. .

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Change log
    10.3.2020 - Z-axis ratio changed to 2:1. Removed 48V power supply from component list. Added Delta 400W servo motors to component list.
    4.3.2020 - Ballscrew dimensions changed.
    4.3.2020 - Motor and power supply alternatives added.


    Hello,

    I’ve decided to start a build log in order to collect all the advice I receive in one single place. I found myself having to go back to all my posted questions, to refresh my memory quite often.
    The idea is to build a good CNC milling machine for myself that I will use for my own projects. I plan to take a modular design approach when building this machine. What this means I can explain in another post upon request! Note that this just an approach that I will use for fun and it will not be a deal breaker if it turns out to be too complicated or doesn’t succeed for other reasons.

    Machine requirements
    The machine will be designed based on following requirements:
    - The budget is undefined but I prefer to stay below 8000€.
    - Stiff enough to machine aluminium with good tolerances and surface finish. What I mean with good finish is that the finished product should not have a terrible surface. If I can achieve the same surface finish as in this video, I would be more than happy: https://www.youtube.com/watch?v=xyVr35pgx7s
    - Fast feed rates for machining large wooden sheets.
    - Auto tool change spindle is preferred. Possibility to downgrade to a manual tool change spindle if the budget requires it.
    - The footprint is not critical but is preferred to be as small as possible for the following working area: Y-axis (base frame): 1400mm, X-axis (gantry): 1000mm, Z-axis (spindle axis): 200mm.

    Machine control and software
    - I already own a Mach3 license and will continue using it. In the future I can upgrade to Mach4 if I find it necessary.
    - Interface cards Ethernet SmoothStepper (ESS) https://www.cncroom.com/interface-cards/ess-mb3. This I already own. Breakout board will be MB3.
    - MB3 breakout board: https://www.cncroom.com/interface-cards/ess-mb3.
    - The MB3 and ESS will be powered with a 24V, 150W & 6.3A power supply: https://www.sorotec.de/shop/Power-su...A-Heng-Fu.html
    - Delta servo motors (400W, 3000rpm) with brake (for Z-axis): https://www.aliexpress.com/item/3267...23d152a8ZJcwMZ. - Was JMC 180W servo motor.
    - Delta servo motors (400W, 3000rpm) without brake (for X- and Y-axis): https://www.aliexpress.com/item/32671356516.html?spm. - Was JMC 180W servo motor.
    - 3kW Auto tool change spindle with BT30 tool interface combined with a 3.7kW VFD: https://www.ebay.com/itm/3KW-220V-AT...r/264448370955

    Z-axis design & components
    The solution I will be using to allow for the heavy ATC spindle is to keep the Z-axis weight as low as possible. Linear rails, ballscrew & bearings, and servo motor will all be mounted on the rear plate. The ballscrew nut housing and guide carriages will be mounted on the front plate. This is based on the advice that there is not much difference between front/rear mounting when it comes to stiffness. Yes, it is slightly stiffer with front mounted linear rails, but this is a compromise I need to take. The gantry clearance will be 200mm. Anyway I will still be able to surface components up to a height of 240mm and with a diameter of around 160mm, since it will be possible to raise the tool above the bottom of the gantry. I could also decide to make the rear plate longer to further increase the height if I want.

    Components that I plan to use:
    - Aluminium tooling plates
    - HIWIN linear rails: 20mm
    - Delta 400W servo motor, with brake - Was JMC 180W servo motor.
    - Ballscrew: 1605 - Was 1605 or 2005.
    - HTD 5M pulleys with a 2:1 ratio Was 3:1
    - 3kW Auto tool change spindle

    X-axis design & components
    The gantry will L-shaped and be made with 120x80 or 160x80 aluminium profiles. Aluminium keys will be inserted into the t-slots and then the profiles are bolted together from the bottom. Side plates will be used to mount the profiles together from the side. I am still debating if I will go for high gantry sides combined with aluminium profiles similar to JAZZCNC’s design, or with raised gantry. Linear rails with be top/front mounted to get maximum gantry clearance and maximum spacing between the guide carriages. It will also allow for Z-axis vertical tram. The ballscrew will be placed on the rear side of the gantry to stay clear of chips.

    Components that I plan to use:
    - Aluminium tooling plates
    - Item equivalent aluminium profiles
    - HIWIN linear rails: 20mm
    - Delta 400W servo motor, without brake - Was JMC 180W servo motor.
    - Ballscrew: 2010 - Was 1610 or 2010.
    - HTD 5M pulleys with a 2:1 ratio

    Y-axis design & components
    I’ve learned that it is recommended to make a welded steel frame and use epoxy levelling to get flat surfaces for the linear rails. It is also cheaper. I consider myself a good welder and I have the possibility to make a welded steel frame. Does the welded frame have to be stress relieved or is that not required? I am not sure where I would find any local company that could do that for me. If I go for the welded steel frame, what are the recommended box section dimensions?

    The machine will have be moved to my own garage at some point in the future (2-3 years from now), since I am building it in my parents garage. This is the main reason why I am still debating on using aluminium profiles for the base frame. With aluminium profiles I would be able to disassemble it and assemble it again once I move to my own garage. If I decide to use aluminium profiles I will probably use 120x80 or 160x80 aluminium profiles.

    To allow for easier alignment of the linear rails I am planning to mount them to the top of the base frame. The guide carriages will be mounted together with separate aluminium plates, which will allow for some adjustment of the X-axis gantry to get the machine square.

    Components that I plan to use:
    - Aluminium tooling plates
    - Item equivalent aluminium profiles
    - HIWIN linear rails: 20mm
    - Double Delta 400W servo motor, without brake - Was double JMC 180W servo motor.
    - Double ballscrew: 2010 - Was 1610 or 2010.
    - HTD 5M pulleys with a 2:1 ratio

    Continuing forward
    I will start posting updates of the design as it progresses. Any advice is very welcome.
    Last edited by NordicCnc; 10-03-2020 at 12:03 PM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. BUILD LOG: New Build - For Your Amusement - MK-2 build
    By Karl in forum DIY Router Build Logs
    Replies: 12
    Last Post: 08-02-2017, 08:03 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •