lathe, precision collect work, turret tailstocks for production work, Multi tool holders both commercial or home made, designs for copying and form work,and the lathe comes equipped for pretty comprehensive gear cutting as standard.

 

It comes usually in a metric form with a metric lead screw, but you can convert it to full imperial, with a complete replacement leadscrew in a few minutes, these are an extra, but are cheap, about ??30 in the UK. The knobs have dual markings on most machines, you do not change the cross slide of course.

 

As standard, it comes with a milling attachment for horizontal milling, and a vertical slide, but check the package offered in Australia, it may vary.

 

The main chuck is accurate, I have tested the three I set up and they were absolutely true, within 10ths of a thou repeats, and true at max and min within usual limits of wear and tear. The tailstock chuck is a typical Chinese Jacobs type and accurate. The taper is Myford fit.

 

The Morse tapers were perfect, and fitted my own BS standard test bars, which also confirm the cast iron bed was true and straight.

 

The headstock takes all types of collett both front closure and draw-bar types, and can take 4 jaw and bell chucks etc. Many watch makers use these lathes these days.

 

The headstock is accurate, and adjustable in future or after service, and the tailstock is true, and again possible to adjust. It will set over for tapers.

 

The tailstock lock is a bit crude in design, simply a bolt, but again it takes only a few minutes to add a commercial replacement or make it yourself, the standard one works though. Some suppliers already fit a cam lever lock as standard, but charge extra.

 

All the extras and mods can be done on the machine, it will work out of the box, but can be converted to a really very high standard, and at the price is simply un-beatable.

 

If you need any more exact details, please post, I am sure others are considering these and may not realise how much can be done on them.

 

Stephen,

[hollywoodfoundry]

Thank you Rob and Stephen, I will PM Rob for that PDF.

 

That was a very detailed reply Stephen, and I must say it was comforting to hear that it works well enough. My old Sherline was one of the original ones when they were made here in Melbourne by Ron Sher, but the problem with the cross-slide is not readily fixed and it is not the same as the new version (made in the USA), so I cannot purchase a spare for it.

 

The old lathe has served me well for about 30 years now, so it does not owe me anything. It was tempting to buy another, but they are just getting too expensive by the time you import them now.

 

I have compatible carbide insert tools and I hope my existing parting tool will fit. Not sure about the tailstock taper though, I have an existing Jacobs chuck that I would lijke to use, but I will have to wait to see if the Sherline taper is the same as the Sieg one.

 

Thank you again.

 

Geoff

[bertiedog]

Thank you Rob and Stephen, I will PM Rob for that PDF.

 

That was a very detailed reply Stephen, and I must say it was comforting to hear that it works well enough. My old Sherline was one of the original ones when they were made here in Melbourne by Ron Sher, but the problem with the cross-slide is not readily fixed and it is not the same as the new version (made in the USA), so I cannot purchase a spare for it.

 

The old lathe has served me well for about 30 years now, so it does not owe me anything. It was tempting to buy another, but they are just getting too expensive by the time you import them now.

 

I have compatible carbide insert tools and I hope my existing parting tool will fit. Not sure about the tailstock taper though, I have an existing Jacobs chuck that I would lijke to use, but I will have to wait to see if the Sherline taper is the same as the Sieg one.

 

Thank you again.

Geoff

 

The tailstock is I think number two,(it's in the specs), anyway as per Myford, if you have number one morse or 0, then sleeves are made, totally accurate. They fit the larger size to allow more to fit.

 

The tooling size is the same as Sherline, plus or minus the adjustment, 1/4 or 3/8, but it takes wider than that if the holder is altered.

 

The larger Morse in the headstock can have a sleeve added to make it match the tailstock and take boring bars etc and flycutters for gear, and rack gear making.

 

The only process it will not do, and the Sherline would not do it, is knurling with a single side roller, too much strain on everything, but double roller clamp types are made, which act as jaws around the work, and the strain is totally removed.

 

The whole lathe is very amenable to taking a full screw chasing bar at the rear, with chaser forms to turn any known thread, any pitch or form, to any precision, there are designs on the net, or I can outline the one I have on my Toolroom Lorch, based on the Unimat design, which came from Shaublin (Swiss).

 

Also there are several suppliers offering full CNC conversion for the Sieg's of most models, the mini -lathe is one that is fully convertible. Usually these are home fitted.

 

I do not know the problem you have with the Sherline, but I suspect fully curable, it may be possible to use the new lathe to make spares. I have made spares for the Lorch, not easy to toolroom standards at home, but anything is possible in servicing or repairing machinery, if it was made it is possible to repair.

 

PM me with details of the fault with pictures if you want further advice on it. It still may pay to buy in another lathe, a backup with a manufacturing outfit is desirable, get things running again with the Sieg, and then service the Sherline, and say devote it to fine collett work.

