Massive variations between dial up and dial down

[Bill2024]

Can anyone help me to interpret these reading from my timegrapher please?  

Background: the movement is my practise movement so has been disassembled/assembled many times; I have also practised oiling it but it has never been cleaned. Movement is an st3620 and has been running from a full wind for around 20 hours.  I have used the lift angle from the eta6498 which this is a clone of. I also had to correct the hairspring on this movement (it was a little twisted) and managed to get it running but I suspect that may be the root of the problem somehow. 

The dial down graph is pretty respectable I think showing between 0 and +2 s/d. 

The dial up graph however is a bit of a mess. There are wild variations in rate and also the lines have many blue dots above. Is this an instantaneous indication that the beat error is variable even if the average beat error is not too bad? I’m wondering if perhaps my hairspring may still be contacting the movement slightly in the dial up position?

Id be really interested to understand what readings like this might generally be an indicator of.

Thanks, Bill

[nevenbekriev]

Yes, this is probably the hairspring rubbing, probably on the balance cock You can see it, just hold the movement dial up while watching.

[Bill2024]

20 hours ago, nevenbekriev said:

Yes, this is probably the hairspring rubbing, probably on the balance cock You can see it, just hold the movement dial up while watching.

It does indeed look like the hairspring is extremely close to the balance cock and may be touching it. There is a slight cone shape to the spring so I guess that’ll need fixing. 

Before attacking the spring I tried changing the depth of the hairspring stud in the holder that fixes it to regulator arm (sorry, don’t know the correct names); I lifted it up slightly and retightened the screw to try and correct some of the coning. This actually made a big difference as the timegrapher traces are now clean, albeit with a beat error I must have introduced when tightening the screw. 

I don’t know if this is a normal adjustment or should the stud always be fitted all the way into the holder?

When I first disassembled it the stud was all the into the holder. 

[GPrideaux]

The height of the stud in the stud holder should be adjusted to make the balance spring flat, so you've done the right thing. Congratulations!

[Bill2024]

2 hours ago, GPrideaux said:

The height of the stud in the stud holder should be adjusted to make the balance spring flat, so you've done the right thing. Congratulations!

Thanks very much - that’s good to know.