Warco minimill OR SIEG Super X2 OR none of them ?

[MarcuSwedenParticipant @marcusweden]

buying milling machine ?

[Peter G. ShawParticipant @peterg-shaw75338]

Hi,

I have a Warco MiniMill. I will tell you what I know, my experiences and  then leave the decision to you. I cannot comment on the Sieg Super X2.

 

The MiniMill is not made by Sieg, although it does use the same basic idea and layout. It does use the same internal gears (see later). My MiniMill was made by Yangzhu Real Bull Machine Tool Co. Ltd. The impression I get is that there are a number of Chinese factories making machine tools to the same basic designs, but with small differences.

 

About my mill.

 

Some of the slides were/are in a very poor state and require work on them to improve them. David White has produced a number of articles in MEW on improving the Sieg X0 which seem equally applicable to the X2 and equivalent. He has also produced an article on the Weiss WMD25LV machine in which there is a photograph of the internal gears. This photo looks to be identical to the MiniMill. White also says that he found lots of casting sand etc on the Weiss. So did I on the MiniMill.

 

The Sieg X2 (350watt motor) is well known for two problems. These are the breakage of the plastic internal gears, and the failure of the electronic control board. I have experienced the gear failure on the MiniMill, but not (yet) any electronic failure, however, the fact that there is a more powerful motor may indicate that the electronics have been uprated and thus eliminated the problem. At least that is what I hope.

 

In respect of the internal gears, these can be difficult to change, however, Arc Euro Trade do a set of  metal gears, supposedly for the Sieg C3 lathe (I think), but advertised by them as suitable for the X2 machine, and I can confirm that they will fit the MiniMill.

Another option to overcome gear breakages is to convert to belt drive. There are kits available which may or may not fit the MiniMill. Claimed advantages are that a higher speed may be obtained and the machine is quieter.

 

On my machine, I could not get the fine vertical movement to work. The handbook didn’t mention it, and did not even have the correct information about switching on. Fortunately, I found a downloadable manual produced by LittleMachineShop.com which explained about the fine vertical movement. I discovered that the fine feed mechanism was binding to such an extent that it was unusable. Careful adjustment made it work.

 

The MiniMill uses a counterbalancing spring to take the weight of the head. On mine the spring has lost some of it’s tension, but that may be because of something I did.

 

I fond the dials difficult to understand. They are not calibrated in anything recognisable, so I made a conversion label which I have stuck to the machine. Also, the variable speed is not calibrated. Again I have made an approximate speed label using a cycle computer to measure the speeds.

 

I suggest you hunt around the forums for the X2. You will find a lot of information on improving the X2 series of mills (which will include the MiniMill) and on setting them up, eg vertical alignment both back to front, side to side, and the alignment of the travelling head. Also information on stiffening the vertical column. David White has a novel method of doing this as well.

 

The Warco MiniMill has a larger table than the Sieg X2.

 

I can’t think of anything else.

 

Good luck in your quest.

 

Peter G. Shaw

 

[MarcuSwedenParticipant @marcusweden]

Thanks for Your answer. I guess I will get about what I pay for.

 

I think the Warco minimill will be what i expect it to be, i dont have high expectations.

 

What I am most afraid of is that the electronic board will brake down and be difficult to repair if the transistors has the labels grinded of.

 

My Chines 500mm lathe has the numbers on the transistors/tyristors grinded of so when it brakes down i dont know what to do , if i had the numbers on the transistors i could easily buy new and exchange the old with new ones.

 

How is Warco when it comes to help the customers with questions after the sale ? Do they have good technical support staff ?I know ArcEurotrade is wery helpful but the dont sell the X2 or similar mill anymore.

 

How is the spindle bearings on the minimill ? on my Chines lathe i had to change the spindle bearings to SKF Taper Rolling Bearing becouse the chines bearings was not so good.

Edited By MarcuSweden on 09/03/2010 17:51:52

[Peter G. ShawParticipant @peterg-shaw75338]

Have a look at this thread on this forum: “Blown X1 Mill speed control”. It has some information which may be of use.

