Member postings for Ketan Swali

In the early days of ARC, we used to sell Stirling engines, and seek advice from Roy Darlington (key member of Stirling Engine Society who sadly passed away in late 2018). His simple advice was to remove all seals/shields and wash the ball raced bearing in paraffin. 'The oil' in paraffin was enough to lubricate the bearing, resulting in the lowest amount of friction.

Most metal shielded bearings have two metal shields. Could you live with one shield, remove the other and wash the bearing grease out?... or remove both shields, wash out the bearing, and clean the bearing when necessary.? Once metal shield/s are removed it is generally difficult to put them back on. They are usually press fitted into a grove on the inner side of the outer ring, or, in some cases, depending on the size and supplier of the bearing, the shield is retained with a snap ring... if you are lucky.

Ceramic ball raced bearings which require no lubrication are available with cage for certain sizes/without cage but with full complement of ceramic balls, where the bearing bore is 3mm and upwards, but I have no idea for how good they would be for your application.

Ketan at ARC

Edited By Ketan Swali on 06/10/2020 15:50:18

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,

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...

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

Joel,

SX3.5ZP with R8 spindle (means without DRO), current estimate Mid-December...early January 2021 if we are lucky. Price to be decided nearer to when the goods are shipped.

Unfortunately ARC don't stock 3MT.

Ketan at ARC.

Hi Martin,

How can I ever insult you? We have known each other for over 10 years now

Ketan at ARC

Nir,

You obviously know what you want, and this machine fails to meet your expectations. So perhaps you may want to call it a day. You have explored all the comments on here, and chosen what you wish to believe. Perhaps it is time for you to return the machine to the supplier and get a refund.

I really do not think you will find a solution to meet your expectations.

Ketan at ARC.

Hi Martin,

There is no logic to argue, but I really don't expect a person with your level of compitance to understand.

Ketan at ARC.

Edited By Ketan Swali on 01/10/2020 18:10:49

Edited By Ketan Swali on 01/10/2020 18:11:12

Just for clarification Dave...

• There is a direct relationship between calibration, inspection, and what the end user is prepared to pay. Living in Europe and USA, our markets are extremely competitive, and that is reflected in the price. Israel seems to be another matter.
• Arc used to offer a tune up service. Demand was good, but noise from competitors about this service which we offered was negative. Sales doubled after we stopped offering the service!
• For hobby machines, Buck and Hickman, Cromwell, Zoro, Granger, MSC, are extremely wealthy companies, but less geared to assist in comparison to Chester. Still, they are a great channel for sales, for those who wish to use them.
• If Nir wants a Western/near Western offering, he can always consider a new EMCO, followed by a WABECO.
• Nir may or may not be unlucky with the machine he has. There may or may not be a problem. Here speculation takes over. The rust/paint touch up are cosmetic - easily fixed by discussion between Nir and his supplier.
• Knowing SIEG, the probability of a bad batch in terms of inspection before they left the factory are low. What happens in transit is another matter. As I mentioned before, there was an issue with the paint on some of the SX3.5DZP machines in a particular batch ARC received, but that was dealt with.

At the end of the day, this really is a conversation to be had between Nir and his supplier.

Ketan at ARC.

Nir,

I would like to suggest that you look at this video from Blondiehacks. If you don't have access to an experienced 'practical' machine tool fitter, this is a good video to see, if you decide to keep the machine.

If you are having issues with the Z axis, again, a 'practical' machine tool fitter can guide you. To beat your distributor with speculative discussion on here is wrong as it is difficult to make a clear judgement for your distributor or you.

If there really is a problem with the Z axis, there are ways of dealing with it, but without physically seeing the machine in front of you - all guidance is just speculation. There are checks I can suggest, but I would only do so if and when I feel it is appropriate. This would be the wrong time for me to get into a discussion on the subject, because again, I would be just speculating.

Machines are calibrated before they get into the packing case. From then on, ALL machines are subjected to changes in temperature in transit, combined with shake, rattle and roll, until you put the machine in its final resting place in your apartment.... there after, the machine needs to settle in its final place of operation for at last a month, before you decide to do any major adjustments to meet your specific requirements. This is a general purpose - general use light weight/light duty hobby mill. It is not a heavy weight, heavy duty industrial machine, nor is it a tool room machine specification.

