lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> Bob, I've done my ailerons and elevators, yet to do the rudder on my ES, coming up soon though. I spent way too much time and money looking for the best counterweight solution. I wanted to have as dense a material as possible to have a lower net weight and also something easy to work. I first used the lead that came with the kit and "having fun" (per the manual) pounding it with a hammer yielded less than desirable results. It was very difficult to have a reasonable looking result that allowed all the travel required for the aileron. I then followed the lead shot cast in epoxy path, this was easy to work but the density was very poor. An SG 0f 6.3 compared 11 of lead. My next path was to add tungsten powder to the above mixture, the idea was that the tungsten would fill the gaps between the lead spheres and improve the SG. Some of the tungsten did indeed stay between the spheres but the majority sank to the bottom and the lead shot "floated" on top of it. The result was an SG 8.5, probably acceptable. But it is near impossible to work once it has cured. It cut through sandpaper like a hot knife through butter (a reverse analogy, sorry) also wore out my tungsten tools with little impact to the material. I finally settled on building a wooden mold, melted shot on my kitchen (gas) stove (while my wife was in, would you believe. Yet another testament to her long suffering.) in and old baked beans tin. Poured the lead into the mold, let it set, shaved out the undulations, roughened it up with 40 grit, bonded it to the aileron, wrapped 2 BID around it, Presto Chango, a perfectly dense, workable and good looking solution. The weight was attached toward the forward end of the arm on the aileron. I cut a piece of foam and set in between the weight and the forward curved part of the aileron with a loose micro mix. I did this on both sides as there were weights on both sides (top and bottom). I then wrapped the 2 BID cloth around that. The point was to make a rigid structure to prevent the weight from vibrating at the end of the arm. The lead was very easy to work with an open rasp. That is a rasp that has openings on the cutting surface. Cost about $5 at Home Depot, you local aeroparts store. Please refer to my web site ( http://www.teleport.com/~peweston ) for any details of this that I may have forgotten here. Someone on LML mentioned that they used solid tungsten rods. This would be the best of all, if the rods are affordable. 10 pounds of Tungsten powder cost me over $100.00. Keep on Sandin' Pat "Only three short years to go!" http://www.teleport.com/~peweston LML website: http://www.olsusa.com/Users/Mkaye/maillist.html Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com.