New Machine Build Another n00b wants to build a CNC machine! - Page 2


Page 2 of 2 FirstFirst 12
Results 13 to 17 of 17

Thread: Another n00b wants to build a CNC machine!

  1. #13
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    33279
    Downloads
    0
    Uploads
    0

    Default Re: Another n00b wants to build a CNC machine!

    I'm assuming you mean the gantry when you say truss?
    One reason, is that the longer it is, the more it will flex. Some people do build machine with the gantry as the longer access, due to space constraints, or better access to the work, when the machine is used for a specific application.

    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  2. #14
    Registered
    Join Date
    Feb 2018
    Location
    United States
    Posts
    10
    Downloads
    0
    Uploads
    0

    Default Re: Another n00b wants to build a CNC machine!

    Gantry! That's the word I was looking for! Here are my thoughts..

    I think that, no matter which way I build it, I'm going to have to drive that gantry from both ends, otherwise the whole things is gonna shift and strain the crap out of the linear bearings, or jam up the whole thing. So that means I have to buy double the ballscrews or rack & pinion parts. It would be cheaper to do that on the short axis than the long one. Also, the machine is going to have the long axis against the wall, and it will be between my lathe table, and some shelves, which means I'll be standing on the long axis while I'm using it. Doing it this way would probably make it easier to use.

    So my understanding now is that it's possible, but generally not a good idea because it could flex more. I wonder if I can beef it up to compensate. I have a few friends who are mechanical engineers. Maybe I can get them to help me figure out just how much force will be on this thing and how much flex I can anticipate.

    J

    "What I DO have is a GED and a Give 'em Hell attitude, and I'll figure it out" -Dean Winchester


  3. #15
    Registered
    Join Date
    Feb 2018
    Location
    United States
    Posts
    10
    Downloads
    0
    Uploads
    0

    Default Re: Another n00b wants to build a CNC machine!

    Checking in. I needed a really straight edge to help with this project, and I came into a 5 foot long chunk of 3 inch I-beam. I found a machine shop about 20 minutes away, and hired them to mill one side flat for me. When I went to pick it up, we got to talking about the project I'm working on, and my interests, and he offered me a part time job on the spot! So besides my normal job, I've started working Saturdays working with actual proper CNC machines. of course, I'm WAY more excited about this than a respectable adult should be, but I never claimed to be respectable in the first place. I'm learning a LOT!

    In the meantime, I've been working with Fusion360 on designing my table, and I think I'm starting to turn a molehill into a mountain. I have this big crazy steel framework and all kinds of goofy stuff that a good quality machine should probably have. But this is my first real build here. Maybe I need to dial it back a little bit and go with something simple. I found a machine junkyard, and I'm looking into the possibility of buying a big steel t-slotted mill bed. It's about 2 1/2 by 5 feet, about 4 inches thick, and it's probably flat enough for a hobbyist like me to get decent results out of if I use it as the base for the table. Bolt the linear rails directly to that, instead of trying to true up a welded nightmare of a homebrew table. Sure, maybe I'm not gonna get 2 tenths out of it, but I'm not making space shuttle parts here. I'm dinking around in my garage. it also seems easier to bolt the rails to the top of the table than the side. I mean easier to drill 2 sets of parallel holes on the same surface than to make them on the sides. By doing so, I'm skipping the overhang to help keep chips out of the rails. Maybe I can find some kind of baffle to shield them with instead.

    Anybody care to chime in and tell me where I'm about to screw it up? Seriously, cuz I'm pretty much winging it here!

    "What I DO have is a GED and a Give 'em Hell attitude, and I'll figure it out" -Dean Winchester


  4. #16
    Registered
    Join Date
    Feb 2018
    Location
    United States
    Posts
    10
    Downloads
    0
    Uploads
    0

    Default Re: Another n00b wants to build a CNC machine!

    Oh, and I got a little distracted by where to put this in my workshop, which I eventually decided is just too damned small. So I ripped out the wall between it and my garage, and just took over the whole place! The machine won't be up against a wall anymore, so there's no reason to try and build the gantry on the long axis, so I can scrap that noise, too.

    "What I DO have is a GED and a Give 'em Hell attitude, and I'll figure it out" -Dean Winchester


  5. #17
    Registered
    Join Date
    Feb 2018
    Location
    United States
    Posts
    10
    Downloads
    0
    Uploads
    0

    Default

    Believe it or not, I still haven't given up yet! I have spent a lot of this year reading and learning, and I'm well on my way to making a whole new level of design mistakes now!

    I pretty much scrapped all the original design ideas I had. The new design will be fixed gantry, with about a 30x30 inch bed. I have everything worked up in fusion360 this time, and it has made it a lot easier for me to figure things out.

    I went with an ethernet smoothstepper and a C25 breakout, and I've been tinkering with that and Mach4Hobby, and I'm getting the hang of how to set up everything. Still using the 2.2kw Chinese spindle, and I think it will be ok for this machine. Maybe I'll get one of those ATC spindles when I'm 4ich and famous one day. I'm building the table out of welded 2 inch square steel, and the whole frame will go in to have the important bits machined once I have the design finished.

    2018 was a Hella busy summer for me, but things are finally beginning to slow down so I can work on this more. More to follow!

    "What I DO have is a GED and a Give 'em Hell attitude, and I'll figure it out" -Dean Winchester


Page 2 of 2 FirstFirst 12

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

Another n00b wants to build a CNC machine!

Another n00b wants to build a CNC machine!