the 120V motors were made by merkle and multiproducts. The merkles were on the early games, and some had a smaller shaft diameter. I've seen people use collars to increase the shaft size so it's snug in the larger diameter cams.

the multiproducts motors came in a few styles, but were generally interchangeable albeit you may have to modify the motor mounting bracket to get the gearbox to fit or use grommets/washers to move the motor position so the roll pin hole lined up appropriately. There were also differences in torque and rpm between the motor model numbers/styles, so it's worth trying to get the right one if possible, but don't agonize over it.

the gearbox itself contained grease. Some people use very heavy weight oil in there to quiet the motor, but it will weep out. You'll see some machines with drip pans installed below the motors. Multiproducts recommended a synthetic grease called magnalube.

the blue 3-in-1 bpc recommends in the oil tubes is for the rotor bearings, not inside the gearbox...not that your gearboxes have a removable plug/screw to let you add lube - the merkles didn't and many multiproducts didn't either. The oil tubes just let felt pads inside the bearing carriers get wet. Imho, oiling is not a big deal on these. They are brass sleeve bearings and are self-aligning. If they are stuck in place, they are stuck aligned. The gear on the end of the rotor will wear out before the bearings do if you just hit it with oil every decade or so. Later model motors have no oil tubes for the bearings.

multiproducts has an agreement with pinball resource, so steve young can rebuild motors. Afaik, he isn't selling the parts you need to diy (mainly the rotor and the first reduction gear it mates to). If you wanted to buy enough motors, multiproducts probably still makes them. They used to sell small quantities, but it was too much hassle for them. Pricing for motors from pbr isn't ideal, so it's worth watching ebay for motors - they pop up occasionally...even NOS ones.

your mixer motor is a merkle. If it works (they collared it to upsize the shaft), don't worry about it. Your control unit motor is a multiproducts, not sure what your issue with it is, but it's the correct type of motor for bikini.

to be more confusing ... the motor output shaft fits snugly into the cam next to it and is pinned in place. The mixer/control unit shafts have a ball on the end which can handle small amounts of misalignment. The "non-motor" roll pin goes through the ball to allow some shaft wobble.

just noticed the info on the other thread.

the mixer and cu motor are connected in parallel. They are either both running or both off. If you cu motor is not spinning but the mixer motor is:

- wiring issue ... I think you said you have 120V in the stator
- stator winding/coil is no good - but you measured a reasonably low resistance for it with it isolated/disconnected from the circuits
- rotor wedged in stator hole due to wrong rotor or dried gunk in there
- clutches are stuck
- drag arm cams are stuck

for the last three, those are mechanical issues with the shaft components. As bcp said, spin the fan blade with your finger - game power off. If you can't spin it so the clutches slip, you'll need to check three things:

- if you can't turn the rotor at all, suspect a problem with the rotor/stator
- look at the metal drag arm cams - are there notches worn in the pins sticking sideways out of them, and is a cam wedged in a notch
- if the metal cams and rotor/stator are good, the clutches are stuck and you'll need to take the assembly apart to clean/lube the clutches. Typical symptom here is you can spin the rotor, but it gets harder and harder until you can't move it more, then the fan springs backwards a lot when you let go. You should be able to spin easily until the gear lash is taken up, then it gets harder until the clutches start slipping, then it's constant force to keep turning.

for moving the machine, I used to just crawl under and lift the machine on my back just enough to be able to slide it across the floor. Some of the early games had a thin bottom panel, tho, so pay attention to too much flexing.

Whether the 16 pulse cam next to the motor is from bikini or from a game that matched the smaller merkle motor shaft ... dunno from picture.

if it's small, you can get the right cam off a parts machine or drill it out bigger if you get a different motor. The merkle should work fine tho as long a the shaft fits snugly in the cam.

it's normal for the shaft to droop down like you show. The shaft is supported on one end by the motor and the other end by the black plastic spotting wiper shaft spinning in the hole going through the spotting disc.

when you put the/a motor back on, lift the mixer shaft end to align it to the motor. Notice the notches in the top of the mixer contact plates - those engage a bar above the plates/rotors...that's what will stop you from lifting the shaft if the notch doesn't line up...just turn the contact plate so it does.

