# Determining pivot point for arcade cabinet lid

I have been constructing my own candy cab-style arcade cabinet, modeled after the Capcom Q25, that has the ability to rotate the monitor so I can play games in both landscape and portrait orientation. Because the cabinet needed to be a specific width (to fit in the house, for the most part) I need to have a similar lid mechanism to the Q25 so that the monitor has enough space to rotate, so it needed a lid. This is what a Q25 looks like with it's lid open:

and you can see the lid/monitor rotation in action here (YouTube link).

My cabinet is not nearly as fancy, but I desire a similar lid mechanic. Where I'm running into trouble is figuring out where to place the pivot and how the pivot should operate so that the sides of the lid don't bind against either the bottom or the top of the cabinet when it opens. The Q25 has a mechanism that I can't quite make out how it does what it does, there's no schematic. (This YouTube video has about the best shot of it I could find).

I don't have a fancy model (Fusion360 has a lot of buttons) but I do have a basic drawing of the problem.

The red section is the lid and the black gear thingie at the top is a possible pivot point. If it's very close to the lid and towards the front, the top of the lid clears nicely but the bottom (as seen here) binds.

Alternatively, if I put the pivot closer to the middle of the lid, the bottom clears fine, but now the top of the lid binds against the top:

I understand that cutting the wood will create a gap and that there won't be zero tolerance between the lid and the frame (even the Q25 doesn't have that). What I'm looking for is help understanding how one determines what to do here. What math/geometry/tools I'm missing that I can learn. Or if there are mechanisms similar to what the Q25 uses that I could study and use to inform how to proceed here. I just don't have the experience/vocabulary here to know what to ask for next.

• Well, consider changing some of your shut angles so they don't bind on opening / closing. Then consider some "hinges" which rotate about a virtual centre - perhaps like a curved rod running in a curved tube. Commented Mar 20 at 5:59
• I have considered removing the angles altogether and make them circular, but it kinda looks a little odd to me. Haven't ruled it out yet though. I also have a hard limit on the space in some dimensions (monitor size, cabinet size) so changing the angles can be tricky. Can you tell me more about the curved rod/tube approach? I'm not sure I'm visualizing what you mean. Commented Mar 20 at 6:09
• It looks to me like a regular door hinge at the top edge. The bottom is a loose fit so there is enough clearance for the problem corner. Commented Mar 20 at 9:41
• I'm not sure it's a door hinge. From this video: youtube.com/watch?v=bgnom4F0MUg&t=617s it looks like there's a downward tab that extends from the lid and the hinge-looking things are attached to it? Via a rod or bolt that goes through them? It's not clear to me if the hinge-looking things rotate at all. Commented Mar 21 at 4:52