 

Little or no experience of Warco after sales service. When I broke the gear wheels, they posted replacements out immediately. I understand that ArcEuro stopped selling the X2 due to the high failure rate of the electronics board, and it was costing them too much. I understand that Machine Mart have a good spares catalogue, but that they do not sell individual components, just assemblies, ie you could get a new controller board, but not the individual transistors.  The Clarke CMD300, sold by Machine Mart,  looks similar, so they may have spares. Also, a company called Amadeal sells the XJ12-300 which looks to be identical to the MiniMill, so they may have spares.

 

The spindle bearings are ball bearing types. On my machine the lower bearing is a 7206AC whilst the upper bearing is a 6206RZ . (They do look to be the same size.) I understand that changing to taper roller does improve matters, and I suspect that this will probably make it easier when changing the gears. (Especially if my experience with the original VW Beetle front wheel bearings is anything to go by.)

 

I have to say that changing the gears was not perhaps the best thing to do for the bearings. So much so that when it happens again, I will probably change to taper rollers then.

 

Regards,

Peter G. Shaw

 

ps I will have a look at the mosfets next time I go into the workshop and see if they do indeed have any numbers on them.

 

 

Edited By Peter G. Shaw on 09/03/2010 20:04:47

[Steve GarnettParticipant @stevegarnett62550]

If you look around, you will find that the general view of Warco after-sales service is that it is very good. We’ve only ever dealt with them once, and had no complaints whatsoever.

[Keith Wardill 1Participant @keithwardill1]

Hi, Marcus,

 

I would like to add one or two comments to those made by Peter – I have a version of the X2 sold by a company in Germany.

 

 Peter mentions the ‘breaking gear syndrome’ , and I have seen this repeated many times, but never found anyone it has happened to!. I have actually had my machine jam on several occasions while learning how to use it, and never stripped a tooth. Arc Euro Trade stocks spare metal gears for this, and they are not particularly difficult to change. AET also stocks taper roller bearings for this machine (and many other spares), and the these bearings reduced bearing and chatter on my machine. (I have no connection with AET – only as a customer)

 

I have never been too happy with the backlash, particularly one the Z axis, and it is not easy to successfully reduce it. I am currently considering ways to modify this.

In discussion with friends, we have come to realise there are at least three different variations of the electronic controller board. The ‘originals’ seem to suffer from burn out of the driver transistors if the machine is overloaded or stalled. I have repaired one of these several times (same board as the C3 lathe), but now I find it is difficult to get hold of the transistors.  I obtained a spare board from the supplier, and it was a completely different design – this board will withstand the machine being stalled without damage (at least in my experience for up to a minute before I was able to remove the cause of the jam. (this is with a 350W motor)

 

I agree with Peters comments about the slides – I had to clean mine up, but this is not too difficult. I suppose you get what you pay for with these small machines, but I have to say I would not be without mine. They are at least affordable for the average (non-professional) modeller, and with a little work can produce good results. There are many websites and forums (try Yahoo) dealing specifically with these machines, showing practical modifications and improvements that can be made, even to the extent of conversion to CNC operation.

 

[MarcuSwedenParticipant @marcusweden]

Ok , Thankyou both very much.

 

I will place my order on one “Warco minimill” tomorrow ,  I phoned them to ask about the shipping cost to Sweden and yesterday i recieved a “Quotation” there the tell me that the minimill will be back in stock in about 4 weeks and that the shipping cost to sweden is 90 Pounds + VAT.

 

Here in sweden those small mills is not available at all but som slightly larger chinese mills at 90 kilo is available but they cost about 1000 Pounds + 50 pounds in shipping, So i´l phone Warco tomorrow and buy the minimill.

 

maybe it is possible to change the bearings for a bearing with the eactly same size but of better quality like SKF or something ? 

