Tamiya 70171 3mm Shaft Set ball joints

Is there a trick to assembling the ball joints from this set? The instructions imply that they just snap together, but the ball seems too big to snap into the plastic part, at least with the amount of force I’ve been using. How much force is required and is there some trick to doing it easily?

Also, does anyone know the thread size of the 3mm shafts in “english” terms (Unified Thread Standard), such as 4-40, or whatever?



I haven’t assembled this particular set, but I’ve assembled other Tamiya ball joints, and you do have to press pretty hard. If you have the ball end screwed into something sturdy, it’s easier to push against it; otherwise, you might have to use pliers or a little clamp to get the plastic part to snap on.

For a 3mm shaft, there’s usually just one thread size (just like you don’t see much else than 40 threads per inch on number 4 screws), so a standard “M3” nut should do. I think the thread pitch is 0.5mm.

- Jan

Jan – Thanks for the tips. I used a pair of pliers, and that works with some force. --jb.