Again, my opinion as both a practical technician and a practical routine engineer (ships and aircraft)(OK, scoots, too!), Hypo is a good guy and is right on with an over-engineered suggestion.
It was so far outside what I was expecting that I didn't see any of that.
Ooops.
I would also tell him to pack sand, I ain'T sinkin' this thing inna bathtub! (Humor intended!)
You go ahead. I'll watch. Popcorn anyone?
So, you want a nearly 1/8" hole not quite 1/2" deep threaded? To answer your first question, there are no specs on materials that I know of available to us. It is like pulling hen's teeth to get ANY answers to our normal questions from either the dealers or Kymco USA.
This I know, which is why I asked here. I figured someone might have an idea, and it would be easier to get an understandable answer here, than from Kymco.
Second, threads in anything other than steel are likely to pull out and a thread insert like Heli-coil (lotsa other brands today for the same thing)is the superior solution ESPECIALLY if this stuff is like fiberglass or other non-metallic structural material.
My intention is to use a self-tapping machine screw. Drill a pilot hole as big as the shank of the screw, and let the threads do the biting. With a little Loctite for good measure.
The neat thing is you want to drill an original hole in something rather than enlarging an existing hole. Enlarging an existing hole with the odd-sized twist drills supplied by the coiled thread repair kit is TOUGH because the drill wants to grab a huge bite right off! So, OK, you get to drill an easy hole then tap it for anchoring a bracket, right?
Right.
Here's what the bracket looks like:
Where the bolt in the center is located, is where the self-tapping, self threading screw will go.
You will have to finish tapping the hole with a bottoming tap. This type of tap will be available for any standard SAE or metric thread.
Now the question: Could you use a deeper or a through hole?
What are you gonna mount with this bracket?
How heavy is this mounted thing?
I don't know about a through-hole. I think that would weaken the grab rail far more than a little bitty hole. I also don't think I could do a through-hole there, without going all the way through to where the seat is. So probably not.
This is what's being mounted:
It's dimensions are 2.26" W x 1.2" H x 0.875" D
It can't weigh more than a couple of ounces. I say this, because it hasn't arrived from Fleabay yet.
My thought was to get one of those self-tapping sheet-metal screws and just attach the very light, thin aluminium bracket (with a thin neoprene foam "gasket" between) straight to the grab-rail. With a little Loctite (or maybe epoxy) for good measure.
In this location:
It won't ever bear any weight, it isn't in a location where anyone can inadvertently grab it, and it really doesn't seem like it's going to cause any difficulties being where and what it is. I had something similar on my Honda, except it was attached to the Tupperware, because there was a convenient place to do it.
So, I need a little-bitty self-tapping, self-threading screw to attach that thin aluminium bracket (less than 3mm thick) to the as-yet undetermined metal of the grab rail in an out-of-the-way location.
Then, mount the light to the bracket, and wire it into the brake light, so that it's only on when I have the brakes applied.
Furthermore, I have one of those little modules to wire in where it strobes 5 times, slow-blinks 5 times, and then stays on.
It gets attention even in the daylight.
