I can see in the console that the element is empty Which leads me to believe I haven't grasped the process of inserting user elements into the shadow DOM. The less than 1k polyfill and the rest is described in this medium post.
I know this didn't exactly solve your issue, but unless you want to wait for all browsers to fix that at least you know there is a standard/better way to extend built-ins.
This is a ridiculously easy (in terms of power tool use - see below) way to make a lower precision XY Table. Tightening the timing belts with screws in wood can be challenging to get just right, but with T-Slot it's very easy.
With the wide availability of T-Slot extrusions on Amazon and Ebay, and using simple home improvement store hardware, this is a great way to build these kinds of projects. This is a second version of a previous Instructable, and is another approach to making a lower cost, lower precision XY table. Here is a list of all the fabrication required: 1) For each of the six timing belt pulley brackets, cut 2.25" of channel aluminum, drill two 1/2" holes (pro-tip: use a step drill), and two 13/64" holes. While the cost is a bit higher by using bearings vs.
Using patio door rollers on an angle is a low cost and easy way to handle what are often complex mechanics on CNC machines. 2) Cut 7" off the ends of two 1"x2" t-slot extrusions. drawer slides, we don't have the drawer slides sticking out like we do now, getting tripped over and caught in bicycle spokes.
:-) The previous approach is working well, but having the ability to easily adjust each of the parts is a great advantage of the T-Slot.
:-) In addition to the T-Slot, we tried to keep the parts easily available (i.e.
From home improvement stores), and as always, requiring the least amount of precision drilling etc.
We've built a lot of projects, and anything that requires a hole to be drilled in a particular spot seems to be hard to get just right.
We do have the tools - punches, drill presses etc., but it's just cooler to be able to use a hacksaw and hand drill!
:-) Here's a video of it in operation during testing: Since a few people have been requesting the stepper code, I have attached what I used in the video to this step - the zip file.
Hopefully it will help, but it is not much, and not well commented or anything.