Preferred method (technology?) for making really small holes?

Mark St Clair Oct 17, 2020

  1. Mark St Clair

    Mark St Clair TrainBoard Member

    44
    177
    4
    I would like your inputs on how to overcome a challenge. Please have a read and let me know how you would approach this problem.

    My need to build some ladders for an N scale tender has become an opportunity to attempt some accelerated learning on modern model building. Here is a drawing, admittedly not machine shop ready, illustrating what I am after. Material is brass.
    Screenshot (9).png

    The next challenge is drilling holes in the rails for the steps. I can actually do a fair job of drilling the holes by hand. Accuracy is quite a different challenge with my current skill set.

    Several idea have been rolling around my head. Here is a summary of thoughts and questions:

    1. My old drill press and cross vise are not going to get me there. Is there a jewelers drill press and x-y table combo that offer the accuracy needed? Which ones: Proxxon, MicroLux, Cameron ($$$$), etc.

    2. Could a 30/40W laser cutter dimple the brass sufficiently to substitute for a center punch?

    3. I wanted to scratch build with brass. Would you use a different approach? Say scratch build with styrene, 3D print, photo etch, etc.?

    My skill set is still stuck at about 1999. I am beginning to see the possibilities of CAD, CNC, laser cutting and 3D printing. Maybe you can help me up a steeper learning curve by sharing your insights and experience.

    Thanks!
     
  2. rray

    rray Staff Member

    7,092
    3,358
    123
    I used a 30W laser to drill these .009" holes in white Polybak (plastic and cellulose mix) for my brakeman platform:
    Image1.jpg

    To use a laser with Brass, you need a 50W Fiber Laser, and several passes, but it could go through. I use a 30W CO2 laser and a combination of Paper, Wood, Polybak, and Plastic, with brass details to build my models.

    I drew up your ladders in Corel in 5 minutes. I would cut them out of .011" black Polybak and they would be 3 layers thick, with the rung layer in the center:
    Capture.JPG
     
    gmorider and Mark St Clair like this.
  3. r_i_straw

    r_i_straw Staff Member

    18,780
    18,578
    233
    I use a Dremel setup.
    IMG_0171.jpg
     
    gmorider and Mark St Clair like this.
  4. Mark St Clair

    Mark St Clair TrainBoard Member

    44
    177
    4
    That's great info. Never would have come up with that approach on my own. How narrow can the rails and rungs be cut?
     
  5. Mark St Clair

    Mark St Clair TrainBoard Member

    44
    177
    4
    Now that technology is familiar enough. I am curious how you clamp the brass (.010" x .030") strip and drill the holes on the centers (.070", .074", .072")?
     
  6. HemiAdda2d

    HemiAdda2d Staff Member

    18,950
    9,448
    232
    3D printing can do dimples for drilling, but the resin material may be brittle when drilling. Tough resins exist, but adds cost (~50-75% more $), and might be an alternative.

    If accurate repeatability is key, why not make a drilling jig out of brass? An example is Gold Medal Models 160-56 http://www.goldmm.com/nscale/gmnlotyp.htm.
     
    Mark St Clair likes this.
  7. wvgca

    wvgca TrainBoard Member

    303
    121
    16
    a drilling jig would give repeatability and accuracy ... a simple dremel as pictured above would be a relatively low cost way to drill the resulting holes
     
    Mark St Clair likes this.
  8. r_i_straw

    r_i_straw Staff Member

    18,780
    18,578
    233
    I use the Gold Medal Models jig and a piece of double stick cellophane tape to position the holes. I also can make dimples with an X-acto awl.
     
    Mark St Clair likes this.
  9. rray

    rray Staff Member

    7,092
    3,358
    123
    .009"
     
    Mark St Clair likes this.
  10. mah2219

    mah2219 New Member

    1
    0
    11
    Hi guys. I'm working on a laser cut project of a local depot. I'm cutting the walls out of 1.5mm ply but hoping to 'skin' this with engraved brick. I've been working with .024 wood veneer and have been able to source .020 polybak. The .011 white polybak sounds like it would be ideal. Do you have a source you can share for this material?

    Thanks,

    Mike
     
  11. rray

    rray Staff Member

    7,092
    3,358
    123
    The .011" polybak used to come only in Black, but I think it is brown now. The .015" polybak used to be white, and came from either Midwest Products or Northeastern Scale Lumber and they called it Laserboard. I have never used the .020" brown, but I do use the .024" brown polybak.

    I bought Karin Snyder's last 20 sheets of white .015" polybak just before she moved away to Alaska earlier this year, and was told the white has been discontinued. I use it exclusively for Z Scale railcars because it is exceptionally smooth and hard, and can represent steel carsides best.

    You can get polybak here, but they call it Laserboard, and I think it is all brown these days:
    http://automatedartists.com/laserboard
     

Share This Page