What the H*ll! My DSN 240 is falling apart.

[Drulee]

Alright, I'm not really blaming Davidsen, just Asian Q.C. in general. In all fairness, I bought this watch from a third party - not directly from Davidsen - so I don't know what it has been through. Here's what happened:

I have a habit of flicking my wrist a couple of times, just to hear (and sometimes feel) the movement's rotor spinning around. Well this morning when I did it, I got a little shock. A loud scraping sound could be heard coming from inside the case. I took a look at the seconds hand and, as it was still moving, pulled out the crown to stop the movement and hopefully prevent any major damage from happening.

I took the watch off and put it away, planning on inspecting it in more detail upon my return home. Luckily, I had received a new PAM 44mm case opener a few days earlier. This is a great tool, made by blackbard on RWG, for "cracking" your cases (he's got them up for sale on eBay, as well). Well, after a few quick turns, I lifted the back off and couldn't believe my eyes - the rotor had fallen apart.

To illustrate just what happened, I found a picture of the 7750 movement in its complete form, and edited it to clarify things.

Here is a picture of what the "unbroken" movement should look like:

Now with the part of the rotor that fell off, in red:

What the rotor should look like:

And what it looks like now:

The inner section of the rotor, which is attached to the winding mechanism, still seems to function - it spins freely when the case is shaken. The outer section (in red on the first pic) has just detached from it. I've removed the outer section from the case and closed it up. The watch is still ticking away now, and keeping time.

So, what I would like to know is, what can I do to fix this? Has anyone else had this happen? Is it just typical Asian workmanship?

 

[d4m.test]

I have seen this happen quite a few times on the a7750 movements. The two pieces are simply pressure fit (tongue and groove) together. Ive never seen that any type of epoxy was used to make it a permanent joint. In the three occasions that it has happened to me, I have simply removed the rotor from the movement and used a very small amount of 2 part epoxy between the two pieces. After they are completely dried (keep it out of the movement for 24 hours), I clean up an excess that may have escaped the joint with the fine tip of an exacto knife and install the rotor again.
They have NEVER come apart a second time!
Its a good time to grease the bearings and seals also!
T

 

[Drulee]

Thanks, I was hoping this was the case. Does the rotor simply lift off? As far as greasing the bearings and seals, is there a thread showing what to do, and what lubricant is best?

Thanks again for confirming what I suspected.

 

[hk45ca]

i use a ball of duct tape to remove any case back i have. it works perfectly and it is imposable to scratch it like that. no scratches and no wasting money on 10 different types of openers. :wink:

 

[d4m.test]

The screw in the center of the rotor that is still attached needs to be removed. Once the screw is removed, the rotor will lift off.
Be careful when lifting it off as to not accidentally make contact with the balance area... Ive hacked a movement dropping a rotor in to the balance assembly before.
I dont know of any tutorials on greasing the rotor, and Im not sure what anyone else uses. I have a top secret formula that I use...

 

[hk45ca]

i use a toothpick and red and tacky lucas high temp bearing grease. it shuts those noisy 7750's up. i learned that trick from flave and it works great.

search and ye shall find,

http://www.rwg.cc/members/index.php?showtopic=17871

 

[Drulee]

i use a ball of duct tape to remove any case back i have. it works perfectly and it is imposable to scratch it like that. no scratches and no wasting money on 10 different types of openers. :wink:

No scratches, just rotor trouble

 

[Drulee]

i use a toothpick and red and tacky lucas high temp bearing grease. it shuts those noisy 7750's up. i learned that trick from flave and it works great.

search and ye shall find,

http://www.rwg.cc/members/index.php?showtopic=17871

Thanks for the link, I usually do search - but I'm used to RG's search system, which is a pain. I'm getting spoiled here

 

[hk45ca]

i use a ball of duct tape to remove any case back i have. it works perfectly and it is imposable to scratch it like that. no scratches and no wasting money on 10 different types of openers. :wink:

No scratches, just rotor trouble

i understand that buy you spent good money on a case back opener for no reason. just sharing information letting you and any body else that reads this know it isn't necessary, i have seen a lot of case backs scratched up because of openers.

? i am not sure what you mean by the search feature. i spent less than 5 minutes to use our search function to track that link all the way back to rwg jr. it was no trouble at all.

 

[Drulee]

i use a ball of duct tape to remove any case back i have. it works perfectly and it is imposable to scratch it like that. no scratches and no wasting money on 10 different types of openers. :wink:

No scratches, just rotor trouble

i understand that buy you spent good money on a case back opener for no reason. just sharing information letting you and any body else that reads this know it isn't necessary, i have seen a lot of case backs scratched up because of openers.

? i am not sure what you mean by the search feature. i spent less than 5 minutes to use our search function to track that link all the way back to rwg jr. it was no trouble at all.

If you read that post again, you'll see I was complaining about RepGeek's (RG) search system, and that your system's is great - which is why I felt spoiled.

As far as openers, this one is like DSN's - fits perfectly and snugly on back - but costs much less. It also has just the right amount of weight to make seating the back on the threads when re-attaching it.

 

[hk45ca]

i have never used rg's search feature so i don't know how it works.

i have had 2 watches sent back to me from watchmakers with the case back scratched so now i don't allow anybody to use one on my watches.

 

[Drulee]

i have never used rg's search feature so i don't know how it works.

i have had 2 watches sent back to me from watchmakers with the case back scratched so now i don't allow anybody to use one on my watches.

I can believe it, they probably all used the three prong opener - that's why I like mine, it is made just for the 44mm PAM cases' hexagonal head (the only type that I will open and close myself).

 

[pedecter]

I'd say that using a ball of duct tape to open a case back and also using an open case opportunity to use a toothpick and red and tacky lucas high temp bearing to grease up the rotor about covers the ends of the spectrum. I'm not even advanced to duct tape yet. Good thing there are good watch repair persons (and good dealers....DSN just did a free & fast repair on my 232) for the rest of us.