So, even after the 'light weight' machine is calibrated before it left the assembly table, you will be extremely lucky if it remains the same by the time you instal it. There is less adjustment to be made with machines which have a heavier casting, smaller table, along with some other factors.

Jason and many others have the same machine, supplied through respective SIEG distributor channels around the world. They are all working as needed, be it with or without adjustments, to meet the users requirements. Where they fail to meet the users expectations, they are simply returned for a refund, after discussion and mutual agreement with the reputable supplier.

I respect your enthusiasm. However, to carry out some of the adjustments to meet your specific requirements requires experience with skills gained over decades. If you decide to keep the machine, I would suggest you use it, let it settle in its final place of operation, and only consider to make very small adjustments over time, as your skills develop. Although I have given you the link to the Blondiehacks video, I would suggest you consider certain bits of it, slowly over time, as your machine starts to settle, and as your skills develop.

If you continue to approach this matter in the manner you are - with speed, it could turn out to be a problem as the machine settles over time.

Ketan at ARC.

Busy Bee owner and Grizzly owner are related... I think brothers. Both have same surname : Balolia. I have met a Craftex inspector who was carrying out an inspection on some machines for Busy Bee in a SIEG Factory during one of my visits. They work independently from each other, even though they both buy from same factories for certain products... but not all.

Ketan at ARC

Thank you Steve and Mike,

Happy to be back - advertising.

Mike: ARC used to sell BA taps and dies about ten years ago. Demand was too low for us to stock the range, and cost prices kept increasing from our suppliers. So we discontinued. Few years later, similar story developed for BSW/BSF, so, once again, these were discontinued. There are about three different sizes of BSW/BSF taps left in clearance.

Ketan at ARC

Edited By Ketan Swali on 29/09/2020 21:06:00

Nir,

I have forwarded your serial numbers to the factory, and suggested that they check their build logs for these two machines, and also check which of the two dealers in Israel they have supplied the machines to, and enter into a conversation with them, if it is felt necessary by all concerned.

As far as I am concerned, the rust and paint touch up you have highlighted is not a big deal. Some people may disagree. Regarding the inaccuracies to which you refer, this is really a matter for you to take up with your supplier. To build up a case to present to your supplier by directing him to this thread to refer to every ones opinion is speculative and wrong. What you really need is an experienced machine tool fitter in your country to assist you to make the necessary adjustments as he feels appropriate, to meet your specific requirements. This is different to your suggestion to get a professional to check out the machine at the dealer for USD200. In my opinion, if you are paying for it, it may be better for you to discuss the matter with your supplier to get an experienced machine tool fitter to assist you, with mutual agreement between the two of you. Although, I am still uncertain if the fitter or anyone else will be able to solve your problems. It may also pay you to do a milling coarse of some description.

There are too many variables in this conversation, to include the human element. It would be wrong of me to speculate, especially as it is a machine sold by a different dealer in a different country. I believe that the dealer would need to be given a chance to deal with your concerns directly. If you would have purchased the machine in the U.K. from ARC, looking at the variables involved, I would have just taken the machine back and directed you to consider purchase from elsewhere. This would not in any way deny your concerns. It would only recognise that it would take too long for ARC to deal with the concerns you have raised - be they right or wrong. There are people on this forum who are aware that this is ARCs company policy, as we simply cannot afford to get into an endless discussion on so many variable issues - regardless of there being so many issues/perceived issues or otherwise. Mind you, in the old days, for $3,000.00 we would have done a full overhaul - preparation service and even polished the machine for you at this price, which is nearly double what we sell at. (Before anyone asks, ARC stopped offering the preparation service about five or six years ago.).

ARC currently sells this machine at around USD1750 inc.U.K. tax. Our profit margins on SIEG machines are very low. So, from your perspective, I can understand your expectation for the price you have paid, but at the same time, I have no idea of what your dealer paid SIEG for the machines, nor do I have knowledge of Israeli import duties, taxes and overheads, so again, it would be wrong for me to make statements of what your dealer should do for you in your particular case.

