Accutron 218 date not advancing

[LittleWatchShop]

This is the same watch I have posted about under different topics.

After assembly, the date does not advance.

In the pictures I show the Date Trip Arm and the Date Trip Wheel in different positions.  What is happening is that the hook on the Date Trip Wheel is releasing the Date Trip Arm BEFORE it moves far enough to grab the Date Indicator. Everything moves freely and I have lubricated according to the manual instructions.

I wonder if the Arm or the Wheel have worn to cause this problem.

BTW, before I opened this watch up for service, I noticed that the date was not working.

Thoughts?

[CYCLOPS]

I noticed the date jumper spring is not positioned correctly, you can see through the opening window in the date bridge that it is not perpendicular to the jumper and more at an angle, it might seem like it does not matter but that issue could be causing too much resistance on the date wheel and maybe shifting the date wheel tooth just enough out of the right position for the date trip arm to strike the date wheel tooth, also on these models the tension on the canon pinion drive wheel could be too loose to carry the trip arm all the way through on its own,, but it should still work with a manual hand turning of the stem, I hope this helps, just more to check on

[LittleWatchShop]

13 minutes ago, CYCLOPS said:

issue could be causing too much resistance

No, because the date ring is never engaged by the Date Trip Arm (DTA).  The Date Trip Arm never gets low enough to hook the date ring.  I have tried to illustrate this below.  The Date Trip Arm rotates counter clockwise as the Date Trip Wheel turns. The red cam is supposed to drag the Date Trip Arm along the trajectory I have drawn.  The fourth position (4) shows that the DTA has been released to grab the date ring and advance it.  As I said, the DTA never gets low enough to grab the hook on the date ring.

I wonder if the cam is worn, or the DTA ledge is worn.

[CYCLOPS]

I have worked on several of these in the past, these movements are easy to find, you should replace the parts you think are defective and see if that is the remedy.... I hope

I did not confuse you with my nomenclature, I should have said what Bulova calls the parts, by date jumper I meant 'date indicator detent spring', and I also wanted to share that the date corrector could be engaged and not free, it does seem like the date trip wheel assembly could be faulty.  

[LittleWatchShop]

11 minutes ago, CYCLOPS said:

I have worked on several of these in the past, these movements are easy to find, you should replace the parts you think are defective and see if that is the remedy.... I hope

I did not confuse you with my nomenclature, I should have said what Bulova calls the parts, by date jumper I meant 'date indicator detent spring', and I also wanted to share that the date corrector could be engaged and not free, it does seem like the date trip wheel assembly could be faulty.  

Thanks.  This is the 2181 which is slightly different.  The difference, however, does not change the situation.  The problem is unrelated to the detent or the detent spring because the date drip arm NEVER reaches the "cogs" on the date indicator ring.
Yes, I have these parts can be replaced.  I have about 50 accutrons to rob parts.  However, this watch is intended for learning, so, in that vein, I wondered if this particular mechanism was known to have issues of wear out.

[CYCLOPS]

never had those issues myself, the parts do inter-change on mine, but the model I showed you is a Day/Date model, press on and keep learning....good luck

[LittleWatchShop]

13 minutes ago, CYCLOPS said:

never had those issues myself, the parts do inter-change on mine, but the model I showed you is a Day/Date model, press on and keep learning....good luck

I just opened up another one.  Indeed, your are correct about the position of the detent spring.  As mentioned that is not the primary issue and I can see that in the other watch.  The date trip arm "notch" is much more pronounced thus allowing the date trip wheel to grab it and pull it down properly engage the cog of the date wheel.

 

[nevenbekriev]

Have never seen such mobement, but obserwing the photos, i guess the mechanism of date changing is a little different. The date change seems to be momentary. There is a spring that presses to the DTArm. The cog on date wheel only charges energy in DTA spring by moving DTA back without touching the teeth of the calendar disk. Then the cog releases the DTA and the spring moves it  forward in a moment, then the disk must be shifted a day ahead. Probably the spring is not correctly installed. It must press DTA towards the data disk.

Edited December 19, 2023 by nevenbekriev

[LittleWatchShop]

2 hours ago, nevenbekriev said:

Have never seen such mobement, but obserwing the photos, i guess the mechanism of date changing is a little different. The date change seems to be momentary. There is a spring that presses to the DTArm. The cog on date wheel only charges energy in DTA spring by moving DTA back without touching the teeth of the calendar disk. Then the cog releases the DTA and the spring moves it  forward in a moment, then the disk must be shifted a day ahead. Probably the spring is not correctly installed. It must press DTA towards the data disk.

No, I believe that the DTA is worn.  The spring is correctly installed.  I serviced another one, and it worked properly.