Spindle, VFD and sensor recommendation

Hi

I'm making on progress on planning my first machine and am now looking for some recommendations to hopefully avoid buying the wrong components.

Spindle and VFD

I'm considering these:
VFD 3.7KW 5HP 17A 220V Variable Frequency Drive Motor Inverter
https://www.omc-stepperonline.com/va...-speed-control

and
Air Cooled 220V 2.2KW 8A 24000RPM 400Hz ER20 Collet
https://www.omc-stepperonline.com/cn...ir%20cooled%5D

This will be my first time with a VFD and "proper" Spindle - how does a 2.2KW spindle compare to a Dewalt 1/4 router (as this is the only reference I have)?

The machine will be used on average 2 hours each day so I'm looking for a set-up that won't give up after a few months, but at the same time, I'm looking to keep costs reasonably low.


Sensors

I plan on using M12 Inductive sensors, NPN, NC, but it seems these can range from £5 - £150. I've been looking on ebay or amazon: https://www.amazon.co.uk/mxuteuk-Ind...&rps=1&sr=8-12

I'm hoping to avoid buying cheap items that are unrelaible.

Thanks

Ian

Here's my tuppenth worth.

Huanyang VFDs are well understood and documented; and the collective experience appears that they are as reliable as you could expect. The VFD you link I'm not familiar with, though the manual looks comprehensive and understandable. I'm not sure quite why you're overspending the drive by 50% compared to the spindle - your money, your call. You can easily interface the linked VFD to any typical CNC set-up.

The spindle?, why air-cooled (rather than water cooled)? Air cooled have a reputation for being noisier because of the fan, and the cooling is less effective at low RPM. Water cooled requires a modest amount more peripheral devices (I use a small PC-cooler reservoir/pump, a 120mm radiator/fan and a couple of 8mm pipes - self contained - and the whole lot (including Spindle) runs quiet enough to have an easy conversation without the howling banshee that an equivalent wood working router would present. Air cooled does offer the issue of cooling surfaces becoming clogged with fine sawdust if wood is your material of choice. Plenty of wood-cutters on the forum that will dispute that, of course.

I don't have a 1/4" DeWalt as a comparison, but my first MD machine came with something like a 800W hand router - the best thing that ever happened to that machine was the spindle burning itself out. I replaced with a 800W water-cooled spindle and the difference in experience - both audible and performance was night-and-day. Many people, myself included, chose the 2.2kW flavour for the benefit of the ER20 collet system. If you're just using 1/4" or 1/2" wood working bits then the benefit is less pronounced.

For the VFD and spindle - you don't mention what it is that you're looking to machine. The spindles aren't particularly good performers under 6-7k RPM. If you're making sawdust, rather than man-glitter then you'll be operating much closer to the higher RPM that these spindles operate very well at. And you'll have a better operator experience with the WC solution.

Inductive sensors?, my £5 sensors have never failed me, and appear to offer reproducible results. I'd hate to crash a bed into a £150 one, during commissioning.

There's plenty of ways to introduce unreliability into your system - VFD, Spindle and cheap inductive sensors don't top the list.

Just my limited experience.

Hi Doddy

Thanks for the reply.

I'm not sure what you mena when you say the "overspending the drive by 50% compared to the spindle" - does this mean the VFD is overpowered for the spindle?

The reason for the air-cooled options was to keep the set-up simpler to options I am a bit more comfortable with. I wasn't aware that the water-cooled version operated with less noise - since the machine will be used a lot in my home office for protyping, that can be a big advantage (although I intend to also build sound insulated enclosure). It seems that it is possible to get some complete kits so I will look into it. What size/volume is your system?

I will mostly cut small enclosures (45mm - 75mm) from hard engineering plastics of ± 12 - 20mm thickness. I need a set-up that can work continuously at speed with good spped/feed rates and DoC and intended to get a 2.2KW spindle - the CNC is primarily for work purposes to get a job done - although I won't really need end mills larger that 1/2'. I just want to be able to machine comfortably.

Thanks

Quote:

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Originally Posted by ian

Hi Doddy

Thanks for the reply.

I'm not sure what you mena when you say the "overspending the drive by 50% compared to the spindle" - does this mean the VFD is overpowered for the spindle?

The reason for the air-cooled options was to keep the set-up simpler to options I am a bit more comfortable with. I wasn't aware that the water-cooled version operated with less noise - since the machine will be used a lot in my home office for protyping, that can be a big advantage (although I intend to also build sound insulated enclosure). It seems that it is possible to get some complete kits so I will look into it. What size/volume is your system?

I will mostly cut small enclosures (45mm - 75mm) from hard engineering plastics of ± 12 - 20mm thickness. I need a set-up that can work continuously at speed with good spped/feed rates and DoC and intended to get a 2.2KW spindle - the CNC is primarily for work purposes to get a job done - although I won't really need end mills larger that 1/2'. I just want to be able to machine comfortably.

Thanks

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My bad... I meant to say "overspecc'ing" (I sometimes wonder about auto-correct). My point is that you can find spindles and VFDs bundles that are matched - a 2.2kW VFD with a 2.2kW spindle. Actually the cost difference is typically much less pronounced than the difference in power between VFD and spindle. But, why specify a VFD that is designed for a larger spindle than you aim to buy? Do you have a 20A supply available for this?

I can understand the attraction of air-cooled - it is notionally simpler... but I wouldn't overthink the complexity of water cooling - kiddies are building water-cooled gaming rigs, plenty of kits around. Unless you're putting the spindle under a large sustained load you'd probably get away without the cooling (not a recommendation!, just an observation).

