More work on what I've taken to calling the "TV tray", because it kind of looks like
a TV tray, and in my application it is the tray the TV bolts to.
The big plate got 3' right-leaning (from this view) drilled countersunk holes for the brackets, and a 3' clockwise rotated 300mm square of M6 holes for the television to mount to.
I probably made a mistake using this 5/16ths inch hardware in the brackets - you can see the edges of the heads of the hardware touch the edges of the plate. The webs of remaining metal on the outside edges of all the countersinks are thinner than I'd like. It's mechanically sound - even if the webs had blown out the plate would still be pinched between the screwheads - but I think the assembly might actually have been a little stronger if I'd only gone for 1/4" hardware instead. I didn't blow out any webs, but there was some pucker factor toward the bottom of drilling out those countersinks deep enough.
(The screw heads, and the dovetail on the left, all had to be flush because the TV will sit on all of this.)
Next, I took a big file to the end brackets and chamfered all the corners that don't touch the plate, by hand. I like the gleam of light an eased edge can catch. Gave the brackets the kind of polish this whole assembly will eventually get, while I was at it.
I also built the op rod that the actuator will grab; .250 steel bearing shaft, which has a nice spring to it, with domed ends, and crossways holes for what I've always called cotter pins but which I just learned are probably correctly called hitch pins?
The pins sit over stainless washers to protect the aluminum.
This oprod will slide through a bushing in the captive eye on the end of the linear actuator, and being able to slide it out to get the actuator out will make assembly easier.
Looking at the TV tray assembly more from the side,
you can see that the oprod runs exactly parallel to the main axle. (You can also see what I mean about that eased corner catching the light pleasantly, under the axle, now that I've knocked the sharp corner off.)
From the other side,
you can see that the oprod very much is NOT parallel to the plate.
This view also gives a sense of the size of this thing - it is moderately massive.
The playfield TV will extend another 9" or so off each end of the plate, so that's how long the axle ends will also end up trimmed to.
I'm going to cut a few window holes in the plate where air vents existed on the back of the TV so I'm not covering over them, and then I'll knock the unneeded sharp corners off the plate like I did the end brackets. I'll also polish it, just because. This assembly will be visible in the final setup when it's in driving mode if you stand on the pinball side of it. There's about $150 of aluminum here - might as well make it look nice.
I think the next steps from here are going to be making the brass bushing for the actuator, measuring out the exact (complex) length for the axle and trimming it, bolting the TV onto the tray, testing the axle bearing block to TV clearance to see if I have to grind one corner of one block down slightly, and then maybe testing the linear actuator rotating the TV. I may need to build a counterweight to balance the final assembly on the shaft instead of relying on the actuator manhandling the unbalanced weight. It's rated for 22lb, so it might be close enough without.
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