(Topic ID: 143014)

1967 williams derby day horses dont always reset?

By Foose

6 years ago

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  • 17 posts
  • 4 Pinsiders participating
  • Latest reply 6 years ago by Foose
  • Topic is favorited by 2 Pinsiders


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#1 6 years ago

hey everyone,

i just spent some time rebuilding the horse unit that races across the back box of my 1967 williams derby day...they all work splendidly, but sadly they do the same thing as before i rebuilt it: once every few games some of the horses will not go back all the way to start....its random horses at random times, never anything standard like "#3 never makes it". if i turn off the power and reset the game after they dont all completely reset, every horse goes back to start like they should. ive got the instruction book and various other original resources, and i feel like ive narrowed it down to the score reset relay, which is apparently controlled by the impulse cam on the score motor. unfortunately, my documentation seems to skip right over the exact function of each of the reels on the score motor, so i basically have no idea which one is the impulse cam. any pointers? ive got the whole instruction book and other things scanned into my computer, so if you need or want i can post the whole shebang for your viewing pleasure. everything else in the game seems to operate as designed....or if it doesnt, i have already figured out why and they dont seem related to the horse problem. namely, the replay unit wont cycle down due to a worn armature, but its in novelty mode so it shouldnt matter. i think.

any help is greatly appreciated, thanks!

#2 6 years ago

If the score motor has three cams then the bottom one is the impulse cam. In the older games the the schematic show the switches on each cam.

#3 6 years ago

Score motor switch functions are usually found on the machine schematic.

#4 6 years ago

Foose, what you describe is a little odd. The forward and return motor move the horses. In the return to start position that happens as part of the restart cycle the return motor cycles no other time. It simply rotates the shaft backwards. If the horses are not moving then the cogs are slipping. The grip on the cogs comes from the springs and they can be as you know reduced by the leather washers 'slipping'.

What you could try is to undo the screw to all cog retainers and let them settle equally and reset. If this does not work then think about switching out the springs.

#5 6 years ago


I have looked at you pictures in the other thread. I see something. The cogs are not all the same distance apart so there is different pressure on the cogs. You may have changed this when you added a washer where one is missing.

When I rebuilt my Nags I had the same issue as you for a while. As well as releasing the cog retainers I also aligned the chain at the connection screw as in the act of tightening I twisted the chain slightly, so they were stopping occasionally at the end stop and slipping.

I think it is a mechanical problem.

#7 6 years ago

I ended up completely remaking my leather washers, and one of the springs had broken so I replaced it, but the spring wasn't exactly like the originals so I gave it a little extra length to compensate for the thinner gage wire. I will go back and check out if the washers are slipping or not, and also cgeck the cgains for binding, but it sounds like the return motor just shuts off prematurely sometimes. It will go for 3 or 5 games just fine and then once in a while they just don't come back the whole way....all the horses come back together in unison, so I don't suspect binding, but I will check it out just in case. I also made new felt washers, for what that's worth. All in all there is probably more spring tension in the system now than there was before, but the mech seems to act the same as it did before i rebuilt it.

#8 6 years ago


I was not aware that the motor operation stopped. If like earlier games it just gets power and will run until the 6 th horse closes to shut down power. Look at the schematic and see if this how your game works. The switches are on the horse metal arm the horse rides on. Should be easy to see if an issue. I am thinking it is your motor power through the jones plug. If it does it again this where I would be looking and possibly have a jumper ready.

#9 6 years ago

ill be honest, pinball schematics dont make much sense to me, so i can only say that i believe this is the area of the schematic i should be concerned with...any chance you can hold my hand through whats going on here? i think im getting some theories the more i stare at it, but this is my second pin and im definitely still learning the basics.


#10 6 years ago

so for instance, my total play meter isnt working either, so assuming everything is fine with the meter itself, i should be looking at a pulse generated by the first reel on the control motor, which should turn on when the coin relay is actuated? (of course, i dont have any coin mechs either...so is this perhaps the reason the total play meter never trips?)

#11 6 years ago

hey whose got two thumbs and a working total play meter because he figured out how to read the schematic? this guy right here! it was the switch in the first wheel of the control motor not making contact! man im soooo excited!

#12 6 years ago

The snip it of the schematic indicates the reset motor 14A 7836 is powered when any of the relay switches are closed. The Go relay (game over) or the ball count relay and the start relay. The start relay will not close until the sixth horse is back to the start of the race position.

Look at the schematic start relay and find all the other switches on this relay and confirm they are all correct positioned.

You reference to the play meter is on a different line. It I assume has the coin relay removed so it should not stop the play meter working. Is the coil burned out?

You sure it's not mechanical?

#13 6 years ago

Coin relay is still in the machine, and all of its switches seemed fine, so i checked the score motor and found a switch that was misadjusted. Now the total play meter works great!
And as I was tracing things out I discovered a switch in the impulse cam that wasnt making contact, and now the replay counter cycles correctly too! Which means I'll have to find coin mechs at some point....I'll keep tripping them by hand for now I guess.
The start relay looked OK but I'm going to go over it again in a bit...and I'll probably rip the horses back out and check those return switches... I thought I had them all adjusted properly but now I want a second look.

#14 6 years ago

I can't see how the reverse motor can stop unless the 6th horse has opened the final switch to shut off power, the horses are wired in series so until the last horse gets home the circuit stays open.
Unless the power is cut off by a bad joint. You say that if you set another game it powers up and finishes the horse reset. If the power is lost for a split second then that is it for that reset so possibly it is a bad joint possibly at the switches or motor.....

I think when you look again you will get it this time.

#15 6 years ago

hahahahaha GOT IT!

i checked out the relay, everything looked great. so i started tracing things out, found that i had continuity from the start relay up to the horse unit, so everything was good there....the only thing it could have been was an intermittent connection up on the horse switches....sure enough, one of the wires had broken right at the solder joint so sometimes it was touching, and other times it wasnt! soldered it back together and shes running like a swiss watch now! thank you so much for your help, i really appreciate it! i guess at this point my only other question is about coin mechs...are they all the same? somehow i cant believe they are, but i havent seem much out there other than those standard looking mechanisms from the "coin mech inc." company. my parts books dont cover the coin mechanisms at all...

#16 6 years ago

Well done. I like your dogged style. Suggestion change the title to fixed! People like success stories. Well I do.

Last suggestion is possibly post a picture in another thread title relevant to your rear door mech needs. State the game and the year and it will get sorted out quickly, I think. Mechs are the same generally but there may be other bits missing hence the picture request.

Steve J.

#17 6 years ago

good call, ill get right on it! thanks againt steve, you're the man

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