I have been using a magnetic building board for many years and would never consider going back to the old way of pushing pins into balsa and then into the building board. Ugh! my thumb can still feel the pressure of the pins!
A magnetic building board is accurate, clean and efficient. It can be built at a relatively low cost and I will show you where to buy the components.
I have been using a Great Planes system for many years but this is no longer available.
The system can be used to build fuselages, wings, tails and all the parts required for a scratch built model airplane.
The power of magnetics can be used to make assembly fixtures for many sub-assemblies and you will soon learn to adapt and enjoy the flexibility that the magnet can offer.
We need to locate a piece of sheet metal to form the building surface. We need a piece large enough to build the biggest component we think we are ever going to build.
The thickness needs to be about 1/32" (0.8mm) or 22 Gauge and it should have some kind of plating that will prevent rusting.
I was able to find a piece at my local Lowes store that was perfect for this application. It is 48" (1219mm) x 24" (609mm) x 1/32" (0.8mm) and is hot dipped galvanized.
Here is a link to the U.S. Lowes site- Click here. The price is shown as $32.48US.
For us Canadians there is a Canadian equivalent- Click here. The price shown here is $48.99CA.
The description of the material is " Hillman 24-in W x 48-in L Hot Dipped Galvanized Steel Solid Sheet Metal"
Alternatively you could find a local sheet metal supplier who should have similar material for your magnetic building board.
We now need a stable and FLAT surface to place the sheet metal on. Let us not go too far in our search for the ideal magnetic building board!
Some RC modelers have used granite which I consider an overkill! A solid core or maybe even a good hollow core door can fill the bill. MDF of 3/8"or 1/2" thick would be good, as long as it was placed on a solid base like a workbench.
Flatness can be measured with a 36" metal straight edge, on edge, across the surface.
I have used an old drawing office reference table that has some kind of plastic coated top that is good and flat, and the sheet metal piece is simply placed on top. No glue or screws are necessary.
I have also used, with complete success, a melamine topped, folding table that I bought at Office Depot. Take a look here.
This is the type of ceramic magnet that I use. Note the 2 steel plates on each side of the magnet. These act as poles and increase the magnetic force of the magnet.
I used to Zap the plates in position but have stopped doing that. I get more flexibility by leaving them free.
They can exert 12 lbs of pull force.
In this photo we see the magnets in use. Notice that when used to position spars and ribs that the side plates are not used. The magnets are set to "attract" each other and clamp the part in place.
The magnets are available on Amazon. Just click here or on the photo to visit the Amazon page.
Price today is $18.00US for a pack of 24. I would suggest you start out with a minimum of 48 magnets and more as you gain experience.
They are also available as a pack of 100. Click here to see the page on Amazon.
Master Magnetics, in the U.S is also a good source. Click here to visit their site
This first video shows the basic principals of using a magnetic building board well.
Note that there is a plate of glass under the sheet metal. This is a way of ensuring that the building surface is flat. If the table it is placed on is not flat,make sure that the glass is shimmed up with paper so as it does not tend to crack when any weight is applied to it.
This video shows a Sig Spacewalker wing construction
One item worth building is a combination hold down and fuselage side guide. It uses material you may have in your workshop and tools you probably have.
It can be adjusted vertically to different heights or the clamp can be removed completely if it is used as a fuselage guide.
Click on the image to access a PDF file of the plate. It is cut from 3/16" thick plywood and the PDF template can be pasted to the plywood prior to cutting out.
Make sure the downloaded image is exactly at the correct size. You should be able to adjust the image a few points to get a 1 to 1 image.
Click on the above image to access a PDF file, that can be printed.
Take a look at this page. Airfield Models is a very interesting site and has a lot of information on magnetic building.
You can buy many parts and magnets from here and I am sure they are all of first class quality.
Note that the majority of the photos above show the construction of a 1/10 scale Fairey Swordfish. This is a model of my own design and features interlocking construction.
This means that a lot less magnets are required for alignment.
For more details of the Swordfish Click Here