Chinese CNC machine...whatchathink?

[HankMcSpank]

Yes, I know the backup/support will suck!

Yes, I know delivery & import duties will be excessive!

but parking that for a mo, what do you reckon to this machine....

http://cgi.ebay.co.uk/CNC-3040-ROUTER-ENGRAVER-DRILLING-MILLING-MACHINE-f1-/110638567716?pt=LH_DefaultDomain_3&hash=item19c2929124

cos bluntly, the one I've built from scrap is not up to it - no surprises there (it's fine for dabbling...but I'm past the dabbling stage now(!) & I just can't justify the time researching & building my next machine.

I'm only really wanting a machine to mill acrylic, mill the odd PCB (but a small bit of ali would be nice though :-) ) .....noise level is one of my overiding concerns (neighbours!)...I'm figuring that the whirring of the steppers is gonna be loud (the driver seems below par....no microstepping)

Thoughts?

[ptjw7uk]

If the work envelope will suit you then seems ok but nearer £600 with all the add ons.
Couldnt find what the nuts were made off or what drivers its got!

Peter

[HankMcSpank]

Actually, I hummed & hah'ed for a while (always a good thing as I often change tack!) then I happened upon a reasonably good site (well, by Chinese Standards anyway).... http://cncdiy.org/ ...they've got a 'which CNC is best for me' matrix listed on there ...and he actually makes some important points. I guess we're all guilty of trying to spec/buy a jack of all trades CNC machine , but as he poijnts out that's a mistake...I really only need a small machine to mill acrylic & PCBs, but I was going to buy a larger one in case I needs to do something bigger, but with size comes weight (obviously), noise, vibration, flexing etc (not welcome if 90% of my stuff is small anyway!).....so I'm just going to buy the minimal I can get away with size wise & go for this one (which his matrix recommends for PCBs)...

https://sites.google.com/site/cncdiyorg/2520 (I reckon about £600 + import duty + VAT)

if push comes to shove, I'll get a larger one for my other needs at a later date.

[M250cnc]

The only thing to be aware is that is gonna be a noisy machine at full revs

The noise will be coming from the tool spindle hardly any from the stepper motors/drivers.

To cut down the noise you need a water cooled spindle but they tend to be bigger in relation to the motor supplied with that machine so a water cooled spindle will not fit that machine.

Be careful of the shipping cost, the ebay machine looks almost identical and that would cost £746 inc shipping, plus any import taxes

Phil

[Jonathan]

The only thing to be aware is that is gonna be a noisy machine at full revs

The noise will be coming from the tool spindle hardly any from the stepper motors/drivers.

To cut down the noise you need a water cooled spindle but they tend to be bigger in relation to the motor supplied with that machine so a water cooled spindle will not fit that machine.


I agree, brushed motors like that are very noisy. Now I've got the water cooled spindle there's no comparison, however the cutting noise is, of course, still a significant contributor to the noise.

[HankMcSpank]

Maybe it's just the way they've all been recorded, but I'm struck at how much noise the Chinese water cooled spindles still seem to put out in some of the youtube videos folks have uploaded ! (perhaps it's just the microphone being too close to the cutter - but for example - http://www.youtube.com/watch?v=2OZCviK0msg&feature=related (2m16 in) ...or maybe the acoustic vibration/whine of the spindle is being amplified by the machine frame?

[ptjw7uk]

In the video it makes the point ' with a lot less noise' Best to sak JohnS as he has one of the spindles.

The noise will vary anyway when its cutting. If its less noise than a router at full tilt ... then its quieter.
If you cut anything at 24000 rpm then its going to make a noise anyway!

peter

[John S]

No my spindle is the air cooled one, not water.
These are not as quiet as the water ones, running at 12,000 they are quiet enough to not be upsetting, flat out at 24,000 they do make a bit of noise, about the same as a kress at number 1 or 2 on the thumb wheel.

I have seen the water cooled ones and they are quiet.

I think a lot of the noise on these video's is picking noise up you don't hear. I have a video here that was filmed out in the desert in Oman and it's unwatchable because of the noise of the wind and you can't hear the conversation but when we were filming it we didn't notice any wind and were talking normally ??

