So I thought this will be a good test bed to try my magic wand/soldering iron on, modified the vagina to fit a North American, and fell in love with her all over!
Anyway, right arm rotation, get a bunch of play, I know what's happening, I already performed an exploratory surgery on the leg to see what it was.
Turns out that the rotation joint is fine, the other end of the "bone" has a 10mm nut welded to it that is threaded on a rod end and all there is to hold it in position is a tack weld, since the threads have play, moving the joint around puts incredible stress on that tack weld and it will fail shortly.
Since she is so beautiful (she's the one front and center in my avatar) I pondered ways to fix her, even had a bourbon induced notion to take my TIG welder to her! Thankfully I fell asleep. Woke up and I came to my senses and came up with this fix.
Something like a Christmas present to her!
I should make clear that I do this sort of stuff for a living doing high-end machining, so it is natural for me to do this kind of thing like walking, so if you've never broke a tap off in anything before, you surly don't want to do it here. I suggest you get some practice!
You've been warned.
Tools needed:
11/64 drill bit
13/64 pilot point drill bit
6mm x 1 tap(s)
Tap Handel
Variable speed drill motor
Scissors
Red Loc-Tite
Gauze
TPE glue
Bench grinder
- Step 1, cut her open! I made a small incision at the underarm to gain access to the problem.
Here you see the nut which is NOT supposed to turn on the threaded rod.
Annotation showing the mission is in orange. - IMG_2539.JPG (565.75 KiB) Viewed 1988 times
- Step 2, pilot drill a smaller hole first, I used a 6mm tap and 13/64 drill, but I first used an 11/64 to start.
The idea is to get through the side of the nut and a little into the threaded rod, around 1/16 or so.
You can use a plastic tube of some sort to keep the drill from winding the TPE up.
Try to drill as straight as possible.
And when you get through to the rod you need to keep it stationary as you drill.
I used a pilot point drill. - IMG_2562.JPG (841.9 KiB) Viewed 1988 times
- IMG_2563.JPG (610.54 KiB) Viewed 1988 times
- IMG_2546.JPG (806.15 KiB) Viewed 1988 times
- Step 3, tap the hole carefully, this is going to require a bottom tapping operation, you can get specific bottom taps, but if you ask for one at a hardware store they will look at you funny.
What I did is grind just the point off, start the thread till it just bottoms out, then grind a little more off and repeat,
It gets a little tricky when you completely ground off the taper, you will need to relieve the cutting point, and not leave a thin piece to break off, also you have to be careful not to burn the tap up as well when grinding it!
Use a tap handel!
The last photo shows what the tap looked like when I was finished. - IMG_2564.JPG (1.23 MiB) Viewed 1988 times
- IMG_2558.JPG (1.75 MiB) Viewed 1988 times
- You should have a reasonably decent threaded blind hole, when tapping you will have to make sure you get as much down into the hole in the rod, you may have to "feel" for it.
- IMG_2559.JPG (455.8 KiB) Viewed 1988 times
- I used a button head, better than a sharp square cap head, you want to make it flat on the end, this is why I used the pilot point drill, if you use a regular point drill, and point the screw, rotational force will try to push the screw out, if you have a flat bottom it's much better.
Even better is to get the threads into both parts.
Loc-tite the screw in and your done!
Now your ready to start carefully cleaning the hole and re-gauze, test the joint first before committing to sealing it up. - IMG_2561.JPG (820.65 KiB) Viewed 1988 times
- IMG_2565.JPG (1.86 MiB) Viewed 1988 times