 

 

[Peter G. ShawParticipant @peterg-shaw75338]

Keith,

 

I have broken my gears. I was aware of this problem before I bought it and so I treated it with a certain amount of care. I find it interesting that Arc Euro Trade sell metal gears. Ok they are for the C3 lathe. But why? Somehow I doubt Arc Euro Trade would stock these items unless there was a proven need for them. One final point. When I rang Warco to obtain a replacement set, the storeman offered the opinion that they usually lasted longer than they had with me. This suggests to me that they do indeed break and that I had perhaps been unlucky that they broke so quick.

 

As regards the electronics boards, there do seem to be a number of different power motors around – 350W, 470W, 550W and possibly more. Now it does seem to me that the original version was the 350W board. It also seems logical to me that the higher power motors will require higher power mosfets, so wouldn’t it be logical to uprate them at the same time? Maybe I’m being too naive!

 

You are right about the Z-axis backlash. I forgot about that.

Regards,

 

Peter.

[Keith Wardill 1Participant @keithwardill1]

Just a small addition to my previous comments on these mills, and the controller electronics. I referred to the output devices as transistors – they are, as Peter Shaw says, MOSFET devices. Mine were type 2SK790 – they were marked. They don’t seem too easy to obtain these days. I also found there was a driver transistor type BC549C (physically mounted close to the MOSFETS) which had also failed.

 

I see you decided on a Warco – good luck and lots of fun!

[Keith Wardill 1Participant @keithwardill1]

Hi, Peter,

 

I haven’t looked at AET for quite a while – but when I ordered mine, their advert mentioned they could also be used in the mill, and I confirmed this by telephone. At the time, I also had the C3 lathe (actually supplied by Rotwerk, in Germany), so I ordered two sets. I actually only fitted the set in the mill, not the lathe (Since then, I got another lathe, another story….)

I take your point about AET stocking them, I only comment I have never seen it. One account said the gear was not stripped, but broke, with the break going through the keyway. As I noted, I have jammed my machine several times, with no breakage. I am beginning to wonder if the machine (which was bought in Germany), has been modified by the shippers, but I have no way of checking this.

 

I have messed about with the control boards many times, hence the comments. I think you are right about the early version being intended for 350W. This is the board which has a small daughter board mounted on it with several adjustment pots. (these pots affect the on/off times of the motor drive current – can cause ‘BIG’ prblems if adjusted incorrectly. These boards were also used in the C3 lathe (at least it was identical in mine – I even interchanged the boards at one point when fault-finding). Since my lathe had a 500W motor, it appears to be OK for this as well. The ratings for 2SL790 Mosfets show they should be able to handle quite a bit higher power, but I have blown them several times, and never really been able to identify a good reason why.

 

 

However, I now have a replacement board (originally bought as a spare), which has a completely differnt design. This has a single mosfet as the output, and as I noted before, I have stalled the motor several times with no damage to the board (yet). Admittedly this led to panic while I removed the jamming cause I case I damaged the board or motor!). This board will also drive the C3 Lathe with no problems, so it seems OK for 500W.

 

Due to house moving, (Germany to Romania) I have not been able to investigate this board further, but when I get chance, I will. It certainly seems ‘fireproof’ compared to the original.

 On a related but different subject, I have a second lathe which had no continuously variable speed control (which I like a lot), so I fitted it with a 1HP 3-phase motor and variable frequency controller. It was expensive (for me!), but has made such a significant improvement in performance (smooth, no chatter, fully variable, reversible, etc, etc), that I am going to junk the DC motors on the mill and C3 Lathe, and fit 1/2 HP motors to them. With any luck, I will only need one VF controller, and use a switch or plug to select the machine. I suppose I could say I have had enough of trying to make the machines operate – I want to make things with them.

[MarcuSwedenParticipant @marcusweden]

Peter : I Think You are right that the stronger mills with 550Watt motor must have a different electronicboard than thoose with the 350Watt motor , As i se it the chinese dont put in nothing that doesnt had to be there som hooking up a 550Watt motor on a 350Watt steering card would probably break it in minutes.

Keith : Good that they atleast where marked, i realy dont know what to do if they break in my chinese lathe.

