Ok group while I am definitely new to this hobby...

Apparently an inherent problem is with the arms and the ball pivot joint as you go up
to the top near the blades. Usually solved by replacing with HM-22E-Z-38 .

As a possible fix.... I have this solution... although I did see on the thread make one out of brass of sorts.

I have used this technique on other plastic parts that a weak post or pinion...
and obviously the little ball on the arm falls into that category.

Soooo.... what we do once the ball has broken off, usually left in the figure eight piece
is insert a wire brace into the ball, push the ball and wire brace through the arm, and
secure them.

Suggestion 1.) when trying to remove the broken ball from the figure eight put a large
white sheet on the ground, so you will be able to find it if you lose control over it.

Now... what we use as a wire brace is a thin small sewing needle.
First nip off the fat end where you would put the thread.
Clean and sand (roughen up) the needle.
Hold the plastic ball in a device that is secure but doesn't squeeze it to death.
Put the needle in some thing... a vice, you third hand device or what ever that can take
some heat.
Make sure you have most of the needle... cut off end that has been roughened up out.

Now heat up the needle in the middle, shove into the ARM, not the ball, where the ball
was broken off. You are essentially drilling a hole with the hot needle.
DON'T twist the hot needle around, go in and out quickly, so you keep a tight fit.

Now the hard part. is you are going to do the same thing with the ball, but you will now leave
the needle in the ball.
Clean the needle if it has soot on the end. If it has melted plastic on it, that might be ok.

Secure the needle in a device, and the ball into another device.
The trick is heating up the needle and then moving quickly it into the broken end of the ball fast
enough that you can penetrate deep into the ball before the needle goes cold, and loses it's
drilling by heat process.

The idea is heat the needle, stick, it into the ball, and leave it in. With the heat, it will fuse into the ball.
You don't have to be dead on... you will see from the picture mine is crooked.

Clean (sand) any soot off the need in preparation for gluing. Sand BOTH sides of the arm where the ball used to
be, where you heat drilled the hole previously so the glue will stick.

Stick the ball with it's now fused in needle through the arm, halfway.
Put some glue on the needle on the side of the ball so when you push it completely through
hopefully some glue will go into the hole.
Push the ball down snuggly on the arm, add some more glue around the base of the ball (I used toothpicks)
Place some glue on the opposite side of the arm so the needle sticking out will have "cap" of glue.
Snip off the excess of needle once glue has completely dried

I used 5 minute epoxy because it wouldn't drip too much, and as it dries you can work it around the joint.
Obviously don't work the unit too much because the initial set up is important.
When you snip off the excess needle wait until it's all fully cured. Although it is 5 minute expoxy, I would
give it over night to fully cure. The longer the better.

Well I haven't tested it yet.... but it really isn't too hard to do. And as long as the glue cements well the
needle post should be quite strong, and relatively light weight.

Here's the picture... it's not pretty but my experience on other plastic projects using the heat needle fusing
process has worked without glue.

Wish me luck as I fly tomorrow and I let you know the end result.
If you could find a way to heat the needle up, as in a soldering iron, you could insert the needle
into the arm backside, before use of a fresh unit, and a fresh unit would now be steel reinforced.

Some filing off of the glue around the ball so the figure eight connector fits properly might need to be done
once the glue has dried completely.