7A28-7020 Restoration so far.

[pip]

Thanks for the info. After last nights fail I will be giving this a go, we shall see what happens!

[Mike_B]

Amazing write up and I will never look at a quartz on the same way again!
pip GuyJ / guy..(Tapatalk woes)

You can get tripods real cheap but then buy a cheap selfie stick with a Bluetooth remote. You can get them for nothing.
9 times out of ten the phone holder on the end unscrews and you can then screw into the tripod as they are all standard 1/4 . Then just use the Bluetooth button to take the photo and clip on macro lenses if you want.
I used this method for my YouTube videos if you watched them . Tripod was less than £20 which I use for my dslr camera but improvised with the selfie stick!

I've now gone one stage further with a massive £120 spend on a smooth Q gimbal. If you search on YouTube you will see what this is. An amazing bit of kit for movie taking on your phone!!

[pip]

Well I went back to this tonight after a bit of a break while I attended to other things. So, another quick strip down just to the movement. Checked the gear train while I was there by putting a very fine oiler through the inspection hole and seeing if it would turn. Well, I have to report that it moves as freely as a freshly buttered whippet. (That's good by the way). Changed the green circuit block spacer and the pcb and also the anti magnetic plate with ones from a 7A38 junk that I have. Put it all back together again and inserted a battery.

Did anything happen? Almost! I got a twitch! If you look closely you can just about see it, apologies for the poor quality (I've not worked out how to take decent pics or vids through my microscope yet).

www.flickr.com/gp/7524919@N05/58SfEG

Sooooooo. Another strip down, check everything. All seems ok. Get out the multimeter and check the battery, just under 1.6V so that passes the test of being above 1.5V that Seiko recommend. Another rebuild and this time nothing. Another strip back and rebuild, again nothing. 
So my thoughts are it is likely a power issue with either not enough getting to the train OR something with the train meaning it needs too much power to operate. The lack of anything at all the 2nd and 3rd times would suggest to me the former. 

Back to the drawing board then. Not quite sure where to take this next. I should work out how to measure the current that is being drawn by the watch, the Seiko manuals show some gizmo being used but it should be possible with a decent multimeter? Anyway, onwards and upwards... 

[pip]

I haven’t forgotten about this movement; it had just been put to one side while I did other things but I have been very aware of it waiting for me to get back to it. Today was the day as I had a few hours to myself.
First things first, inspect it all again under my visor for an overview then my microscope for close up views. Checked each of the wheels in the gear train and found one that wasn’t rotating when its neighbour did. Never a good sign! This was Step Rotor B which is the chrono seconds one. Stripped down the bridges and trains again and hooked it out. Broken pivot. (By the way, I have been referring to pivots as pinions previously. My bad, I had the wrong term in my head). I dug out my knackered 7A38 and inspected the B from that. Much better! Installed it and rebuilt the trains, built it back up, dial on. Popped the hands on to make it easier to see what was happening if anything. Battery in............ nothing again.


But some good news, this time the chrono works, albeit a bit strangely. It starts, all the chrono hands do what I want them to. It stops, and it resets. However, if I press the ‘lap’ button while it’s running it just resets.

So having just re-read the thread from the start to remind myself, I realise that I have taken a watch where the clock part worked and the chrono didn’t and I’ve now reversed that!! Got to pack up for a few hours now as family will be back shortly, back to this later.

[pip]

Ok, the evenings tinkering gave me some clues. I pulled the stem to it’s 3rd position and found that the centre wheel is a lot stiffer to turn than I think it should be. This is might be stopping the movement? Although I’m not sure why it would stop the ticking small second hand. Train removed, stem moves centre wheel very smoothly. Train back, stiff. Train out, remove 3rd/4th wheels and second counting intermediate, bridge back on.


Smooth again. Put second counting back and test without bridge. Smooth. Put the rest back and bridge on, stiff once more.

So I think the issue is with the 3rd wheel and pinion, somehow binding the centre wheel. I’m off to have a G&T and watch MOTD and have a think.

[pip]

I went back to this the other day. Only one thing for it I thought: complete tear down again to mainplate, clean & oil & rebuild.
So I won’t post hundreds of photos this time, I’ve done that. The rebuild went smoothly, I’m quite competent with 7Axx movements now. One glitch, I managed to put the clutch in back to front so had to disassemble the keyless and rebuild it, managed to do that in situ so no drama.
And here we are at last after all this time with a wrist shot of a fully functioning 7A28-7020 on a nice clean original bracelet that’s actually a tiny bit big for my farmers wrists:


It’s amazing how much your views and ambitions change as your competence increases. I look at it now and have decided to try and source new small hands and to redo the h/m and long second counting hand (or replace them?) and it definitely needs a new crystal.

Anyway, thanks for sticking with me, I have learnt a ton doing this one because it’s been so new to me over several months but I can finally close this thread. Next!

[tritto]

Well done Pip. You’ve obviously learnt a lot along the way. I shall dream of one day being competent enough to do what you’ve done.

[time4seiko]

Fine job pip! Thanks for a fascinating post😀👍🏻

[GuyJ]

Great job pip. I have two here I need to get around to for Jonas but finished a relume recently.

Did you update the Dropbox with any picture by chance? Need to check it..

Well done again. What did you find was the issue? The third wheel?

[pip]

Nov 9, 2017 20:26:36 GMT -8 GuyJ said:

Great job pip. I have two here I need to get around to for Jonas but finished a relume recently.

Did you update the Dropbox with any picture by chance? Need to check it..

Well done again. What did you find was the issue? The third wheel?

I think the issue was the centre wheel was very slightly out of kilter or there was a minuscule piece of dirt on it. Just enough so the train ran well until the bridge was tightened down which put it under just enough pressure to stop it working properly. Another clean/oil/build did the trick.

Haven’t updated the Dropbox with more photos but I may well do. There are some more builds in there from the restoration challenge though so check it out.

[Mr.Jones]

Nov 9, 2017 20:26:36 GMT -8 GuyJ said:

Great job pip. I have two here I need to get around to for Jonas but finished a relume recently.

Did you update the Dropbox with any picture by chance? Need to check it..

Well done again. What did you find was the issue? The third wheel?

One (the better) of those two was serviced recently, Guy Only the time won't run...

The other... Oh my. That one looks much better now thanks to your efforts, but the movement...

[seacreechur]

Great job PIP. I have a deep admiration for all of you who are tasked for this detailed and rewarding hobby!
Michael

[GuyJ]

Good point, Jonas I hadn't forgotten!

[69ChevelleSS]

WOW . . . . kudos pip (and all you who can tinker inside these wonderful devices).  My 7A28-7049 had to go off to Spencer for a service since I have 10 fat thumbs on the ends of my mits!

[doomguy10011]

Excellent job, Pip! I really hope that I could one day find it in me to attempt to rebuild a watch, too.
This thread has been quite an inspiration!