Sieg sc3

Hi guys. Having done some research i ended up looking to buy a sie SC3 mini lathe from arceurotrade, the only reservation is the price. It is £250 more than this

Link removed see C of C

From that auction site. (have included postage from arceuro)

Now i know you get what you pay for but what exactly will i get for the extra cash?

Fleabay's one has 550w dc motor. Tapered roller bearings for the spindle, so i thought i would ask the folk who knew about mini lathes. An ancient myford etc is out as i do not have the room in my workshop for it.

Thanx in advance for any advice.

Edited By JasonB on 05/10/2020 13:07:31

More a case of you don't get.

For a start that is not an SC3, it is a BRUSHED DC motor most likely of 550wINPUT power not a 500W OUTPUT power of the BRUSHLESS motor that is fitted to a Sieg SC3. This will also have the 2 stage plastic gears that the SC3 does not.

The e-bay prices says is it excludes taxes, import duties and shipping, bit hard to say what this will be as it says it is located in Belgium, shipped from the Czech republic and being sold by a Chinese company so you may get additional costs.

You also don't get the aftersales and parts backup from a known company, what will you do if you need a replacement part or have to send it back if there is a problem.

Also a bit put off by some of the descriptions such as "STURDY ALUMINIUM CONSTRUCTION" and some of the photos they show of it's applications are not of the same lathe

No sign of a CE mark on it unlike the SC3 or what type of plug it will have.

J

Edited By JasonB on 05/10/2020 13:19:55

In addition to what Jason said check the sellers Terms and Conditions carefully. A similar offer I looked at recently required faulty machines to be returned at buyers cost to Germany. Not cheap and a fair amount of bother.

Good question to ask is 'what happens if this purchase fails to arrive or is unsatisfactory'. Always stressful sorting a bad buy out but UK suppliers are far easier to deal with if it goes sour. Look on it as a gamble, above a certain value I choose not to risk it!

Dave

I did not see any indication of whether it was a brushless or brushed motor, and from what i have read you have to push it hard to overheat the brushed motor, which was the major problem with them.

The sieg, according to the downlaodable review does use nylon gears to drive the leadscrew.

The ebay one has a cast iron bed, the aluminium would refer to the gear/ main shaft housing. Looking at the weight of the sieg i would expect a similar construction.

As i understand their are two manufacturers, sieg and real bull, both using the same russian design.

The parts diagram of the sieg sc3 shows ball races on the main spindle shaft, as opposed to tapered roller, which are a superior bearing in terms of load bearing and alignment.

I'll tell you what I got when I brought my first lathe from a popular auction site.

I got to repair the motor driver when it went bang on it's first use.
I got to add some optional safety features like an earth connection & move the fuse to the Live.
I got to hammer out the seized tailstock quill, and then hone the bore.
I got a random collection of change gears at doesn't match the manual, or allow popular threads to be configured.
I got to re-drill the mounting holes & threads in the faceplate, so they lined up with the spindle backplate.
...

it goes on, in short I got a "kit" of lathe parts that need a lot of work.

When I purchased my Mill from Arc, I got a machine that worked out the crate.

Bought Sieg SC3 from ArcEuro

It works as it should and has done from day one.

Cannot see the same machine cheaper from major suppliers, most more expensive and/or lower spec or older designs

Hi Mark,

SIEG makes following models of mini-lathe: C2, C3, SC2, SC3.

The C2 and C3 are brushed motor versions with hi/lo gears.

The SC2/SC3 are hi- torque brushless motor versions with belt drive.

C2 is the cheapest. The SC3 the most expensive in SIEG mini-lathe range.

Most of the ones I have seen on ebay are models which are based on the C2, or sit in-between the C2 and the C3, and generally not made by SIEG. Generally, on most mini-lathes the gearbox covers are made from plastic.

Unless specifically stated, most mini-lathes are factory fitted with ball-raced bearings. If factory fitted with taper rollers bearings, or angular contact bearings (ball), then the probability of reaching 2500 RPM are reduced, unless there really is a powerful motor combined with appropriately geared/belt driven/control board torque adjusted output to deliver the RPM.

