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Chinese clone demagnetizers


Levine98

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16 hours ago, Levine98 said:

So I wrapped the anvil it in bubble wrap and passed ot through the demag only. Still no go—the unit is simply too strong. 
next experiment is to use a VARIAC to lower the voltage and see if that reduces the magnetic field. 

Well my VARIAC experiment worked sort of. By lowering the input voltage I was able to dramatically lower the magnetic field. However try as I might I was not able to demag either anvil. Even wrapped in bubble wrap to ensure it passed through the opening at equa-distance in the hole, the ends still come out highly magnetized. So time to throw in the towel and move on to purchasing the Chinese Elma-like unit from Amazon (I don’t do Ali express since I can’t return stuff if not satisfied like i can on Amazon).

 

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I use on of these Eclipse demagnetisers. https://www.eclipsemagnetics.com/products/workholding-systems/table-top-demagnetiser/ I got fed up with those Mickey Mouse blue things and went industrial

You can pick them up on eBay from between £70 to £100. They will demagnetise anything. I mean, anything, from a hairspring to a hammer head.

The table is about 5 x 6 inches. You are not going to find anything close to being this good! It will demagnetise the biggest and chunkiest of cases with the movement inside. You'll never wonder again if your demagnetiser did the job.

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54 minutes ago, Jon said:

I use on of these Eclipse demagnetisers. https://www.eclipsemagnetics.com/products/workholding-systems/table-top-demagnetiser/ I got fed up with those Mickey Mouse blue things and went industrial

You can pick them up on eBay from between £70 to £100. They will demagnetise anything. I mean, anything, from a hairspring to a hammer head.

The table is about 5 x 6 inches. You are not going to find anything close to being this good! It will demagnetise the biggest and chunkiest of cases with the movement inside. You'll never wonder again if your demagnetiser did the job.

Looks like it’s be perfect for my anvil problem, but I’d be concerned about using on a watch movement re: I’d be afraid to apply that much magnetic force to a hairspring.

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1 hour ago, Jon said:

I use on of these Eclipse demagnetisers.

Yup, I have one of those up in my shed and it's extremely effective. I picked mine up at a car boot sale for a couple of quid because nobody knew what it was. Mine looks like it came out of the Ark so I guess that they've been around for a long time.

Generally for watch stuff I use an equally ancient pass through type which is usually sufficient but for really stubborn items, particularly tools I use the Eclipse.

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3 hours ago, Levine98 said:

Well my VARIAC experiment worked sort of. By lowering the input voltage I was able to dramatically lower the magnetic field. However try as I might I was not able to demag either anvil. Even wrapped in bubble wrap to ensure it passed through the opening at equa-distance in the hole, the ends still come out highly magnetized. So time to throw in the towel and move on to purchasing the Chinese Elma-like unit from Amazon (I don’t do Ali express since I can’t return stuff if not satisfied like i can on Amazon).

 

You know when you pass pieces through the hole, how far do you continue to move them away from the demag ?   With the blue china ones if i don't move the steel far enough away it doesn't fully demag it , i also carry out the process twice. For a tenner its working perfectly for me up to now.

1 hour ago, Jon said:

I use on of these Eclipse demagnetisers. https://www.eclipsemagnetics.com/products/workholding-systems/table-top-demagnetiser/ I got fed up with those Mickey Mouse blue things and went industrial

You can pick them up on eBay from between £70 to £100. They will demagnetise anything. I mean, anything, from a hairspring to a hammer head.

The table is about 5 x 6 inches. You are not going to find anything close to being this good! It will demagnetise the biggest and chunkiest of cases with the movement inside. You'll never wonder again if your demagnetiser did the job.

Thats a big jobby Jon, even though the blue effort is working fine for me this will look well cool sat in the corner of the watchroom and might pull a few lost parts from their hidding places as a bonus . Flick the switch with a bargepole from the doorway to avoid a zinging barrel arbor taking an eyeball out.

