Water cooled chinese spindle collets, Advice from owners please

[craigrobbo]

Hey guys, I have ordered a chinese cnc 3040 with a 1.5kw spindle.

I am wondering from owners of the watercooled 0.8kw 1.5kw and 2.2kw could tell me if you have ever dismantled one?

The one i bought comes with an ER11 collets, but there seems to be replacement collet system for spindles from ER11 ER16 and ER20 and i am wondering if they are actually interchangeable?

Would anyone be able to supply detailed pictures and if possible show one dismantled and/or confirm they are changeable?

If so which one its changeable from/to


here is a link to just one replacement i found on ebay, but there are lots on there like it with different shanks (ie some taperd some straight)

http://www.ebay.co.uk/itm/C16-ER20A-100L-Extension-Milling-Collet-Chuck-Holder-/270604590365?pt=LH_DefaultDomain_3&hash=item3f014a5d1d

and

http://www.ebay.co.uk/itm/ER20-MT2-MK2-M10-SPRING-COLLET-CHUCK-CNC-MILLING-LATHE-TOOL-WORKHOLDING-A22-/150802221717?pt=LH_DefaultDomain_3&hash=item231c834a95
Thanks

Craig

[JAZZCNC]

Hey guys, I have ordered a chinese cnc 3040 with a 1.5kw spindle.

I am wondering from owners of the watercooled 0.8kw 1.5kw and 2.2kw could tell me if you have ever dismantled one?

The one i bought comes with an ER11 collets, but there seems to be replacement collet system for spindles from ER11 ER16 and ER20 and i am wondering if they are actually interchangeable?

Would anyone be able to supply detailed pictures and if possible show one dismantled and/or confirm they are changeable?



Yes I have striped one and no they wont because of the way the rotor is part of the collet shaft.
The different spindle KW and ER sizes etc make them completely different so therefore not interchangable.

The ER shafts you link to are not replacenments but more extensions and adapters for drilling machines etc or building your own spindle. One of them is MT2 to ER adapter used on mills and lathes.

Here's some pics of a 2.2KW I killed.!!

596459655966

[Ali Kat]

I can confirm Jazzcnc statement. The chuck is integral with the main motor shaft. I have noth 0.8 kw and 2.2 kw and you just use whatever is on the end.

Hey Jazz, How did you kill that 2.2?

[GMCNC]

Hiya, Will the suppliers not supply you with a larger collet system if you specify it?

[JAZZCNC]

Hey Jazz, How did you kill that 2.2?

My own silly fault, I'd had the spindle off a few times to check fit for some mounts I'd made for someone and didn't fasten the cable guide correctly, So over time the connector was bending and snapped wire inside main connector at the spindle causing dead short and great big blue flash.!!!!!. . . . . Killed both spindle and ABB350 VFD stone dead. .:neglected:

[Ali Kat]

As these items are mass produced I would doubt that a special would be considered. Even if it was, I would expect a hefty premium to produce a one off. It's not quite as simple as putting a larger shaft into to smaller motor casing as it simply doesn't fit.

Ali Kat

[Ali Kat]

Whoa - expensive smoke!!!! Let me know if you want to part with the dead bits as it may be useful to have a couple of bearing housings on the spares shelf for my own 2.2.

Ali Kat

[JAZZCNC]

Whoa - expensive smoke!!!! Let me know if you want to part with the dead bits as it may be useful to have a couple of bearing housings on the spares shelf for my own 2.2.

Ali Kat

Nope sorry. It's going to be modified to belt drive then used either has a secondery slow running spindle for steel work or be used for the spindle of a mini lathe.?

Just don't ask when.!!

[Ali Kat]

Very good idea Jazz. The spindles seem to be fairly well built and certainly they are mechanically robust. Should make a good spindle with, perhaps, a multi step pulley to give speed variances etc. Put up some pics when it's done as I'm sure that you won't be the only owner to "kill" one of these spindles!

Ali Kat

[GMCNC]

hiya, Yeah, they are mass produced... With different collets etc :) I would have thought the 'manufacturer' of the machine could just fit a different one...

Its something I have done in the past.

[JAZZCNC]

hiya, Yeah, they are mass produced... With different collets etc :) I would have thought the 'manufacturer' of the machine could just fit a different one...

Its something I have done in the past.

I would imagine because of the small rotor diameter of low powered spindles then the large ER collet systems wont fit or be enough material left to safely adapt.
The cost to re-tool for an upgraded rotor for just a few specials wont be worth the expense in relation to demand.?