I know from many years back when i was working in an electronic repair company with a soldering iron that many old transistors that is still no longer in production could be replaced by a newer and slightly better equivalent, maybe that is the case with the 2SK790 ?

I found the specifikations for the 2SK790 :

http://www.datasheet.org.uk/pdf-datasheets/Datasheets-39/DSA-764443.pdf

 

I´ve learned the hard way that owning stuff you dont know the numbers on the semiconductors is likely to become very expensive.

[Nigel HydeParticipant @nigelhyde97004]

Hello

Re the Warco Minimill, I bought one and I  found that the cross-feed dials bore no relationship to actual movement. I thought it was just mine…………….Warco did not understand it. They did, in fairness offer me a free digital scale to fit to the machine. I declined the offer, Warco took it back in exchange for a WM-14 (I paid the difference)

 

So if you rely on the dials, you may have a problem with the minimill

 

[Peter G. ShawParticipant @peterg-shaw75338]

Keith,

 

I do wonder if your comment about owning a German made machine is the crux of the matter.

 

Referring back to David White’s articles in MEW, without looking them up, I seem to think he thought the German made machines were better. Of course, memory being what it is, I could be completely and utterly wrong. Nevertheless, I do believe the German machines in general are better put together than the Chinese.

 

Nevertheless, as long as people are aware of what they are buying, and accept that the machines will need some fettling, then ok, they are probably reasonable. In my case, I do have a lot of work still to do – unfortunately temperature (the garage just doesn’t get warm quickly enough!) and other jobs are against me!

 

Regards,

 

Peter G. Shaw

 

[Peter G. ShawParticipant @peterg-shaw75338]

Hi folks,

Well I had a look at my controller. Assuming that the largest devices are for the power output, then the mystery deepens even further.

 

I have: 2 off A69108, and 3 off D8010L.

 

The A69108 is a SCR (Silicon Controlled Rectifier whilst the D8010L is a rectifier both confirmed by the PCB legend. But… (there’s always a but!) the D8010L has THREE legs which makes me wonder if it may be a dual diode.  I did also find a reference to the Chester Conquest which also had two SCR’s and three three-legged diodes.

 

So, it  looks as if my MiniMill does not have mosfets!

 

Regards,

 

Peter G. Shaw

[Keith Wardill 1Participant @keithwardill1]

Peter,

 

You may well be right about the German machine – however, all the information I have ever seen on the machine I bought in Germany (Rotwerk – they have a website), appears to indicate it is an identical machine to all the other ‘Chinese’ machines sold under various ‘badge-engineered’ brands the world over – I guess you have seen some of the many websites devoted to modifying, upgrading or otherwise improving these machines. 

It seems a bit odd to me that they would upgrade the gearing somehow, yet leave the slides needing work.

 

Incidentally, there seem to be more companies selling these Chinese machines in England than in Germany. I bought mine from Rotwerk (based in  Stuttgart) because I bought a woodturning lathe from them, then found they also stocked engineering machine tools (and accessories).

 

There is also a large company called Westfalia which sells just about anything you think of – they also sell a range of (apparently) chinese-sourced machines. There is also a very good company called RC Machines at Junglinster in Luxembourg, who sell a wide range of machine tools, new and second-hand. Their website shows very similar new machines to those sold by Warco – almost all available from stock, either 230V or 400V (three phase). I bought my second lathe from them, and was highly impressed by their service, and the standard of the machine.

 

I believe AET in England rebuild the machines (at least the lathes) which they supply, as a customer option. I have not looked at their site recently, but I seem to remember they offered this service. If I remember correctly, this service basically involved cleaning and aligning the machines, but I guess obvious problems would be rectified, but probably the gear problem is not apparent until it actually breaks! I understand they will also install the taper bearings if you request them on ordering.

 

In general, I guess that the state of these machines depends on who you buy from, and the price you pay.

 

Sympathies on the freezing garage – its got to improve soon. So far my workshop is largely in boxes in the garage since the move. However, I have so far built the foundations for a large brick-built workshop behind the garage – another week or two and it should be warm enough to start laying bricks. (sorry, not bragging – buildings are cheap in Romania, so I thought I’d build what I always wanted).