[HankMcSpank]

Thanks guys....well I thought I had this one sorted, but it's a fair point about not being able to mount a VFD water cooled spindle, so that choice above is now in doubt. There's another good, solid little machine here....

http://sites.google.com/site/cncdiyorg/3018

but it's a little on the small side & takes a while for them to put together(a bit like ordering a sofa from DFS!), not to mention a lot more expensive, but it'll mill steel, aluminium...the whole gammut!

[Jonathan]

I have seen the water cooled ones and they are quiet.


I can confirm that they are very quiet. My 2.2kW one makes less noise than the Sieg C3 lathe when the lathe is at 3000rpm and spindle at 24000rpm. 'Chip' on this forum will also confirm that the spindle itself is much quieter than a router.

When I had the router running I'd wear ear defenders - not any more!

It's the cutting noise that's the issue since it's louder than the spindle, though if you're just making PCBs the cutting noise is small.

[Jonathan]

https://sites.google.com/site/cncdiyorg/2520 (I reckon about £600 + import duty + VAT)


Seems expensive to me, why are you so sure you don't want to make one? A machine that size is relatively simple.
Anyway, it says the spindle speed is only 10,000rpm. That's good with regards to noise, but you're not going to cut PCBs very fast at that speed. I generally use about 25mm/min per 1000rpm. So 250mm/min with that spindle, which is a lot less than the machine is capable of.

[HankMcSpank]

Seems expensive to me, why are you so sure you don't want to make one? A machine that size is relatively simple.
Anyway, it says the spindle speed is only 10,000rpm. That's good with regards to noise, but you're not going to cut PCBs very fast at that speed. I generally use about 25mm/min per 1000rpm. So 250mm/min with that spindle, which is a lot less than the machine is capable of.

It's a time thing really...I've just been made redundant (20yrs with the same company! Hey ho...at least they gave me a big fat cheque, which rather than spend on loose women and fast cars - which my wife says I can't - I thought I'd put it towards some stuff that will make some stuff) ....so I now need to get some of these 'widget' ideas out of my head & into the market to see if they're viable! (if not, I'm gonna have some fun anyway! "March of the makers" eh"?!!)) I don't want to be dicking about spec'ing a machine. then ordeing a bit from here, a bit from there, then assembling blah blah....that takes time & for all you think I'd have loads of time on my hands, I don't (not to be building a machine anyways).

The more I mull this, I realise/concede that it's probably best to have a machine that's capable of milling aluminium...some of the widgets I have in mind are gonna need injection moudling (there only small simple pieces, but nevertheless the cost of getting them made is prohibiitve), so having a machine strong enough to mill steel/ali will be of great help if I do need to make simple injection moulds (but best do that when the neighbours are out!) .... a bench top injection moulding machine would be nice too!

[ptjw7uk]

At least the last one has ball screws!!

Peter

[M250cnc]

At least the last one has ball screws!!

Peter

It also has a much smaller working area 300x180x55 IIRC

It won't do milling particularly well either and there is no way to overcome the limitations to do milling on it. Have a look at specs of milling machines what you will find is they are heavy. The heavier the machine the bigger the cut you can make.

You will not even get a vice on the table, i have a drilling vice that has a height of 45mm and it is not suitable for milling just drilling.

But if you bought a mill it would do milling and with an extra WC VFD run spindle you could do your pcbs etc the alternative is two machines.

Phil

[gorbo]

http://www.facebook.com/photo.php?fbid=1742639813076&set=a.1050048698731.9417.1451139850&theater
Yes, I know the backup/support will suck!

Yes, I know delivery & import duties will be excessive!

but parking that for a mo, what do you reckon to this machine....

http://cgi.ebay.co.uk/CNC-3040-ROUTER-ENGRAVER-DRILLING-MILLING-MACHINE-f1-/110638567716?pt=LH_DefaultDomain_3&hash=item19c2929124

cos bluntly, the one I've built from scrap is not up to it - no surprises there (it's fine for dabbling...but I'm past the dabbling stage now(!) & I just can't justify the time researching & building my next machine.

I'm only really wanting a machine to mill acrylic, mill the odd PCB (but a small bit of ali would be nice though :-) ) .....noise level is one of my overiding concerns (neighbours!)...I'm figuring that the whirring of the steppers is gonna be loud (the driver seems below par....no microstepping)

Thoughts?


I had the same problems, so when I built my workshop I filled the walls with acoustic insulation, then built a cover over the whole CNC, this really quietened the machine down to such a state that 3 yards from the workshop I hear nothing, incidental I brought a Chinese machine and apart from the odd tweak I have had no trouble with it, and it has done hours of work

[HankMcSpank]

Thanks...yes I think building a cover is the best bang per buck approach to keeping your cutting rate/strength high, but noise low - I'd like to have seen a photo of your acoustic shroud ...any chance?

I've gone full circle, and will actually buy the Walter/Borsh 4030 CNC http://sites.google.com/site/cncdiyorg/4030 (it has 1605 ballscrews *& can take a VFD water cooled spindle) ...there are youtube videos showing it cutting aluminium too ...so that'll do for me - only one problem - the seller isn't responding to emails!

[brandon_costa]

The price seems high for a Chinese made one.

Also Chinese made products don't have a good track record yet as being quality products.

[ptjw7uk]

Not sure about the statement about quality as most of the stepper motors we all use are of chinese origin!

Peter

[m_c]

The good old adage of 'You only get what you pay for' applies, as the Chinese are masters of building to a price.

[HankMcSpank]

Now having never dealt with water cooled spindles, inverters etc, I'm a little confused by the seller's response to me asking him to quote me for one! (the ad is here... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180604201748&ssPageName=ADME:X:RTQ:GB:1123 )

Me: "Could you please let me know if this machine can be supplied not only with the 300W spindle (as per your advert) but also a VFD & water cooled spndle + spindle mounting bracket too? If so, how much extra would that be (including shipping) to the UK?"

Sellers reply: "Dear friendthis machine come with water cooled spndle + spindle mounting bracket too but it does not have inverter for you.and This item is ready for using there is no need the inverter
best regards,

This wil be the bit where I get confused - a water cooled spindle but with no inverter that's ready for use?!!

Me: "I am confused at your response....

"this machine come with water cooled spndle + spindle mounting bracket too but it does not have inverter for you"

....but your listed spindle specification doesn't mention 'water cooled' spindle, here's the extract from your advert.....

"Spindle motor 300w dc motor 1000~9500PRM/Min"

So once again, does this listing include a water cooled spindle with mount or not?

All of the water cooled spindles I've seen listed for CNC machines, typically look like this one you have listed....

http://cgi.ebay.co.uk/0-8KW-WATER-COOLED-SPINDLE-MOTOR-ENGRAVING-MILL-GRIND-/180508850988?pt=LH_DefaultDomain_0&hash=item2a072a7b2c (http://cgi.ebay.co.uk/0-8KW-WATER-COOLED-SPINDLE-MOTOR-ENGRAVING-MILL-GRIND-/180508850988?pt=LH_DefaultDomain_0&hash=item2a072a7b2c)

(also I though all the water cooled spindles *needed an inverter?)

I am familiar that most sellers of the CNC 3040t supply a 300W air cooled spindle...this is why I am confused?

Please clarify asap....many thanks.


Seller: "this listing include a water cooled spindle with mount"




So, can anyone here clarify what the gig is likely to be here - a water cooled spindle will work without an inverter?

[M250cnc]

This is the problem everyone mentioned, you are buying from someone who cannot speak English he cannot confirm what is supplied how would anyone know what you are gonna get.

In the main water cooled spindles have an inverter but that doesn't necessarily have to be the case.

I was thinking about taking of the fan in a standard router encasing it in a water cooled jacket to cool it and so cut down the noise.

Looking at the link you are gonna get an air cooled spindle of 300W and we already pointed out that that machine is too small for a water cooled spindle.

Phil

[Philly]

I bought one of these machines around 3 weeks ago and it seems pretty good. I looked through the youtube vids (some are here http://www.youtube.com/user/DCTTeacher1#p/u/2/J1QZrtVcv5c) and the guy who uploaded it is a DT teacher in Australia and was very helpful in assisting with the set up(I didnt quite grasp motor tuning). I bought it based on his review of the machine but from a UK supplier.

So far it has made a few nice PCBs and couple of 3d reliefs in MDF and I havent had any trouble except figuring out what type of tool does what :)

CNCDIY will mark the package as a gift, a friend ordered a different size machine and paid only £13 VAT.



On another note without high jacking this thread, where do I buy sheet wood from(pine, birch, oak etc) Im not having much luck and MDF is boring ;)