TZ - clock minute hand opto fouling decal plate

[Durzel]

Ello

Spent most of today very carefully and fastidiously disassembling and reassembling my TZ clock, fitting an Ingo clock board, clear clock housing, prototype PETG clock face, lubed the gears, etc.

Everything went well, managed to suss out how to get it bang on 12 (will do a guide at some point). Put it back in the game to test - and whilst it worked the minute hand opto fouls the clock decal plate occasionally, making a horrible clicking noise when it does (not sure whether this is the hand making the noise or one of the gears skipping a tooth)

It never did this previously. The only practical difference is the addition of the PETG clock decal plate, which is not very thick at all.

There doesn't really seem to be any flexibility in how proud the hands sit, in fact there is no adjustment in them at all due to the minute hand pin, etc. The pin is ever so slightly bent - if that matters (I can't see how when it just turns the hand)

Thanks in advance for any help!

 

[DRD]

The tolerance on that minute hand breaking the optos on a twilight zone is extremely right.
And there is usually play in the minute hand, it will probably move in and out about 1mm if you push and pull it along the axel it sits on

Folk over the years have tried all manner of bodges to make sure this God-awful arrangement works. My game had black insulation tape added to the minute hand to elongate the arm that runs between the optos . This smeared glue on the dial !

If your arm is bent, it would probably have been how a previous owner got this to work.

You may be able to insert a washer into the clock mech somewhere to remove the play on the minute hand, then bend it so it works.

Sorry, but for me this was an horrendous trial and error, sink loads of time into it, get very frustrated exercise . I ended up buying a NOS set of gears and that improved it a bit . But my clock still fails every few hours due to the inherent play in the mech

 

[Durzel]

Thanks for the comprehensive reply!

I replaced quite a lot of the clock with NOS (I assume?) parts from Marco Specialities, including the gears and the housing. The only things I didn't change were the backplate (I had bought a new one, but upon disassembly found that the previous owner had glued the non-moving shafts into the housing), the gear shafts and the hands. There was a loose washer fitted to the main shaft which wasn't mentioned in the manual, but doing some research other people have noticed this.

There is - as you say - a tiny bit of play in the minute hand, but it's probably not enough to clear the decal plate in my case. Even from just running the clock for about a minute and the hand getting snagged several times, when I took the clock back out of the machine it has already scored a line around the decal plate.

Apart from that the clock worked perfectly, all the optos registered properly, etc. It was louder than I was expecting it to be - especially given that I put some lube on the gears, but will give it time to settle.

People on Pinside have suggested using sandpaper to grind down the opto interrupter a bit, so I will give that a try.

 

[Sam C]

Trial and error as @DRD says. When I had mine I constantly had a clock failure. Same solution as him, the plastic on the hand wasn't quite long enough to break the opto beam and as such a small piece of black tape on the end to make it longer worked a treat. It seems to be a huge amount of trial and error depending on what the problem is.

Saw the pinside thread and I'd give their solutions a go first as you have seem to have the opposite issue of needing more space!

 

[Durzel]

Yeah. I don't know what the clearance was like before, but when I took the clock apart the standoffs from the clock decal plate just fell out - so I found out I've got a non-OEM decal plate anyway. I have no idea if this is thicker than the standard part.

I can only presume that the minute hand must've been almost touching the plate before, when I was just using a clock sticker, but with the PETG plate this has made the difference between the hand clearing it and getting snagged.

I'm anxious about trimming too much off the opto interrupter, despite what was said on Pinside, because if I went back to using a sticker it might need that extra length. Will experiment I guess.

Is there any (easy) way of running the motor off the machine? It'll be a massive pain in the ass pulling the wires through and installing it to keep playing with it.

 

[DRD]

I would not shorten the interrupters, you are swimming against the tide doing that.

In your shoes I would go for a clock sticker instead of the thicker petg one, to try to address the source of your trouble. I got mine from pinball Heaven I think .

That bloody clock is one of the most hateful things to make it onto a playfield .

 

[Durzel]

I did actually buy a sticker from Marcos before, but I made a right pigs ear of trying to apply it, and ended up ripping it off. Of course like an idiot I'd only bought one - despite the fact I was ordering it from the States and it took more than 2 weeks to arrive.

I ordered another 3 and will try applying wet this time Do Pinball Heaven have the prototype sticker?

 

[Durzel]

And yeah - you're right - it's a pretty intimidating thing. I was really chuffed with myself that I figured out how to get it dead on 12 first time. The instructions aren't the clearest, I don't think I would've had a clue what to do without following various guides, etc.

 

[Durzel]

Another quick question - is oil on the shafts necessary? It didn't occur to me to put some on there. I did put a very small amount of the stuff everyone seems to recommend (this stuff) on each of the gears mating points.

Because I have a bit of an OCD I'm wondering now whether I should've oiled the shafts as well, and pondering taking it all back apart again to do it...

 

[Deleted member 2463]

if it aint broke...