Sieg KX3 spindle motor replacement/upgrade

[Beardy MikeParticipant @beardymike]

My mill spindle has been cutting out at higher speeds for a while now, so I’ve been burying my head in the sand and using it at lower speeds until I got time to look at it. On Friday it started making awful noises and creating so much electrical noise it was interfering with the LCD monitor (I’ve never seen that before!).

I’ve torn the head apart, and the coils inside the motor have a blackened section and smell of burning. Is this the sort of thing that I can get a new coils component for, or is it a whole new motor time?

If I do need a new motor, that opens up the question of what to buy from where. The original part is labelled W92-1000K1, which I’ve briefly searched for a datasheet for to no avail. It’s very similar to the number W92-1000A that Arc sell for the SX3; would that be a drop-in replacement? Littlemachineshop seem to have the exact part – does anyone have any experience in dealing with them shipping to the UK?

Another option I’d be interested in understanding is whether this is my opportunity to upgrade it. I know that the later KX3s had a 5,000rpm spindle – is that just an upgraded motor, or were there other changes? Anyone know what that motor is?

Alternatively, do I even need to be buying this specific motor? How cross-compatable are servo motors – can I just buy one the right size/rating from elsewhere for less? I’ve got access to a mill at work if I need to cut a keyway etc. I can afford to spend £400 to get this machine back in action if I have to, but spending less wouldn’t be a bad thing!

Thanks,
Mike

[John HaineParticipant @johnhaine32865]

You might look at the Jack industrial sewing machine motors that a number of people have used.

https://www.tysew.co.uk/jack-jk-513a-550w-3-4hp-energy-saving-servo-motor

Widely available and probably even cheaper on eBay or AliExpress.  Several people have posted about using them on here.  Getting Mach3 to control the speed might be tricky.

[Robert Atkinson 2Participant @robertatkinson2]

The sewing machine motor motor is NOT a direct replacement. It is also 550W compared to the originals 1000W.
It is probably not economic to rewind the motor and may not be possible.
The other concern is that the drive board may be damaged as well. Let’s hope not. The ARC Euro motor should fit OK. Generic motors are more of a risk. Even with the same physical size and voltage rating there are many variables for both the motor and encoder.

Robert.

[JasonBModerator @jasonb]

I’d be inclined to give ARC a call on Monday and see if the one they have will be OK in the KX3 and if not they may have something hanging around that is not listed on the website.

[Matt HarringtonParticipant @mattharrington87221]

I did some research on this with my similar Syil X4+ – it ended up with me changing the motor driver/inverter rather than the motor itself. I’ll see if I can fish the info out on a replacement motor for you – I’m fairly certain the Sieg & the Syil are v.similar. You may find a suitable BLDC motor from AliExpress….

Matt

[HuubParticipant @huub]

A new VFD for my Paulimot 1kW F207-V milling machine cost € 270,–. A cheap Chines AC servo set € 170. So I bought the Chinese AC servo set and the cheapest (€ 28) 1.5kW VFD on AliExpress. I mounted the VFD and it works OK for 2 month now. In 10 months I will replace the AC motor for the AC servo so I have electronic torque control for tapping threads.

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