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Seig X3 has died

Motor not powering up

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norm norton05/06/2020 15:07:25
162 forum posts
7 photos

I have a nice old Seig X3, bought more than ten years ago from ARC, in the days when you had to take them apart and clean it all before switching on!

It has been a good machine and I listened to others' reports of motors failing and thought, well maybe one day.. and that day has come, perhaps.

I know there are a few X3 users on the forum so I am asking if anyone can comment from personal experience. I know I can contact ARC and will do that next.

Yesterday I was running the motor at maximum speed for a 1mm drill and switched off by putting the forward/reverse switch to zero, which is what I usually do. Today I get the green power light on the front motor panel, there is no yellow trip error, and the single fuse I have tested as ok. I can switch on in the 'wrong' sequence and cause the yellow error to light, and clear it, but no power to the motor and no noises whatsoever.

Looking at the PCB in the back it all looks clean and I can see no overheating.

So have I got a failed PCB or a failed motor? Anyone got some tips for simple circuit checks to look for volts or continuity in the motor?

I wonder if ARC might carry parts? I have thought in the past about fitting a half horsepower 3 phase motor and VFD if mine ever went pop. For now I would just like to get the DC motor running again.



Rod Ashton05/06/2020 15:31:27
339 forum posts
12 photos

Do you have a cutout safety guard fitted? I had a similar problem and that was the source. Hope it helps.

Old School05/06/2020 15:32:30
391 forum posts
39 photos

My X3 died a few years ago and I replaced the control board with one from Arc. My mate had one that died as well the fault was found on his by a friendly electrician it turned out to be a resistor the big white pot one one of the wires was broken on inspection mine had the same fault.

John Haine05/06/2020 15:37:16
4172 forum posts
242 photos

The motor is probably a fairly generic type of DC, either shunt wound or permanent magnet, motor, designed to run from ~180 volts or so. Other than the brushes there isn't much to go wrong with these. Lots of people seem to have trouble with the controllers though and they seem to be a marginal design.

There are a lot of controllers available, both from China via eBay and ones such as the KB Electronics ones designed more for professional applications. This one on eBay is the kind of thing. People on here have used similar to replace the whole controller. Depending on the price of spares this could be a good way to go provided the motor itself is OK.

KB drives are available in the UK from Axis Controls - I fitted one to my Novamill and it works extremely well. Blew a fuse once when I tried to plunge a cutter too fast into a chunk of metal, but perfectly fine once fuse replaced.

norm norton06/06/2020 10:54:10
162 forum posts
7 photos

Thank you Chaps. I will have a look at the PCB carefully for a broken section. I think also I need to note down a few details about the circuitry and see if one of the Chinese £25 controllers will wire in, or I follow my new inclination to avoid China and support the British company.

I assume I can just put 12v DC across that motor and see if it drives forward and reverse smoothly? I guess it will want to suck a few amps so I would use a battery rather than a power supply. The label says - ZYT-600 DC 230v 600w 4000r/min 3.2A CLASS E FORWARD. I am not sure what the 'class E forward' means?

Clive Foster06/06/2020 11:08:09
2836 forum posts
103 photos


Class E refers to the temperature rating of the insulation on the motor windings. Motor can be run up to to 120 C, 248°F internal temperatures. Outside sase temperature will, of course, be lower.

Specifying forward suggests that any airflow through and around the motor is different when running forwards to when running in reverse so the maximum safe temperature may need to be reduced due to possible hot-spots wherein going backwards.

Also possibly something to due with assuming the motor will normally be running forwards.


John Haine06/06/2020 11:13:35
4172 forum posts
242 photos

It may be a wound field motor - how many wires go to it? 12 volts should make it run albeit slowly. Just checking for continuity with an ohmmeter should give a good indication. FTAOD I think KB is US made (though probably in China as with most stuff these days). It's just that they are designed for industrial use.

norm norton06/06/2020 12:31:10
162 forum posts
7 photos

I have just found Les Jones' website with information on his X3 motor that he took apart in 2008. It is a two wire DC supply, 13 slot and 39 segment brushed motor. DC 230v max, 600W, 3.2A. It seems I can test it with a DC power supply and watch for a smooth current draw of up to 200mA at 40v with no load. So I will do that next. Apparently if the motor has a failed winding it will have popped the PCB.

