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Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 1:01 pm
by Simple
I have been thinking about a Magnetic non pen. roof mount that involves some engineering. I would like the mount to be 2 parts. 1 part inside the attic attached to the roof stud. This would be an angle mount that screwed to the stud and had a flat plate parallel to the roof angle with powerful magnets on all threads attached to the plate. Im unsure how many magnets it would take but they need to be able to thread away from the interior roof surface. The outside part would be a solid plate with a matching amount of magnets so that when the inside pieice is attached and in place would simply attach to the surface of the roof using magnetic presure. The plate could have a J-arm or even just a small mast. I do not pocess the proper engineering background to manufacture such a device, and feel safe installing it on a residence, however I know getting the convo started might bring this much needed device to the market. RF Armor I feel is more than capable. I have passed on quite a few installs because I refuse to do what my competitor does by simply screwing a J-arm to the peak of a brand new homes roof.

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 1:23 pm
by rebelwireless
sounds complicated, pricey, and risky...

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 2:13 pm
by sirhc
Yea you would need POWERFUL magnets (rare earth) and they are pricy.

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 2:32 pm
by lligetfa
The problem is with the gap created by the sheathing and then the shingles. The strength of the magnetic pull is subject to the inverse-square law.

In coating engineering, a magnet is sometimes used to measure the thickness of the coating on metal. The force required to break away from the attraction is used in the calculation to determine the gap and therefore the thickness.
http://www.defelsko.com/technotes/coati ... rement.htm

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 3:19 pm
by rebelwireless
also this would only work, if you got powerful enough magnets, on non-ferrous roofing. I do understand the want for a non-pen system, but there isn't much except gravity or straps to accomplish this.

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 3:22 pm
by sirhc
rebelwireless wrote:also this would only work, if you got powerful enough magnets, on non-ferrous roofing. I do understand the want for a non-pen system, but there isn't much except gravity or straps to accomplish this.


Have you seen the price of gravity lately.....it just is not in our budget

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 3:29 pm
by Simple
rebelwireless wrote:sounds complicated, pricey, and risky...


That pretty much sums up every engineering challenge I've been involved in. I will have to go it alone on this one I think. Thanks for the input guys.

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 3:56 pm
by lligetfa
OK, when you do find a strong enough magnet, post a YouTube video of you trying to unstick it from the bed of your pickup truck. :rofl4:

When handling it watch you don't get your fingers between it and metal.

https://www.youtube.com/watch?v=0t8yDnyOaQ8

Re: Non Penetrating Roof Mount

Posted: Sat Jul 11, 2015 4:02 pm
by rebelwireless
keep in mind that magnets have poles, and so that implies that their strength is in a specific direction of pull. In other words, the mount might be stuck on nicely from lifting force, but a little lateral force and it will slide of with an order of magnitude less force. To solve this you need something to stop the lateral slide, which would be mounted on the roof and the rooftop magnet. Some epoxy or something maybe. Very complicated mount when a lag bolt and some caulk would be better.