Advice for a newbie build

Results 1 to 5 of 5

Thread: Advice for a newbie build

  1. #1
    Member Uurgh's Avatar
    Join Date
    Sep 2022
    Posts
    4
    Downloads
    0
    Uploads
    0

    Default Advice for a newbie build

    Hello, new user just getting into CNC, posting first build plans for advice and critique.

    I'm intentionally keeping this brief. Not too lazy to get into details if anyone asks.

    The build in the pictures is what I've been able to come up with cheaply available stuff. Essentially I'm asking for better ideas for arranging the parts shown, opinions on whether this will work at all/work for aluminium.

    The plan is to use this to mill some plates and brackets for constructing an improved version. Then keep iterating.

    I feel I'm at the point where hands-on experience will be more effective than designing my 10th concept - I'd rather back further study of theory with practical experiments.

    My end goal for this project is a small (around 50cm cube in size) machine for milling copper and aluminium, with good precision and ergonomics. The journey is more important though - I'm doing this to learn, to get some hands-on experience, and for the fun of it. Reaching the goal is optional.

    BOM:
    - 4x 50cm C-beam actuator
    - 2x 30cm C-beam actuator
    - 2x 50cm x 12cm x 8cm steel profiles, 4mm thick
    - 5x 50cm x 10cm x 2cm steel profiles, 2mm thick
    - Chinese 1.5kW spindle
    - 4x 2.8N-m stepper motors

    Only 4 motors will initially be installed - I'll keep the unpowered actuators for structure with lead screws removed.

    Considerations for picking parts:
    - easy to put together (don't have a workshop)
    - most will remain useful when upgrading
    - good value (capability) for money

    Similar Threads:
    Attached Thumbnails Attached Thumbnails Advice for a newbie build-screenshot_20220912_210101-jpg   Advice for a newbie build-screenshot_20220912_210030-jpg   Advice for a newbie build-screenshot_20220912_210005-jpg   Advice for a newbie build-screenshot_20220912_205830-jpg  

    Advice for a newbie build-screenshot_20220912_205047-jpg   Advice for a newbie build-screenshot_20220912_204913-jpg  


  2. #2
    Member peteeng's Avatar
    Join Date
    Jul 2018
    Location
    dum dum
    Posts
    6254
    Downloads
    0
    Uploads
    0

    Default Re: Advice for a newbie build

    Hi Uurgh - firstly I'd not use wheels. Since cost is an issue I'd use round rail. Wheels need constant adjustment and you'll be unhappy with them pretty quickly. 1.5kW router is a bit heavy for such a machine get an AC 800W much lighter and smaller more appropriate for your machine size. Plus its a bit cheaper. Peter

    Upgrading a machine is sort of an issue. Sure you can upgrade electronics and motors and bits and bobs but the structure is the basic DNA and if thats wrong then you have to build a new machine to "upgrade". So get your structure right for what you want to do up front. Why do you have two machines hanging off the gantry? That creates a lot of dead space on the machine. Peter



  3. #3
    Member Uurgh's Avatar
    Join Date
    Sep 2022
    Posts
    4
    Downloads
    0
    Uploads
    0

    Default Re: Advice for a newbie build

    Thanks for the feedback!

    Quote Originally Posted by peteeng View Post
    Hi Uurgh - firstly I'd not use wheels. Since cost is an issue I'd use round rail. Wheels need constant adjustment and you'll be unhappy with them pretty quickly.
    I hope to only rely on those rollers for load bearing at the start, before I can make some plates/adapters for supported rods. Ultimately I plan to go with light linear rails, however aligning them properly takes tools and skills I don't have yet, so I'll stick to more accessible methods for now.

    Quote Originally Posted by peteeng View Post
    1.5kW router is a bit heavy for such a machine get an AC 800W much lighter and smaller more appropriate for your machine size. Plus its a bit cheaper.
    Good points.

    Quote Originally Posted by peteeng View Post
    Upgrading a machine is sort of an issue. Sure you can upgrade electronics and motors and bits and bobs but the structure is the basic DNA and if thats wrong then you have to build a new machine to "upgrade". So get your structure right for what you want to do up front.
    Currently the focus of this project is fiddling with different builds to get a feel for what works. Sure I can mock up designs in 3D but after a few weeks of that I decided I'd rather mash some parts together.

    I considered designs made out of steel profiles, but then grasped the amount of drilling/tapping/cutting involved and decided to get a feel for this sort of work while building the base for this machine. I have an old drill press, so maybe it won't be so bad, I'll see after drilling those 100 holes I have planned. Also I've yet to see if my precision is anywhere good enough to bolt rails straight to steel, and if the parts I get will be straight enough.

    Quote Originally Posted by peteeng View Post
    Why do you have two machines hanging off the gantry? That creates a lot of dead space on the machine. Peter
    I decided to go for dual c-beam for the X-axis as I've seen complaints that c-beams tend to twist under load, so hopefully that will stiffen the gantry a bit.

    I attached the second Z-axis actuator to offset the weight a bit. They are connected to transfer some of the load to the second gantry plate, so the spindle isn't hanging on a single set of flimsy rollers. Granted I don't have high hopes for those flimsy 20x20 extrusions either, but I don't mind experimenting a bit.



  4. #4
    Member Uurgh's Avatar
    Join Date
    Sep 2022
    Posts
    4
    Downloads
    0
    Uploads
    0

    Default Re: Advice for a newbie build

    I gave this some more thought and it struck me that the initial layout was indeed pretty dumb. Moving both Z-axis actuators to the front seems to have more benefits than... Whatever that previous idea was trying to do.

    Advice for a newbie build-screenshot_20220913_225934-jpg

    Also this gave me an idea, now that both gantry plates are in the front, maybe I can brace the whole X-axis with a 100mm*80mm, 4mm thick steel C profile.

    Advice for a newbie build-screenshot_20220913_235332-jpg

    Would that work to make the machine a bit stiffer? Or would the weight be too much for the Y-axis rollers?

    Also I'm not sure how to attach it from the top - should the screws catch the t-nuts in the C-beams, and pull to tension the assembly, or should I thread the holes in the top of the steel profile and use the screws to push down on the C-beams? Obviously I don't mean to push directly on the aluminium extrusions, I'd put some plate in there to spread the force.

    Attached Thumbnails Attached Thumbnails Advice for a newbie build-screenshot_20220913_225934-jpg   Advice for a newbie build-screenshot_20220913_230329-jpg   Advice for a newbie build-screenshot_20220913_235332-jpg   Advice for a newbie build-screenshot_20220914_003257-jpg  

    Advice for a newbie build-screenshot_20220914_002701-jpg  


  5. #5
    Member peteeng's Avatar
    Join Date
    Jul 2018
    Location
    dum dum
    Posts
    6254
    Downloads
    0
    Uploads
    0

    Default Re: Advice for a newbie build

    Hi uurg - There are many ways to skin the cat and you will need to wade through all of those variables. As bolted in the images I'd expect that the efficiency of the connection is not very high so although the steel angle will be quite stiff it won't translate well to improving the stiffness of the gantry as drawn. If your CAD system has fea then use it. It will answer these sorts of questions. Peter



Tags for this Thread

Posting Permissions

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


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Advice for a newbie build

Advice for a newbie build