I usually remove the bracket from the machine and mount the motor on it, then reinstall the bracket with just the top screw loose. Pivot the motor/bracket counter-clockwise, lift the mixer shaft and swing the motor back down to get the motor shaft into the cam. Install the roll pin, then put in the bottom bracket screw and tighten the top one.

don't worry if the lobes on the two 16 pulse cams are misaligned a bit. Doesn't matter.

assuming there isn't a sleeve on the merkle motor shaft to get the diameter up to 3/8", then your choices are:
- put in a motor with the right shaft size
- find something to increase the shaft size 1/16"- I've seen copper/brass rings that were probably made for the job, wrapping the shaft in aluminum (a cut up beer can) or even duct tape. Anything works since all you are trying to do is keep the motor shaft more-or-less centered in the hole in the cam. A slight wobble is handled by the ball-and-socket shaft joint, but you want to minimize it.

if you do get a different motor, just be prepared/aware that the most common multiproducts motor was the 1124, and it's gearbox shape would require you to cut notches in the bracket you have, and probably add washers to move the motor a little further to the right - the motor was intended to bolt to the bracket through rubber grommets to help with noise, so the motor was shifted right by the grommet thickness and the motor shaft roll pin hole was moved left to compensate.

put another way, if you bolt on another motor and the spotting wipers want to hit the contact plate mounting brackets or mash down on the rivets, you'll need to move the motor appropriately ... many things wouldn't line up quite right between the shaft stuff and the pieces around it (but things still work), but the spotting wipers are the most noticeable and possibly a problem. The other problem would be the mixer rotor latch cams possibly not lining up on the rollers on the latch arms.

if you get a motor from someone like joe shope or another parts machine source, the easiest thing is to get a matching bracket as well.

your cu motor stator looks new. Whether the gearbox was also...who knows.

if someone replaced just the stator, the normal reason for the cooked coil is too much current draw ... the motor will pull whatever it needs to overcome the clutch resistance up to the max the wire is capable of handling, so if your clutches are sticky or the shaft is jammed somehow, the stator winding will get too hot.

you should be able to spin the fan blade - if you can't, don't just swap the motor - you need to fix the resistance problem.

the control unit shaft never spins completely freely because the timer cams and replay cams are not normally both turning at the same time, so there's always a little resistance.

the shaft never stops turning unless the motor power is off.

the normal operating state is the timer cams, replay cams and search wipers all locked, and occasionally a drag arm cam stalling. That's the maximum resistance the motor should see.

when spinning the fan with your finger, it will be easy->hard->in between. Easy is taking up the gear lash, hard is overcoming the clutch stickiness to get the slipping started, and in between keeping the slipping going.

not sure how to quantify the effort required - enough to leave a line on your finger, not enough to cut your finger off?

I was looking at a video of a clutch and plate stuck to a spotting index cam. Couldn't pull the clutch apart off with fingers - had to insert the shaft into the clutch plate and lever the plate off, then had to peel the clutch washer off. The motor couldn't turn that one.

the leftmost metal cam? The two metal cams next to the motor are the drag arm cams. The combination of the pins on those cams and the drag arms varies how long the timer cams spin. See a little video on the bottom of:
https://bingo.cdyn.com/techno/howtheywork/spincycle/dragarms.html

I'd just do it. You're only a few screws away from getting the CU switches out of the way and getting the search wipers / slip ring wipers off. See:
https://bingo.cdyn.com/techno/overhaul/magic_ring/controlunit.html

I guess magic ring wasn't a great example for this procedure. You'll also want to remove the search wiper lock relay from the bottom plate, unscrew the entire slip ring assembly from the search disc mounting bracket, remove the shaft screw and pull off the search wipers (by the arms - don't pull on the hub).

also note the search wipers slot into the search ratchet, and there's a red mark on the ratchet/cams that more-or-less lines up with the red mark on the search wipers. Don't put the search ratchet/cams on 180 degrees off or payout won't work right.