How did you fit a larger ER collet taper system into a smaller ER taper.?

[Jonathan]

Very good idea Jazz. The spindles seem to be fairly well built and certainly they are mechanically robust.

I wouldn't be so sure. They're well built for high rpm use...

I don't think it would make that good a spindle for a lathe, unless the lathe is very small, since it uses angular contact bearings. Most lathes use tapered roller bearings since their load ratings are much much higher. Angular contact bearings are the only bearings suitable for high speed and axial loads, but you don't need that high a speed on a lathe (unless it's something special) so why compromise the rigidity so much by using the wrong bearing type. Same is probably true for a spindle for cutting steel since again that's low rpm and you need higher rigidity for cutting steel.

[Ali Kat]

I assume that the spindles are made on CNC equipment and it's probably not going to be straight forward to redesign the rotor with a larger nose to accept the larger diameter ER collets and nut that would be required to go from ER 16 to ER 20 for instance.

As I said previously, the manufacturer may be prepared to make a "one off" but I would think that the cost would quite high.

Is it not a case of just ordering the CNC3040 with a larger spindle to cover a larger range of sizes? The 2.2 kw spindle can handle up to 1/2" and is man enough for most jobs including steel milling. I would have thought that this would be cheaper than getting a lower powered spindle but with a bespoke larger collet size.

Ali Kat

[JAZZCNC]

I wouldn't be so sure. They're well built for high rpm use...

I don't think it would make that good a spindle for a lathe, unless the lathe is very small, since it uses angular contact bearings. Most lathes use tapered roller bearings since their load ratings are much much higher. Angular contact bearings are the only bearings suitable for high speed and axial loads, but you don't need that high a speed on a lathe (unless it's something special) so why compromise the rigidity so much by using the wrong bearing type. Same is probably true for a spindle for cutting steel since again that's low rpm and you need higher rigidity for cutting steel.

Yep but better than sat on a shelf or in the scrap bin.!!
Plus it's no big deal or expense to change the bearings know is it.! . . Remember Jonathan I'm the original 5968

[Jonathan]

Yep but better than sat on a shelf or in the scrap bin.!!


True, but even better would be to just couple it to a brushless RC motor and keep it as a high speed spindle. With the right motor it could be better than new...something like this:


http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11187



Plus it's no big deal or expense to change the bearings know is it.!


Assuming you can find tapered roller bearings the same size, but that's rather unlikely as I think those spindles use a pair of 70xx series bearings?



Is it not a case of just ordering the CNC3040 with a larger spindle to cover a larger range of sizes? The 2.2 kw spindle can handle up to 1/2" and is man enough for most jobs including steel milling.

Ordering the CNC3040 without a spindle and getting the 2.2kW spindle separately might be easier? Either way it's worth asking.
I've found it's not really man enough for steel milling. I've made a couple of bits from mild steel with my cnc router and that spindle, but the problem is the torque at low rpm for that type of spindle is so low that you're limited to only very small cutters and running them a bit fast. A VFD with vector current control would help matters, but it's still going to have limited torque and rigidity.
If you actually want to cut steel regularly you need a lower rpm spindle and a much stronger machine than a CNC3040!

[JAZZCNC]

True, but even better would be to just couple it to a brushless RC motor and keep it as a high speed spindle. With the right motor it could be better than new...something like this:

Yep thats an option but not one I'll be taking and for what I need it will be fine just the how it is.





Assuming you can find tapered roller bearings the same size, but that's rather unlikely as I think those spindles use a pair of 70xx series bearings?

But I have lathe and know how to use it so again no great deal, but again won't happen has it won't be needed for my needs.



Is it not a case of just ordering the CNC3040 with a larger spindle to cover a larger range of sizes?

Ah ah best laugh I've had all morning.! . . . My experience with these small crap machines is they struggle to even lift the Z axis with 2.2KW weight never mind be usable.!!



I've found it's not really man enough for steel milling. I've made a couple of bits from mild steel with my cnc router and that spindle, but the problem is the torque at low rpm for that type of spindle is so low that you're limited to only very small cutters and running them a bit fast. A VFD with vector current control would help matters, but it's still going to have limited torque and rigidity.

Not strictly correct.!
Yes using standard milling cutters and techniques then yes they are way too fast but with correct high speed tooling designed to run dry and high speed milling techniques then they work fine in steel. The down side being the cutters are expensive and it can take longer because you can't hog big lumps out but it still does a good job without stressing the machine or spindle.