Nice idea, I've never understood the need for watch winders, though..

 

Watch winding on the cheap... Old 18VDC B&D wired to bench power supply set to 5VDC

How many rotations per minute does it do?

Nice idea, I've never understood the need for watch winders, though..

To test the power reserve of an automatic watch?

 

By constantly winding it?

To test the power reserve of an automatic watch?

I mean, I know what you're saying... But why not just oscillate the watch in your hand or wear it and then leave it be to time the power reserve?

The only thing I can see these things benefitting is wear on the movement and a lazy person who can't be bothered to set the time.

 

Googling Seiko Auto winding said it required 500 (24hr charge) to 900 (full charge) rotations.

I set it to run at 50 rpm approx and ran it 10 mins clockwise and 10 mins anticlockwise.

Now timing it.

 

Well I stand corrected. I have just been manually winding or using the ratchet wheel to wind fully. I still don't believe in watch winders for the other uses, though. Especially on old parts that would shorten the life span?

 

After using the winder the watch has been sitting on my desk and it's still running at 46 hours

 

Two issues affect PR in an automatic watch (assuming you have the correct mainspring installed):
-Bridle slippage in the barrel...should not slip until full power is developed (usually about 8 full turns of the ratchet wheel).
-Complete use of power before train stoppage...when the train stops, there should be no more than 1/4 to 1/2 turn left on the ratchet wheel. If there is more, you have a problem either with power delivery through the train...or lever/escapement issue.

7S26 requires about 1000 turns for full power. This can be accomplished by counting to/fro movements winding...you can feel the rotor turning when you are in the correct rhythm...and counting is not really a daunting task. Alternatively, just put full power on by winding the ratchet wheel with a screwdriver about 10 turns. To check the bridle slippage, then let it down half a turn at a time and count the number of turns...7 1/2 to 8 1/2 means your bridle is slipping correctly.
My drill cost more than a dedicated winder...and thoughts of 500 rpm conjures images of parts flying...!!!
I think I'll stick to my final test...

 

The watch stopped at 2 pm equating to a 47.5 hour run.

 

The fores and against watch winders has been debated before so this post is not meant to continue that old cake.

Yesterday I was trolling through the usual places looking for watches and related things when this winder appeared for £20 and local to me. A check on tinternet revealed they can be had new for about £45 so the asking was not a problem. It was collected and found to be new, unused and still in its boxed wrappings.

I wanted something other than my B&D to test run watches I have worked and this fitted the bill. Also it's very therapeutic watching it roll over a couple of Seiko's that might just sit in the finished box until I decided what to do with them. It has a number of setting which equate to 8 turns a minute and is dead silent.

So I have moved on from the B&D...for the time being anyway.

 

I retract my posting below, the cam action of the automatic works will allow constant rotation of the rotor to wind the mainspring - Seiko's simple design is more flexible than I initially thought. Jake

I can't see the electric drill approach working with a Seiko at least. Their 'magic lever' requires the direction of the rotor to change periodically - as it would when swinging on your arm.
Leaving it on a drill constantly rotating in the same direction will serve only to add one 'swing' to the power reserve, and a whole lot of wearing down the magic lever ratchets.
Jake

 

I can't see the electric drill approach working with a Seiko at least. Their 'magic lever' requires the direction of the rotor to change periodically - as it would when swinging on your arm.
Leaving it on a drill constantly rotating in the same direction will serve only to add one 'swing' to the power reserve, and a whole lot of wearing down the magic lever ratchets.
Jake

When I used it I changed directions every 10 or 15 mins.

Least we forget watch winders, while they are bi directional when running automatically, do run for long periods in one direction. As per the one above, 33 seconds, 10, 30 and 60 minutes. At the end of each cycle it changes direction. OR there is a switch to maintain either direction.

 

Well protected it works well on the dogs collar.