![\"8003\"](\"http:\/\/www.balsaworkbench.com\/wp-content\/uploads\/2020\/09\/8003.jpg\")
<\/a><\/p>\nChuck also designed several very popular RC planes including the Lazy Ace, and he manufactured kits of some of his designs. \u00a0One of the topics that Chuck liked to cover in his magazine column was float design. \u00a0During the heyday of monthly magazines\u00a0new guys were always coming along and asking the same old questions, so Chuck would simply re-run his old article on floats every so often. \u00a0The article tells you how to calculate the dimensions of your own set of floats for whatever airplane you happen to have. \u00a0Once you have the dimensions, you cut out the foam, you add a hard spine, and you finish the float to whatever extent you are satisfied with. \u00a0Chuck liked things quick and easy, so he would sometimes reinforce the bottom of his floats with tape and leave it at that.<\/p>\n
If you’re not into cutting foam, skip ahead to Part 3<\/a> of the Cunningham float series, which addresses floats made of wood.<\/p>\n Following Chuck Cunningham’s directions from the magazine (probably the last time it was reprinted in RCM) I built a couple of sets of foam floats for myself and a friend. \u00a0I covered them with 1\/16″ plywood on the forward part of the hull bottom and 1\/16″ balsa everywhere else. \u00a0Then I brushed on Balsarite (similar to Sig Stixit) to enhance film adhesion and waterproofing, then I finished the floats with\u00a0yellow Super Monokote. \u00a0The whole project was a resounding success, and I had a great time flying my plane on floats. \u00a0Unfortunately my friend’s Cub got stuck in a tree about 40 feet off the ground, but I guess you can’t win them all.<\/p>\n I’ve been thinking for years that I should\u00a0do some more float flying, so now I’m going to build a set of Cunningham foam floats, and I’m going to document the process here to show you how easy it is. \u00a0First, here’s Chuck’s article.<\/a>\u00a0 You can open it in a PDF reader and refer to it as we go along.<\/p>\n My new float plane is an Aerostar 40, so the first thing I need to know is that my floats are 3 inches wide. \u00a0Calculating from Chuck’s guidelines I figured out that my total float length is 36″. \u00a0From there I got the other dimensions and cut out the float sides from 1\/16″ balsa.<\/p>\n You probably guessed that I cut these out on the laser cutter, and you would be right, but this whole project is very easy to cut out with a long straight edge and a hobby knife.<\/p>\n The next thing I did was I took out the big plank of white styrofoam I’ve been hanging onto for about 20 years, thinking I would build a set of foam floats some day. \u00a0Well, today is some day and\u00a0I’m building floats! \u00a0I used a plain sheet of 3 x 48 balsa wood pinned to either side of the foam plank as a template for cutting out two\u00a03 x 3 x 48 blocks of foam with a hot wire.<\/p>\n This is the view from the side, where the balsa skin is to be stuck on and then used as a hot wire template.<\/p>\n The cores were then passed\u00a0through the table saw to make a half inch wide groove\u00a0for the 1\/4″ plywood spine. \u00a0I\u00a0want the top of the spine\u00a0to\u00a0be flush with the 1\/16″ balsa skin, so I made the groove 3\/16″ deep.<\/p>\n According to the article, Chuck drilled the plywood spine with 1\/4″ holes in several places for dowels to anchor the spine into the foam. \u00a0Since my laser cutter doesn’t like 1\/4″ plywood I make all such pieces out of two layers of 1\/8″. \u00a0I made one\u00a0layer\u00a0with holes and one without, so the dowels will go through only the inner layer, and the outer layer will be smooth and pretty.\u00a0\u00a0Where Chuck made a few large holes, I opted to make a larger number of smaller holes. \u00a0I ended up with eight holes 3\/16″ in diameter.<\/p>\n First I cut eight pieces of dowel, each one long enough to anchor the spine but not long enough to protrude past the finished depth of the float. \u00a0The dowels were numbered and lined\u00a0up in order.<\/p>\n The plywood strip was taped into place in\u00a0the groove to make sure it couldn’t move<\/p>\n A 3\/16″ music wire rod was used to melt holes into the foam for the dowels.<\/p>\n The dowels were used to measure the correct depth on the hot wire, and the wire was gripped with a pair of pliers at the correct length, and then inserted into the holes to melt the foam underneath.<\/p>\n Here’s the foam core with the holes.<\/p>\n The holes were filled with glue, then the groove was coated, and the strip was laid in place. \u00a0The dowels were inserted through the holes. \u00a0I suppose I should have taken a photo of that step. \u00a0Then more glue was added on top and the top strip was laid in place. \u00a0The whole thing was weighted with heavy jars. \u00a0Because the top is to be sheeted with 1\/16″ balsa, the spine sticks up a bit above the surface of the foam. \u00a0To keep the jars level, 1\/16″ balsa shims were added on either side of the spine.<\/p>\n I eventually got the whole spine held down with weights, and now I’m waiting for it to dry.<\/p>\n If you don’t pickle your own home grown jalape\u00f1os you’re missing a good thing.<\/p><\/div>\n In retrospect, it would have been a good idea, probably a better idea, to attach the top plate in one piece, as was done in the wood floats in Part 3. \u00a0This is done by gluing the top balsa on either side of the hard spine to make a single top plate, as shown in the following photos.<\/p>\n Do it either way, and it will be a good float. \u00a0For my own part, I would prefer attaching the top in one piece.<\/p>\n Check Part 2<\/a> for the rest of the Cunningham foam float project.<\/p>\n","protected":false},"excerpt":{"rendered":" Back in the days when we learned about RC by reading hobby magazines there was a guy named Chuck Cunningham who was a columnist for\u00a0RC Modeler magazine. Chuck also designed several very popular RC planes including the Lazy Ace, and … Continue reading <\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/a><\/p>\n<\/a><\/p>\n