See if you can find something like this

https://www.bunnings.com.au/craftright-3-piece-screw-remover-set_p6330067

The thread is reversed, so as you reverse the drill the thread end bites into the hole you have drilled

You can try a screw extractor, there may be just enough meat in the screw to bite and remove it.

I can tell you from experience I've screwed a million things up by trying to work on a tiny part while it's still in the game to "save" a few minutes. By the looks of the pic it's pretty mangled. If you could get it on your bench it should be easy to drill it out and re tap it one size bigger. Maybe you could save it with a screw extractor, but it would be difficult in the game. Good luck, that stinks.

Ive had a few of these happen. If you can get a clean hole in the top down close to the shaft contact point, then soak it with a few drops of WD40 or Breakfree with a few layers of paper towels underneath and let it set overnight. Then ...

- try first to twist it out using a small jewelers screwdriver. Might be loosened enough to spin out
- if not, then move to trying the screw extraction tool. There were about 20 different types on Amazon when I looked but, like you said you will need to find a smallish set
- if all else fails, ive had luck by drilling just one 16th smaller than original bolt/screw diameter, then using needle nose and tiny screwdriver to twist the remaing shell/hull removed most times without even damaging original threads.

Tough spot for it to happen but I'll bet you'll sort it successfully

When a screw is damaged or broken I usually start reverse drilling with a left hand drill bit (about ⅔ of the screw size) at low speed with pressure, if your lucky it will grab the screw and turn it out but most of the times it's stuck and won't move.
With the hole drilled in the screw I smack in a torx bit and turn it out which works most of the times, finding out right torx size is the hardest part and it's hard to tell by the picture if you will be able to grab the screw with it, if the screw walls are too thin you may damage the threads on the gearbox shaft.
In case like this with a hex screw I would have tried directly with a bigger torx before drilling.
Edit: The torx bits are usually made of pretty hard material and will break at some point so take it easy and don't use the ones with a hole inside, you'll end up with a bigger problem with a piece of the bit stuck inside the screw
Otherwise I would drill and re tap it one size bigger like suggested by @Shredso, hope it works out for you.

You have to drill it out and re-tap it man that's the only way. You can get an easy out bit, but I'm sure its rusted in there. If you do go that way try using some PB penetrating oil and some heat first you might get lucky. I know Ive done everything from cutting a new flat head notch in the keeper screws to hammering in a torx bit into them to get them out.

I would just drill it out to get it apart and then tap it one size bigger like others have suggested, it will be fine, unless its gonna lower the value cause its not stock anymore.

They do make screw extractors small enough for that. I have a Craftsman set that goes down very small. You can either use a simple screw extractor or something like this that also includes the drill bit in one tool:

https://www.amazon.com/Alden-4507P-Grabit-Broken-Extractor/dp/B000Q60UOO/ref=sr_1_3

https://www.amazon.com/IRWIN-HANSON-Spiral-Extractors-53545/dp/B001D1FXDE/ref=sr_1_18

This is true, I've screwed up and then removed very small screws before. This is your best bet right now.

Wouldn't worry about this. It will just make the next set screw sit more securely. Or you can rotate it so it is in a different position. It's not high-speed, so balance won't matter.

Could you try the torx bit again and instead of just trying to turn it add a dab of crazy glue (CA) on the end of it and hold the bit in with pressure until it stands by it's self. Let the dry and harden then come back with the bit driver and see if you can slowly turn it out. Might sound kind of country but I've gotten alot of busted screws out that way.

Still wouldn't worry about it, but you should start with an extractor either way. After you do one the first time, you'll never worry about broken screws again.

left handed drill bit is what you could try spinning counter clockwise

Forceflow, I would recommend you take the whole thing off the game. Meaning, the POA and the motor all at once. Just unscrew the motor assembly and bracket from the rear panel and remove the mini playfield with the motor all at once. This way you can set it on your workbench and have more control and more space to work with. Then you can try the methods mentioned above to try and get the screw out. I'm restoring my IJ at the moment and it can be done. I recommend you carefully drill it out so you won't damage the shaft.

If its in the right position now a divot wont matter, alot of times when installing a coupler on a shaft I will partialy drill into the shaft so the the coupler cant slide on the shaft out of position, it has a flat on the shaft so you will drill thru the setscrew relieving the pressure before you drill into the shaft.

game is clearly junk now. i will buy for 2 grand. be doing you a favor...

as others have said remove it from the game, get in a bench vice, slowly drill then retap it a larger size.

Hahahaha, I think most of us know this feeling well.

Stop delaying it and get it out of the machine.

No worries Forceflow! Just desolder the 2 motor wires and it should be pretty straightforward from there. 5 minute job.

Get it out of the game, your not going to be able to do anything but damage trying to save 15 minutes.

You've shown that the metal is soft enough to drill a hole in, so you know that on a bench you will be able to fix this quickly.

As others have said; reverse drill bit, if it does not "catch" then just use a small screw extractor.

If that's a #6 then drill and re-tap for a #8, so you've got some meat for the threads.

...you can do it, you can do it......

It doesn't matter man if you leave a divot in the flat part of the shaft drilling it out because a new set screw will seat right in the divot anyways man.

Can’t you do a threaded insert like you had previously (just of a larger size)

You could just cut off the head of the hex bolt and cut a flat head notch in the threads for a screwdriver.

I would go straight to a socket head set screw, no head to deal with

Forceflow, Can you post a picture of what you currently have going on? Thanks

Setscrew for the win.

Those things are hardened better than a cheap bolt

You can buy them at a hardware store, you don't have to make it.