Welcome to Our Community

Unlock hidden features. Sign Up for Free Today!

Introductions come first right?

Discussion in 'General Talk' started by Brianc, Nov 1, 2015.

  1. Brianc

    Brianc New
    Builder

    Joined:
    Dec 16, 2014
    Messages:
    6
    Likes Received:
    0
    Hi all,
    Brian here, been a long time lurker on this forum, trying to read and absorb all I can. I have answered lots of my own questions, but still have plenty more.

    Earlier this year I purchased a set of waterjet cut plates with the intention of using them for a senior mechanical design project. Our eventual goal is to build something in a near vertical orientation to save space. The gantry will be counter-weighted vertically, with a moving counterweight on the "X" axis to oppose the router head. That's our initial idea anyway. I have spent lots of years around horizontal spindle machine tools and can appreciate the advantages they have in chip removal as well as space saving.

    In the meantime we are going to build the more conventional OX version. This will allow us to get our feet wet and increase our understanding of all the other details involved. Looking at something in the 2' x 3' range, not sure what sort of footprint optimizes the available stock extrusion lengths. Controller will be a Tinyg, with either the Dewalt or Bosch routers for a spindle. Not looking to do any serious cutting, light aluminum seems to be what is reasonable to expect

    Any suggestions or words of experience much appreciated. I just found the calculator, so playing with that.

    Thanks

    Brian
     
  2. Giarc

    Giarc Master
    Builder

    Joined:
    Jan 24, 2015
    Messages:
    254
    Likes Received:
    115
    Interesting idea. Now you got me thinking...
     
  3. Brianc

    Brianc New
    Builder

    Joined:
    Dec 16, 2014
    Messages:
    6
    Likes Received:
    0
    Starting to get things assembled and my x axis gantry is really tight on the 20 x 60 rail. I measured the hole spacings for the wheels and they seem to correspond to the Build 80 step models in the Resources section. I have heard rumors of a Build 81 but can't find any models for that. Are there known issues with Build 80?
     
  4. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder

    Joined:
    Dec 20, 2013
    Messages:
    1,104
    Likes Received:
    407
    The only difference between the build 8.0 and the 8.1 is the spacing of the holes on the plates. The spacing was a bit too close on the 8.0 version which resulted in too much pre-load on the wheels, making the rolling too tight.
     
  5. Brianc

    Brianc New
    Builder

    Joined:
    Dec 16, 2014
    Messages:
    6
    Likes Received:
    0
    I haven't fit up the 20 x 80 in the Y gantry, are those dimensions undersize as well? I'm going to have to re-work my plates, will probably redrill the eccentric holes next to the originals, but at the correct centers. Where can I find this information, ideally in some format other than sketchup?

    This also begs the question, why are the incorrect files still in the resources section. It seems they should at least be flagged as incorrect or obsolete
     
  6. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder

    Joined:
    Dec 20, 2013
    Messages:
    1,104
    Likes Received:
    407
    Hole spacing for V-wheels should be extrusion depth + 19.8mm. In most cases you should be able to oversize the smaller holes to around 7mm and gain enough space by setting the bolts to the outside edge of the holes. If you are going to actually move holes, move the larger ones unless you have a good enough setup to where you can guarantee the smaller ones will remain in a true and perfectly straight line when the new holes are drilled. The adjustment happens at the larger holes. If the smaller holes get out of alignment you're screwed and there is no way to fix that.

    As far as why there are incorrect files, the error has to be corrected by the original poster. Far too often, files are posted by several different people in several different locations and unless all of these people go back and fix the error it will remain. Best suggestion is when you find bad information, flag it. Maybe then it will get taken care of.
     
  7. Brianc

    Brianc New
    Builder

    Joined:
    Dec 16, 2014
    Messages:
    6
    Likes Received:
    0
    I have a Bridgeport so accurately moving the holes is no trouble. Does that 19.8 mm dimension allow for some adjustment on the eccentrics or is that the nominal dimension?

    Thanks for the assistance
     
  8. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder

    Joined:
    Dec 20, 2013
    Messages:
    1,104
    Likes Received:
    407
    That allows for adjustment. Personally I use 20mm even. The actual adjusted wheels generally come up somewhere around 20.3mm.
     

Share This Page

  • About Us

    The OpenBuilds Team is dedicated helping you to Dream it - Build it - Share it! Collaborate on our forums and be sure to visit the Part Store for all your Building needs!
  • Like us on Facebook

  • Support Open Source FairShare Program!

    OpenBuilds FairShare Give Back Program provide resources to Open Source projects, developers and schools around the world. Invest in your future by helping others develop theirs!

    Donate to FairShare!