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3 hours ago, Levine98 said:

Well my VARIAC experiment worked sort of. By lowering the input voltage I was able to dramatically lower the magnetic field. However try as I might I was not able to demag either anvil. Even wrapped in bubble wrap to ensure it passed through the opening at equa-distance in the hole, the ends still come out highly magnetized. So time to throw in the towel and move on to purchasing the Chinese Elma-like unit from Amazon (I don’t do Ali express since I can’t return stuff if not satisfied like i can on Amazon).

 

I don't understand why did You use the bubble wrap. If You think there is any use to hold the thing exactly in the middle of the hole - wrong, there is no matter, just pass it tru the hole and take it away to at least 40 cm before release of the button. If You reduce the current, then You reduce the field strenght too, thus not alowing the tool to be demagnetised if it is holding stronger field than the coil can create. My advice is to eat You breakfast (for more muscle strenght) and to fix the demagnetiser to the table or bench top with some clamp so You will be able to use the both hands, then ask You wife to press the button for You...

Edited by nevenbekriev
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2 hours ago, nevenbekriev said:

I don't understand why did You use the bubble wrap. If You think there is any use to hold the thing exactly in the middle of the hole - wrong, there is no matter, just pass it tru the hole and take it away to at least 40 cm before release of the button. If You reduce the current, then You reduce the field strenght too, thus not alowing the tool to be demagnetised if it is holding stronger field than the coil can create. My advice is to eat You breakfast (for more muscle strenght) and to fix the demagnetiser to the table or bench top with some clamp so You will be able to use the both hands, then ask You wife to press the button for You...

You made a funny Nev 🙂

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if we look at and understand why steel becomes magnetised and unmagnetised then its possible to work out why some devices are better than others. Simpy it is a parallel alignment of atoms , electrons within a material caused by external magnetic fields. Different magnetic fields cause different alignments and non alignment of atoms. Fields by AC currents are changing atom direction approx 50 times per second ( 50hz ). As a material is drawn away from a demagging device the field is becoming progressively weaker while also changing the material's atom direction having the effect of returning their random directions ( demagnetising ) . To improve on this demagetising effect, try changing the material's orientation as it is drawn away.  Fields caused by DC currents have the most permanent magnetising effect as the currect is flowing one way only. A good demagger would produce random magnet fields and disorientation of the material's atoms.  

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12 hours ago, watchweasol said:

@VWatchie you guys had some decent Air craft, Saab Dracken, the cars were good too the Saab 95.

Yeah, those were the days! Now, sorry for going OT again but I just can't help myself!

As a kid, I saw Draken (The Dragon) pass over my parents' house almost daily going to and fro the air base about 15 km from our house. Me and my friends used to play in the basement and when my mother called from the kitchen "Now they're coming" we'd drop whatever we were doing, ran out and looked into the sky. The roar from the engines felt like thunder and when they had passed we'd look at each other and say "That was the Hammer of the Commander-in-Chief" and it made us feel invincible. Happy days!

As said in this video "When it thundered into the sky it immediately became one of the few war birds that Soviet Russia ever truly feared".

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7 minutes ago, VWatchie said:

Yeah, those were the days! Now, sorry for going OT again but I just can't help myself!

As a kid, I saw Draken (The Dragon) pass over my parents' house almost daily going to and fro the air base about 15 km from our house. Me and my friends used to play in the basement and when my mother called from the kitchen "Now they're coming" we'd drop whatever we were doing, ran out and looked into the sky. The roar from the engines felt like thunder and when they had passed we'd look at each other and say "That was the Hammer of the Commander-in-Chief" and it made us feel invincible. Happy days!

As said in this video "When it thundered into the sky it immediately became one of the few war birds that Soviet Russia ever truly feared".

Stories of younger years, love it H 👍

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23 hours ago, Levine98 said:

Looks like it’s be perfect for my anvil problem, but I’d be concerned about using on a watch movement re: I’d be afraid to apply that much magnetic force to a hairspring.