Ketan at ARC

Nir,

Welcome to the forum Nir. Where are you from?... just asking as I am sure that it is not a machine supplied by ARC.

The issues you raise are of concern. However, before you explore comments and advice which may follow from various forum contributors, could I ask about your engineering background and knowledge of checking machines? Did you use the machine as received, or, did you strip it apart and re-assemble it?. How did you lift and place the machine in its final place of operation? There are several methods of measuring alignment - good and bad. Checking alignment is a subject which most people - new to the hobby have less experience with, and I do say this with the greatest of respect. Most people will speculate. This is not something which I would/could discuss at length, because it is difficult to be sure without sight of the specific machine.

How old is your machine and what is the serial number (you will find it on the bed of the Y axis, near the front). Is your machine the standard length table or the longer 'L' version?. There will be variation from one end to the other. the longer the table, the more the variation, but it is normally addressed by use of shim/s under the work piece being machined - if the workpiece being machined is long (I will keep away from getting into a debate on this point - as there are too many variable factors involved), based on how the variations are measured, combined with expectations over the length of the table. There was a batch of SX3.5 machines which had a paint issue, which has now been rectified. However, I am unaware of such an issue with the SX2.7.

I am surprised to read that a corner of the top-back cover on the second machine had 'sheared apart'. Could you show some pictures of this?.

It is true that most Chinese factories will touch up paintwork where it may have come off, be it SIEG or any other. With reference to alignment, ALL Chinese machines in this price range are first assembled, and then checked and adjusted for alignment. Possibly not the best practice, but that is the way it is.

Once the machine leaves the factory, temperature, handling, mis-handling can effect alignment too. In your case, I would suggest that you employ the services of a machine tool fitter to adjust and align this or any other machines you may be considering, be they SIEG or otherwise.

The SX2.7s and SX3s are very popular sellers for ARC in the U.K. and Europe. Most customers are happy with them, and our general advice has been to use them as they come out of the box, making slight adjustments for anything which may have become loose for example. Only consider 'major' adjustments if they have the knowledge, once the machine has settled into their working environment. This is possibly different from advice you may get from some others, but that is our view on the subject. In the U.S. these machines are sold 3x more than in the U.K., even after the Trump tariff, and usually, the users there invest in a pack of shims to deal with their specific needs. With a few Friday afternoon exceptions, these machines are great for most hobby users.

Before anyone says anything, in our opinion, these machines are fit for general use as supplied. Yes there will be some Friday afternoon assemblies, which most good sellers will replace or refund, but if one is expecting a toolroom spec., or a machine which is adjusted or prepared by a toolroom fitter at the installation end, they they should consider alternatives or budget for the extras, depending on their own knowledge and experience. In this respect, some Youtube knowledge is great and some is poor.

Finally, if you are considering an SX3, the assembly teams which assemble the SX2.7s are the same as the teams which assemble the SX3s. So, I hope that in some way that answers your question about the SX3, to a certain extent, excluding other peoples opinion. No doubt Paul Lousak from Australia will come along shortly to tell you how happy/disappointed he was with his SX3 which he used outside/beyond the limitations of the SX3.

Ketan at ARC.

Welcome Stephen,

just a clarification on Howard’s post... the CL300 is more or less a SIEG C2. The machine you have has a brushed motor with hi/low gears.

The SIEG SC2 and SC3 have a brushless motor with belt drive. No hi/low gears.

Some people get confused when ordering electrical spare parts.

Ketan @ ARC

Having just checked our records, I am happy to confirm that the dead centres which Alan has are not from ARC.

Ketan at ARC.

Edited By Ketan Swali on 18/08/2020 20:07:39

+1

Ron,

have a look at this You Tube link

Ketan at ARC.

Edited By JasonB on 26/07/2020 13:38:59

Fair enough Mark. Your logic understood and accepted.

Ketan at ARC

You really have some strange logic tarring us all with one brush!

ARCs comes from the same place/region/pot as MSC Direct. Cromwell probably from some other place. So by your logic, you should be loathed to buy from them too!

Ketan at ARC