What size is mine?, I have two milling machines (rather than the possibly more popular routers) - the skeleton of an old Starmill 80kg, working volume about 150mmx100mmx200mm, actual footprint more like 800mmx600mmx500mm), which has the 2.2kW WC spindle. The second, a 130kg SX2.7 converted to CNC - working volume around 500mmx180mmx400mm, practical footprint around 1200mmx600mmx800mm, with - ironically - a much smaller 800W servo spindle which max's out around 2krpm - which is used for cutting steel and alloys. Previously I had a router - a Marchant Dice machine as mentioned earlier - work area was something like 300x200x200mm, weighing in around 30kg - which couldn't butter toast, let alone cut it. Don't get fooled into thinking that the spindle is the heart of the machine - look at the rigidity of the machine - that will define the limits of what it can cut, and at what speeds. My experience with routers was a poor introduction, driven by a poor choice. I predict you'll get advice from others here to treat kits with caution, you'd be sensible to listen - and by all means challenge - that advice.

If your build volume is truly as constrained as you say, a mill may be more appropriate than a router - but that's a decision that only you can make.

Ok here's my tuppence which is very much like Doddy's thou I'm reasonably sure I'm safe to say I've got a lot more experience of these spindles than Doddy or just about anyone on this forum as I've literally fitted 100's to the machines I build over 15+ yrs.

The Chinese 2.2Kw WC spindles with Huanyang Vfd's is pretty much rock solid in a Hobby environment, I have fitted dozens to machines working in business environments working 12hr, 6day weeks that are cutting none stop and only to change tools or sheets. Some of these are over 10yrs old and still going strong. My own machine which cuts exclusively aluminum is over 6yrs old and on short jobs(20-30mins), I don't even turn on the water, that's how robust they are. The WC side isn't critical unless your cutting long jobs at high RPM.

I can honestly say I've had less than 10 faulty units out of maybe 300+ sets over a 15yr period and out of those most arrive DOA and it's always the VFD. The Huanyang Vfd's have got better over the years and I wouldn't hesitate to buy one. Paying high bucks for a VFD doesn't always guarantee reliability and I have a very expensive ABB drive here to prove this as it died less than 3yr old for no apparent reason I can see, I didn't abuse it or miss wire. Just didn't start one day.!!

Regards Air or WC then it's a funny one. Air-cooled is ok provided you have a good electric Fan which can be controlled and monitored. The cheap spindles like what you have shown are rubbish and will overheat if run for any lengthy jobs, the duty cycle is very low on the cheap offerings. The high-end spindles are perfectly fine and while they make slightly more noise than WC it's not a massive difference.
However, I'd always choose WC over Air because of the duty cycle, WC doesn't really have a duty cycle and you can run them continuously for days without any issues, again I have customers who run 3D jobs that take 18-24hrs without stopping.!

It's a similar thing with the Inductive proximity SW, don't waste money on expensive SW as the cheap proximity SW is more than good enough. For less than 1 moderate brand name SW you'll get all the SW for the machine plus a spare set. Again I've fit 100's, no actually 1000's over a 15yr period and I have very few fails in comparison to how many I've fit.



Somewhere on Youtube several yrs ago I did a little test showing how accurate and repeatable the cheap Chinese SW is, check it out you'll be surprised.

I bought the bundled 2.2KW WC spindle and matching VFD direct from the Huan Yang Drive shop on Aliexpress and have been very happy with it, though I cannot comment on their after sales service as I've never needed it. One advantage of this is that you know you are getting compatible components and the VFD configuration is correct for the spindle, though there will be a few numbers to change for best operation.

For cooling I simply have a submersible fish-tank pump in a tub of about 20l of distilled water and no radiator. This has been fine in tropical Western Australia and never become more than luke-warm after up to 4 hours running.

The difference in noise level between a hand router and the WC spindle is amazing. The spindle itself makes no significant noise, it's the tool cutting material and any dust extraction that will.

You mention that you may want to put the machine in an enclosure. If you do that without adding dust extraction, which will pull cooling air into the box, then water cooling would be simpler to engineer than having to force air through the box just for spindle cooling, though some small airflow for cooling the steppers/servos would be advisable.

Kit

All

Thanks for the info. After further consideration and research, it seems WC may be better suited as I'l be running the spindel for hours a day and I'm looking at this VFD / Spindle combination from th HY store on AliExpress: https://www.aliexpress.com/item/9050...c008xEitI&mp=1

It seems it is going to be a learning curve to programme the VFD and to get it set-up and tuned properly.

As for the comment re: the enclosure - I intend to run dust extraction unit continuously to keep a clean working are and prevent buuild-up of chips which can melt and cause issues. I'll turn my attentoin to the enclosure at a later stage, but I am considering the airflow and sound dampening as well.

I'll be surprised if you're disappointed, although you could possibly find better priced bundles in Europe, but that's your call.

I'm starting to realise the benefit of chip-control, even if just with a few pieces of strategically placed perspex.

Quote:

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Originally Posted by ian

All

Thanks for the info. After further consideration and research, it seems WC may be better suited as I'l be running the spindel for hours a day and I'm looking at this VFD / Spindle combination from th HY store on AliExpress: https://www.aliexpress.com/item/9050...c008xEitI&mp=1

It seems it is going to be a learning curve to programme the VFD and to get it set-up and tuned properly.

As for the comment re: the enclosure - I intend to run dust extraction unit continuously to keep a clean working are and prevent buuild-up of chips which can melt and cause issues. I'll turn my attentoin to the enclosure at a later stage, but I am considering the airflow and sound dampening as well.

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Without confirming the exact model number, that looks to be the exact unit I bought. There isn't a cheaper supplier here in Australia but that may not be the case for you in the UK.