Thanks for the discussion. I guess we should not continue on this thread – poor Marcus must be wondering what happened to his request for info – good to talk to you – model engineers are scarce in Romania!.

[Keith Wardill 1Participant @keithwardill1]

Peter,

 

Just saw your note on the controller board – you are confirming what I have also found out the hard way – there are several versions of the controller boards – some with SCRs some with Mosfets. As I noted earleir, I have seen at least three different board types. I wonder if they are interchangeable (connections, ratings, etc). Makes life very confusing if you need to source spares, or replace controller boards.

 

D8010 is a high current rectifier diode. One of the three leadouts is unused.  Sounds like Conquest is the same, but I have no personal knowledge of that one. 

[Sub MandrelParticipant @submandrel]

I have an Arc Euro Trade Sieg Mini-Mill – serial number 5!

 

I haven’t had any gear problems, though I had to have the controller  board replaced FOC – but the failure happened because a mounting screw for the controller box came loose and shorted the board. I also had to change the speed control pot – try finding a pot with a normally closed switch! I finally found a company who could custom build me a few thousand, but tehy kindly took pity on me and sent me a free one!

 

When I bought it I got the definite impression they would have rather sold me an X1, but I was sure I wanted the extra capacity. They also said they did certain ‘modifications’ that other sellers did not, but would not reveal what these were… very mystrerious.

 

Main thing is, they no longer stock the X2, but still do the C3 lathe which doesn’t seem to suffer the failures despite essentially similar hardware.

 

All grist to the mill <HEH HEH>!

 

Neil

[MarcuSwedenParticipant @marcusweden]

Nigel :

 

thanks for letting know, my plan is to buy the Warco DRO without connectors:

 

http://www.warco.co.uk/Digital-scale-with-attached-remote-readout-32C4E98774.aspx

 

The scale with attached digital remote readout i think looks more solid than thoose with connectors in each end of tha cable.

 

But it´s still strange that  the crossfeeds doesnt indicate whats realy happening, i hope they have fixed this on the machines they are selling now.

I still have 4 weeks to decide what to buy becouse minimill is not in stock untill 4 weeks, maybe the  Warco WM-14 is a better choice, I dont want a bigger machine couse im planning to buy a real milling machine at about 1000kg if i like milling, this small machine is more to try out and for learning a few basics about milling.

 

Keith : I think its great how this thread developed, lot of good information and exactly what i wanted.

[MarcuSwedenParticipant @marcusweden]

In MEW No. 145 on Page 33 we can clearly se that also tha machine beeing tested, WMD25LV , has the information on the semiconductors grinded away, this seem to be very common amongs chinese steeringcards and I think this will be a large problerm if the semiconductors brake down.

 

 

 

[Nigel HydeParticipant @nigelhyde97004]

Marcus

It may well be that my minimill was very much a one off problem but then Peter  mentioned it re his machine(9/3/10)…..bells rang!. My first thoughts were that I had imperial dials with a metric screw. my calculations told me this was not the case.

To me accuracy of the dials is all important, I really could not be bothered with multiplying every dimensional movement by a calculated factor……life’s too short.

Quite simply the machine was not fit for its intended purpose and the supplier accepted it back. Can I suggest that you request from the supplier details of the accuracy of the dials on the minimill before purchase.

I stress this may have been a one (or two) off. My replacement WM-14 with 8900 swivel base machine vice is very good,giving me the precision I require and doing all I ask of it. .

[Peter Wood 5Participant @peterwood5]

Marcus

 

I have owned Warco mini mill for three years now. The problems with the gears have been well documented so I won’t comment further other than to say I have just broken my fourth set!!

 

I quickly realised the problems with backlash in all three axes. The X axis is the worst with about 1/2 turn of the lead screw, equivalent to 0.8mm, but there is also backlash in the Y-axis.

