Pre-threaded screw holes(!) in a 3D model

[bbussey]

Have you tried printing them vertically, as would happen if you are printing a car vertically? I don't think the slicer would necessarily add any supports in there, nor should there be need to.

The coupler adapters were printed vertically. I’ve printed additional models since horizontally and at an angle. So far, no issues.

It's an amazing possibility. I have to wonder how long the printed threads will hold up, especially if the screws are taken in and out. I have the same type of concern about wear resistance for gears that are 3D-printed.

I would think no different than if blank holes were threaded with a physical tap.

[Chris333]

So you're telling me I need a DLP printer 

[garethashenden]

It's an amazing possibility. I have to wonder how long the printed threads will hold up, especially if the screws are taken in and out. I have the same type of concern about wear resistance for gears that are 3D-printed.

Rich K.

I think the choice of resin would be a huge factor. Some are far more brittle than others.

[dem34]

@dem34

Regarding Fusion, did you simply use the out of the box library for creating your threads, or did you end up doing something like mentioned below with the die threads? Did you have to do any cleanup or did it work fairly well? Last, was it a through hole or a blind hole? I plan on experimenting with the much smaller 2-56 and 00-90 but the ideal would be blind holes.

Used the built in functionality. It was FDM with a fairly chunky relative size bolt so it was cleaned on the first screw in. And it was through. Didn't do a ton of experimentation with it since I felt it was overall easier to just do what everyone else does  by drilling a hole in a 1x2 and smacking in a T nut.

[samusi01]

Thanks. Some experimentation is in progress.

[nkalanaga]

For removable parts, that's a good question.  Trucks and couplers aren't removed very often, so the threads should last for years there.

[JeffB]

It's an amazing possibility. I have to wonder how long the printed threads will hold up, especially if the screws are taken in and out. I have the same type of concern about wear resistance for gears that are 3D-printed.

Rich K.

I wouldn't use 3D printed gears in anything that gets a lot of run time, at least 3D printed resin.  Nylon gears printed with an FDM printer might be different though, but then you have to contend with the surface roughness you get on cheaper FDM printed parts.

It's rare that I've stripped threads in form threaded 3D printed parts, usually only after I grossly over tighten the screw.  The bigger issue is not having enough "meat" around the tapped hole.  This often leads to the material splitting around the hole.

Very interested in trying 3D printing threads, though I don't see how it'll work on resin printers, for the 1 and 1.2mm screws I use most of the time.

Jeff

[draskouasshat]

Fusion360 has the capability as well but i haven't tried it yet.

[samusi01]

First attempt - used Fusion's native 2-56 threads, the 2b variant in an NSH90 deck. These were very tight, even after trying - carefully! - to enlarge with a 2-56 tap. I need to go back and try 3b as that looked like it might make a very slightly larger diameter hole. I also intend to try offsetting the faces to see if I can get a even larger diameter to work with. Next up: tweaking the 00-90...

[bbussey]

I’m still tweaking also, but this concept definitely will work. I have the pre-tapped holes perfected for #000-120 but still trying to perfect #00-90. The smallest size that comes with SolidWorks is #0-80 so I had to create the tap profiles for the smaller sizes using engineering specs. I know I have the thread specs correct. It’s the diameter that I’m still tweaking.

[bbussey]

I’ve perfected both the #00-90 threads and the M2x8 threads. SolidWorks allows you to create threads for both dies and taps. I was using the die template instead of the tap template. Once I switched to tap and created the new parameters there, everything fit.

I’m using #00-90 for embedded MTL coupler boxes and for fastening parts together that I don’t want to cement. The M2x8 is the Kato vintage truck bolster screw, and I’m going to adapt that concept for MTL heavyweight trucks on 3D printed models.

[nickelplate759]

@bbussey  Is the 3D print that you are showing the 00-90 screw in a Solarium car?

[bbussey]

It is a New Haven "Flying" series obs built for the Yankee Clipper consist.  It's all but a solarium car in name, but it includes a very short porch and NH did not consider them to be true solarium cars.