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  1. #11
    Quote Originally Posted by GMCNC View Post
    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.?

  2. #12
    Quote Originally Posted by Ali Kat View Post
    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.
    Old router build log here. New router build log here. Lathe build log here.
    Electric motorbike project here.

  3. #13
    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

  4. #14
    Quote Originally Posted by Jonathan View Post
    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 Click image for larger version. 

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  5. #15
    Quote Originally Posted by JAZZCNC View Post
    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/s...dProduct=11187


    Quote Originally Posted by JAZZCNC View Post
    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?


    Quote Originally Posted by Ali Kat View Post
    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!
    Old router build log here. New router build log here. Lathe build log here.
    Electric motorbike project here.

  6. #16
    Quote Originally Posted by Jonathan View Post
    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.



    Quote Originally Posted by Jonathan View Post
    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.

    Quote Originally Posted by Ali Kat View Post
    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.!!


    Quote Originally Posted by Jonathan View Post
    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.

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