Engineering help needed

[Cobrajet]

What's the cross section dimension of the square shaft?

I was think'n something like this...in stainless, of course...

It's a standard 5/16" square rod. Your idea is ideal, however, I don't happen to have any of those in my junk box.

Kinda hard to tell if the "threaded weight" is supposed to attach to the bottom of the silver/chrome cylinder (with loop) or what.
Clamp sounds like a reasonable option
Obviously drilling/tapping with a stud is an option.
I'll also tell you that I've found (and used) a 2000-deg adhesive in the past. You could fill the cylinder if it's suppose to wrap around that square peg.
http://www.cotronics.com/vo/cotr/newprod.htm

The "threaded weight" is not a weight. but more of a threaded "stop" to be used with a screw-on handle found on many spits. My rod is not threaded, so I can't use that part. I do have a set of dies, but my rod end sits in a cradle, so attaching the counter weight to the end is not an option. It has to be inside the grill, close to the bird. I do need some kind of clamping hardware, but what and where. I have some ideas I will try to post later.

Why do you need the counter-weight at all??????

Turkeys are very hard to balance, and also tend to move around during cooking. My last two attempts have resulted in stripped gears and/or failed motors leading to brurnt turkey! Not good.

Just run a Google image search for "rotisserie" and "counterweight" and you'll surely find enough visual examples to figure out how you can utilize the pieces you have.

I did that and found no one using this style counterweight without the screw-on handle mount. I need to improvise.