Force to move/remove magnet held Camera.

Can you retain the self centering ability of disc shaped magnets of different diameters/thickness, like 20mm x 3mm thick on bottom and 12mm x 5mm on top. This is just a hypothetical question I was wondering about ?

I ordered the following disc magnets from http://www.banggood.com/ :
15mm x 3mm
20mm x 3mm
12mm x 5mm
20mm x 5mm
This covers a varying amount of pull force from about 5 lb to over 18 lb .

You guys better get a Flu shot, this stuff is really messing me up!
Different thicknesses is no issue, in fact it can be good to have a thinner magnet on the device and a thicker magnet on the mount since then there is less need to remove the magnet from the device when you are using it for other purposes. The pull is then approximately the total of both magnets, so if you make one thinner you should make the other thicker to get back to the original combined pull.

Different diameters is not so good, if there is a big difference then the narrow+thick magnet will have a more concentrated pull which will be sufficient to create enough friction that the centering effect may not be able to overcome it so while it will still ensure that it is close to the right position, it may not centre it exactly. It is best to match the diameters.

Be careful with multiple 20x5 magnets, or they will eat your fingers. I suggest you put a layer of duct tape around them while you play and maybe leave it there when finished, if not then wear some eye protection just in case you shatter one.
 
Same diameter magnets on camera and on mount will give fixed positioning.
 
Different thicknesses is no issue, in fact it can be good to have a thinner magnet on the device and a thicker magnet on the mount since then there is less need to remove the magnet from the device when you are using it for other purposes. The pull is then approximately the total of both magnets, so if you make one thinner you should make the other thicker to get back to the original combined pull.

Different diameters is not so good, if there is a big difference then the narrow+thick magnet will have a more concentrated pull which will be sufficient to create enough friction that the centering effect may not be able to overcome it so while it will still ensure that it is close to the right position, it may not centre it exactly. It is best to match the diameters.

Be careful with multiple 20x5 magnets, or they will eat your fingers. I suggest you put a layer of duct tape around them while you play and maybe leave it there when finished, if not then wear some eye protection just in case you shatter one.

Hi Nigel Thanks for all the great information, I really appreciate it.

One more question, is it OK to have the two magnets that are mounted on the piece of plastic (or anything really) to be glued relatively close to each other Like 1/16 inch (2mm) ? This will tell me how large I can go in diameter of magnets in general on a specific size of a plate like the plastic/credit card ?

Do you prefer two part epoxy, Gorilla glue, or what to glue the magnets.
 
Cyano don't work at least on unprepped magnets, but i think no matter what glue you are going to be using, sanding the magnets so there is a ( paint technical term ) a anchor profile for the glue to get a good grip on.

For sure next time i will play with magnets i will prep them with some corse sanding paper and then use 2 part epoxy.
 
Same diameter magnets on camera and on mount will give fixed positioning.

Hi Bungus, I'm not quite sure what you mean by fixed positioning using the same diameter magnets?
 
Cyano don't work at least on unprepped magnets, but i think no matter what glue you are going to be using, sanding the magnets so there is a ( paint technical term ) a anchor profile for the glue to get a good grip on.

For sure next time i will play with magnets i will prep them with some corse sanding paper and then use 2 part epoxy.

Hi kamkar1, That is sound advice if you want them to stay put.
 
Hi Bungus, I'm not quite sure what you mean by fixed positioning using the same diameter magnets?

What I mean is once you've position your camera, ie positioning, aiming etc and your magnets are glued in position, you can twist camera and slide out to separate it from mount either to remove micro sd card, or use camera as action camera (if it use battery). When you wish to remount back to your car, it'll be in the same position as before you remove it. Always.

Re size of magnets to use, will depend on space you have on camera mount. Wider magnet gives more gluing space as @Nigel says.
 
Hi Nigel Thanks for all the great information, I really appreciate it.

One more question, is it OK to have the two magnets that are mounted on the piece of plastic (or anything really) to be glued relatively close to each other Like 1/16 inch (2mm) ? This will tell me how large I can go in diameter of magnets in general on a specific size of a plate like the plastic/credit card ?

