Automatic watch winders, does your watch lose or gain time in them?

Have noticed of late that some of my watches loose there normal accuracy as compared to wrist time or bedside table time.

Any one else noticed this or is this an old chestnut?

It depends on the watch. You are seeing what's called "Positional Variation", the difference in rates in different positions. The amplitude is generally highest in dial up or dial down positions because of less balance pivot friction, but by definition, a winder wouldn't work in those positions.

Whether your watch is faster or slower at high amplitude depends on the watch, but generally they run slower at higher amplitudes (opposite your observation).

For example, I have a SMPO chrono and when I wear it to work, I get +0.5 to +1.0 s/d, day in and out. When I take it on a dive trip to some sketchy part of the world, I wear it 24/7. It loses a few s/d in that case. The difference is that when at work, it's typically dial up as I'm on the keyboard but then I take it off at night and store it crown up, usually for about 12 hours each. In this case, the positional variations average out and I get such good accuracy.

My two SEIKO autos pictured below [6309-7049 and SRP777K1 respectively] seem to lose a few seconds per 24 hours while on their winders...compared to on the wrist or dial up on the nightstand.

Regardless, I dig the winders...machines that’ll keep your machines running...or machines that’ll wear out your machines prematurely.

Pic from a few minutes ago...because I dig seeing pics of my watches...on my watch winders...on the internet...

For the record, utilizing a Mad Dog action figure watch winder [pictured below] seems to cause a gain of several seconds per 24 hours...compared to on the wrist or dial up on the nightstand.

I would NOT recommend a Mad Dog action figure watch winder due to:

1. It does not dress appropriately for various situations...for example, wearing Metallica t-shirts and Levi’s 511 “stretchy jeans” at the gym.

2. It heckles military veterans who served [or are serving] in the USMC, USA, USAF and USCG...the Mad Dog action figure watch winder supposedly served as a watch winder in the USN...and is immature and has a big mouth.

3. It has bad hair days fairly often.

Yes I figured it had to be positional variation but hadnt expected it to be so marked, Have had the watch winder about 18 months or so but hadnt really started using it until recently with a couple of new NH35A movement watches which daily seem to loose or gain 4 or 5 seconds a day with a net weekly change of not a lot as it averages out. On the winder for a few days and I have lost a couple of minutes!

Will soon buy a multiple watch winder as I have too many autos that I want to wear thru the week ( the collection is becoming excessive!) at that point I will probably get a bit spread sheety and work out what each of the different movements does.

yes you have been doing it all wrong until you get all spread sheety 😁

Mine (Sub Date) loses a second or two a day. Have it turning 650 times a day, which I’ve read (for whatever that’s worth) is the minimum to keep it powered.

The most accurate watch straight out of the wrap without being fine tuned that I own is a Indian refurb with a hand winding ST96 movement. Probably one in a million in this respect.
Anyway it gains one second in five days if worn part of the day then left dial up on a shelf for a day or more at a time.
Once every week or ten days I place it crown up, the band wrapped around a conveniently sized vitamin bottle, for an hour or two checking it frequently till it loses just enough to be back in exact time.

Since the second hand doesn't hack or pause when back pressure is placed on the pulled out crown like some do I use this method to zero the second hand in to cross the twelve marker exactly in time with the NIST online clock.
I let the watch run down to a full stop then wait till the online clock second counter almost reaches the point of the position of the second hand then give the watch a shake. There's just enough residual spring power to get the second hand moving while I quickly give the crown a few turns. I then set the minute and hour positions.
If timed right it will be no more than a few seconds ahead so I place the watch crown up and check often till its right on time.

Of course a hand winder isn't going to be put on a winder, but the process translates to most non hacking self winders as well.

My Bulova with A Schilde movement, My Sona with licensed Citizen clone and my Midlands 2453 will all pause the second hand if back pressure is placed on the crown, so then they get a few seconds ahead it easy to get them back in tune without any hassles.

I like having the second hand as close to TDC as possible as the NIST second counter reaches double zero.