I have had a call from Ketan at ARC and he has been really helpful. Apparently I might have one of the longest running and oldest X3s and it has probably benefitted from my humidifier dried workshop. He has motors available and has kindly made enquiries about getting me a controller.

What he does not know is whether any other, modern DC power supplies will work. Fair enough, you need to be a DC brushed motor expert. Anyone out there have a view?

Edited By norm norton on 06/06/2020 12:32:01

AdrianR06/06/2020 14:14:21
540 forum posts
36 photos

To check for poped windings, you can use an ohmmeter across it and turn the rotor slowly. It should measure the same resistance all the way around.

From the picture on the ARC site, the board looks quite simple so if you can find an electronics guy it should be fixable.

But the link above, £25 for a controller, if the motor is PM it is almost worth just giving it a go.


Martin 10006/06/2020 14:18:28
274 forum posts
6 photos

I’ve had my X3 from ArcEuroTrade in maybe 2007/8 but it’s that long ago I can’t be sure. It was around £700 It’s an early one for sure (the motor has a different brush end housing in black with protruding brush holders) and a complex sliding metal and plastic safety guard rather the later two part plastic one. The belt drive is I think the slightly later one with a conventional T5 profile.

I echo the safety guard issue mentioned above, the switch position can be tweaked to get it reliable. Cuts in one direction had the habit of opening the switch but it was with the guard closed. Holding the guard slightly open and it would never fail.

My motor lasted the period of any guarantee and maybe a week (dry conditions, 18 deg C round the clock and with very light use) The motor then failed without taking out the controller.

I got mine back into service with a dc motor from a Boxford TCL125/160. I made a new mounting plate, bored and broached a keyway into an off the shelf T5 pulley, using the original belt and connected it to the original controller.

The setting up procedure for the controller would be very useful but it appears to be unobtainium.

Three setting potentiometers, one possibly to compensate for the droop on load, the other for max current, another for max speed?

The motor is a permanent magnet one.  Three wires to the controller are Positive, Negative and an Earth 

PS most (all?) the connections to the controller are marked with ferrules that tie up with markings on the controller  but they are all loose on the wires, the wire ends having no crimps, so the ferrules will fall off in a random heap unless you tie a knot in the wire or affix a suitable crimp as you remove each connection. 


Edited By Martin 100 on 06/06/2020 14:41:53

JasonB06/06/2020 16:06:05
21436 forum posts
2448 photos
1 articles

Mine must be older as I have the old odd style belt, bought early 2007 do I get a prize?

You should be able to check the board by replacing the motor with a conventional light bulb.

norm norton06/06/2020 18:01:35
162 forum posts
7 photos

Thanks for all your help, it's now running again after taking it all to bits and reassembling.

I apologise for for jumping to the wrong assumption that the PCB or motor had failed, when I should have checked the wiring first. I apologise to Mr Sieg for spelling his name wrongly in the title and my text (I before E except after...) I apologise to Ketan for wasting his time with his kindly offering to help.

Yes it is a 2008 machine with the later aluminium end to the motor. I took that off, checked that it ran on 12v and it drew just 80mA, so that seemed ok. I took out the PCB and could see no surface evidence of overheating. I then worked out where all the wiring went through the switches and measured the resistances - no breaks found. Hmmm. Lets put the PCB back in as a lash-up and connect the motor again to see if there are any volts at all. Oh, it now works!

So, a whole day and somewhere in the process I have cured a poor connection. I would guess it might have been in the cut out switch circuit - I had many years ago removed the chuck guard and joined those wires to the switch together, but perhaps not very well.


Edited By norm norton on 06/06/2020 18:02:45

Clive Farrar06/06/2020 20:10:49
108 forum posts
41 photos

sounds exactly the same as the problem I had on my Warco clone a few years ago.

I tracked mine down to one of the brass housings for the motor brushes. It had become loose in the plastic end housing and moved forward so that the brass " cage" was touching the commutator.

When I repositioned it with a 0.5 mm clearance and epoxied it back in place all was, and has been, fine ever since.

Bear that in mind in case it happens again.

Regards Clive

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