cutting aluminum angle

prkaye · #1 08-20-2006, 06:05 PM

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?

Guy Prevost · #2 08-20-2006, 06:28 PM

"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

Captain_John · #3 08-20-2006, 07:00 PM

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

szicree · #4 08-20-2006, 07:03 PM

Built the whole beast with a hacksaw. Right forearm looks like Popeye's!!

prkaye · #5 08-20-2006, 07:15 PM

how about the rounded corners? Can these be made with the hacksaw??

ge9a · #6 08-20-2006, 07:20 PM

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.

jrdalton · #7 08-20-2006, 07:24 PM

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.

Paul Eastham · #8 08-20-2006, 07:50 PM

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

cytoxin · #9 08-20-2006, 07:58 PM

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

markerthebarker · #10 08-20-2006, 08:09 PM

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