SW200 vs NH35

[Barryboy]

Hi.. just wondering if there's any real world difference between these two movements. I know that the Sellita is more expensive than the Seiko piece but in your opinion is it worth the extra? Over the years I have had umpteen Seikos of differing values and never once had a dodgy movement so I rate them highly. I have never had a SW200 powered watch so would appreciate your thoughts and comments.
Rob

[Dynam0humm]

Hi.. just wondering if there's any real world difference between these two movements. I know that the Sellita is more expensive than the Seiko piece but in your opinion is it worth the extra? Over the years I have had umpteen Seikos of differing values and never once had a dodgy movement so I rate them highly. I have never had a SW200 powered watch so would appreciate your thoughts and comments.
Rob

The SW200 is in a different league to the NH35 and the 4R and 6R Seiko movements for that matter. A new SW will have an amplitude over 300 and typically around 4s/d variation over five positions for the standard version, whereas an NH is usually around 270 amplitude and average around 12s/d variation.

The NH is still a decent movement, but they tend to be poorly assembled and regulated with pallet pivots being oiled and a lack of oil or too much on the other pivots and jewels. Often the beat error is way over 1ms (it should never be more than 0.5ms in any position) but the rate is good, which suggests a 'that'll do' attitude during adjustment which is likely encouraged by the pathetic -30/+40 s/d standard spec they have to aim for. Then there are things like the hairspring being incorrectly bent which exaggerates positional errors and I've seen a couple where the wrong screws have been fitted on the dial side and are pressing on the setting lever, so when you try to adjust the time the crown comes out in your hand.

The SW on the other hand usually arrives with beat error at 0 or 0.1ms and a few seconds per day accuracy on the wrist. There's fine tuning adjustment on the regulator too so if it does need a tweak it's quick and easy to do, as opposed to the NH where you can spend 20 minutes moving the regulator arm back and forwards before it finally lands where you want it.

One place the NH is superior is the auto winding with the pawl lever teeth only really wearing if moisture and corrosion gets in. The SW200 reverser wheels can be a weak point if not lubricated and often need replacing during servicing, but apart from that it blows the NH out of the water and is well worth paying more for, IMO of course.

[Idontgram]

It depends on how one judges real world difference, OP. If you rotate your watches daily and your only criteria is something that’s still ticking and within 15 secs of the actual time, when you go to bed, then no; not much difference.

If you want something more reliably accurate, then yes.

Whether it’s worth the price difference, is a more personal choice.

[NickRed71]

The SW200 is in a different league to the NH35 and the 4R and 6R Seiko movements for that matter. A new SW will have an amplitude over 300 and typically around 4s/d variation over five positions for the standard version, whereas an NH is usually around 270 amplitude and average around 12s/d variation.

Once in a while, visiting this forum really is an education. Thank you.


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[snowman]

If you look at any SW200 and a NH35, you can see the SW200 is better made, but as others have said, neither is bad (The NH35 in my Helm is one of the most accurate movements in my collection) and the value is dependent on the individual.

M

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[learningtofly]

The SW200 is in a different league to the NH35 and the 4R and 6R Seiko movements for that matter. A new SW will have an amplitude over 300 and typically around 4s/d variation over five positions for the standard version, whereas an NH is usually around 270 amplitude and average around 12s/d variation.

The NH is still a decent movement, but they tend to be poorly assembled and regulated with pallet pivots being oiled and a lack of oil or too much on the other pivots and jewels. Often the beat error is way over 1ms (it should never be more than 0.5ms in any position) but the rate is good, which suggests a 'that'll do' attitude during adjustment which is likely encouraged by the pathetic -30/+40 s/d standard spec they have to aim for. Then there are things like the hairspring being incorrectly bent which exaggerates positional errors and I've seen a couple where the wrong screws have been fitted on the dial side and are pressing on the setting lever, so when you try to adjust the time the crown comes out in your hand.

The SW on the other hand usually arrives with beat error at 0 or 0.1ms and a few seconds per day accuracy on the wrist. There's fine tuning adjustment on the regulator too so if it does need a tweak it's quick and easy to do, as opposed to the NH where you can spend 20 minutes moving the regulator arm back and forwards before it finally lands where you want it.

One place the NH is superior is the auto winding with the pawl lever teeth only really wearing if moisture and corrosion gets in. The SW200 reverser wheels can be a weak point if not lubricated and often need replacing during servicing, but apart from that it blows the NH out of the water and is well worth paying more for, IMO of course.

Great post, thank you.

[Stringer]

Insightful post,
DynamOhumm - thanks.

