Can WSF be effectively tapped/threaded for screws?

Discussion in 'Finishing Techniques' started by CodeCreations, Feb 7, 2010.

  1. CodeCreations
    CodeCreations New Member
    I'm working up a small part that will attach to the bottom of a camera. It has a flange at the bottom that will allow it to be clamped into a special tripod. But I'm brand spankin' new to shapeways, and I haven't seen the materials except for on the videos.

    My plan right now is to print it with a tap hole for the 1/4-20 UNC threads and tap the part when I receive it. Then I'll glue in the screw.

    Will this work? Should I just add the threads to the model? (Is the detail good enough to print screw threads?) It is tapable?

    Also, I'm assuming the "flexible" part of the name comes from when the parts are thin. If the flange is about 5mm thick will the flexibility go away enough to hold a camera? If it's just rubbery and squishy, then it won't work, but so long as the material holds together, it can give a just a little bit and still work fine.

    Finally, does it compress? For example, if I pressed down on a solid piece with the shaft of a screwdriver with about 20lb / 10kg, would it dent or compress?

    Any advice here would be greatly appreciated!!
  2. rawkstar320
    rawkstar320 New Member
    Generally in plastic parts they do one of two things: put an metal insert with threads into a mounting boss in the plastic part, or simply drive a screw into the hole or mounting boss. The material should be soft enough to do the later.

    I know some people have talked about tapping holes in the WSF, but in my opinion, I would just make the hole 1/4inch, then drive the screw into that hole. It should tap itself into the plastic. I really dont see the point in taping plastic parts.

    If your tripod is anything like the tripods that I have seen before, I think that the wsf should be strong enough. However, I might recommend that you use the Gray Robust material because it is made from an ABS plastic. ABS is strong and resilient and might be better suited for your application. Plus it isnt a powder, it is an extruded plastic wire. Ive used it for mounting brackets for high torque 12volt motors and it help up really well.

    As for compression, its pretty hard. Im sure you could dent it with a screwdriver, just like any other plastic. Same for the ABS plastic. But its definitely not rubbery and squishy.
  3. rawkstar320
    rawkstar320 New Member
    I apologize for the double post, but i wanted to show these images of what shapeways calls Grey Robust, which is a FDM machine that uses ABS plastic. I printed mine at school, but its very strong, and this robot, with batteries, was probably 20+ pounds. The blue printed parts never broke.

    For set screws, I just drilled a hole and screwed drywalls screws into it and it held together really well. I dont have pictures of the gripper assembly, but it was also printed on a FDM. I screwed machine screws into it to mount some motors and gears.

    Let me know if you have any questions about this project!
    robot 003 small.jpg

    Bugger, only one file per message...let me know if you want to see a few other pics.
  4. crsdfr
    crsdfr New Member
    It is tappable, but most people go for the methods rawkstar suggested, using metal inserts in a boss or just screwing straight into it. The metal inserts are cheap, and available at any hardware store. Just get a soldering iron, pick up one of the inserts with the hot end of the soldering iron, and drive it into the boss slowly (it will melt in).
  5. virtox
    virtox Active Member Moderator
  6. iguffick
    iguffick New Member
    I've been using threaded inserts for WSF. But that's mainly because I'm using M3 machine screws, so the thread is quite fine. The threaded inserts can just be pressed in if you get the hole size right. If you don't have a press, you can use a bench drill with a large drill in upside down, or carefully hammer them in. You don't need much pressure, the press just ensures they go in parallel.

    See this post for a picture:- mp;start=0&S=de91f4d55740a088dd59281a900a1183

    I would have a fair bit of material surrounding the insert, so that it doesn't split.

  7. CodeCreations
    CodeCreations New Member
    Thanks, everyone. This is great info! :)

    I was planning to actually glue the screws into the plastic pieces -- the threads would be extra gluing surface in addition to resisting pull out. The end result would be like a plastic knob with a threaded metal shaft.

    The inserts are a good idea, though -- I'll have to see who carries them in the area.

    Thanks again! :