(Topic ID: 204073)

Tech: GTB Sky Jump ball count unit (stepper) teardown & rebuild


By spinal

1 year ago



Topic Stats

  • 68 posts
  • 10 Pinsiders participating
  • Latest reply 1 year ago by spinal
  • Topic is favorited by 6 Pinsiders

You

Linked Games

Topic Gallery

There have been 109 images uploaded to this topic. (View topic image gallery).

image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg
image (resized).jpeg

You're currently viewing posts by Pinsider ajfclark.
Click here to go back to viewing the entire thread.

#7 1 year ago
Quoted from spinal:

Of course, as always, your comments and suggestions are greatly appreciated!

I think one of the most important parts of the page you linked should be highlighted:

WARNING. This shoulder bolt has a nut on the back side. If this nut is not removed, and a big screwdriver is put on the shoulder bolt to turn it, the shoulder bolt will shear. This renders the shoulder bolt useless. If this happens nothing short of ordering a new shoulder bolt from Pinball Resource (part# a1059) will fix the problem. So the moral of this story is to first remove the nut from the shoulder bolt before removing/adjusting this bolt. (And even then during nut removal sometimes the shoulder bolt still shears.)

Before disassembling the whole unit, I would loosen that shoulder bolt, clean the pivot point (http://www.pinrepair.com/em/gtbcred1.jpg), etc and make sure the lever moves freely. I've found a lot of steppers that were completely non-functional only needed a bit of care at that one point.

#12 1 year ago

If you are stuck for a replacement, in the past I have machined down a case screw from a PC using a drill and a file. Not pretty, but did the job.

20pcs-Desktop-Computer-PC-Case-Thumbscrews-Thumb-Screw-6-32-Black-Metal (resized).jpg

#33 1 year ago

You're not the first, and won't be the last. You may also have found it sheered off anyway. I'm sitting at 50/50 over 2 machines on that nut sheering the bolt.

Here's a pic of the quick replacement I made from an old PC case thumb screw:
16123238_268544953558420_436900583203405824_n (resized).jpg
The shoulder was marginally too big so I put it in the drill chuck and filed it down a bit.

2 months later
#51 1 year ago

Whilst slightly overkill, this thing is going to end up better than new. No grease to go hard and gum things up for a start.

#67 1 year ago
Quoted from spinal:

Question: does anyone know where one can buy the black fabric wrap that covers flexible wires seen above? (PBR does not sell)

It's just cotton isn't it? Could you use a round shoe lace? Otherwise I'd be looking for spaghetti insulation like this maybe? https://www.tubesandmore.com/products/spaghetti-old-style-white-20-awg

Promoted items from the Pinside Marketplace
$ 399.95
Wanted
Machine - Wanted
Tabor, NJ
$ 20.90
Apparel - Unisex
Bright Lights Pinball
$ 29.95
Gameroom - Decorations
ULEKstore
$ 7,500.00
Pinball Machine
Nitro Pinball Shop
$ 48.00
Cabinet - Other
ModFather Pinball Mods
$ 149.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 79.00
Cabinet - Shooter Rods
Super Skill Shot Shop
$ 49.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 149.00
$ 65.00
Cabinet - Armor And Blades
Texas Pinball
From: $ 218.00
Lighting - Backbox
Lermods
From: $ 5,599.00
Pinball Machine
Great American Pinball
$ 19.99
From: $ 9.99
$ 7,999.00
Pinball Machine
Little Shop Of Games
$ 19.95
Playfield - Toys/Add-ons
ULEKstore
$ 144.00
Lighting - Backbox
The MOD Couple

You're currently viewing posts by Pinsider ajfclark.
Click here to go back to viewing the entire thread.

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside