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  1. #1
    I want a compact VMC that I can run on a good household 240V connection, I say it's a good connection because in addition to the house it has in the past happily dealt with a draughty garage where a 3hp compressor and enough convector heaters to get it warm enough for full 2k car resprays were in use.

    I can't just buy a commercial VMC as they expect 3 Phase and more power draw than I suspect I could manage even through inverter drives, the Skyfire sounded ideal but recent discussions have knocked the shine off that a little as I will be working in Steel, Stainless Steel and Aluminium Alloys and expect a carousel tool changer to know where it is without intervention.

    Do I go for a commercial compact VMC with a converter for all the motion and ancillaries and downgrade the spindle motor then run that from a VFD?
    I think a diesel genny is out of the question from a noise and emissions standpoint.

    Should I embark on an epic mill conversion journey or scratch build?
    B*gger me, this has all just stepped a little sideways and well out of my comfort zone!

    ~Nick
    You think that's too expensive? You're not a Model Engineer are you? :D

  2. #2
    To me people are comparing apples with oranges when comes to VMC's and machines like Skyfire, Tormach etc.

    Skyfire, Tormach etc are not VMC's they are Bench mounted Mills sat on a lightly built steel frame. True Vmc is floor mounted solid cast iron structure and column.
    If you notice even Haas don't call there "Mini Mill's" VMC's because they are not. They are just heavily constructed base mounted machines. That is mounted on heavy constructed welded steel base frame. Unlike Skyfire or Tormach which in comparison are sat on light weight and bolted together benches.

    To be fair were not even comparing apples to oranges when comparing to Haas "MiniMill" or other commercial MiniMill's like XYZ 2-OP because the difference is construction is night and day.

    Skyfire, Tormach etc are just glorified Bench mills that come with all the weaknesses and traits associated with there manual cousins. Sticking servo's on them and wrapping in tin sheet doesn't make them VMC's or any stronger.

    So to me, people need to start looking past all the eye candy sheet metal etc and pay attention to what they are truly buying with there "Starting from 16'950" lump of money, which in reality soon becomes 20K when they fall for few over priced extra's.!

    Those are my ramblings anyway.!
    Last edited by JAZZCNC; 10-02-2018 at 10:25 PM.

  3. The problem is, this size of machine is always going to be a compromise.

    I like my Triac for what it is, and it does the job I bought it for, but I can see something with more power and travel in the future.

    A Tormach or Skyfire would fit that bill well enough, but for the same money, I could get a secondhand industrial machine. Somewhat ironically, I can get 3 phase installed for not that much money, but the current workshop isn't high enough for anything above 2.0m.
    I could really do with a bigger lathe as well, but every enclosed slantbed I've looked at is also too high.

    The big problem is with spindles. Without going to some kind of gear head, you're either looking at limited RPM to achieve reasonable torque, or high speed with limited torque. Although with a larger spindle, and with a suitable drive and/or controller, you could program it to operate in a power limited way.


    At the moment, short of building a new workshop, I'm actually considering a solid router to handle aluminium work, and finally finishing the Matchmaker for steel work (every time I get back to actually working on it, some other retrofit comes along..).
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  4. #4
    Quote Originally Posted by JAZZCNC View Post
    So to me, people need to start looking past all the eye candy sheet metal etc and pay attention to what they are truly buying with there "Starting from 16'950" lump of money, which in reality soon becomes 20K when they fall for few over priced extra's.
    You've carried me to that point but having looked beyond it's all a bit dark, at this point the best option I can put together is a new Bed Mill with a custom head incorporating a decent spindle cartridge and 3-4hp motor with ball screws and servos and a decent motion controller, PC and software.
    More ramblings welcome ;-)
    You think that's too expensive? You're not a Model Engineer are you? :D

  5. That's just reminded me that Fadal's were weldments, and David Decaussin was making the UMC10 for a while, which was a welded steel.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  6. #6
    I can see a whole raft of time with the MIG, TIG and MMA sets in my near future ;-)
    You think that's too expensive? You're not a Model Engineer are you? :D

  7. #7
    Quote Originally Posted by m_c View Post
    That's just reminded me that Fadal's were weldments, and David Decaussin was making the UMC10 for a while, which was a welded steel.
    Exactly.!!. . . Weldment machine isn't beyond commited DIY builder. Steel is cheap and plasma/Waterjet cutting isn't that expensive. Out source some heat treatment/stress relief and grinding/machining services then you'll soon have strong base machine to start with. 15-20K gives you fare amount of room to play.

    To be honest I'd even look towards EG or Concrete Fixed Gantry machine because could build a Very strong machine with larger cutting area in same footprint.

  8. My big worry with welding that kind of thing, is accuracy, and finishing the mounting surfaces. Unless you do it so things bolt together, access to finishing surfaces is going to be a challenge.

    I've often wondered if there would be much price difference between welding and casting. By the time you factor in materials, machining them, welding them, stress relieving them, and finishing them, would it be more expensive than a set of patterns, getting them cast, and chucking the casting outside for year or so before machining/finishing them?
    Plus spec the right grade of cast, and you get inbuilt damping, without having to worry that you're building a big resonator.

    There are certainly lots of options. It just comes down to time and cost, as to what one suits.


    If in your research, you happen to come across a Fadal with it's clothes of, I'd be interested in seeing how they've done the main construction.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  9. #9
    Quote Originally Posted by m_c View Post
    would it be more expensive than a set of patterns, getting them cast, and chucking the casting outside for year or so before machining/finishing them?.
    Pretty much yes, there is an element of "Time is Money" so I'm not really after a kit I can start to build in 18 months time or so, hence looking for a product and considering a conversion on a new Bed Mill or an adaptation of a second hand VMC.
    You think that's too expensive? You're not a Model Engineer are you? :D

  10. Quote Originally Posted by magicniner View Post
    Pretty much yes, there is an element of "Time is Money" so I'm not really after a kit I can start to build in 18 months time or so, hence looking for a product and considering a conversion on a new Bed Mill or an adaptation of a second hand VMC.
    That was more just me rambling :)

    How about something like this? - https://www.ebay.co.uk/itm/Cincinnat...R/162890979240
    I'd want to know what exactly why it was non-running, but set of servos, new controller, and the basics are done. The hardest part is always the tool changer. Off course it depends just how much space you've got...

    Attached are some plans that Dave Walsh (of BT15 spindle cartridge fame/saga) posted at some point.

    And here's some notes I made about the UMC10 (IIRC I noted them down from his videos)-
    6" x 6" x 1/2" wall thickness column
    10" x 4" x 1/2" wall thickness base

    6500rpm spindle = ~11000rpm motor speed
    3hp spindle

    table 1 1/2" x 8" crmo steel
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Attached Files Attached Files
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

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