 

regards,

 

Stephen.

[KBscale]

I have the C2A - this has the digital displays, but these are the most frustrating thing about the lathe for me as the batteries don't last very long and it seems I am forever changing them. Probably it would help if I remember to turn them off. The 2nd is the standard clamp on the tail stock - I have changed mine to a lever and cam and it makes the a big difference to the usability.

 

 

d

[bertiedog]

Personally I would not bother with the Digital read-outs, the batteries available are often not proper silver oxide types, and there is little way to fit others.

 

Also I do not worry about the readings on the knobs, I simply don't care if they are MM or thou, I only use them to estimate taking the carriage in by the same amount each time, no measurement should ever be trusted to the knobs, bad, bad practice! after saying that I would trust my Lorch, it's so well made.

 

I had mentioned the single bolt which needs a spanner to move the tailstock, but dozens of home made or commercial solutions exist, and some of the latest versions come modified by Sieg, or the importer fits them as standard.

 

The other query often raised is the knobs, a bit basic, but all changeable to suit you, solid metal or traditional ball ended, often made on the lathe itself.

 

The most important addition is the missing carriage lock, it is vital, and easy to make your own, plenty of ways and plans on the net, plus commercial ones. Do not attempt to part off steel without it.

 

For repeat commercial work a set of carriage limit clamps are a good idea, and addition bed strip of flat steel at the front, with an arm on the carriage, with clamps on the strip, to position and acts as stops, which can be adjusted for multiple positions with an old set of slip gauges.

 

The Lorch is about the same size as the Sieg and has a 3/8 x3/4 strip the whole length of the lathe at the front below the main lead screw. The carrige has a bar, removable, that goes down from the carriage to run it's end over the 3/4 wide track, till it hits the stops, or slip stacks, or job specific gauges.

 

The screw cutting consists of a 2 inch dia metal bar running the full length of the whole lathe at the back, secured to the base plate, and in ball bearings, with two arms, one takes a follower to sample threads attached to the back of the headstock mandrill, and the other arm goes to a rest on the cross slide surface, with an adjustable screw holder with the single point tool.

 

The lathe is switched on, with the work in the chuck and the arm raised, and whilst running at slow speed, the arm is dropped on to the work for one pass, and lifted, leaving the lathe running, the arm is moved back to the start, and adjusting the tool screw is passed over the work again and again till the thread fit is achieved.

 

As the arm lifts out of the way instantly, the thread is easy to check with a gauge, no moving the cutter out of the way still engaged to the lead screw as in normal screw cutting.

 

Any thread and follower, (a scrap nut will do sawn up), that can be fitted to the mandrill end, can be reproduced, perfect BA threads, square threads, buttress threads, photographic threads for filters and lens etc., and all left hand threads.

 

Also any, say 1mm pitch chaser thread, will turn any diameter of thread, so you do not need huge sets of chasers, just a handful to cover most types.

 

The Siegs size lends itself well to this system, and if anybody wants more details, post or PM. It is based on the Swiss precision method used by Shaublin and Boley.

 

Stephen.

[bertiedog]

The quickie modified drawing from my Lorch handbook shows a thread chaser, in fact the Lorch in the shot moved the whole headstock to achieve the same effect, the bar is two inch diameter and the arms are CNC cut from dural one inch thick. They are cranked on the Lorch I have to allow the main bar to be at the bottom of the lathe out of the way, and the support bearings are car front axle bearings, 2inch dia type.

 

The master thread is attached into the mandrill tube, how you do it is up to you!!! I use and expanding mandrill inserted , bolted up, and then the drilled out master chasers are slipped on with a retaining nut.

 

And I should have added it works fine with practice for all internal threads as well, you add a withdrawing tool tip on a lever on the tool rest..

 

Stephen.

[bertiedog]

There is a change to report, there are new versions of the Sieg with a completely new drive, from a large coreless motor, and this change does away with the existing duel belt system, and gives a single stepless speed range. The coreless DC motor is AC frequency controlled, a pulse drive, that maintains high power at low revolutions. It is claimed to be more efficient, with little or no heat build up.

 

Super low speed drive would be easy to add, a belt to a separate pulley and back to the main spindle, would give a dual range with even more power to use with cast iron, or to ease thread cutting using the gear set.

 

The new versions are just about to appear on the UK market, check locally for delivery and pricing.

 

Stephen.

[hollywoodfoundry]

Hmm, that could be a good reason why this one has turned up on evilBay, it is probably the older version. I should know if I got it by the end of today.

[bertiedog]

Although the improved motor is an advantage, the older type is no disadvantage, as the thousands in use prove!..and I expect conversions will appear if the motor is a lot better.

 

Dealers that are promising the new model are pricing it higher as well, and running both models together. I can't quite work out whether any new ones are due yet or not. Most UK suppliers are not showing any details as yet.