I'll try and screengrab some pictures of this off some video and add it to the above page.

the nut/bolt adjusts the movement range of the relay armature. When the coil isn't powered, the armature should be pretty close to the ratchet teeth, but obviously not touching them. There's a balance here ... more armature movement means more switch blade movement, which is good. Too much armature movement means the wrong ratchet tooth may get grabbed when a winner is detected...bad.

who's been eating the green wire?

sure, your shaft is jammed or the clutches are stuck. The common way to jam the shaft was the drag arm stops wearing grooves into the pins sticking out of the drag arm cams. When the slots got deep enough, the stop could wedge in there. Bally went with a wider stop on the games around the time of the screen games to reduce this.

clutches stuck is way more common. Time to take the shaft apart.

I just posted a bit of a control unit write-up here:
https://bingo.cdyn.com/techno/howto/control_unit/

kinda ran out of steam on the assembly part and no motor rebuilt details, but it's pretty much what you need to do. Let me know what other info would be useful to put there or what needs changing to make sense.

I don't see a need to lube bakelite cams under switch stacks either. The cup-shaped metal cam followers that are riding on the cam edge are already smooth.

the drag arm stops and the metal cams/pins ... a little grease is good and makes it quieter.

'course, bally did say this on an engineering drawing for shutter motor unit adjustments:

"all cam edge surfaces must be greased without excess grease visible on adjacent and cam edges"

that almost makes sense.

the switch stacks on that drawing used the roller pin style of cam follower which would be a little more prone to scraping if the pin didn't roll, but in any case a film of grease won't hurt. Most of the games I worked on had grease on the cams that had hardened to a plastic-like coating. No cam wear there

oops...did you mean you can spin the fan blade and have the shaft turn and the clutches slip, but the motor won't do it?

if so, when you had the motor powered on the bench, did you grab the output shaft between thumb and finger and try and stop it ... you shouldn't be able to unless you have a really strong grip, but you can usually slow it down.

if you can stop the shaft or there's any resistance to turning the fan when then motor is disconnected, time to open the gearbox and see if the grease is hardened or if there's a ton of grease in between the gear faces bogging the motor down.

you can spin the fan and the shaft turns, but the motor won't start with 120V applied directly to the stator terminals...that's fun.

if you put the 120V on the stator and give the fan a nudge, will that start it?

I guess you'll probably swap the motor anyway, so I'd probably pull it out again and see if it will start running on the bench if you hold the output shaft. If not, might as well open up the gearbox and see what's in there.

the only thing to pay attention to is shim washers that may be between the gears. They usually stay stuck to a gear if there's grease in there and you don't notice them until you clean off the old grease. Their job is to center the gears between the surrounding gears.

the original motor on bikini was a multiproducts. The main differences in brackets is whether there's notches cut for the gearbox ears and whether the motor mounting holes are threaded or take grommets.

put the motor on and make sure the mixer rotors aren't jamming against the top plate - the one the mixer contact plates slot into. Also check the spotting wipers clear the spotting disc mounting brackets.

the worst case is normally the the motor wants the grommet style bracket and you need to use longer mounting bolts and washers to shift the motor - and therefore the whole shaft - to the right a little.

The bracket should be the same as the one on the CU, not the older one the merckle motor is mounted on.

I'd still open the gearbox on the current CU motor....it's pretty easy to clean it out, add new grease, and you're good if the rotor and the gear it mates too aren't completely worn.

according to another thread, dennis dodel sent a bunch of those parts to pinball resource, so if they've got them inventoried and are selling them, you can make the motor like new.