Rare earth magnets - attaching 'em

[mclarkson]

I'm thinking of using strong magnets in various places in my fleet, but I'm not sure how best to do it. What is best practice?

How do I attach them in a way that's stronger than the magnets' attraction? Will CA glue do it?

Should I use magnet/magnet or magnet/metal?

Any tricks for drilling out the 'socket' for the magnets to go into?

Any random recommendations?

Danke!

[Grasshopper]

I usually use sand paper to rough up the side I want to glue, clean it with alcohol and glue in place with a little epoxy. I haven't had one come loose yet.

[CHELLIE]

I use a magnet on one side, and on the other side, i use a 1/2" roofing nail, they have a big flat head that works great to hold the magnet, i also epoxy the nail in place, if the bond has to be really strong, then use magnet to magnet, hope that helps, Chellie

[Stevephoon]

What are you attaching the magnuts to?? I have used thick CA on balsa with no issues so far. I have done both magnut to magnut and magnut to a flat washer. I think it depends on the holding strength needed and the fit of the parts....

I drilled a hole in a piece of balsa as thick as the magnut, then glued that to balsa backer glued the magnut in then glued the whole thing to structure.... It all depends on the hold force required. I don't think there is a right or wrong answer, but you'll never be sure until you try.

The more I build, the more I see different ways to do everything and they all could work in the proper settings.

If you have a pict or can describe what is being held together, that would help.

Steve

[Grasshopper]

Good point Chellie. I use a small flat washer on the other side, rough it up and epoxy it in place too.

[mclarkson]

Thanks guys. This would (usually) be in foam, as that's all I fly at the moment. Thinking about various uses (making Radian's wings more secure, putting a canopy on my flying wing, etc. etc.)

Chellie, do you really use that whole nail? That'd stick pretty far out the bottom of my flying wing!

[hillbillynamedpossum]

Ive had pretty good luck with low temp hot glue.

As far as drilling out a pocket goes, get you an assortment of "brad point" drill bits. they are about $5 a piece and drill a nice flat bottomed hole.


Possum

[Saddlebum]

I've been succesful dropping the magnet into a bed of epoxy and letting the epoxy cover the top of the magnet with a thin coat, so it is encapsulated.

I added six rare earth magnet to the wing roots of my Radian and now the wing "snaps together".

...The Bum

[CHELLIE]

Originally Posted by mclarkson

Thanks guys. This would (usually) be in foam, as that's all I fly at the moment. Thinking about various uses (making Radian's wings more secure, putting a canopy on my flying wing, etc. etc.)

Chellie, do you really use that whole nail? That'd stick pretty far out the bottom of my flying wing!

Gee, Dont you Like The Goth Look JK, Cut the spike of the nail with Dikes if its to long, Gee I failed to mention that LOL, Take care, Chellie

[eagle33]

I used 1/2" circular magnets at the wing roots of my Hawk Sky (just back from the leading edge and just forward of the trailing edge). Fastened them to the foam with Great Planes 30-minute epoxy. They work great and the wings now snap together.

[Glacier Girl]

I now mark the two mating ends when I use two magnets together.
Nothing worse then gluing them in only to find they repel instead of attract.............
Simple magic marker on the two ends that need to go together. Wipes off afterwords.

For cutting out foam for them, I go one of two ways. Dremel with a cutting bit, or a heated metal rod.

Also if you take a T pin and poke it into the foam it lets the glue get down into it. So rather then a surface bond, the glue gets a better bite.

And like Tom, I sand the face and sides of the magnet for the same reasons.

I use a washer on the other side if it's a low strength grab that's needed. Dual magnets if I need a stronger one. Or you can even use magnets on top of each other (doubles the strength) to make a really strong bond.

[Grasshopper]

If you're ever looking for a cheap place to buy rare earth magnets, here's a place I've used. Shipping is free on most items. It can take a couple of weeks to get items from them but I've always received my stuff in good shape.

http://www.dealextreme.com/p/super-s...m-20-pack-4248

They have several sizes. Just do a search for rare earth magnets.

[mclarkson]

Thanks, Grasshopper. I just ordered a bunch from them.

[Grasshopper]

Originally Posted by mclarkson

Thanks, Grasshopper. I just ordered a bunch from them.

Any time. I've also ordered some of their smaller ESCs too. They work great on the little foamies and are cheap.