flyrotary@lancaironline.net Mailing List Archive

Ernest, Although I must agree with Ed, I also understand your approach. Mt very first job was in a Foundry, pouring molten metal by hand with an old chap on the other handle end of the crucible. Since then I've done a lot of things but I'm glad I moved on from that. Aluminium casting is, as much a dark art as much as it is science. Large thin parts are difficult without pressure injection casting- which is high cost Hand casting can leave unseen voids and evenly distributed bubbles in overheated metal - which all lead to low strength parts. The beauty of commercial plate is the consistency in strength, without porosity. That's why Tracy used plate instead of a cast bellhousing. There wouldn't be enough demand to set-up for a pressure injection unit which is the compromise between strength , cost and weight. For motor mounts I would use chrome molley. George (down under) I was getting worry, Ernest about the "level" to which you were descending to produce components - I figured next you would start building an electric ore furnance to smart smelting your own aluminum for you casting efforts {:>) Personally I think you are better off machining it out of know quality plate aluminum - as you have undoubted found out consistency can be difficult to achieve with large castings of aluminum - and therefore strength and hidden flaws can be of concern - particularly when used as a motor mount. We all want you to stop goofing off and fire up that engine - its been - what three years or more since I flew up and blessed your engine assembly {:>) - and still no engine start? Get busy, Ernest and stopped getting diverted by undoubtedly interesting - but time consuming side projects. There's way too many projects and only so much time (and money) to build and airplane{:>) Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com -------------------------------------------------- From: "Ernest Christley" <echristley@att.net> Sent: Tuesday, October 05, 2010 9:51 AM To: "Rotary motors in aircraft" <flyrotary@lancaironline.net> Subject: [FlyRotary] Re: Permanent Magnet Alternators Kelly Troyer wrote: Todd and Ernest, Anything to report on your Permanent Magnet Alternator installations ??............... I spent last Saturday trying to cast an aluminum mount for my rotor. I'm really not happy with the sheet metal mount I built. I've been practicing casting, and I've made several parts, including a couple of crank angle sensor mounts (1/4" of aluminum makes for a really stiff mount). It turns out that the difficulty of metal casting is proportional to the cube of the parts size. Right now, I have a chunk of aluminum the size of a one-gallon paint can stuck in my furnace. I ran out of fuel just as the last ingot was starting to melt, and after that disaster I discovered a small hole had formed in my crucible and was slowly filling the bottom of the furnace. That's when I decided that I would just order a 12"x12"x2" 6061-T3 aluminum plate and machine it. I started down the path of a casting before I bought my 12" lathe, but the machining makes more sense anyway. This is the last major part I need before moving on to an engine start, so the delay kinda sucks, but at least I have a new skill. I'm going to apply it to making tap handles for the kegs that we use at work during our Friday Beer Bash. -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html