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JD Planet Motor

O

orchid

Registered
10 Years
Joined
Apr 18, 2012
Messages
57
Yet another problem with my JD... Spend the last day taking most of the machine apart to clean and put back together. That all went well, and just as I was playing my first game I had a ball that was heading towards the lock, but it slipped out past the planet (PF newly waxed and moving quite fast) and back onto the PF. Since then, or perhaps just before (within 5 minutes of me starting playing again anyway) the planet slowed to almost a halt, and has now stopped and refuses to move at all.

Massively frustrating, as what I've read seems to suggest this is a $200 fix, for something that was working perfectly before I cleaned the machine (and I didn't even touch the motor assembly...).

I don't know what to do, and I can't even get the motor/gearbox off the machine as I can't seem to detach the globe from above the playfield. From what I can see, all the gears visible from outside the gearbox are all turning, and the globe itself can be turned manually, so I'm not sure what the problem is.

Any advice on how to fix, or at least take it apart?
 
Here's a post from someone with a similar symptom, with pics: kcpins.com/archives/720.

I had a similar symptom with gears slipping round a shaft on a Dr Who motor, and had to solder the gear to the shaft like this guy did. For my DW, getting the gear box apart involved drilling out the rivets, then I bought appropriate nuts and bolts to put it back together.

Not sure how you remove the gear box on the JD though - sure someone else will be able to help. This is the manual, page 2-27, if it is any help: http://www.ipdb.org/files/1322/Bally_1993_Judge_Dredd_Manual.pdf
 
Thanks JT - I was having a look at that page, but I guess the first problem is getting the gearbox out of the machine. Frustratingly the manual isn't a huge amount of help (there's no visible way of removing the metal plate below the light assembly to get access to the lockwasher or nut below).
 
It's been a while since I looked at a JD, but I seem to remember you unscrew the top half of the deadworld to access a few screws in the bottom half of the deadworld... I think once the bottom half is out then you can gain access to various bits...

Good luck... although I wonder if you're being a little too hasty and that there maybe a simpler answer that's been overlooked... eg have you checked the wiring for continunity? Are the correct voltages present to operate the motor, etc...?
 
Thanks - I don't think there's any problems with the wiring since the motor works fine and the gears rotate - up to a point.

Here's a video which should make things clearer.

[video=youtube;mKK9Vm5SjVE]

All the gears are turning, apart from the one at the back, which will turn when I manually rotate the planet (which I do a few times in the video). I think that fits the detached gear scenario.

Just need to get some additional tools to remove the gearbox from the machine, and then to see if I can drill out the rivets to get inside.
 
I can't quite believe I managed it, given my lack of metalworking experience, but I got the gearbox apart, added some supporting pins between the freespinning gear and a working one on the same spindle, cleaned the whole thing and put it back together (having sanded out some gaps for the bolts that replaced the rivets I drilled out). Working a charm now!

I'll post more thorough instructions about how I took it apart later, since I had trouble at first myself.
 
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