The Z- axis presents real problems because the tool tends to pull the head down into the work which can cause it to grab, stall the motor or break a gear. I always make sure that I ‘lean’ on the capstan when I am advancing the fine feed, to ensure all the backlash has been taken up, and then make sure that the head is firmly locked before starting to cut.

 

Fitting DRO on all three axes transformed the machine and positioning became much more accurate. Rather than spend almost as much again on a commercial DRO as the mill cost in the first place, I installed the YADRO system.

 

http://www.yadro.de/index.html

 

 It is based on digital scales but feeds the output into a computer which provides funtions such as edge finding, PCD etc

 

Hope that helps.

 

Peter

[Peter G. ShawParticipant @peterg-shaw75338]

Hi all,

 

I’d just like to expand a little on what I have already said.

 

Gear breakages.

In my case these were teeth that snapped off, and although the smaller gear does have a tooth broken adjacent to the keyway, there does not seem to a crack. The same gear does have another two teeth broken off elsewhere.

 

Dials.

As I said, I have made out a suitable conversion chart that I can easily look up. The major problem is that whilst the graduations for the X and Y axes are marked as 0.02mm, there are 75 graduations to per revolution which makes for difficult counting. On top of that, the Z axis fine feed is marked as 0.025mm and has 60 graduations per revolution. Hence there is plenty of scope for getting it wrong. Hence the chart.

So, all screws are the same pitch, 1.5mm which is itself an odd value. Wonder why they didn’t do 2mm? I suppose 1mm might have been too fine.

 

Electronics.

I rather fancy that if mine fails, I will have to do a reverse engineering job on it to find out how it works, and then try for substitute components. I have to say that I am at one with Harold Hall on this, in that my lathe, a non-electronic beltchanging job will simply work, and work, and …. And could well be passed on to my grandchildren in years to come. However, an electronic failure could turn the MinimIll into an expensive doorstop – unless I, or some other amateur, can reverse engineer and repair. Professionally, it won’t be worth it. <Rant mode on> Just like modern cars, having just forked out for an electronic diagnosis to find a blocked fuel filter!<Rant mode off>! (Sorry about that.)

Regards,

 

Peter G. Shaw

[MarcuSwedenParticipant @marcusweden]

Nigel, ok i hope then one i have ordered now doesnt have faulty dials.

 

I finaly maked the decission to not buy from Warco but to buy from Amadeal, today I got very good help from Amadeal who answeared all my questions in phone.

 

Amadeal calls the minimill for “XJ12-300” and it has a different gray color the other thing should be the same besides the electronic steering card , Amadeal told me that their machine has an american made steering card which is made by :  http://www.kbelectronics.com/ and that they can provide schematics . I will try to get the schematics as fast as i can.

 

Amadeal had a little bit lower price than Warco , but for me the most important thing was that i want to be sure that i can repair the electronic steering card if (when ?) it breaks down.

 

I vill come back with photos of the machine in a few weeks as fast as it comes here and the snow and cold goes away, also with pictures of the steering card.

[Peter G. ShawParticipant @peterg-shaw75338]

Hi MarcuSweden,

 

Following your post  and that of others on the X3 mill thread, i have had another look at my MiniMill controller board.

It would seem that I do indeed have a KB board. From the KB website, I picked up the following:

There seem to be two possible boards – KBLC and KBIC. I suspect the IC board is newer than the LC board. Also, KB state that from a set date, all their boards have a nine digit serial number on a sticky label. Mine does not have this label, but  it does have a date 02-23-05 which is before KB started the 9 -digit scheme. Otherwise the connections, layout and physical design agree with both boards. I therefore think that mine is an LC board.

Which all seems to suggest that the idea that the higher powered motors have a different controller, hence controller failure may be a thing of the past. (Fingers crossed.)

 

Regards,

 

Peter G. Shaw

[MarcuSwedenParticipant @marcusweden]

It will be exciting to what my mill has for board when it arrives maybe this week or next week.

 

If it is a KB-board made in USA, then it will probably be easy to get infomation on exactly what type of semiconductors it is equipped with.

 

 

 

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