About three years ago, HMRC issued a warning to freight forwarders based in Southampton mainly, which were acting as fulfilment centers for mainland Chinese companies. The Chinese companies would collect revenue, fail to pay, and go bust, and start in a new name the next day, operating with the same freight forwarders - warehousing.. HMRC advised freight forwarders that changes in rules were on their way to hold the freight forwarder responsible for revenue which the Chinese company failed to pay. Being aware of what is coming, this kind of fulfilment business moved to certain ports in the EU, where the regulations are more relaxed.

You also state at the beginning: ' from what I have read you have to push it hard to overheat the brushed motor, which was the major problem with them. ' - Your reading and understanding in incomplete, as it all depends on your own knowledge and skills to ascertain meaning of 'pushing it hard' - this is a very loose term, especially in the hands of a beginner. Add to this, 'the base model' depending on manufacturer, combined with what the seller specified to the manufacturer as their requirement for cheap, cheap, cheap, may have failed to provide any form of 'overload protection'.... so chances of failure of control board, motor, gears breaking in these set-ups increase. There is a direct relationship between beginner and mini-lathe failure.

Unfortunately, we get calls each and every day from beginners looking for electrical components,who think they have a SIEG mini-lathe gone wrong... especially from those who have purchased from ebay. Whatever you decide, good luck with your purchase. Do consider Amadeal, WARCO and Chester in your decision making process, all of whom will also provide spares and after sales service, even if their mini-lathes are made by factories other than SIEG.

Ketan at ARC.

Edited By Ketan Swali on 05/10/2020 16:19:16

If in the market for a machine, I would not buy on E bay, because it is too open to non existent or poor back up.

Buying from a reputable importer, you should have a warranty and help if you need it

That is why an E bay purchase might be cheaper in the short term, but if there is a problem where do you go?

Shipping a faulty machine back to the Czech republic or to China might prove to be expensive, plus the time and risks in transporting that distance..

The end result of that might be that the machine eventually turns out be more expensive than if you had bought from a supplier in your country.

And probably a supplier from a long distance may be less concerned about reputation than one relatively nearby.

It may be worth travelling a hundred miles to sort out a problem, in person, but not a thousand!

On the few occasions that I needed it, I have had support from Warco and from Arc Euro, less so from Chester. But those are my experiences, others may be different. Not having dealt with other machine tool suppliers in UK, am unable to comment.

As a supplier, I think that is extremely fair of Ketan to advise looking at products from competitors, but a satisfied customer has always seemed to be one of his objectives.

Howard.

Mark,

You might save £100.

Make sure it's has a 3 way cord earthed at both ends.

Effectively you are dealing with China direct.

You need to compare apples with apples.

If you actually know these machines then the tell tale lever at the back says it has two speed ranges which is what is needed due to the lower torque of a brushed motor

This same lever moves additional nylon gears that the SC3 does not have. It is the spindle drive gears that usually fail not the feed/screwcutting change gears

The Sieg has a cast iron head, your guess is as good as mine as to what is aluminium on the e-bay offering

Although of the same general layout the SC3 has evolved more from the base design than the cheaper C3

Ketan is the bearing expert so see his comments.

Comparison between buying from an unknown dealer on an auction site and an established outfit with an excellent reputation in the field would be a no-brainer for me, whatever the specs on the unknown product said.

I bought a Sieg C0 from Arc, their smallest, cheapest lathe to fit into a temporary and extremely limited workspace. They tested it in front of me, and discussed its similarities to the Emco Unimat 3 I'd owned 20 years before, the differences, improvements and limitations. I think it was Ketan who held a 15-20 minute conversation with me about it.

Listen to what he says.

Hi all. Thanks for your input, it has been invaluable.

Ketan, thanks, brilliant post. Was looking at amadeal coz they are based in london, i am in kent but they dont have the reputation of sieg. Not sure about your comments on taper needle brgs needing more power to drive them. Properly set up they should require no more power than a ball race. I am not a beginner, I am a time served turner who has worked mainly for sub contract machine shops for most of my life, turning components for nuclear submarines, power stations and formula 1 racing cars to name just a few. I have been using chester chinese lathes to reverse engineer components for about 10 years now. Chester are chinese made, a bit rough around the edges, not as refined as european manufactured lathes but are very capable machines. Colchester outsourced their manufacturing to china for many years.

I am conversant with machining on an industrial level but have no knowledge of mini lathes. I have enough room in my garage/workshop for one and think it a useful addition. My hobby is building custom motorcycles. I have read that a 0.25mm cut would be classed a fairly heavy cut for these machines, is this so? Is not an issue but a usefull bit of knowledge. I am leaning towards an sc3 at the moment, do these take 8mm square max tooling?

