Rowe 1100 mech stopping switch gear microswitch replacement

[Marcel Bogert]

As many of you know when working on the Rowe 1100 mechanism microswitches are giving more and more problems.
Replacing them is the best option as they are cheap and will help get the mech much more reliable (do not try cheap chines knock offs and use the right switch pressure)
The service manual will help adjusting everything so far no issue's.

Because microswitches will sooner or later go bad on the stopping switch gear replacing those will also be needed but here is were it get's uncomfortable.
I've seen many times instead of replacing the microswitches folks start playing with adjustments or even the stop screws that are factory adjusted.
Getting the basket to stop at the right record is now in jeopardy.
Especially when selecting both the A and B side of the record.

The machine i'm working on at the moment has the following issue:

Magazine motor moves the mech to the selected pin.
Attempts to stop at this locations but does not causing the stopping arm to skip over the selected pin (and end up in the wrong position)but does detent 1 or 2 positions away from the selected record position.
Skipping over the selected pins is actually a built in safety feature to prevent damage to the stopping switch gear unit and other parts.
Basically the magazine motor does not stop in time.

I've checked the detent wheel as these tend to go bad, seems OK.
I've checked the stopping microswitches are OK.
Stop screws have been messed with on this unit but was able to get the machine working after spending some time adjusting these 2 screws.
After playing dozens of records not a single failure but issue has returned.

Obviously a microswitch can be intermittent but my suspicion is those stop screws that are factory adjusted are not adjusted properly.
Any one know how those 2 stop screws were adjusted at the factory or have a reliable method for adjusting these.

[Ron Rich]

Hi Marcel,
Is the motor that drives this unit an AC "fly clutch" unit. If so, is it oiled so that the armature is instantly, dis-connected, from the gear train, when power is turned off ? Ron Rich

[jukenorman]

There's also a detent assembly associated with the magazine motor that might be sluggish in its operation causing overrun?
Norman.

[Marcel Bogert]

Hi Ron,

the magazine motor is a separate motor than the one that drives the actual mech and cam switches (which has the fly clutch)
The magazine motor also drives the stopping switch gear.
The fly clutch motor is not yet activated this motor is used to pickup the record and perform the transfer to and from play.

The cycle that is supposed to happen when a selected pin is encountered is to have the scan control coil activate to setup the sequence for locking the detent wheel in position which if the lever locks in the detent wheel will stop the magazine motor.
This sequence does work as a record is always being played except not the one selected (some of the time seems some positions are more prone to skip a position).

So either the detent action does not work as is a common occurrence when the detent wheel is worn or just affected by age.
By activating the scan control coil a lever is pulled in that will lock in the next detent position.
This lever will then open a microswitch locking the basket in place and stopping the magazine motor starting the mech motor to pickup the selected record.

The reason i suspect an issue with the factory adjusted stop screws on the stopping switch gear is the relation of the detent position and basket is more or less controlled by these 2 screws.
When a pin is "found" the stopping switches will have some over travel before activating, this over travel is setup by the stop screws.
This also puts some spring tension on the arm that hits the pin.
I suspect the mis adjustment will cause the relation to detent and basket to move out of alignment after several rotations of the basket and stopping switch gear.
There is a reason for these 2 screws to be factory adjusted.

The above being my interpretation of the more comprehensive sequence as described in the manual.

I would have asked Warren Rowe but that option is no longer available.

[Ron Rich]

Hi Marcel,
Thanks for the explanation --
Did Warren pass away ? Last I heard he was in the Hospital --- Ron Rich

[Marcel Bogert]

Hi Norman, i'm aware of the detent wheel being a strong candidate, this would be my first thing to check too.
I am however pretty sure it's clean and working properly.

But if everything else fails i will be sitting in front of the mech to check what happens when the skipping occurs.
I do not have the machine in the shop at the moment and it's not nearby too for me to double check.

That's why i wanted to dig up the proper procedure for adjusting those stopping screws.
just because i want to know how it's done and more importantly to rule it out.
Timing is pretty crucial as with most (all) AMI's

Too much over travel will put too much tension on the arm against the pin reset lever will not reset the pin detent out of alignment etc. 

[Marcel Bogert]

Hi Ron,

as far as I know Warren is still in hospital but no longer able to provide assistance.
I contacted Don from Jukes Unl. some weeks ago when I did not get a reply from Warren directly.

I expect Warren would know how the factory did it.

