I made this for my DR Trimmer 8.75 Pro-XL walk behind string trimmer to have extra line handy whenever I may need it. The one they offer just didn't make sense to me since it's a clear tube and the line is affected my sunlight. This one uses PVC so the line is protected from sunlight.
The purpose of the spacer is to keep the lines from going down all the way to the drain plug and to keep them all even. It's NOT to stop the water so it's like a screen but more durable than regular window screen.
The drain plug is to drain the water out for winter so it doesn't freeze and break the pipe.
The trimmer line is kept in water to keep it hydrated and supple. If you ever had dry line then you know how easily it breaks.
I don't see any reason it wouldn't work with the other DR Trimmer models. As for other brands it would all depend on the size of their bar.
I used 1" PVC so it has enough room to get my finger in to get hold of one of the lines to pull it out. The cap is pushed on. All parts were made with TPU.
Spacer infill was 80% if I remember right (I made it last year) with 0 top and bottom layers so it becomes a screen with 4 outside/perimeter layers to make it strong.
The Cap you want to be a little flexible so it can be put on and taken off and since it's on top it shouldn't leak but you don't want the water to evaporate or for air to get in and out allowing it to start growing in there so 4 top + bottom and 3 perimeter worked for me.
The TubeMounts I did at 80% for long life with enough flexibility to install on the pipe. They are designed to keep the cable ties centered and can be printed as is without supports.