HO scale Dry Bulk trailer.

Discussion in 'My Work In Progress' started by SteveS3D, Jan 3, 2013.

  1. SteveS3D
    SteveS3D Member
    New guy here. Although I've been playing around with 3D modeling since the mid '90s and I've been aware of 3D printing for a few years now, this is the first model that I've bothered to print out.

    This is an HO scale (1:87) dry bulk trailer that I'm about to have printed. When I first uploaded the model, the price was pretty steep, so I did everything I could to minimize the cost. I hollowed out the tires, rebuilt the tank with thinner walls (from 2mm to 1.3mm.) And I packed all the parts as close as possible to reduce the amount of sprue needed. I managed to cut the volume down from 22.2 cm3 to 17.6cm3.

    One thing I'm wondering about is whether Frosted Detail will be good enough, or will it require FUD. Since I'm going to be offering it for sale, I want to be able to let people know if FD is no good, so I think I'll order it in that material. But before I do, I thought I'd check here and see if people with experience with FD could give some input. The overall length of the trailer is 15cm. The piping that runs under the trailer is 2 mm thick. The handrails are 1mm.



    Steve S
  2. stonysmith
    stonysmith Well-Known Member Moderator
    For FD, the minimum wall can be as low as 0.5mm and for FUD, it can be as low as 0.3mm. If you are at 1.3mm, I would take a serious look at thinning the walls down - in theory, you could drop half the volume or more.

    It's simple or straightforward as "cut it in half", because you do have to worry about material stresses, but many surfaces around your model can likely be thinner.
  3. SteveS3D
    SteveS3D Member
    Thanks for the response. My main concern was strength. I was aware of the minimum thicknesses, but thought that was for fairly small areas. For something as large as the tank (about 4" long) I was concerned it might warp. It may have to withstand some sanding.

    Steve S
  4. Dragoman
    Dragoman New Member
    You could thin down the walls to the minimum, but leave some reinforcing ribs on the inside. This should be good enough. Also, have a good look at the material desing rules, The FUD ones are especially detailed. But in the end, there is nothing like experience. Get it printed and see if it works out. OK, not that cheap with FD / FUD.

    Something else: don't forget the escape holes for the support material. I don't see any holes in you model's tanks.

    Last edited: Jan 7, 2013
  5. SteveS3D
    SteveS3D Member

    The first pic shows that the tank is divided into two halves. The second pic just shows what the finished model will look like.

    Steve S.
  6. Mhagan
    Mhagan New Member
    Also make sure you look at the minimum wire thickness on the design guidelines for FUD (0.6mm). The ladder on the back looks quite thin. :)

    I agree with some of the other members, The walls of the tank could be thinned down a bit. In my experience 0.8-1.0 mm in a curved shape strikes a nice balance between Cost and Fragility. Of course Thicker walls would be needed if this will be handled regularly.