Force to move/remove magnet held Camera.

[Lola]

I've been reading a lot about magnets lately and "may" use them on a mount to the rear. However the magnet manufacturers have in their descriptions a lb force for removing each magnet design and I really have a heard time identifying with what would be sufficient force in lbs without overkill.

Now I know there are other factors but can some of you that have used magnet mounts give me some kind of idea of what Lb force you used in your application and your opinions on whether it was sufficient.

Off hand I would think something around 30 Lbs or so would be OK, but rather here what others have to say before buying. In size's for a dash cam using a 3m pad it seems 30Lb or so would rip the pad off before it would let go!

This would be for a Mobius cam and either a modified helmet mount are one used with a gimbal tripod mount 3M sticky pad oval/squared off

 

[kamkar]

I use a Neodymium magnet for 2 of my cameras.

In the rear the X camera is fitted with a pice of metal bend in shape to space it out from the magnet on my hatch frame, the magnet is round and about 15 mm in diameter and 8 mm thick.
It have a good grip on the camera, i have tried to slam shut the hatch as hard as i dared for fear of braking the glass, and the camera did not let go from the magnet.

My left side mobius 1 camera is fitted with 2 smaller magnets, they are only 8 mm i diameter and the same in thickness i think.
This one is mounted off a pice of sheet metal folded together so it sandwich the headliner and can slide in under the rubber that hold the headliner in place over my rear doors..
I have yet to see it change places due to my driving, and the 2 magnets are in the rear of the mobius so the camera do have some leverage.

All the magnets is from a neodymium magnet kit you could buy online with magnets in different sizes, the smallest ones is about 3 mm in diameter and 12 mm long, 4 of those have a good grab on a car body for a rc car ( slow moving scale truck ) you can barrel roll the car down a embankment and it will make a few turns before the body come off the magnets.

I think there was something like 10 of each size of magnets, and the largest ones is the ones i mention first above, and truck me 1 of those together and you have to fight real hard to get them apart ( sliding them apart cuz no way in hell you can pull them strait from each other )

Something like this should be small enough for just about any DIY job, and strong enough to hold any small camera, and maybe use 2-3-4 of them for a larger camera.

Think its same size i use on my x camera in the back, could also use 1 on my mobius, but when i put that in i was home and i only had 2 of the smaller magnets.

https://www.ebay.com/itm/151745753327
If the setup is under some load from wind and such you might want to add a little rubber between the magnet and the metal to increase friction in the bond between the 2.
Sliding neodymium magnets apart is more or less the only way to get them apart, even the 1/2 x 1/4 inch ones are surprisingly strong.

Not sure if its a good thing to place such strong magnets near the brain.

https://dashcamtalk.com/forum/threa...ra-post-your-pictures.502/page-38#post-261776

 

[Lola]

KamKar1 thanks a million, you just kept me from making a BIG mistake. I was going to order a rectangular magnet 1.5 inches long (38.1 mm), had a rating of over 30 pounds (neodymium)! I would never have been able to get it off without using a pry bar!

I believe I will take your advice and see how things go with magnets in the size range you used .

Whoops ! 3 more questions, the magnets you used, did they slide of easily or what?
Were your magnet glued to the connector you built ?
When you removed the connector/camera what kept the magnet from sliding also?

 

[Dashmellow]

@Lola, if you can wait a couple of weeks for delivery Banggood is an excellent source of neodymium magnets at very attractive prices. I don't always like to recommend Banggood because they somethings have a habit of offering goods they don't actually have in stock but ordering magnets from them should be fine. Yeah, you'll be amazed at how strong some of these neodymium magnets can be. I've accidentally broken a few because they slammed against each other unexpectedly from several inches apart from one another on the table. They can be a bit brittle, so be careful.

They have an amazing selection.

 

[Nigel]

I find the ones that are 20 or 25mm diameter and 2 or 3mm thick are a good strength. If you have 2 pairs then there is no problem with the wind or vibrations rotating the camera. If you get them too strong then you can put a bit of electrical tape over them, the thickness of the tape is enough to reduce the pull significantly, it also cushions the impact when they snap together. Being thin and wide spreads the load so it is easier to stick them firmly on to plastic cases.

 

[Dashmellow]

I find the ones that are 20 or 25mm diameter and 2 or 3mm thick are a good strength. If you have 2 pairs then there is no problem with the wind or vibrations rotating the camera. If you get them too strong then you can put a bit of electrical tape over them, the thickness of the tape is enough to reduce the pull significantly, it also cushions the impact when they snap together. Being thin and wide spreads the load so it is easier to stick them firmly on to plastic cases.

I agree, that's a good size. Depends on the particular camera mount though.

 

[Dashmellow]

I've always kinda' wanted one or two of these to play with.

This outfit always has an unusual and intriguing selection of magnets and other items.

https://unitednuclear.com/index.php?main_page=index&cPath=70_71

 

[Nigel]

Also good to have circular ones since when they snap together they are self centering - they will always go back to the same spot.

I've always kinda' wanted one or two of these to play with.

This outfit always has an unusual and intriguing selection of magnets and other items.

https://unitednuclear.com/index.php?main_page=index&cPath=70_71

View attachment 26367

Two of those would lift my car, but how would you ever get them off again?

