One way is to use a fly cutter to cut out a hole from MDF that is the diameter that you need . The plug that comes out will be what you'll use for the die. You can use a 45-degree chamfer bit on your router and go around the edge of the plug with it, creating the beveled edge you need. It ends up looking like the piece in Eric's manual.
As for welding, which welding are you referring to? The steel parts in the wing (a few brackets for pullies and such) or the fuselage itself? In either case, the answer is pretty much the same. You'll typically either use an oxyacetylene torch, or a TIG welder (your preference). There are a lot of religious debates about the merits of both, but in the end it comes down to your preference. I have both and plan to use both, depending on the need at the time.
There is also some aluminum welding to be done for the fuel tanks. That can also be done with either an OA torch or TIG.
EAA has some nice videos available about both welding technologies that you can learn a lot from. Also, SportAir Workshops in January in Oshkosh (the ones that Brooks and I talked about with you earlier in this thread) teach gas welding. There is an EAA TIG workshop that is typically held in the Lincoln facility in Georgia in the spring that you could look into. Also, local technical colleges often teach classes in different types of welding. That would be a good choice if you're limited to something closer to home.
If you find that welding isn't your thing, or don't care to take up the task, then you can always buy the frame and other steel parts, as well as the aluminum fuel tanks, from Mark Goldberg at the factory. If that's not to your liking, you might be able to find a project that someone else isn't going to finish and buy that. It'll give you a good jump on the process.
Lastly, if none of those work out, then maybe a steel-tube airplane isn't for you.
You could also join your local EAA and seek help from experienced homebuilders/welders in the EAA chapter. Airplane people tend to be pretty generous with their time and skills to help out newcomers.
You could also join your local EAA and seek help from experienced homebuilders/welders in the EAA chapter. Airplane people tend to be pretty generous with their time and skills to help out newcomers.
Very true. For more expensive pieces of equipment, it's likely a chapter member has the equipment you need, and would gladly loan it to you or offer their services.
Christopher Owens
Bearhawk 4-Place Scratch Built, Plans 991
Bearhawk Patrol Scratch Built, Plans P313
Germantown, Wisconsin, USA
If you use the rubber press method, no die is needed.
First, you use a fly cutter or hole saw to put the appropriate size lightening holes in your routing templates.
Then you use a 45 degree router bit to chamfer these holes. Set the router depth so that you get around a 3/8 or so chamfer.
Put the router template on a steel plate in the press.
Put the rib blank on the template, locating it with the jig holes.
Put some rubber mat on top of this. I used some old ESD mat but rubber floor mat likely would work as well. Use enough layers to get about 1/2 inch build up.
Put a good thick (1/2" or so) steel plate on top of the rubber and then press it
Basically, when you press the stack up, the rubber "flows" and forms the aluminum.
Work your way down the rib until you have all the hole flanges formed.
You will need to route reliefs into your master form block to clear the lightening hole flanges when you hammer in the edge flanges.
If you look through my LSA wing build log (can be found in a few different posts in the LSA Scratch Build forum), you will see this method applied to the aileron ribs
Harbor Freight has their 20-ton hydraulic arbor press (the preferred version) on sale for $149. Now is the time to invest! You certainly won't regret it.
Christopher Owens
Bearhawk 4-Place Scratch Built, Plans 991
Bearhawk Patrol Scratch Built, Plans P313
Germantown, Wisconsin, USA
+1 for this press! I have the same one and it is a great value piece of kit. For the repetitive nature of pressing the ribs I also got the air over hydraulic jack.
I have a youtube video where I did the rubber mat method to form my lightening holes. I have some other videos on how i built the wing on my patrol. Do a search for N3UW on youtube or find them. where is the rubber press video.
John Snapp (Started build in Denver, CO) Now KAWO -Arlington Washington Bearhawk Patrol - Plans #255 Scratch built wing and Quickbuild Fuselage as of 11/2021. Working on skinning the left wing! -Ribs : DONE -Spars: DONE, Left wing assembly's: DONE., Top skins : DONE YouTube Videos on my building of patrol :https://m.youtube.com/user/n3uw
If you look on bearhawk 1227 which my FB page for the airplane I had the mdf patterns screwed up not only was I cutting metal I was cutting the pattern to...plus I'm battling snow because I got no place to cut this stuff....the garage at my dads house isn't heated. So all I can do is hope and pray for warmer weather here in Minnesota.
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