Starting work on the rudder and elevators I ran across the same time worn question. How best to cut off the excess material from the stiffeners? If you have been here awhile you'll remember this topic and perhaps some of my own suggestions. But imagining a process and actually being faced with having to do it are two different things. At heart I'm the kind of person that likes to "Git r done" I'm also not crazy about the jagged crooked edge left with a band saw. With that said here is what I did.
I thought I was pretty smart and wasn't feeling to bad about the money spent on a paper cutter. Now someone at Van's decided, I don't know why but they did, to make the rudder and elevator stiffeners "Handed". So the rudder is say left handed and the elevators are right handed. I had lots of mechanical advantage for the rudder parts since I was cutting way back there near the fulcrum of the cutter but the stiffeners for the elevator are way out there in the front. So it's all brute force cuttin those babies.
It's hard to see in these pictures but the edges are smooth and nice and the parts are VERY consistant.
So at this point I will add that all of the stiffeners for both the rudder and elevators are cut. My next installment to this will be pictures and a
how too for more or less safely GITTIN R DONE with a table saw.
Wont that be fun?
great idea jim!! i think i may head to staples this weekend now! i don't think i've ever been there before! hmm, so staples for airplane building stuff. whoodu thunk it!
Wait before you buy anything. A paper cutter has very limited usefullness since there is the problem of handedness of the stiffeners. It would be wonderfull if Van's would orient the cut off at the same end of the elevator stiffeners as the rudder stiffeners. If Vans were to do that a paper cutter could be used for all of the stiffeners on an RV project. Also I don't know what the oreientation of the flap and aileron stiffeners is so this may be overall a very limited process. I may be willing to mail my paper cutter to other builders if it would help them.
They're $60.00 and require a small amount of modification to the lower cutter. For some reason when they manufacture these paper cutters they set the lower cutter about and 1/16th of an inch below surface. That allows the part even though being held in place to deflect down and slighty drift as you begin making your cut. That small deflection and drift of the work piece causes a not quite straight cut. The part is just not supported well. What I have done is use a narrow piece of scrap formica (which was exactly the right thickness as it turned out) to shim up the lower cutting edge. Supporting the edge being cut corrected the problem of the work piece drifting and the stiffeners cut straight from then on. Only one of the stiffiners was below par that being my first one cut which put me on to the problem. In the end that stiffener was easily cleaned up with a file.
I use a 14 tpi on my band saw. For general use I am not greatly happy with the edge left behind when using a
band saw to cut metal. Although that said I used it quite a bit today while cutting the stiffeners for the rudder to length.
More about that later.
So here it is. Cutting elevator stiffeners with a table saw. In the picture below notice how many clecos I've used to hold the stiffener suport in place. This is not a process for the faint hearted. I use a 10 inch sixty tooth narrow kerf blade the style of which is called a triple chip. I wouldn't try this with a standard blade. Feed the work piece fairly slow and stand way the h*ll back from the stuff flying out. Also keep your hands well away from anything that could let loose. Actually it would be better to do this from another room.
The actual piece to be cut is clecod with at least three cleco clamps. Not the pin variety but the squeezy type. If it weren't for the fact that I was trying to find alternative ways to cut these things I'd have gone ahead and used my bandsaw. My all time favorite is the paper cutter though. After spending the day preping all the stiffeners it was very clear that the edge left using the paper cutter was better then the factory edge found on the formed kit parts.
Moving right along the picture below is that of a tool commonly found in most cabinet shops. Thought it would be interesting to see how it performed in a sheet metal shop.
Actually it performed very well and with an 80 grit belt on it the work went fast.
It takes a very light touch. Once done with that scotch bright the parts and you're ready to match drill.
Jim, looks like you have a very nice shop. The $89 delta saw from Lowes is the only band saw we have. The 18 TPI metal cutting blade on it does a reasonably good job. However the only thing we have cut so far is the stiffeners for the training project. Wish we were as far along as you are. We still are in the shop building stage.
collecting tools, planning shop, studying -9A preview plans, old and new training project on hand, fabricating stiffeners.
dirtmanf800
John, Yes I admit it I am a woodworker. I've been building custom furniture for almost thirty years now. I didn't know they used these belt sanders in metal shops though. I thought it would be more like grinders and such.
Dirtman, 18 tpi is gettin pretty high count. 14 is the best I could do and it still leaves things a bit jagged. After having gone through this whole excercise I could have used the bandsaw and been just as happy. But it wouldn't have been as much fun.
By the way, I used to work with a guy that built VW based sand buggys. He used a Porter Cable router to fly cut his cylinder heads. Free handed no less. They ran great when he was done.
Last edited by jim_geo on Wed Aug 24, 2005 12:59 pm, edited 1 time in total.
CJ