[Bobbyf]

Thanks for taking the time to post that, genuinely interesting.


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[number2]

A couple of years ago I became an NH35 snob, so many microbrands with varying prices, whenever I see NH35 I automatically move along, that said Steeldive and the like do manage to knock together some decent offerings.

[walkerwek1958]

DynamOhumm sums it up well, the Sellita is a far better movement. However, an NH35 that’s been carefully stripped, lubricated properly and adjusted can be capable of good results. They are a pain to regulate, anyone who’s tried will attest to this.

NH35 movements do vary, I’ve just fitted one to my own Seiko 5 as a replacement for the original 7S26 and its given excellent results with v. little adjustment required, in orher cases I’ve ended up stripping and servicing a new movement to get it running as I wanted.

The Sellita is prone to reverser issues, I recently had to replace a reverser on a 3 month old watch, but that’s quite rare.

[Barryboy]

Many thanks to all who have responded. The reason for my asking this was the difference in price between San Martin watches fitted with either movement. As it transpires it looks like my available cash will be going elsewhere as there's something on SC that has caught my eye in the meantime.
Rob

[catch21]

Many thanks Dynam0humm, very interesting read.

[wallyuk]

SW200 in my Navigator is consistently -1spd, which I think is incredible.
Timegrapher also shows very little positional deviation.
But with SM, it's not so much the extra £120, but the extra 30% ish price rise.

[walkerwek1958]

My vote would always go to the Sellita, but the auto- winding can occasionally give problems owing to the reversers sticking. The Seiko system is a basic design that works well and doesn’t give problems.

[wallyuk]

So the hand wound SW200 (1) in the Smiths Navigator is as sound as a pound?

[walkerwek1958]

So the hand wound SW200 (1) in the Smiths Navigator is as sound as a pound?

Sounder than a pound........apart from one fault.

Sellita, in their wisdom, altered the design of part 203, known as the intermediate wheel or great wheel, which is driven directly from the teeth on the mainspring barrel. This part consists of two pieces press-fitted together. The ETA version is stronger and has more surface area at the point where the two parts are joined, Sellita decided to redesign this and their offering isn`t as strong. Over-enthusiastic winding of the hand-wound movement, applying too much force when the watch is fully wound, can cause the part to fail, with the inner section rotating relative to the outer. I`ve replaced a few of these, they can be fixed by staking the parts back together but given the modest cost of replacement it isn`t worth it. This part is the same on both the SW200 Automatic and hand-wound SW2010 but I`ve never seen a failure on a automatic movement.

Don't let this put you off the hand-wound Sellita, it's excellent, but it doesn`t take kindly to heavy-handed winding. Why Sellita altered the design of this part is beyond me. Replacing part 203 can be done without totally stripping the movement and it takes about 20 mins. Not sure whether the ETA and Sellita parts are interchangeable, never tried it, but they may be.

Symptoms of this fault are the same as a broken mainspring, watch will wind but nothing happens, that's because the mainspring barrel is able to rotate as tension is applied to the spring. First one I saw had me puzzled till I worked out what was wrong!

[wallyuk]

I am in debt to your advice already, so what is the very best advice about hand winding a SW200.
1) go to stop point with a very gentle Swiss Tony light touch?
2) get practiced to getting to the stop point each morning, but aim to never reach it. Remembering 12 turns does just enough for the day.

[walkerwek1958]

Turn to the stop point but don't exert excessive force. Grip the crown lightly and as soon as full wind is reached the crown will slip through your finger and thumb.

I always advise winding a hand-wound watch twice/day, morning and last thing at night. This ensures it is always running in a high state of wind and should therefore produce it's most consistent performance.

[number2]

Thanks Paul, all useful advice.

[prexelor]

Turn to the stop point but don't exert excessive force. Grip the crown lightly and as soon as full wind is reached the crown will slip through your finger and thumb.

I always advise winding a hand-wound watch twice/day, morning and last thing at night. This ensures it is always running in a high state of wind and should therefore produce it's most consistent performance.

Thank you. I have CWC Mellor which would lose a second or so during the day but when placed dial up overnight, it would gain by two seconds or so and be ahead. This was great but I think I jinxed myself as it dropped to losing four seconds or so during the day and not making a difference when placed dial up overnight.

Then one day I gave the watch a wind in the evening as well and the following morning, the watch lost 2.5 seconds only. This I am assuming is what you are referring to in running in a high state of wind.

The watch is really comfortable and light. However lots of micro scratches from desk diving but that is expected with acrylic.