[Ron Rich]

Hi Marcel,
Yes-- I sure agree with you-- if anyone in the world would know, it would be Warren ( I do believe he's forgotten more then I ever knew !) ! I hope he's doing better-- I shall contact Don too-- Thanks, Ron

[Ron Rich]

Marcel,
Great news-- I just spoke with Warren-- He got out of the hospital yesterday, and sounds great. Ron Rich

[Marcel Bogert]

That's great to hear,

you're grapevine is a lot better than mine :-)

As said the only info i had was Warren no longer available and in Hospital.

When he is up for it mayby you could ask the 6 million dollar question, how to adjust the stop screws :-)
This would be a greate piece of info to share too.

If he wonders were his 100A project ended up, i have it at least the mech via Bill butterfield :-)

[Ron Rich]

Hi Marcel,
My "grapevine" is onna dem dare old fashioned "telephones" with crank in it's side-- Spin it once to contact "Mildred", and axk her to "contact Warren"-- Magic-- a minute later and Warren is on the phone-- ??
Try emailing him direct-- [e-mail] He said he would be "doing emails" today --
What was the "A" project ? Ron Rich

[jukenorman]

Hi Marcel,
I think the reason the stopping switch screws are factory set is that one has to be adjusted relative to the other for proper operation. There is still an adjustment for the stopping switches themselves should they be replaced.

While your stopping switch screws might have been messed with, I cannot see that (my opinion of course) being the root cause of the problem that you are experiencing for the following reasons
1 If it was a stopping switch screw adjustment problem, you would expect any issue to be absolutely repeatable if all other components were OK.
2 When a selection fails and a pin is "jumped", the stopping switch should revert to the non actuated state.
3 The search unit was designed to be able to make selections from adjacent pins so you would expect it and the carousel to stop in an instant (relatively speaking).

You may need a bit of trial and error adjustments on the stopping switch screws but when you can successfully select a consecutive A, B, A, B selection sequence, you should be pretty close.

Norman.

[Marcel Bogert]

Hi Norman,

I do not think this to be the sole root cause either.
and i appreciate your opinion, i will find the issue sooner or later and will report back.
The stop screws is something i want to rule out.

I'm not talking about the stopping switch screws as these are indeed adjustable and not an issue when replacing the microswitches.
I'm talking about the stop screws.
They basically adjust the amount of over travel before the stopping microswitches activate.
These also align the 200 mark to the basket position.

The microswitches are on a armature that rotates first before the microswitches activate.
These put spring tension on the arm that has stopped against a pin.
The further the armature needs to move before activating the stop switches the more spring tension is put on the arm against the pin.
This is not a good thing as this will also start to lift the arm over the pin.
If a pin is not pushed out all the way which will happen this excess in over travel will cause the arm to jump over the pin 

adjusting the stop screw to get proper A en B play is not an issue this you can do in any position these screws are in use one to set a-side adjust the other to match the position to get b-side.

As usual with AMI if you adjust one thing wrong a whole lot of parts of the sequence will be offset which can cause numerous issue's.
Same for the seeburg switch stack.

Question remains how were these stop switches adjusted at the factory.

[jukenorman]

Hi Marcel,
You have an advantage over me in that you have a search unit to look at whereas I am relying on memory and the service manual (the JAL). According to the JAL manual, the stopping switches are set relative to the stop screws (which the manual states are factory set and should not be adjusted) so I'm sticking by my opinion that the stop screws have to be set as a pair. I imagine that in the factory they would have used some sort of jig to do it.

Best of luck, Norman.

[Marcel Bogert]

I've been spending some time with this machine again to either fix it or return it to the owner.

I did find diode D1 thats part of the breaking circuit to be shorted.
It would also interfere with the detent circuit.

Detent coil is now turned off as it should when finding a selection pin.
Skipping over the detent position was actually the detent coil not being de-energised completely

Issue now remaining is still the timing.

It will not always detent at the right position.



Most of the time this machine is picking the correct record, but some of the time it will detent one record space past selected record.
Making a couple more selections and all is well again....

Detent is actually controlled by the cam switches and not the actual stopping switch or left-side switch, these just setup the circuit and set a or b side play.

B side is a single action circuit triggers the stopping switch a- sides first has to trigger the left-side switch and then trigger the stopping switch during the scan cycle.

Stopping screws setup the alignment of a and b side and the 200 mark.

My closing remark on this topic as i was unable to get any info on the factory adjustments is the common failure of diodes in these early 1100 mech's (JAN/JAO) I found the 3 diodes in the search unit to go bad very often.
These can be replaced with a 1n4007, found BY127 as an original part in these. Later 1100 mechs have a different setup and i suspect improved the design to increase reliability.