cajet

My Feedback: (10)

I am looking for ideas on how to make my wing tip sidewinders removable without using screws. I was thinking about a system where the missile slodes backward and the force of the air keeps it on there but also do not want those things vibrating in flight or coming loose.

Any help/pictures would be appreciated.

Thanks,
Jim

Dave03B

heavy duty velco? I've been faced with the same problem, on my F16, so far i've decided to leave them off....

DavidR

My Feedback: (1)

Jim,

I have a set of Nalpalm canisters on my Phantom that are held on with a piece of I channel "plastruct" that is glued to the bottom of the pylon, and then there is a piece of plastruct square tubing that has a slit cut in one side of it so that you slide it on. Slide the missle on from the front and you should have no problems.

DanSavage

My Feedback: (5)

Hi Jim,

Rare earth magnets.

Embed a pair into the wingtip and a matching set into the missiles. They will hold in flight and if they get bumped on the ground they will simply "break apart" instead of busting the mounts.

For extra peace of mind, recess one pair so they're about 1/32" below the surface and then when you glue in the matching pair, leave them raised above the surface by the same amount so they'll forms a "socket" for the magnets. This will more or less "lock" the magnets into place while still allowing them to "break apart" on the ground.

You can find neodim magnets at Radio Shack for a few bucks. I'd use either the 3/16" x 1/4" or 1/4" x 1/4" round magnets depending upon your missiles.

I also use them to hold hatches in place. Works great!

Dan

cajet

My Feedback: (10)

Dan and David thanks for the ideas. I have a hard time believing the magnets will hold in flight. I am going to go to radio shack to check this out. I guess the missile is clean so there may not be forces enough to break it off. What speeds have you tested that?

Heer

Solution of my F16. Important; Nylon-Screws easy and fast removable wing tip missiles.
Regards Fritz : www.jetmodel.ch

Dave03B

seems like a good solution to me.......cheers.[sm=thumbup.gif]

Dave03B

Heer....btw...what F16 is that?

here's my cbm F16 (.91) with amraams (one or two f16's apparently carry them on the tips.) (??)

DanSavage

My Feedback: (5)

~100 mph. Missile is clean so the aerodynamic forces aren't strong enough to break the magnetic bond.

Dan

cajet

My Feedback: (10)

I went and checked out those Magnets today... Wow now I can see how they would work.... They only had 1/8 magnets and the on lone store for radioshak was useless...no specs on the size for magnets. Will nee to find another source..

DanSavage

My Feedback: (5)

Check: http://www.kjmagnetics.com

They have all shapes and sizes to suit your particular application.

Dan

Heer

Dave 03 B

my F-16 is from Liebetrau in scale 1:6 fired with Behotec JB 165. More pics under www.jetmodel.ch

JetMax

My Feedback: (4)

Or you could take off with them and return without them. Ha!

RAMFlyer

My Feedback: (65)

[sm=confused.gif]Dan--Let's see if I understand correctly the pull force table at the magnet website!? If I used two magnets (magnet to magnet) that had a pull force of 5 lbs each, then the force to separate them would be a total of 10 lbs?? If the pull force works that way then these little things will hold a heck of a lot...

Is epoxy enough to hold the magnets into a wingtip or against a bulkhead with that kind of pull force or do they need to also be screwed down??

Bill

DanSavage

My Feedback: (5)

Hi Bill,

Until you mentioned it, I'd never seen the pull force table. Interesting. Thanks for pointing it out. Keep in mind their disclaimer at the bottom of the page: "* Note: All Pull Force values are approximate and assume a straight pull with the magnet in flat contact with a steel plate". IOW, ideal conditions.

The missile shown in the pic I posted uses two pairs of D42 magnets. Each has a pull force of 2.65 lbs. So, if we're reading the table correctly, then the total pull force holding the missile onto the wingtip is 10.6 lbs. (2.65 * 4) They are strong. That is for sure.

I can't say about how well epoxy will hold as we've only ever used CA. CA grabs and hold them (1/4" x 1/16" & 1/4" x 1/8" ) without a problem. I haven't found the need to screw them down as I usually just drill a slightly-undersized hold, then push the magnet in until it's flush with the surface, then wick some thin CA into the joint. I've never had a magnet pull out of a hole. I couldn't speak for the larger and stronger magnets.

Dan

cajet

My Feedback: (10)

Dan Thanks for the link!

Jim

DanSavage

My Feedback: (5)

You're welcome, Jim.

The only thing to keep in mind when using these magnets is that aren't very tolerant to heat. I read on the site that temperatures above 175F will cause them to lose their magnetism.

Dan

RAMFlyer

My Feedback: (65)

[sm=biggrin.gif]Thanks Dan--the site and info are great.

Bill

DanSavage

My Feedback: (5)

You're welcome, Bill.

Dan