3D Printing Forum

Hi all,

I have a couple of 3.5mm audio jack plugs here where the plastic cover is so brittle that it breaks into pieces on the first touch. Since these covers are not too complex, I had the idea of printing new ones. The only problem is the thread that connects the metal part of the plug with the plastic housing. I have no idea what thread size it could be as it seems to be a non-metric thread. The outside diameter of the metal thread is 0.3 inches, the inner diameter seems to be something around 0.285 inches. Under which name could I find such a thread in Fusion 360?

Best regards,
Reiner

Hi Reiner
I have been "searching" threads before and tried to replicate them in F360. If it really is a non standard thread, you can create your own ... but anyway you will need to know the pitch. It's actually preatty easy to measure normaly, but as yours is rather small, probabyl not so much. I would just take one that is pretty close (a bit bigger) and then try. Threads with this size are hard to print (shrinks to much). Try and error is your friend...

Martin

I ran into an issue like this and wound up buying something like this

Yes, @martin-bienz, the lenght is a problem there. The whole thread is only three turns. I am tempted to print the part in PLA without threads and then heat up one of the plugs and screw it into the plastic. That might be easier than spending a lot of time on finding out the correct thread size.

Maybe you can replace that screw with a metric one that is close enough?

You could use threaded inserts for the plastic parts. The inserts have larger holes and wider threads which makes them much easier to fit into the plastic than getting the thread itself into the plastic. The result is also much, much stronger than a tiny thread in brittle plastic

Threaded inserts will not work in this case I think: I would like to create a spare part for the black cover.

first thing I would try, 2 part ninjaflex / pla piece that can be glued (or even screwed, snapped) together. Like you would cut the old black piece in half. Fun to create this!

What about M6x0.5?
(Form here)

They are not all the same, but most are, and you can check if it makes sense on yours

Edit: my bad, I looked for 2.5mm yours is 3.5mm

reibuehl wrote:Hi all,

I have a couple of 3.5mm audio jack plugs here where the plastic cover is so brittle that it breaks into pieces on the first touch. Since these covers are not too complex, I had the idea of printing new ones. The only problem is the thread that connects the metal part of the plug with the plastic housing. I have no idea what thread size it could be as it seems to be a non-metric thread. The outside diameter of the metal thread is 0.3 inches, the inner diameter seems to be something around 0.285 inches. Under which name could I find such a thread in Fusion 360?

Best regards,
Reiner

Hi all
Hi Reiner
A customized metric thread D 8.26 x 1mm pitch works well
here a direct download link for the STL and STEP file of the 3.5 jack plug cover

http://www.casimages.com/fd/PKKeYPwRuj48wur



print with 0.4mm( max) nozzle & 0.1mm layer

Hope that helps !

I tried the M8x0.75 that is used in the 3.5mm version of the manufacturer that @Amedee found and I tried the 8.26x1 that @gudo suggested, but both do not match. I think I will use that design without a thread and then use the heated plug as a "self-tapping" screw

reibuehl wrote:I tried the M8x0.75 that is used in the 3.5mm version of the manufacturer that @Amedee found and I tried the 8.26x1 that @gudo suggested, but both do not match. I think I will use that design without a thread and then use the heated plug as a "self-tapping" screw

I have one 3.5 jack plug under hand and it seems the same of yours shown on the pic you posted
I print a test before share the files, I had just to screw easely with the the fingers..

when seeing your pic, the thread of the metal part is very deformed, may be the problem is here !?

Print it in PLA, then dip the end into hot water and screw it on. Hey presto, thread. Will take a couple of goes until you get it right, probably.

yes