As you all by this point know, the core of this design is the notion that the pinball table screen is mechanically actuated to rotate through 90' to be the windshield for cockpit type games.
I've got the axle and the TV mount built, and I'm now working down the long long road of having this actuation work.
The playfield rotation is done by a high speed electric linear actuator pushing or pulling on a long 1/4" spring rod on the TV mount, which accounts for the upper moving ram end of the actuator. The lower end of the actuator needs to be anchored into what is the left-hand wall of the pinball cabinet / the back wall of the cockpit. This needs to be on an axle, since it rotates on an arc, which is parallel with the 3'-by-3' skewed TV axle. Additionally, I know already that it will drive my OCD crazy if the pinball table isn't level, left-to-right, so I want this lower mounting axle to be micro-adjustable vertically to get that position perfect.
The goal is a sliding clamp that bears that mounting axle.
I found a chunk of aluminum in my metal stock that was 0.750" thick, which is a bit thicker than the 0.720" I measure off plywood. It had a few threaded holes in it, which you can ignore - none of them are important to this.
I sawed a bit off it, twice as long as my finished clamp is to be high. Here it is fresh off the bandsaw, clamped in the mill.
Then I used the mill to cut down until I got rid of all the saw marks, because these faces will be sliding against plywood and should therefore be smooth.
Next, I milled both sides of this block, to give it a little bit of a T shape, leaving flanges on both sides. The flanges stay 0.750, aka "thicker than plywood" - and the sides come down to about .710, aka "thinner than plywood".
Lastly, I cut this profiled bar in half, because I need two cores, one for each side of the slot.
Since they were machined together, I know they have the same profile as one another.
Next, I started making the side plates.
I used one big chunk of 1/4" aluminum plate to start, and milled two channels into it.
This produces a piece like so:
This big sheet contains all four of my side plates - I cut this plate into quarters on the bandsaw to liberate them from one another.
(Step right up! Pick a sideplate, any sideplate!)
This completes the rough "build a clamp anchor" kit - 2 cores, 4 sideplates, and 4 1/4-20 clamping screws long enough to reach through the stack with nuts.
From this point, it's a lot of layout and drilling.
I want two screws per clamp, high and low, but the axle should ride lower than the bottom screw. I want the screws to provide the best leverage possible as clamps, so they go right along the outside edges of the cores. The holes in the cores should be snug, but the holes in the plates should be a little oversized to let them tilt freely.
I drilled all my holes, screwed each clamp assembly tightly together over a plywood scrap as a spacer, and then grabbed it in the mill vice tilted at the 3' face angle I want...
Then milled the sideplates and the core together, to make sure they are flush and precisely crooked in the way most everything surrounding the playfield must be.
For everyone puzzled thus far, this shot should explain how the clamps work - this is the final profile:
The [ shaped sideplates each bridge the T-flange on their side of the core across to the plywood on the far side, as the screw clamps the center together. The idea is that I can loosen the clamps, slide the whole assembly up and down to -precisely- level the pinball playfield, and then tighten the four screws and grab the heck out of the plywood to nail the actuator's axle in place anywhere along the slot in the back wall that I need it to fall for the geometry to work.
The faces of the clamps are crooked, because the axle that joins them needs to match the 3' offset of the TV axle above so nothing binds. Also, the actuator body itself needs to fit between these faces, and I didn't leave any more width here than I needed to.
Here's the clamps face to face, in the orientation they'll eventually live in:
I drilled and tapped the angled faces crooked, tapped one side hole, threaded one end of a stainless axle, and assembled it with the actuator so that you can see the goal of all this:
This is the lowest position the actuator could be in, it almost hits the bottom of the plywood slot. You can slide this clamp up from here and bolt it down anywhere along the slot. The actuator body just fits between the clamps. The axle is crooked 3', closer to us on the left, further from us on the right, but level in the slot. The slot itself is crooked 3' in the plywood, counterclockwise from what would be "true" in this view. Those two angles form the same compound 3' x 3' that the TV axle is on, so the actuator should run nicely perpendicular between parallel axles - this one on the back wall, and the other being that rod you've seen on the TV tray mount.
I slipped a spare piece of the 1/4" upper op rod through the actuator, to help illustrate.
There's the actuator with all my custom hardware on both ends.
From here I still need to mount the back wall (removably) into the machine, and build the counterweight arm for the playfield TV, but after those two big projects are done, it'll be time to test motorized transformation and that will hopefully be fun.