Poor Man’s Magnet PCB Holder – Every Expense Spared!

Each of these magnetic PCB holder stanchions can be built for much less than $1 each. And the whole set up can be built for less than $15 – including the storage rack!

This system for making a magnetic PCB holder is so cheap and easy, and works so well, that I wanted to share it.  It holds the board firmly even with cables attached.

Note: Click on the images for higher resolution.

Rationale
I was looking for a method to hold circuit boards while I was working on them. Mostly I was concerned with securing the board during debugging – to keep the board in place with cables attached and to prevent shorting it out while probing. The board I was working on at the time was an odd shape; so, I was drawn to the magnetic systems which seemed the most adaptable. The commercial solutions I saw weren’t too terribly expensive – if you only wanted one. But I often worked on multiple boards at the same time; and so, I wanted to have multiple PCB holders at a reasonable cost. Over time I developed this system made from simple hardware and Dollar Tree items.

Stanchions

The stanchions are just stacks of magnets with hardware glued on top.  The magnetic stanchions can be used in several ways on PCBs with and without mounting holes. The rubber grommets provide a non-conductive slot to fit the edge of the PCB.  Just glue the standoff to the top of a magnet and push the grommet down over the standoff. You can adjust the stanchion height by stacking more magnets or you can stack another standoff on top.  I chose ceramic magnets because they are cheaper than rare earth magnets and they are nonconductive.  On top, I use a Female-Female standoff instead of a standard nut because it is much easier to handle with my stubby fingers.
Lesson Learned: Place the standoffs off-center on the magnets. This helps the stanchions to avoid interfering with components on the backside of some boards.

Metal Base
The base can be any sheet of ferrous metal, but I use steel baking pans. Dollar Tree has multiple choices; but, baking pans are the jetsam of yard sales and thrift stores. Use a pie pan for small boards and a pizza pan for larger boards or for more working space.  I prefer a round base so I can rotate the work without shifting things out of the way.

Angled Holder
If you prefer to work on a PCB that is angled toward you, 45° adapters can easily be made using office binder clips.  Magnetic attraction to the binder clip doesn’t hold strongly enough; so I glued a magnet to each side of the clip.

Storage Rack
And finally, you may need a way to conveniently store your PCB holders. I came up with a $1 storage rack made from a pair of kitchen cooling racks from Dollar Tree – just bend to shape and wire them together. The result is a surprisingly rigid structure. I put wire across the open side of the rack to prevent it from spreading; but, I don’t think this was really necessary.
[Click Here for Dimensions]

Helping Hand
And as a bonus, I show a magnetic based “helping hand” device. It is designed to be inexpensive; but, you may have to buy a lot more of the armature wire than you need. I paid $8 for 25 feet of armature wire; but this seems expensive to me. The key to attaching the aluminum armature wire to the base is cutting #4-40 threads on one end. The wire then threads into a 1/2 inch long standoff. BE CAREFUL – the aluminum wire is very soft and the threads will strip easily. I suggest gluing the wire into the standoff – but it isn’t necessary. The alligator clips simply crimp on to the other end of the wire.  After crimping, I struck the crimps a couple of times with a cold chisel (screwdriver?) to make them more secure.

Parts Lists

Stanchion:
grommet, 0.25 inch inner diameter; Mouser: 5164-5115
Standoff, #4-40, M-F, length 0.5″, hex, 0.25″ outer diameter ; Mouser, 761-4534-440-AL-7
Standoff, #4-40, F-F, length 0.25″, hex, 0.25″ outer diameter ; Mouser, 761-2100-440-AL-7
Magnets, Promag Round Magnets, 3/4″ dia. by 3/16″ thick, 50/pkg ; Walmart #563259471
Adhesive, cyanoacrylate (Super Glue)

Base:
Steel Pan, Cooking Concepts Pie Pan, 9 in. ; Dollar Tree, SKU: 10068
Steel Pan, Cooking Concepts Pizza Pan, 12 in. ; Dollar Tree, SKU: 10067
Cooking Concepts Stove Burner Covers, 2-ct. Packs ; Dollar Tree, SKU: 988891

Storage Rack:
Metal Cooling Racks, 9″x13″ , Cooking Concepts, (2-pack) ; Dollar Tree, SKU: 145657
Uninsulated Wire, 24 AWG

45° Adapter:
Binder Clip, 19mm, from nearest office supply cabinet (or Dollar Tree, SKU: 172855)
Magnets, Promag Round Magnets, 3/4″ dia. by 3/16″ thick, 50/pkg ; Walmart #563259471
Adhesive, cyanoacrylate (Super Glue)

Helping Hand:
Alligator clips, crimp style, fits 1/8 inch diameter wire ; Mouser, 835-501784
Armature Wire, aluminum, 1/8 inch diameter, 16 in length (Art Supply)
Everbilt, 3 in. x 3 in. Zinc-Plated T-Plate (2-Pack) ; Home Depot, Model # 15169, Internet #202033997, Store SKU #241202
Standoff, 4-40, F-F, length 0.5″, hex, 0.25″ outer diameter ; Mouser, 761-2104-440-AL-7
Fender Washer, 0.125 in x 0.75 in
Machine screw, #4-40, 5/16 in length
Magnets, Promag Round Magnets, 3/4″, 50/pkg ; Walmart #563259471
Adhesive, cyanoacrylate (Super Glue)

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