Do you prefer two part epoxy, Gorilla glue, or what to glue the magnets.
You will find it hard to glue them at 2mm distance, if you are short of space then the easiest is to put one pair the opposite way up to the other, then the pairs will attach to themselves magnetically at zero distance, this will give a very firm attachment.

I've used two part epoxy before, works OK but can fail after a lot of use, as Kamkar says - try to give it a key to hold on to. 3M pads work very nicely as long as they can cope with the magnetic pull when you separate the camera from its base, your magnets may be a bit too strong for it. The strongest solution I've used was to put a single sheet of very fine weave carbon fibre fabric over the top of the magnet and a small area around it and soak that in epoxy.
 
A trick I use to mount magnets to plastic (expired credit card in my case) is to:-
1) cut piece to size to mount on camera.
2)set magnets in position and mark it.
3)remove magnets, put plastic on top of metal piece, (on top of tin can or any piece of ferrous material) and put glue on marked magnet position. (If you use epoxy) Not necessary if using VHB tape.
4) place magnets in glued position.
Magnets will stick to ferrous material through plastic and thereby bond in position to plastic as epoxy dries.

Once magnets are in position in camera, then do the same to mount.
 
You will find it hard to glue them at 2mm distance, if you are short of space then the easiest is to put one pair the opposite way up to the other, then the pairs will attach to themselves magnetically at zero distance, this will give a very firm attachment.
Nigel, I don't know what "put one pair the opposite way up to the other", means.

I've used two part epoxy before, works OK but can fail after a lot of use, as Kamkar says - try to give it a key to hold on to. 3M pads work very nicely as long as they can cope with the magnetic pull when you separate the camera from its base, your magnets may be a bit too strong for it. The strongest solution I've used was to put a single sheet of very fine weave carbon fibre fabric over the top of the magnet and a small area around it and soak that in epoxy.
"When you put the sheet of carbon fiber over the magnet and a small area around it and soak that in epoxy"
Does this mean put one magnet on the plate/plastic, cover with carbon fiber, and soak epoxy over the fiber and magnet to glue it to the plate/plastic ? Then do the same for magnet # 2 ?
 
A trick I use to mount magnets to plastic (expired credit card in my case) is to:-
1) cut piece to size to mount on camera.
2)set magnets in position and mark it.
3)remove magnets, put plastic on top of metal piece, (on top of tin can or any piece of ferrous material) and put glue on marked magnet position. (If you use epoxy) Not necessary if using VHB tape.
4) place magnets in glued position.
Magnets will stick to ferrous material through plastic and thereby bond in position to plastic as epoxy dries.

Once magnets are in position in camera, then do the same to mount.

That I understand, sounds like a very good idea.
 
"When you put the sheet of carbon fiber over the magnet and a small area around it and soak that in epoxy"
Does this mean put one magnet on the plate/plastic, cover with carbon fiber, and soak epoxy over the fiber and magnet to glue it to the plate/plastic ? Then do the same for magnet # 2 ?
I think this method is unnecessary for mounting a 100g camera, you should be OK just gluing the magnets in place or using 3M pads, but if you want to use the carbon fibre then I suggest you put the two magnets on the camera touching each other, one with the north pole up and the other with north pole down, then put the carbon fabric over both, then soak the fabric in epoxy to turn it into carbon reinforced epoxy. Don't overdo the amount of epoxy, you just want to soak the fabric leaving it as a thin sheet over the magnets holding them down all around the edges. That method should be good to lift 10Kg - 100x what you need.
 
