If you don't have a socket that fits that you could use a breaker bar or big ratchet on. I'd clamp a small vice grip on it, and a big vice grip to that, and crank it. And hope you don't break it off.

LTG : )

Those square-head screws are not original.
I'd let some penetrating oil do it's job for a while before attempting to remove them. I'd say the possibility of breaking one off is high.
Good Luck!
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Your "set screws" are square-head. OEM screws were either hex-head or, later, allen key. The hex-head set screws were too easily snapped off which causes a huge problem. It is my theory that Gottlieb transitioned to allen key screws because you can't snap them off.

I wouldn't be surprised if those screws aren't set screws at all but instead something a prior owner had laying around and came in handy.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

BTW, those flipper mechs are far superior to the mechs that "should" be on the game.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Opinions vary on that. Those linear assemblies can lack feel and feel clunky at times. Harder to rebuild than the generation before them too.

I concur those are not original setscrews. Get rid of them

I've never seen square head screws on a Gottlieb flipper assembly. What should have been there is Allen socket head screws. Before the Allen heads were decided on, Gottlieb was using some chintzy hex head screws which they over-tightened at the factory. When you needed to remove them, the heads snapped off!

If they snap off, that's when the fun begins. Not too long ago on a EM Bally I had to break out the angle grinder with a cut off wheel and totally cut off both flippers mid shaft destroying the cranks in the process. Shooting a ten foot shower of sparks should never be part of a flipper rebuild!

4th of July!

You could try heating it with a heat gun on low power, or a hair dryer. It might have Loctite on the threads that may soften after heating. Be careful not to melt anything in the area.

Look up "8 point socket" for use removing square bolts. Sears even sold them at one time.

I can confirm they are suppose to be Allen head, just rebuilt flippers on a 1986 Gottlieb last night.

As someone said earlier I'd just spray PB Blaster on it and then give it a turn in an hour.

My 76 Volley has the hex head screws as well as a friend's Joker Poker so the use of Allen heads was not the only thing out there.

Your explanation is how I learned to set this style of flipper up. The flange of the flipper shaft sitting on the top bearing/bushing.

The crank arm is then clamped to the flipper shaft without contacting either the upper or lower bearing/bushing.

I have found the flipper bat covers close to the playfield also. My solution is to take the bottom edge of the flipper bat cover to a sanding block and remove some of the edges that extend close to the playfield. You can easily take 1/32+ off and make it a comfortable clearance.

If the hex head does snap off what is the best way of getting the rest of the screw out of the shaft because i am working on a machine that needs a flipper batton changed.
Raff

You could try vampliers if the threads have some movement to them.

Or, cut a notch in the screw and try to use that to help turn it.

Have cut a notch with a dremal but no luck its too tight.
Raff

On my Gottliebs I used a standard credit/bank card slid between flipper bat and PF then tighten my shaft screws. I have a gap of about 3/16 doing this and I think it keeps every thing at the same height from flipper to flipper.

Looks like you may be closer to using my method.

000cutoff wheel (resized).jpg

Drill out the broken piece and plan on getting a new flipper bat and maybe lower piece. Less chance of debris flying than grinding.

That is what I have had to do several times on Gottliebs which had the hex head screws. I end up destroying the shaft, pawl, and bushing.

Waste of time.

LTG : )

PB Blaster, then let it set for 2-3 hrs.. Come back wipe it down then heat it with a blow dryer before you try to break it loose. Don't use any type of flame as PB is highly volatile. Also you don't have to spray it on you can spray it in a cup and then use Q-tips to apply.