Again, thank you to everyone who has taken the time to post. We can only learn by asking questions.

My view of cheap sites? Yes, buy from there - but only if you can afford to throw it away if it does not work as expected (or at all).

Simple as that. Your lottery.

I buy a lot of things from China, like we probably all do. Latest is LED solar outside lights, / a Bench disc,belt sander + i could go on. All ok stuff for the price. I would never even consider buying any expensive machinery from any country. As said by others buy from a source you can badger if there is a problem. I have had shallow dealings with Ketan at ARC. He is a pretty straight honest guy. You would not go far short to deal with him.

He put me straight a few times on which chinese tooling was good or bad. Just to add i have never purchased from them. But would if i needed anything in there Catalogue.

Steve.

Hopefully Ketan will be along to answer some of those questions but regarding the 0.25mm DOC. This is very subjective particularly with regards to diameter. I have a larger Warco Chinese made machine that is able to take a 6.35mm cut off 1" steel bar eg take it down to 1/2" in one pass. But if turning say a 10" cast iron flywheel will stall at much over 0.75mm DOC. There are ways around this such as using carbide so you can run it faster than a typical Myford user would do so two fast cuts at say 0.25mm each take no longer than one slow pass at 0.5mm

This is due to the variable speed machine starting to loose torque as the spindle speed is reduced as the motors are not running at their optimum speed unlike a geared or belt head machine where motor is always running at full speed.

This is due to the variable speed machine starting to loose torque as the spindle speed is reduced as the motors are not running at their optimum speed unlike a geared or belt head machine where motor is always running at full speed.

It follows, from what JB posted above, (because power is torque multiplied by speed) that if the torque were the same, the motor power would be reduced by half at half speed. Reduce the torque as well and you can see why the machine will no longer cut very much at lower speeds.🙂

Hi Mark,

This is a long post...sorry.

The original headstock casting design from the East German-Russian days was made to accept Taper Roller bearings (TRBs). As U.S. demand for cheaper source of production grew, the sourcing moved to Taiwan where bearings were changed from TRBs to ball-race, and as the Taiwan production costs increased, the machine moved to Mainland China production, when the Chairman of SIEG brought it back with him from Germany where he was stationed for a while; initially for demand from a German company, followed by Harbor Freight in the U.S., and so on.

Ball raced bearings (BB), Angular Contact Bearings (ACB), Taper Roller Bearings (TRB) :

The balls in the BB have a small area of contact between the ball and the raceway/groves - Generally not designed for pre-load - but still done.
ACBs have a greater area of contact between the balls and the raceway surface.
TRBs have the greatest area of contact between the ROLLERS (not needles) and the raceway.

So, when you put on pre-load by tightening the nut/nuts (depending on who you buy the mini-lathe from), your motor/assembly needs to work harder to drive the spindle. For brushed motor machines, there are pots (can't remember the technical word) on the control board used to control torque/speed. This would have been factory set, based on the bearings used in the assembly, along with the gear/belt arrangement. So, where BBs are used, the pots are set accordingly. General advice is leave the posts on the board alone, unless you really know what you are doing. There really is no need to worry about the reduction in maximum speed.

Based on the two above factors, the RPM will drop if and when you change the bearings from BB to ACB to TRB.

The assembly is designed for hobby, rather than industrial - continuos use. Under certain scenarios, the motor could over heat, especially brushed motors where the brushes could wear faster, the drive belt could wear faster/break, if there is a hi/low gear arrangement, the gears could break under heavy load, the circuit board could also blow - based on load. So, when you change from BB to ACB to TRB, the load will increase. As long as you are aware of the factors which can effect the machine by making any changes, you can use the machine within its limitations, before something goes wrong.

You may wish to read these threads to get further ideas:
Pre-load of new bearings
SC3 Headstock bearings

In the SIEG mini-lathe range, there are brushed motors and brushless motor versions. How things work electronically with brushed motor versions is explained above.

For the SC brushless versions, there is no hi/lo to control torque. These machines are purely belt drive, and the torque is controlled via programing of a chip on the control board.