 

[DT MI]

I've always kinda' wanted one or two of these to play with.

This outfit always has an unusual and intriguing selection of magnets and other items.

https://unitednuclear.com/index.php?main_page=index&cPath=70_71

View attachment 26367

Just don't get your finger caught between two of them.

 

[Dashmellow]

Just don't get your finger caught between two of them.

Forget the fingers, I'd worry about my whole arm!

 

[Dashmellow]

Also good to have circular ones since when they snap together they are self centering - they will always go back to the same spot.


Two of those would lift my car, but how would you ever get them off again?

I know! Someone could get into some serious mischief with one or two of those.

 

[Lola]

@Lola, if you can wait a couple of weeks for delivery Banggood is an excellent source of neodymium magnets at very attractive prices. I don't always like to recommend Banggood because they somethings have a habit of offering goods they don't actually have in stock but ordering magnets from them should be fine. Yeah, you'll be amazed at how strong some of these neodymium magnets can be. I've accidentally broken a few because the slammed aginst each other unexpectedly from several inches apart from one another on the table. They can be a bit brittle, so be careful.

I find the ones that are 20 or 25mm diameter and 2 or 3mm thick are a good strength. If you have 2 pairs then there is no problem with the wind or vibrations rotating the camera. If you get them too strong then you can put a bit of electrical tape over them, the thickness of the tape is enough to reduce the pull significantly, it also cushions the impact when they snap together. Being thin and wide spreads the load so it is easier to stick them firmly on to plastic cases.

Little confusion here. I want to use a Helmet mount with the first layer (one with 3M pad) removed, put another 3M pad on the second layer "or" epoxy a small metal plate to the second layer. Then see if I can get a round or rectangular magnet/s to stick to the roof metal by going through the headliner which is about 1/8 " thick at most.
If this doesn't make sense tell me what's wrong with the idea, please?

 

[Dashmellow]

Little confusion here. I want to use a Helmet mount with the first layer (one with 3M pad) removed, put another 3M pad on the second layer "or" epoxy a small metal plate to the second layer. Then see if I can get a round or rectangular magnet/s to stick to the roof metal by going through the headliner which is about 1/8 " thick at most.
If this doesn't make sense tell me what's wrong with the idea, please?

That sounds most of the way there. If at all possible, you may need to get a piece of metal up behind the headliner that the magnets can attach to rather than just the roof metal that will be farther away. Member @Gibson99 has a Tacoma that he's done something like that with and maybe he might be willing to offer some advice. He's very knowledgeable about how to remove and reinstall Toyota headliners for projects like this. It's not all that difficult really, if you know the right techniques.

 

[DT MI]

I've always kinda' wanted one or two of these to play with.

This outfit always has an unusual and intriguing selection of magnets and other items.

https://unitednuclear.com/index.php?main_page=index&cPath=70_71

View attachment 26367

Just another thought, if you order 2 of these how would they be shipped?

 

[Harsh]

I've always kinda' wanted one or two of these to play with.

This outfit always has an unusual and intriguing selection of magnets and other items.

https://unitednuclear.com/index.php?main_page=index&cPath=70_71

View attachment 26367

That's humungous! I've already pinched my fingers between the ones below, there are plastic inserts so you can separate them a tad easier. These are just 40mm x 25mm x 4mm. I had planned to use these for a Mobius headliner install but the FPV mount worked out great.

 

[Harsh]

Just another thought, if you order 2 of these how would they be shipped?

Stuck together.

 

[Dashmellow]

Just another thought, if you order 2 of these how would they be shipped?

Good question! I can imagine even one of them getting stuck to the side of a UPS truck or interacting with other packages in the shipment like erasing hard drives and other magnetically sensitive items. The whole question of selling magnets like this raises all kinds of intriguing questions as do some of the other items they sell.

I bought a couple of one inch by 3/4 inch neodymium magnets from Banggood that I can hardly remove from my refrigerator door!

 

[Lola]

Good question! I can imagine even one of them getting stuck to the side of a UPS truck or interacting with other packages in the shipment like erasing hard drives and other magnetically sensitive items. The whole question of selling magnets like this raises all kinds of intriguing questions as do some of the other items they sell.

I bought a couple of one inch by 3/4 inch neodymium magnets from Banggood that I can hardly remove from my refrigerator door!

DashMellow, how thick are they ?

 

[Dashmellow]

DashMellow, how thick are they ?

Just measured one. It is 1-1/8 inches long x 3/4 inches wide x 3/8 inch thick - 30mm x 20mm x 10mm

It is THIS one on Banggood.

Here's one of them holding my DIY Mobius Eyeball Cam from behind a piece of glass for the photo.

 

[kamkar]

They come with something in between the individual magnets, at least i assume she stronger versions.

The 1/2 x 1/4 inch ones i mention is impossible to pull directly apart, not least since they are also so small and slippery its hard to get a grip on them.
But just sliding 2 apart is a challenge too, and one on each side of your palm grip it pretty good too, i do not want to try the same with my ear lobe.

I bet a few have been lost in postage over the years, if they get too close to the side of the box then they will stick in any postal or parcel sorting facility.

The Myth busters used really big neodymium magnets a couple of times, and they always said be careful with these magnets they are dangerous, but off course those was fist sized magnets.