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prkaye

Well Known Member
One of the very first tasks on my empennage is to fabricate these HS attach angles from AA6-187x2x2.5 aluminum angle. The plans drawing says "full scale", but they are not full-size (maybe I mis-understand what "full-scale" means?)

To make these parts I have to cut this aluminum angle... it looks a bit thick for a hack-saw job. I guess I should go out and get a bandsaw for this? Do I need a particularly big bandsaw, or will a small table-top unit from HD suffice? What kind of blade do I need to cut the aluminum angle?

Another question - how nervous do I have to be about getting the dimensions exact on these HS attach angle parts?
 
"Full Scale" should mean full size. Might be a mistake in the plans.

A hack saw will cut these angles fine. However, a bandsaw is really, really nice to have. You're going to have to cut out a lot of parts in the future. A small benchtop one is fine. No need to spring for variable speed, or a special metal cutting one since wood and aluminum like similar blade speeds. You'll want a blade with at least 12 teeth per inch. Ideally, you want a blade fine enough so that there are always at least 2 teeth bearing on the material being cut. If the space between the teeth is wider than the material being cut, the blade will tear up the material. It will also make a lot of noise and scare the *()! out of you.

There's no need to be nervous, just precise ;). I guess the answer to that is just get everything as close as you can. I still often wish that Van's would tolerance drawings. Then you would know the relative importance of various dimensions.

Cheers,
Guy
 
Phil, I have been having great success with a sawzall and jigsaw with 18-24 tooth blades!

I have been whittling firewall parts with ease and don't miss the fact that I have no bandsaw!

If storage is an issue and you have some skill in cutting straight lines, try the jigsaw!

:) CJ
 
For what it's worth, I bought a fairly inexpensive band saw before I even ordered my empennage, trying to get the airplane factory set up just right. Now I cut all angle angle pieces with a hack saw - it's faster and I don't have the band saw in the way. If I were to do it over, I wouldn't buy a band saw, unless I had room for a really good free-standing model, one with the cast iron base and some meat to it. I might get some good use from one of those, but the cheapies (like Ryobi) aren't worth it, in my opinion.

I did buy an air-driven recip saw from Home Depot. That thing works pretty good, and is nice for rough-cutting the odd angles that you have to do occasionally, then sand to the finished dimension.
 
There's a few ways to go about this

Phil,

It's great to hear your question. Now that I'm done with my tail kit I feel like a "pro" - but I had all of the same questions and concerns.

I cut rough with a hacksaw and then used my stationary belt sander to make it nice and smooth. I'm always amazed how the belt sander works better than a saw or a cutting wheel - and easy to control too.

As far as being precise - since the cut edge is not the side riveted to spar it's more cosmetic than structural. You need to be close.

Some would argue that every piece has to be perfect - but Vans would say "just build it." I don't have any problem with the perfectionists, but if it's non-structural, can't be seen, and us permantly covered up, it won't make any difference.
 
Regarding precision: the problem with this particular part is that the holes are packed quite tightly on it. If you're too small, you're going to have a problem. Got a ruler with 1/32"s on it? That should give you sufficient precision.

Regarding cutting: I have a <$100 cheap bandsaw with a fine-tooth blade. If you are not quickbuilding, I think it is an excellent investment.

Regarding 9A HS: You should really start with the VS first. The HS is quite difficult, especially the first few rivets. The VS is easier, smaller, and a better place to learn the basics.

Paul
 
always remember

to save the line that you marked and finish to final size .try to do it so the finished part meets the dimension.if you meet the dimension before than you will always come out under. i have a small three wheeler band saw from harbor freight works great. comes with a wood cutting blade be sure to get a metal cuting blade. i have the popeye arms as well but from 20+ years of being a mechanic. i didnt want to have to always clamp to cut. the band saw can really get you close on the first cut. it is like cutting paper with a new pair of scissors. the 5" disc /belt sander from harbor freight reeeeeaaaaly is the deal for shaping parts.. good luck
 
Bandsaw

I went down to my local saw sharpening shop years ago and bought an aluminum bandsaw blade. She's about 1/2in wide and goes through 2 in aluminum barstock like it was butter, boelube really helps.

George Henson
RV-10 Empennage Intransit
Regina, SK
 
Band saw blades

I recommend getting a bandsaw and highly recommend using bimetallic blades in it. You can get them from McMaster Carr. Regular carbon steel blades work fine for cutting sheet metal and light angles, but the first time you cut something thick, the blade will dull quickly. Bimetallic blades will last a LOT longer.
 
A bandsaw is good & the Delta model that sells for around $100 will work fine. Be sure to follow the manual & set up the guide rollers properly. If not set right, it will not cut straight. 12 teeth per inch sounds a little coarse; I suggest you use a finer toothed blade if you can get one.

As someone else said, don't cut too close to your line. Leave at least 1/16" and finish with you belt sander, then your Scotchbrite wheel.

I showed my finished piece to Tom Green & he said I was spending way too much time on the part and that I should have been able to make both parts in somehting like half an hour or less. That told me something & I think I could easily make them that quickly now, but I think I spent a couple hours on them the first time.

Van's instructions call for dimensions in 32nds of an inch which implies a certain level of precision. I won't know until I am finishing the plane & attaching the HS if that level of precision is necessary or if that was simply what the engineering solution led to.
 
I used a cutoff wheel and sanding/scotchbrite pads for these. I was really particular about them too, I'm stil in the save-weight mode, so everything that could have extra aluminum removed did.
 
I guess everyone's different when it comes to tool. I was just thinking last week while cutting the one millionth piece of aluminum angle that my cheap-o Delta band saw was the best C note I've spent on tools for the entire project. Huge time saver.
 
Bandsaw

I broke down and bought a Bandsaw from Canadian Tire... $160 (CAD). The blade it came with was only 6tpi, so I bought an 18tpi blade to put on it. I figure this way I'll be able to get the parts accurate enough even to satisfy my level of paranoia ;)

Also picked up a nice little benchtop drill press for $60 (CAD), and a 20"x17"x1/4" steel plate from a metal place ($30) to clean up and use as a back-riveting plate.

I'm good-to-go!!
 
Bandsaw

I couldnt imagine building without my buddy the bandsaw...I do this for a living, and it is without a doubt the best,fastest way to make short work of aluminum parts..hands down.For homebuilders, a little 12" throat table or stand model is fine...I have a second hand Craftsman from a pawn shop that I used for my entire -4 project (and all the bird house and kid projects) that cost less than a pack of cut-off wheels. I make my own blades at the shop I work in, and I am sure most can find a local machine shop to make blades from the left over spools....they are simply spot welded together using an attachment on the big comercial bandsaws. Most small bandsaws use a 80" blade...I like a narrow 1/4 width for making radius cuts. After the bandsaw cut, a quick dressing with a diegrinder/sander then scotch bright to finish.Walla, just like at the airline !

Bill E....done with bandsaw, prepping for paint!
 
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