 

You have by the way "C2" on the post, but most of the 7x10 and 7x12 are "C3" numbered. There have been other Sieg numbers in the past and some have letters added, but it is hard to work whether it's Sieg or the importer

 

Is the one on Ebay the same as the picture, The standard mini lathe C3?

 

Stephen.

[bertiedog]

I have just had a look at Ebay in Australia, and the C2 is the 7x12 lathe, and the C3 is the 7x14 lathe, the longer bed. Other than that they are identical units bar some cosmetic differences, very minor. All main parts are interchangeable, like steadies and toolpost additions, and all modifications apply to both.

 

The very first mod is to add a felt pad to the leadscrew where it enters the headstock, a disc of 1/4 felt will stop swarf getting into the area, keeps it clean.

 

Stephen.

[bertiedog]

 

I have had a look at Sieg's own Chinese website http://www.siegind.com/index.php and the new C2A is the one with the coreless motor, that is a 7x12 and is in the picture with a slightly bigger headstock cover etc, the C3 remains at the moment in the original form and is 7x14.

 

So the C2 is the original 7x12, the most popular type of all. (Over here in UK marketed by Chester, Warco, Axminster Tools, Machine mart, Arc Euro trade, and Clarkes, apologies to any others missed!

 

Stephen.

[hollywoodfoundry]

Well, my C2 arrived last week in good order and condition. I was able to get it on EvilBay at more than $300 less than I could have from a local dealer. However it took a couple of days to clean the protective grease off it, set it up and adjust everything.

 

But, generally speaking, I am impressed. It does just about anything I will want it to do, having used it already to shorten a batch of flywheels and make up some custom axle lengths for a customer.

 

The only criticism I have so far is that you need to start it with a defined sequence. If you do as they say in the book, it will not run. It is a bit like: Look to the left, stick your tongue out, reset safety switch, blow a raspberry, engage forward gear and roll your eyes

 

Also puzzling, it runs much slower in reverse than it does in forward?? I am wondering if these things are symptomatic of a problem with the control card?

 

Anyway, I have now also purchased a chuck for the tailstock and a nice parting tool, so I have just about everything I need now.

[bertiedog]

Speed in reverse is slower, DC motors tend to be biased forward, but not by much. I had never noticed any problem. The control cards are usually US sourced over here, but recent Chinese ones are OK now. As it being used commercially I would look around for a spare anyway, any will fit all models within reason.

 

The instructions not matching may indicate it has a replacement card and start switch fitted for your market. In UK it has to be a no volt cut off, power failure and machine stops type, with re-set to re-start. direct switching is not allowed, power off/stop/re-power start would not be allowed on safety grounds.

 

Have a look at the 7x12 forums and see if the card is adjustable, I will check as well.

 

Stephen.

[hollywoodfoundry]

Speed in reverse is slower, DC motors tend to be biased forward, but not by much. I had never noticed any problem. The control cards are usually US sourced over here, but recent Chinese ones are OK now. As it being used commercially I would look around for a spare anyway, any will fit all models within reason.

 

The instructions not matching may indicate it has a replacement card and start switch fitted for your market. In UK it has to be a no volt cut off, power failure and machine stops type, with re-set to re-start. direct switching is not allowed, power off/stop/re-power start would not be allowed on safety grounds.

 

Have a look at the 7x12 forums and see if the card is adjustable, I will check as well.

 

Stephen.

 

Stephen,

 

Yes, well the way it starts would certainly meet those rules. You have to release the large red emergency stop switch, take the forward/reverse switch from STOP to forward, then increase the speed potentiometer. If the forward/reverse switch is already in forward and the pot ramped up, just releasing the emergency switch will not start it. From a safety point of view, that seems fair.

 

As for reverse, I am quite unlikely to use it, just thought it was a bit odd.

[polybear]

Hi,

 

There's discussion groups dedicated to the 7x12 (and also the smaller 7x10) lathe on Yahoo, which are a mine of useful information and well worth joining. HTH

 

Brian

[hollywoodfoundry]

Having used the new lathe off and on for the past month, I have to say I am generally impressed with its quality and capability. However I do have one criticism, the amount of available travel on the cross-slide. I purchased a small parting tool that appeared suitable for the lathe, only to find I can only get it about 1/2" back from the lathe centre.

 

The main reason is the tool has a hump at the front to accomodate the tool securing mechanism, and this prevents it being held closer in the tool rest. So for anyone looking to buy a parting tool, I would recommend the type of parting tool that does not have this feature.

 

The photograph (poorly) shows the position of the tool relative to the chuck.

[bertiedog]

The type of parting off tool holder to get for a smaller toolpost is a clamp grip, which also grip the blade better as well. It is quite easy to make one, just examine the angles on the blade carefully, and mill to match in the jaws of the clamp. It can also take the type of blade with a carbide insert.

Stephen