Rare Earth Magnets and LOR Controllers

[dibblejr]

In my quest to come up with an easier way of setting up my ccr Mega Tree I am contemplating some small rare earth magnets. I have been looking and for the size of my 1/2" emt conduit I can get anywhere from 13 to 88 lbs of strength each.

We used rare earth magnets in the military but never around electronic equipment.

I know if I had a large enough rare earth magnet and laid a controller or ribbon strip on it could/ would damage it but I am wondering if the emt conduit would act as an insulator to prevent damage. I'm thinking only 3 or so would be required per section using an 88 lb magnet but probably more with the 13 lb.

These magnets are about 1" diameter and have a predrilled hole. Perfect for emt.

Thoughts, anyone using the, with pixel stuff.

My thought is to stop using straps and use a hook at the top and then 2-3 magnets for the rest, would make setup and take down fast.

TIA

JR

Edited January 5, 2019 by dibblejr

[TheDucks]

As long as you don't move them past (fairly close) the transformer in the AC controller, I see no problem.

Pixies and CMB24D have no inductors that could be driven by a strong magnet moving close.

 

[dibblejr]

16 minutes ago, TheDucks said:

As long as you don't move them past (fairly close) the transformer in the AC controller, I see no problem.

Pixies and CMB24D have no inductors that could be driven by a strong magnet moving close.

 

Im talking pixels not AC controllers. However last I knew a large enough magnetic field could interfere with data transmission. The same reason we wouldn't put magnets near the old 12" floppies unless we needed to destroy them in a hurry,

Not worried about the controller since the magnets would be near the ribbon which have a chip, controller is about 2' and more from each strip.

JR

 

[k6ccc]

I'm not quite sure I get what you are trying to use the magnets for.  I gather that your ribbons are mounted to EMT.  You said that you would use a hook head at the top.  I get that far, but are you thinking about using magnets to hold the bottom of the strip in place by putting a magnet on a bottom piece or on the strip to stick to a bottom piece?

When I say "bottom piece", think an A frame with the cross piece way down low such as my pixel tree:

 

[dibblejr]

32 minutes ago, k6ccc said:

I'm not quite sure I get what you are trying to use the magnets for.  I gather that your ribbons are mounted to EMT.  You said that you would use a hook head at the top.  I get that far, but are you thinking about using magnets to hold the bottom of the strip in place by putting a magnet on a bottom piece or on the strip to stick to a bottom piece?

When I say "bottom piece", think an A frame with the cross piece way down low such as my pixel tree:

 

Jim- My original design was sort of based on yours. My second design was even closer to yours. 

My latest design is a large AL frame. The frame is very light, very. But very difficult to erect on its own. Add the strands and its 16X more difficult. It has cross members and currently use emt straps at the top and 4 other cross braces going down the frame including the base. For me it is a major pain setting it up and taking it down. This last season I doubled the pain because after setting it up discovered 6 bad ribbons. So it had to come back down and because of the qty being bad and not chancing color variations I changed all 16 strips.

At that time I started thinking of a better/ easier way.

The plan

Use existing top holes and place a hook on the top support. The hook would really only ensure that if something did go wrong the strand would not fall. (peace of mind).

Then screw a rare earth magnetic in 2-3 of the cross braces where the emt intersects. No need for EMT straps and I think the 88lb magnet in 2 or 3 spots should be overly sufficient to hold the emt in place.

I just worry about the data transmission and the pixel pcb. Possible interference. I did research on google and it says bad things about placing rare earth magnets on electronics so figured Id post it up tp see if anyone is using them for their lights.

JR

[k6ccc]

OK, so the hook head at the top is supporting the weight, and the magnets are on multiple cross pieces attract the EMT and keep it aligned.  You have multiple horizontal supports.  So the construction process would be to erect the empty frame, then hang the strips by holding them up to grab the hook at the top and then settle the rest of each EMT onto it's magnets.  The rest of my comments are based on that assumption.

Off hand, I doubt you need as much magnetic force as you are talking about.  Of course since the round EMT is engaging the flat surface of a magnet, you are not getting the full strength because only part of the EMT is in contact with the magnet and most of it is spaced a small distance away from the magnet.  Since the magnet is only keeping the EMT from moving horizontally  (either left / right as viewed from the audience, or pulling off the magnet - i.e. towards the audience), there should not be that much force on it.  Static force would be quite small, but high winds would add to that quite a bit.

I would be surprised if the magnetic field bothered the pixels, but you will have to test that to see.  Let us know the results.

1 hour ago, dibblejr said:

However last I knew a large enough magnetic field could interfere with data transmission. The same reason we wouldn't put magnets near the old 12" floppies unless we needed to destroy them in a hurry,

Remember that floppy disks are a magnetic storage medium - hence the reason that a magnet would wipe the data from it.

One thing to keep in mind is that Neodymium magnets are fairly brittle.  You could end up with an issue of the magnets cracking when the EMT slaps into place.

One other note.  The photo I posed above is my 2012 - 2017 version of the tree (slight change in 2014).  That version would get assembled on the ground and erected fairly easily with three people - one on each bottom leg and me walking the top up a ladder.  With my 2018 version (four times as many pixles, two controllers and four power supplies), I knew that the unistrut frame could not survive that erection method so I erect the steel frame with only the star and pixel controller box at the top and the power supply box at the 11 foot mark installed.  Then the strips were added using a 12 foot ladder.  I am going to make a slight change when I take it down and for next year's construction.  Besides the 24 strips, I will also remove the pixel controller and power supplies boxes before taking the frame down.  Each of those is only two bolts.  In the photo below, you can see a horizontal cross piece at the 11 foot level that has the power supply box mounted to it.  That piece also is the attachment point for the strut back to the eve of the house that keeps the whole tree vertical.

 

[dibblejr]

K6CCC - didn't want to quote that reply, thanks.

I took the breakage affect into play. They actually make a special coated rem that adds a layer of protection from this but I will be using a ladder to get the top over the hook and as gently as possible place the strands to the magnet.

I don't take the frame apart. Its been standing upright outside since I purchased in May 2017. I didn't use it until Halloween 2018. Its a self standing frame. I did place wheels on it today after taking it down. Its some of the strongest square AL tubing I have had. Def not the cheap stuff my matrix frame is made out of. Because of where I place it in my driveway I use red heads to secure it. During setup I realized just how difficult it was so last week I add hinges to the hold down point. This allows 2 people to be able to tilt it down without the base kicking out. That helped a lot but as lights as emt is, it still was a bit heavy. 

I started researching the magnets a few weeks ago but today with all the broken screw heads and the time it takes to unstrap it made me decide I would try this.

I will def test. The good on that is I am storing the strands in my garage hanging above the garage doors so I can stick the magnets on them, hook them up to the controller and test for unwanted affects.

Not being a pcb person I do not know what they are composed of. You are correct though, I may not need 88 lbs for each. I may go with 88 on base and 13 on the other 2 supports. I may even gp with just rem's and no hook at the top after thinking more, though I still like the peace of mind.

The frame is large enough that this year I will be adding 8 more strands as well. Had to use my stash to replace the 6 bad ones or it would have happened at Christmas. Thanks to Brian and SS makes it easy to make the sequence fit the larger tree,

JR