I've never had a hairspring distort on me by passing the movement or just the balance in a plastic pot over this demagnetiser. Have you seen how fast a cleaning machine spins to spin-off fluid and that does no harm to a hairspring. I was a little concerned when I first used it, thinking it might be too strong, but I was wrong. It is strong, but it does no damage. I pass the part over the demagnetiser and keep going for about an arms length, so about a metre, to properly demag the part.

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31 minutes ago, Jon said:

I've never had a hairspring distort on me by passing the movement or just the balance in a plastic pot over this demagnetiser. Have you seen how fast a cleaning machine spins to spin-off fluid and that does no harm to a hairspring. I was a little concerned when I first used it, thinking it might be too strong, but I was wrong. It is strong, but it does no damage. I pass the part over the demagnetiser and keep going for about an arms length, so about a metre, to properly demag the part.

I'm guessing, but this commercial demag machine maybe produces random magnetic fields to re-randomise  the iron particles.

So heres one for you, synthetic rubies are coloured predominantly with chromium oxide . But natural rubies and old synthetic watch rubies were also coloured with iron oxide in higher percentages than chromium oxide. Which gave them a degree of.................🤔

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Is magnetism such a major problem that we (as home hobbyists) need to spend $$$ on a fancy demagnetiser?

I use one of the cheap blue Chinese demagnetisers (£10 from ebay). It works, and has never failed to demagnetise a movement, or my screwdrivers.

Magnetometer - who needs one?  Take a very small screw. If it sticks to the clean part, it is magnetised 🤣

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1 hour ago, mikepilk said:

Is magnetism such a major problem that we (as home hobbyists) need to spend $$$ on a fancy demagnetiser?

I use one of the cheap blue Chinese demagnetisers (£10 from ebay). It works, and has never failed to demagnetise a movement, or my screwdrivers.

Magnetometer - who needs one?  Take a very small screw. If it sticks to the clean part, it is magnetised 🤣

Mike, you have summed it up following the KISS principle.

 

Tom

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1 hour ago, mikepilk said:

Is magnetism such a major problem that we (as home hobbyists) need to spend $$$ on a fancy demagnetiser?

I use one of the cheap blue Chinese demagnetisers (£10 from ebay). It works, and has never failed to demagnetise a movement, or my screwdrivers.

Magnetometer - who needs one?  Take a very small screw. If it sticks to the clean part, it is magnetised 🤣

Yep Mike , i use exactly the same gauge for it.

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1 hour ago, mikepilk said:

Is magnetism such a major problem that we (as home hobbyists) need to spend $$$ on a fancy demagnetiser?

Unfortunately yes! Magnetism can wreak havoc on a mechanical watch movement if the balance hairspring becomes magnetised. The cheap blue Chinese demagnetise-rs are useless if you feed them the wrong voltage (> 110 V), and even so, they don't work very well. The one I got when I was new worked so poorly that it drove me nuts. Eventually, I was lucky to get a Greiner Magnomatic for a little money. It's an amazing tool that can be trusted to do its job perfectly in seconds. A new one comes with a price tag of  £885 excluding tax and shipping, and if you think that's a bit steep (I believe most of us would) and can't find a used one I'd go with @Jon's recommendation.

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5 minutes ago, VWatchie said:

Unfortunately yes! Magnetism can wreak havoc on a mechanical watch movement if the balance hairspring becomes magnetised. The cheap blue Chinese demagnetise-rs are useless if you feed them the wrong voltage (> 110 V), and even so, they don't work very well. The one I got when I was new worked so poorly that it drove me nuts. Eventually, I was lucky to get a Greiner Magnomatic for a little money. It's an amazing tool that can be trusted to do its job perfectly in seconds. A new one comes with a price tag of  £885 excluding tax and shipping, and if you think that's a bit steep (I believe most of us would) and can't find a used one I'd go with @Jon's recommendation.

Maybe you had a bad one H, the cheap blue one i use has been fine for nearly 3 years now. It demags enough to stop the tiniest of screws sticking to the carbon steel tweezers i use. If it were to fail at some point in the future i very  probably would go up a level of device just because. 

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