Copal T7 repair

[davidm]

Just bought this orange Copal tuning fork flip clock a few minutes ago, I think it's a T7

The descrption was "Not working Looks in great condition, but unable to get it to work. It starts to turn with the 'start' switch is pressed, but soon stops again."

I'm pretty excited about my first orange flip clock which is also probably not too common and I'm looking forward to seeing if it can be repaired.

I figure it should be feasible if it's not missing parts or damaged internally.

If I have any trouble I figure there's 777 other members who's brains I can call on.

[flipoclock]

That is rare indeed! Only have seen one or two of these come by in the past 10/15 years...

What is hopefully the case with your clocks is that it needs some oil. I have a tuning fork clock here humming away happily for months now and it was not working and only got a few drops of oil.

[davidm]

The parcel came from a store on the mainland, so as soon as I got it home from the post office and unpacked I wiped it down with methylated spirits, and did the obligatory hand wash.

I have a tuning fork clock here humming away happily

You're not wrong about the humming, when this clock goes you can hear a tone of what sounds like a few hundred Hz.

I say when it goes as it's a bit intermittent atm due to the rust on the +ve battery terminal which I've roughly scraped off but it needs a better clean up.

I put a new D cell in after I thought I'd cleaned off the rust but it wouldn't start, so I put the multimeter on the battery and got 1.6v then on the battery holder solder connections & got 0v!

I'll have to go shopping for a small brass wire brush and some conductive grease, then clean that terminal properly & see if that fixes it.

I'm surprised at how big this flip clock is, it dwarfs my other two battery flippers and most of the mains ones too.

I use the battery clocks to tell the time and only flick the other 240v clocks on to run for a day then run another the next, the c/o time is random as you can see!

[davidm]

The battery terminal cleaned up well using a dental tool on the big rust lumps and then the small brass brush on the rest.

I also rubbed on some conductive grease with a cotton bud, the rear label reads "Carbon conductive grease is a high temperature(200°C) and electrically conductive grease that keeps metals free from rust and corrosion."

I think it's mainly designed for a petrol engine's spark plug connections, but I think it should stop the battery terminal from rusting again.

The clock now seems to be starting, running and keeping good time, but next I want to see if that humming sound can be quietened down a little.

I can't hear any of my other flip clocks running unless I put my ear on the case, but this tuning fork clock I can hear from across the room!

The interesting thing is the humming starts as soon as the battery is inserted, even before the motor is started with the lever.

Does anyone else with a tuning fork flip clock find them a bit loud?

[davidm]

The clock mech and motor are attached to the clock base with 4 threads in rubber mounts, maybe there was something missing idk, but it appeared that the metal underside of the mech was being pulled down onto the plastic base.

When the clock was off the base the humming noise was almost inaudible.

I decided to add some more rubber insulation and after some experimenting with different insulators I settled for putting 4 rubber O rings between the base and the mech's bottom plate.

I should have done a before and after with my sound level meter, but as the clock will have to be dismantled for cleaning I'll try to remember to do it then, but I would estimate that the sound level has dropped to at least half of what it was, maybe more, and I can live with that.

[flipoclock]

Nice work and yeah, I do believe that there should be some rubber insulation between the clockwork and the casing.

Mine is present, 'soundwise', but not loud or too loud.

[davidm]

I have a tuning fork clock here humming away happily for months now and it was not working and only got a few drops of oil.

Could you advise on oil points please, my clock seems to be running fine but I don't know if the Jeco motor and gears have ever been lubricated.

[flipoclock]

Didn't take any pics I'm afraid..... Maybe Mackey has some, I know he has lubricated clocks like these before. If you know what you're looking for, they're fairly easy to recognize.

[davidm]

Mackey Have you got any information on lubricating these Jeco motors?

They're well sealed so dust shouldn't be a problem, but I expect any oiled bearings will be dry after 60 years or so.

[Mackey]

Mackey Have you got any information on lubricating these Jeco motors?

They're well sealed so dust shouldn't be a problem, but I expect any oiled bearings will be dry after 60 years or so.

Not a clue. I don't remember getting into one of these. I do have a T7 but it was working when I got it.

[davidm]

I couldn't find any information online about lubricating the clock mechanism, so I figured I'd just lubricate the pivot points.

There are a couple of obvious pivot points so I applied a tiny drop of oil to them and did the same to their opposite points which were inside the mechanism being careful not to get oil on any other parts.





I'm happy to let the clock run now as I know it's not running dry.

Will see how accurate it is, you can see the speed adjuster in the second image, which is in it's centre position at the moment.

[davidm]

Something interesting I've noticed since lubing the clock mechanism, the sound of the 300 Hz tuning fork has again been reduced.

I've concluded that fitting the 4 suspension O rings was treating the symptom but lubricating the clockwork bearings and pivots was treating the cause and was even more effective.

[davidm]

Found this image of a Jeco sticker recently, it's low resolution but readable, seems that one turn of the adjuster in either direction is about 10 seconds in 24hrs.

So I'm going to set the T-7 going at 1:30 today and see how accurate it is after a week or so, using the 2nd setting method as detailed in RetroFlip's post here:

https://www.flipclockfans.com/forum/...6-red-and-blue

How to set the time
1. Simple method (Use this method in general.) While the power is on,
turn the time adjustment dial to proceed for about 2 minutes from the current correct time.
In the example, it will be displayed at 10:02 AM at 10:00:00 AM will be displayed at PM 10:00 at 9:58:30 PM

2. A more accurate method (how to match with the time signal) While energizing, turn the time adjustment dial,
recommend for 2 to 3 minutes from the current time, then adjust, and at the moment when the minute number plate is changed,
AC Unplug the cord from the power supply. When the time displayed on the clock and the time signal are the same,
plug the AC cord into the power supply to get the correct time display.



Except I'm stopping & starting the T-7 using the battery & start lever instead of an AC cord.

[davidm]

After 1 week the T-7 is 76 seconds fast, which is about 12 secs per day.

The label above says one full turn of the adjuster is about + or - 10 secs in 24hrs, so as I'd rather the clock was slightly fast than slow, I've given the adjuster one full turn anti-clockwise, and will check again in a week or so.

[flipoclock]

That's interesting, my T11 is showing the similar signs. I have rejuvenated it and it is running perfect, albeit it a bit slow.... Have not been bothered in opening it up to adjust it, it is slightly more work with the T11 than with your clock

[davidm]

Yes, the T-7 must be the easiest flip clock ever to get into, 2 screws and Bob's your auntie.