The WARCO version of the brushless motor is smaller (lower power rated), combined with a belt and hi/lo gear arrangement. Their version is discussed of the following thread:
WARCO Super mini-lathe Brushless motor version

As far as mechanical components and assembly are concerned, regardless of factories used by ARC, Chester, Amadeal, WARCO are concerned, they are broadly similar (from about four different factories). Generally, 80mm chucks are fitted as standard on mini-lathes - based on an engineers view point. There are versions available with 100mm chucks factory fitted. Initially around 19 years ago we liked that idea, but after discussion with the SIEG factory technical engineer who explained the limitations/extra load mechanically over distance of spindle, combined with load on motor/board, size on machine, I had a better understanding, learned and decided to keep with the 80mm arrangement. ARC can get 100mm chuck based spindle assemblies, along with other features, but we are happy with the situation as it stands. We do offer the backplate with 100mm chuck as optional accessories, but generally I would suggest that they are used on limited occassions.

In support of Hugh (Harry) - Amadeal, some of the bad press you read - especially ebay linked, is because on ebay, many buyers confuse the mini-lathe he sells with mini-lathes sold by 'Hu Flung Dung' sellers, because of the common name CJ-18. These buyers purchased from HFD sellers because it was cheaper than Amadeal.

So when the HFD control boards on their brushed motor mini-lathes fail, they will buy a new board from Amadeal, thinking that the board will be the same - which it might not be, or, they have failed to check the brushed motor before buying a new board. If the motor has blown, it will take out the new board!.

Amadeal sell a lot of mini-lathes directly and via ebay, and you will find happy/un-happy customers using their mini-lathe, just as much as you will find for WARCO, Chester and ARC.

What is classed as 'heavy-cut' on a mini-lathe is down to several factors: User, material being turned, feed, speed, DOC, use of coolant, tooling - HSS/carbide.

Continued...

Generally, there are four categories of buyers we come across in the hobby industry:

a. Total beginners who don't know what they are doing, but are prepared to listen and be guided. When they break things, they don't whinge. They ask what they did wrong, replace broken part, get on with it.

b. Total beginners who know think they know everything. Everything the seller says is wrong. 'I am a qualified so and so'. Everything is a warranty issue, not fit for purse purpose, 'I read this, saw that on You Tube' (70% garbage 30% good), 'I will write about this on forum, I will give you a bad Trustpilot review, I will take you to court'.

c. People who generally use small hobby machines who are prepared to tweak things to their requirements, keeping in mind the price they paid for the product. Most hobby machines (with a few Friday afternoon exceptions) regardless of which U.K. reputable dealer you buy from are fit for general engineering use. There after, it is up to the user and their ability to get the best result out of the machine, to tweak it to meet their specific accuracy/precision requirement. This category is the least likely to break parts on a machine, and if they do, they usually know why it happened.

d. Engineers who use big industrial machines in their day job. They usually break machine components/tooling because when they use a hobby machine at the end of the working day, in their garage, sometimes they are still 'in work mode'.. forget, and introduce work related feed rates to material being turned. The second something breaks, they usually say some expletives and immediately realise what they did. That evening they will place an order for a replacement part, or phone us for it the next day, and tell us what happened.

Chinese built hobby lathes are light weight, and NOT anything like the accuracy or precision or assembly you may be used to with the heavy weight industrial machines which you may use in your full time job. To get the result you want, you may/will have to tweak them to meet your expectations. If you are expecting anything beyond the 'general engineering use', and if you are prepared to pay the price, look at the EMCO WABECO offering in the advert on the right hand side of this page.

The SC3 and most mini-lathes will take 8mm tooling - HSS or Carbide insert lathe tools. Depending on tool post being used - fixed or QCTP, you may need to make your own shims and use them to pack the tooling to get it to the correct height for turning, depending on tool form.

Ketan at ARC.

Hi Mark,

The issues have been pretty well covered.

I have a 21-year old brushed style Clarke CL300M which I ended up fitting a 3-phase motor to, which says something about the brushed motors. I've taken 3mm cuts with it just to prove I can, but in ordinary use 1mm cuts are fine, it's down to good tooling and technique really.

If you are used to industrial machines and have deeper pockets, you might want to look at the SC4 which is a step up in capability and capacity.

Neil

Mark,

Neils Clarke CL300M is a SIEG C2. Before he became editor, he changed the bearings to TRBs on his standard machine... I think about 12 years ago. Once he became editor of MEW magazine, he did his hells angel mod to 3-phase motor too.

Ketan at ARC.