I think this method is unnecessary for mounting a 100g camera, you should be OK just gluing the magnets in place or using 3M pads, but if you want to use the carbon fibre then I suggest you put the two magnets on the camera touching each other, one with the north pole up and the other with north pole down, then put the carbon fabric over both, then soak the fabric in epoxy to turn it into carbon reinforced epoxy. Don't overdo the amount of epoxy, you just want to soak the fabric leaving it as a thin sheet over the magnets holding them down all around the edges. That method should be good to lift 10Kg - 100x what you need.
Thanks Nigel, I understand perfectly now. I ordered some 20MM x 2mm magnets from BangGood. last night. These are more in line with what you were telling/advising me to use. So now I don't have to worry about magnets, I've plenty to play with. I'll start with the 20mm x 2mm and see how it goes. I,m going to get some 3M 5952 tape also and give that a try as suggested.

On the Mobius camera I guess the 1 inch wide roll would be the most desirable, is that correct?
 
1 inch = 25.4mm so you will have a bit spare, if you put it on the magnet first then it is easy to trim off the excess if you want it to look neat, easiest with non-magnetic scissors!

I hope that 3m tape is strong enough, I know it will easily work with 2mm magnets against steel, probably OK with 2mm against 2mm magnet but you might want to key the surfaces a bit with abrasive, take care to clean the surfaces properly and then leave it attached for a few days for the glue to set properly before abusing it - a greasy fingerprint for it to attach to would not be good.
 
1 inch = 25.4mm so you will have a bit spare, if you put it on the magnet first then it is easy to trim off the excess if you want it to look neat, easiest with non-magnetic scissors!

I hope that 3m tape is strong enough, I know it will easily work with 2mm magnets against steel, probably OK with 2mm against 2mm magnet but you might want to key the surfaces a bit with abrasive, take care to clean the surfaces properly and then leave it attached for a few days for the glue to set properly before abusing it - a greasy fingerprint for it to attach to would not be good.

Thanks Nigel, I understand, I've handled situations before where handling gluing projects correctly was essential.

I was looking at the 3M tapes today on line and in the 5952 family there is a tape #5962 which sounded even better then 5952. It is a little thicker (foam) then 5952, that should help some in dampening vibration from rough roads or whatever. Have you ever heard of anyone trying it (5962)?
 
Thanks Nigel, I understand, I've handled situations before where handling gluing projects correctly was essential.

I was looking at the 3M tapes today on line and in the 5952 family there is a tape #5962 which sounded even better then 5952. It is a little thicker (foam) then 5952, that should help some in dampening vibration from rough roads or whatever. Have you ever heard of anyone trying it (5962)?

Thicker foam!! Not a good idea. You want a solid mount. Any vibration will show up as jumpy.
 
Thicker foam!! Not a good idea. You want a solid mount. Any vibration will show up as jumpy.
Hi Bungus, Well, you guys are the experts, I could have made another big mistake. I thought a cushion like the thicker foam would help in absorbing, road chatter, tire not quite balanced, etc,. I guess you have been through doing this, nothing like experience.
 
Hi Bungus, Well, you guys are the experts, I could have made another big mistake. I thought a cushion like the thicker foam would help in absorbing, road chatter, tire not quite balanced, etc,. I guess you have been through doing this, nothing like experience.

it would actually have the opposite effect and give you micro vibration, you'll get a better picture through solid mounting and keeping video in sync with any vibration
 
Hi Bungus, Well, you guys are the experts, I could have made another big mistake. I thought a cushion like the thicker foam would help in absorbing, road chatter, tire not quite balanced, etc,. I guess you have been through doing this, nothing like experience.

I'm no expert. I also learned from mistakes. Sometimes expensive. I'm also very grateful for members here for their expert advise and sharing their expertise. You too will learn and later share with others that needs it.
 
it would actually have the opposite effect and give you micro vibration, you'll get a better picture through solid mounting and keeping video in sync with any vibration

Hi Jokiin, thanks for the reply. I went up to Home Depot today to pick up some 3M 5952, they only had a few on the racks and not a single package had a part # number on the package. The only identifier was a "Lb" figure and the highest was 20 lb. It seems I remember seeing 5952 had a pound figure of 30Lb so I didn't buy it. I'll check it out at 3M to be sure.
Hard to believe that as much as they want for the stuff they can't put the part # on the package instead of a Lb rating or actually both. One doesn't actually know what they are getting!
 
Back
Top